Journal articles on the topic 'Staphylococcus aureus biofilms'
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Wu, Julie A., Caroline Kusuma, James J. Mond, and John F. Kokai-Kun. "Lysostaphin Disrupts Staphylococcus aureus and Staphylococcus epidermidis Biofilms on Artificial Surfaces." Antimicrobial Agents and Chemotherapy 47, no. 11 (November 2003): 3407–14. http://dx.doi.org/10.1128/aac.47.11.3407-3414.2003.
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ABSTRACT Staphylococci often form biofilms, sessile communities of microcolonies encased in an extracellular matrix that adhere to biomedical implants or damaged tissue. Infections associated with biofilms are difficult to treat, and it is estimated that sessile bacteria in biofilms are 1,000 to 1,500 times more resistant to antibiotics than their planktonic counterparts. This antibiotic resistance of biofilms often leads to the failure of conventional antibiotic therapy and necessitates the removal of infected devices. Lysostaphin is a glycylglycine endopeptidase which specifically cleaves the pentaglycine cross bridges found in the staphylococcal peptidoglycan. Lysostaphin kills Staphylococcus aureus within minutes (MIC at which 90% of the strains are inhibited [MIC90], 0.001 to 0.064 μg/ml) and is also effective against Staphylococcus epidermidis at higher concentrations (MIC90, 12.5 to 64 μg/ml). The activity of lysostaphin against staphylococci present in biofilms compared to those of other antibiotics was, however, never explored. Surprisingly, lysostaphin not only killed S. aureus in biofilms but also disrupted the extracellular matrix of S. aureus biofilms in vitro on plastic and glass surfaces at concentrations as low as 1 μg/ml. Scanning electron microscopy confirmed that lysostaphin eradicated both the sessile cells and the extracellular matrix of the biofilm. This disruption of S. aureus biofilms was specific for lysostaphin-sensitive S. aureus, as biofilms of lysostaphin-resistant S. aureus were not affected. High concentrations of oxacillin (400 μg/ml), vancomycin (800 μg/ml), and clindamycin (800 μg/ml) had no effect on the established S. aureus biofilms in this system, even after 24 h. Higher concentrations of lysostaphin also disrupted S. epidermidis biofilms.
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Izano, Era A., Matthew A. Amarante, William B. Kher, and Jeffrey B. Kaplan. "Differential Roles of Poly-N-Acetylglucosamine Surface Polysaccharide and Extracellular DNA in Staphylococcus aureus and Staphylococcus epidermidis Biofilms." Applied and Environmental Microbiology 74, no. 2 (November 26, 2007): 470–76. http://dx.doi.org/10.1128/aem.02073-07.
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ABSTRACT Staphylococcus aureus and Staphylococcus epidermidis are major human pathogens of increasing importance due to the dissemination of antibiotic-resistant strains. Evidence suggests that the ability to form matrix-encased biofilms contributes to the pathogenesis of S. aureus and S. epidermidis. In this study, we investigated the functions of two staphylococcal biofilm matrix polymers: poly-N-acetylglucosamine surface polysaccharide (PNAG) and extracellular DNA (ecDNA). We measured the ability of a PNAG-degrading enzyme (dispersin B) and DNase I to inhibit biofilm formation, detach preformed biofilms, and sensitize biofilms to killing by the cationic detergent cetylpyridinium chloride (CPC) in a 96-well microtiter plate assay. When added to growth medium, both dispersin B and DNase I inhibited biofilm formation by both S. aureus and S. epidermidis. Dispersin B detached preformed S. epidermidis biofilms but not S. aureus biofilms, whereas DNase I detached S. aureus biofilms but not S. epidermidis biofilms. Similarly, dispersin B sensitized S. epidermidis biofilms to CPC killing, whereas DNase I sensitized S. aureus biofilms to CPC killing. We concluded that PNAG and ecDNA play fundamentally different structural roles in S. aureus and S. epidermidis biofilms.
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Saising, Jongkon, Linda Dube, Anne-Kathrin Ziebandt, Supayang Piyawan Voravuthikunchai, Mulugeta Nega, and Friedrich Götz. "Activity of Gallidermin on Staphylococcus aureus and Staphylococcus epidermidis Biofilms." Antimicrobial Agents and Chemotherapy 56, no. 11 (August 27, 2012): 5804–10. http://dx.doi.org/10.1128/aac.01296-12.
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ABSTRACTDue to their abilities to form strong biofilms,Staphylococcus aureusandStaphylococcus epidermidisare the most frequently isolated pathogens in persistent and chronic implant-associated infections. As biofilm-embedded bacteria are more resistant to antibiotics and the immune system, they are extremely difficult to treat. Therefore, biofilm-active antibiotics are a major challenge. Here we investigated the effect of the lantibiotic gallidermin on two representative biofilm-forming staphylococcal species. Gallidermin inhibits not only the growth of staphylococci in a dose-dependent manner but also efficiently prevents biofilm formation by both species. The effect on biofilm might be due to repression of biofilm-related targets, such asica(intercellular adhesin) andatl(major autolysin). However, gallidermin's killing activity on 24-h and 5-day-old biofilms was significantly decreased. A subpopulation of 0.1 to 1.0% of cells survived, comprising “persister” cells of an unknown genetic and physiological state. Like many other antibiotics, gallidermin showed only limited activity on cells within mature biofilms.
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Horiuk, Y. V., M. D. Kukhtyn, Y. S. Stravskyy, S. I. Klymnyuk, K. M. Vergeles, and V. V. Horiuk. "Influence of staphylococcal Phage SAvB14 on biofilms, formed by Staphylococcus aureus variant bovis." Regulatory Mechanisms in Biosystems 10, no. 3 (August 22, 2019): 314–18. http://dx.doi.org/10.15421/021948.
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The use of bacteriophages for the treatment of chronic inflammatory processes has proved to be relevant, especially during isolation of antibiotic-resistant pathogens formed in biofilms. The article presents the results of research on the influence of Phage SAvB14 on young and mature biofilms formed by Staphylococcus aureus variant bovis. In the experiments we used cultures of S. aureus and a specific Phage SAvB14 isolated from the secretion of the mammary gland of cows suffering from chronic mastitis. In the study of the influence of bacteriophage on formed biofilms we determined the optical density of the dye solution that was washed from the biofilm photometrically on a spectrophotometer PE-5400UV (Ecroskhim, Russia) and the number of staphylococcal cells in the biofilm after the action of the bacteriophage on 24-hour and 72-hour biofilms by a ten-fold dilution on beef-extract agar. It was determined that under the influence of the bacteriophage on young 24-hour biofilms of S. aureus var. bovis, the optical density of the dye solution from biofilm increased within 4 hours up to 10% and the number of microbial cells increased by 1.8 times. After 32 hours of bacteriophage action, the optical density of the dye solution decreased on average by 34% compared to the initial density and the number of S. aureus cells in the biofilm decreased by 30 times. This indicates that microbial cells of young biofilms are not subject to complete lysis during the action of even this specific bacteriophage. Degradation of 77.5% of biofilm under the influence of the bacteriophage was observed on mature 72-hour biofilm within 32 hours at 37 °C. At the same time, viable cells of S. aureus were not isolated from the biofilm. This indicates the high lytic activity of the bacteriophage against mature biofilm bacteria and the possibility of its use in chronic staphylococcal infections caused by S. aureus var. bovis. Thus, the obtained data indicate that when mature 72-hour biofilms are exposed to the researched bacteriophage, their degradation is more intense compared with the young 24-hour biofilms, and the amount of destroyed biofilm was on average 2 times higher. This suggests that the use of specific staphylococcal Phage SAvB14 isolated by us for the destruction of biofilm, formed by S. aureus var. bovis, is promising.
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Hrynchuk, N. I., N. O. Vrynchanu, T. A. Buchtyarova, D. M. Dudikova, Yu V. Korotkyi, and L. B. Bondarenko. "Antibiofilm Effect of Adamantane Derivative against Staphylococcus aureus." Mikrobiolohichnyi Zhurnal 83, no. 1 (February 17, 2021): 58–67. http://dx.doi.org/10.15407/microbiolj83.01.058.
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Currently, one of the most urgent problems in clinical practice is the antibiotic therapy ineffectiveness at chronic diseases treatment caused by biofilms-forming microorganisms. One of the ways to its solution is the search for new compounds with antibiofilm activity which can prevent the adhesion of microorganisms, disrupt the structure of the biofilm matrix and affect the Quorum sensing system. The aim of the study was to investigate adamantane derivative 1-[4-(1-adamantyl) phenoxy]-3-(N-benzyl,N-dimethylamino)-2-propanol chloride (KVM-97) antimicrobial activity mechanism against Staphylococcus aureus biofilms. Methods. The ability of the adamantane derivative KVM-97 to prevent S. aureus biofilm formation and to destroy previously formed biofilms has been tested on polystyrene plates by gentian violet sorption on these structures, followed by desorption with organic solvent and use of resazurin (redox indicator). The S. aureus cells viability in mature biofilms was evaluated with specific dyes for living (acridine orange) and dead (propidium iodide) cells. Lowry method was used to assess the effect of KVM-97 on the matrix components for the total protein contents determination, the polysaccharides were detected spectrophotometrically (using phenol and sulfuric acid), Bap-protein – by test with Congo red. Persisters’ subpopulation was detected by activation of the SOS response in bacteria when exposed to high concentrations of antimicrobial substances. Results. It was found that KVM-97 (the compound with the adamantyl radical) showed an antibiofilm effect against S. aureus, decreasing biofilm biomass: at the biofilm formation stage – by 22.5% and 75.0%, while in case of 2-day biofilms treatment – by 34.5% and 32.4% at 0.5 MIC and 5.0 MIC respectively. Compound KVM-97 was able to reduce the number of metabolically active S. aureus cells only at the stage of biofilm formation (reduction by 92.7 and 95.8% at 2.0 and 5.0 MIC). Obtained results indicated that this adamantane-containing compound did not affect the protein and polysaccharides contents of S. aureus biofilms matrix. The changes of Bap-protein level caused by KVM-97 were not statistically significant (p>0.05). It was shown that KVM-97 did not prevent the formation of metabolically inactive persister cells; their share was 0.71% of the control. Conclusions. Thus, adamantane-containing compound KVM-97 is able to prevent S. aureus biofilm formation, causing significant biofilms’ mass reduction, as well as lowering the viable cells number in them and destroying already formed biofilms. Its antibiofilm effects are not associated with matrix protein and polysaccharides synthesis impairments. Further thorough investigations are needed to establish the effect of this compound on eDNA synthesis, the Quorum sensing system, and the ica and arg genes expression of S. aureus responsible for biofilm formation.
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Yarwood, Jeremy M., Douglas J. Bartels, Esther M. Volper, and E. Peter Greenberg. "Quorum Sensing in Staphylococcus aureus Biofilms." Journal of Bacteriology 186, no. 6 (March 15, 2004): 1838–50. http://dx.doi.org/10.1128/jb.186.6.1838-1850.2004.
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ABSTRACT Several serious diseases are caused by biofilm-associated Staphylococcus aureus, infections in which the accessory gene regulator (agr) quorum-sensing system is thought to play an important role. We studied the contribution of agr to biofilm development, and we examined agr-dependent transcription in biofilms. Under some conditions, disruption of agr expression had no discernible influence on biofilm formation, while under others it either inhibited or enhanced biofilm formation. Under those conditions where agr expression enhanced biofilm formation, biofilms of an agr signaling mutant were particularly sensitive to rifampin but not to oxacillin. Time lapse confocal scanning laser microscopy showed that, similar to the expression of an agr-independent fluorescent reporter, biofilm expression of an agr-dependent reporter was in patches within cell clusters and oscillated with time. In some cases, loss of fluorescence appeared to coincide with detachment of cells from the biofilm. Our studies indicate that the role of agr expression in biofilm development and behavior depends on environmental conditions. We also suggest that detachment of cells expressing agr from biofilms may have important clinical implications.
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Singhal, Deepti, Andrew Foreman, Josh-Jervis Bardy, and Peter-John Wormald. "Staphylococcus aureus biofilms." Laryngoscope 121, no. 7 (June 6, 2011): 1578–83. http://dx.doi.org/10.1002/lary.21805.
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Tuon, Felipe Francisco, Paula Hansen Suss, Joao Paulo Telles, Leticia Ramos Dantas, Nícolas Henrique Borges, and Victoria Stadler Tasca Ribeiro. "Antimicrobial Treatment of Staphylococcus aureus Biofilms." Antibiotics 12, no. 1 (January 4, 2023): 87. http://dx.doi.org/10.3390/antibiotics12010087.
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Staphylococcus aureus is a microorganism frequently associated with implant-related infections, owing to its ability to produce biofilms. These infections are difficult to treat because antimicrobials must cross the biofilm to effectively inhibit bacterial growth. Although some antibiotics can penetrate the biofilm and reduce the bacterial load, it is important to understand that the results of routine sensitivity tests are not always valid for interpreting the activity of different drugs. In this review, a broad discussion on the genes involved in biofilm formation, quorum sensing, and antimicrobial activity in monotherapy and combination therapy is presented that should benefit researchers engaged in optimizing the treatment of infections associated with S. aureus biofilms.
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Achek, Rachid, Helmut Hotzel, Ibrahim Nabi, Souad Kechida, Djamila Mami, Nassima Didouh, Herbert Tomaso, et al. "Phenotypic and Molecular Detection of Biofilm Formation in Staphylococcus aureus Isolated from Different Sources in Algeria." Pathogens 9, no. 2 (February 24, 2020): 153. http://dx.doi.org/10.3390/pathogens9020153.
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Staphylococcus aureus is an opportunistic bacterium causing a wide variety of diseases. Biofilm formation of Staphylococcus aureus is of primary public and animal health concern. The purposes of the present study were to investigate the ability of Staphylococcus aureus isolated from animals, humans, and food samples to form biofilms and to screen for the presence of biofilm-associated and regulatory genes. In total, 55 Staphylococcus aureus isolated from sheep mastitis cases (n = 28), humans (n = 19), and from food matrices (n = 8) were identified using matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS). The ability of Staphylococcus aureus for slime production and biofilm formation was determined quantitatively. A DNA microarray examination was performed to detect adhesion genes (icaACD and biofilm-associated protein gene (bap)), genes encoding microbial surface components recognizing adhesive matrix molecules (MSCRAMMs), regulatory genes (accessory gene regulator (agr) and staphylococcal accessory regulator (sarA)), and the staphylococcal cassette chromosome mec elements (SCCmec). Out of 55 Staphylococcus aureus isolates, 39 (71.0%) and 23 (41.8%) were producing slime and biofilm, respectively. All Staphylococcus aureus strains isolated from food showed biofilm formation ability. 52.6% of the Staphylococcus aureus strains isolated from sheep with mastitis, and 17.9% of isolates from humans, were able to form a biofilm. Microarray analysis typed the Staphylococcus aureus into 15 clonal complexes. Among all Staphylococcus aureus isolates, four of the human isolates (21.1%) harbored the mecA gene (SCCmec type IV) typed into 2 clonal complexes (CC22-MRSA-IV and CC80-MRSA-IV) and were considered as methicillin-resistant, while two of them were slime-producing. None of the isolates from sheep with mastitis harbored the cna gene which is associated with biofilm production. The fnbB gene was found in 100%, 60% and 40% of biofilm-producing Staphylococcus aureus isolated from food, humans, and sheep with mastitis, respectively. Three agr groups were present and agr group III was predominant with 43.6%, followed by agr group I (38.2%), and agr group II (18.2%). This study revealed the capacity of Staphylococcus aureus isolates to form biofilms and highlighted the genetic background displayed by Staphylococcus aureus isolates from different sources in Algeria.
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Sharma, Mrinalini, Livia Visai, Francesca Bragheri, Ilaria Cristiani, Pradeep Kumar Gupta, and Pietro Speziale. "Toluidine Blue-Mediated Photodynamic Effects on Staphylococcal Biofilms." Antimicrobial Agents and Chemotherapy 52, no. 1 (October 29, 2007): 299–305. http://dx.doi.org/10.1128/aac.00988-07.
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ABSTRACT Staphylococci are important causes of nosocomial and medical-device-related infections. Their virulence is attributed to the elaboration of biofilms that protect the organisms from immune system clearance and to increased resistance to phagocytosis and antibiotics. Photodynamic treatment (PDT) has been proposed as an alternative approach for the inactivation of bacteria in biofilms. In this study, we have investigated the effect of the photodynamic action of toluidine blue O (TBO) on the viability and structure of biofilms of Staphylococcus epidermidis and of a methicillin-resistant Staphylococcus aureus strain. Significant inactivation of cells was observed when staphylococcal biofilms were exposed to TBO and laser simultaneously. The effect was found to be light dose dependent. Confocal laser scanning microscopic study suggested damage to bacterial cell membranes in photodynamically treated biofilms. In addition, scanning electron microscopy provided direct evidence for the disruption of biofilm structure and a decrease in cell numbers in photodynamically treated biofilms. Furthermore, the treatment of biofilms with tetrasodium EDTA followed by PDT enhanced the photodynamic efficacy of TBO in S. epidermidis, but not in S. aureus, biofilms. The results suggest that photodynamic treatment may be a useful approach for the inactivation of staphylococcal biofilms adhering to solid surfaces of medical implants.
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Chebotar, Igor’ V., Evgenia D. Konchakova, and Andrey N. Maianskii. "Vesicle formation as a result of interaction between polymorphonuclear neutrophils and Staphylococcus aureus biofilm." Journal of Medical Microbiology 62, no. 8 (August 1, 2013): 1153–59. http://dx.doi.org/10.1099/jmm.0.048967-0.
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Staphylococcus aureus, a major opportunistic pathogen, is a leading cause of biofilm-related infections in clinical practice. Staphylococcal biofilms are highly resistant to antibacterial medicines and immune effector cells. The main result of our work is the discovery of nano-vesicles in the supernatant of the human neutrophil–S. aureus biofilm system. We also found that phospholipase C treatment causes complete destruction of these vesicles. While the addition of proteinase K led to a partial structural disorganization of the vesicles, DNase treatment did not influence the vesicle structure. These observations allowed us to conclude that phospholipids and proteins play a structure-forming role in the formation of these nano-vesicles. The vesicles demonstrated anti-biofilm activities when tested against Staphylococcus epidermidis (strains 178M and 328/5) biofilms, but were ineffective for S. aureus (strains 5983/2, 5663 and 18A) biofilms.
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Trotonda, María Pilar, Sandeep Tamber, Guido Memmi, and Ambrose L. Cheung. "MgrA Represses Biofilm Formation in Staphylococcus aureus." Infection and Immunity 76, no. 12 (October 13, 2008): 5645–54. http://dx.doi.org/10.1128/iai.00735-08.
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ABSTRACT MgrA is a pleiotropic regulator that controls autolysis, virulence, and efflux pump activity in Staphylococcus aureus. We recently found that mgrA mutants of strains RN6390, SH1000, and MW2 also displayed enhanced biofilm formation compared with their respective parents. The biofilms formed by mgrA mutants of RN6390 and MW2 are independent of sigB and ica loci, two genetic elements that have been previously associated with biofilm formation in S. aureus. Biofilms formed by mgrA mutants are dependent on the expression of surface proteins mediated by the sortase gene srtA. Extracellular DNA was also a crucial component of the early biofilm of mgrA mutants. Genetic analysis indicated that biofilm formation in mgrA mutants is mediated in part by agr RNAIII, a genetic locus regulated by mgrA. Additionally, SarA is important to biofilm formation in mgrA mutants since the double sarA mgrA mutants failed to form biofilms compared to single mgrA mutants of RN6390 and MW2. However, the SarA-mediated effect is independent of agr and proteases such as V8 protease and aureolysin. Collectively, our data showed MgrA to be a repressor of biofilm formation, and biofilms formed by mgrA mutants have features that are distinct from other reported biofilm types in S. aureus.
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Pant, Narayan, and Damon P. Eisen. "Non-Antimicrobial Adjuvant Strategies to Tackle Biofilm-Related Staphylococcus aureus Prosthetic Joint Infections." Antibiotics 10, no. 9 (September 1, 2021): 1060. http://dx.doi.org/10.3390/antibiotics10091060.
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Staphylococcus aureus frequently causes community- and hospital-acquired infections. S. aureus attachment followed by biofilm formation on tissues and medical devices plays a significant role in the establishment of chronic infections. Staphylococcal biofilms encase bacteria in a matrix and protect the cells from antimicrobials and the immune system, resulting in infections that are highly resistant to treatment. The biology of biofilms is complex and varies between organisms. In this review, we focus our discussion on S. aureus biofilms and describe the stages of their formation. We particularly emphasize genetic and biochemical processes that may be vulnerable to novel treatment approaches. Against this background, we discuss treatment strategies that have been successful in animal models of S. aureus biofilm-related infection and consider their possible use for the prevention and eradication of biofilm-related S. aureus prosthetic joint infection.
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Hasyrul Hamzah, Triana Hertiani, Sylvia Utami Tunjung Pratiwi, and Titik Nuryastuti. "The biofilm eradication activity of C-10 massoialactone against Staphylococcus aureus." International Journal of Research in Pharmaceutical Sciences 11, no. 4 (September 29, 2020): 5797–802. http://dx.doi.org/10.26452/ijrps.v11i4.3228.
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C-10 massoaialactone is a major component of stem bark essential oils Massoia aromatica Becc, which has potential as antibacterial and antifungal but antibiofilm activity against S. aureus has never been reported. The discovery of anti-biofilm drug candidates is needed to overcome infections associated with biofilms. This study aims to determine the eradication activity of C-10 massoialactone against S. aureus biofilms. Antibacterial testing and eradication activity of S. aureus biofilms was determined using the microtiter broth method. The effectiveness of C-10 massoilactone against S. aureus biofilm was analyzed by calculating the value of minimum biofilm eradication concentration. The mechanism of action of C-10 massoilactone against S. aureus biofilms was tested using scanning electron microscopy (SEM). C-10 massoilactone 1% gives antibacterial activity of 86.80% ± 0.01 and can eradication S. aureus biofilm by 68.98% ± 0.01 and not much different from the eradication activity of chloramphenicol drug control. The results also provide evidence that C-10 masoaialactone can damage the extracellular polymeric substance (EPS) matrix and S. aureus biofilm morphology. Therefore, C-10 masoaialactone is very potential to be developed as a candidate for a new antibiofilm drug against S. aureus biofilm.
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Lesmana, Muhamad Arfan, Dahliatul Qosimah, and Sri Murwani. "Detection of Staphylococcus aureus Biofilm from Subclinical Mastitis Milk." Veterinary Biomedical and Clinical Journal 1, no. 1 (January 1, 2019): 19–25. http://dx.doi.org/10.21776/ub.vetbioclinj.2019.001.01.3.
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One of S.aureus's virulence factors is biofilm formation. When biofilms are formed, the bacteria will undergo phenotypic changes that require higher concentrations of antibiotics to inhibit proliferation. Phenotypic changes will lead to increase the production of extracellular matrix and multilayered colonies as well as decrease of metabolic rates, multiplication and polymicrobial colonization resulting in recurrent infection in the host and difficulty being treated with antibiotics due to resistance. The aim of this research was to know the formation of bacterial biofim by slime and quantitative by microplate titer method. The research method was qualitative descriptive using 27 samples of Staphylococcus aureus with characterized from mastitis infected milk. The bacteria were grown on CRA (Congo Red Agar) media to observe the slime biofilm through bacteria black colony followed by MicrotiterPlate method with 570nm wave lenght. The results showed that 27 samples of Staphylococcus aureus which positive to form slime biofilm were 10 samples and continued to microtiter plate showed 3 positive samples of biofilm. The conclusions of this study, Staphylococcus aureus in subclinical mastitis milk samples were positive to form biofilms.
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Harriott, Melphine M., and Mairi C. Noverr. "Candida albicans and Staphylococcus aureus Form Polymicrobial Biofilms: Effects on Antimicrobial Resistance." Antimicrobial Agents and Chemotherapy 53, no. 9 (June 29, 2009): 3914–22. http://dx.doi.org/10.1128/aac.00657-09.
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ABSTRACT Candida albicans readily forms biofilms on the surface on indwelling medical devices, and these biofilms serve as a source of local and systemic infections. It is estimated that 27% of nosocomial C. albicans bloodstream infections are polymicrobial, with Staphylococcus aureus as the third most common organism isolated in conjunction with C. albicans. We tested whether S. aureus and C. albicans are able to form a polymicrobial biofilm. Although S. aureus formed poor monoculture biofilms in serum, it formed a substantial polymicrobial biofilm in the presence of C. albicans. In terms of architecture, S. aureus formed microcolonies on the surface of the biofilm, with C. albicans serving as the underlying scaffolding. In addition, S. aureus matrix staining revealed a different phenotype in polymicrobial versus monomicrobial biofilms, suggesting that S. aureus may become coated in the matrix secreted by C. albicans. S. aureus resistance to vancomycin was enhanced within the polymicrobial biofilm, required viable C. albicans, and was in part mediated by C. albicans matrix. However, the growth or sensitivity to amphotericin B of C. albicans is not altered in the polymicrobial biofilm.
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Yarwood, Jeremy M., Kara M. Paquette, Ilya B. Tikh, Esther M. Volper, and E. Peter Greenberg. "Generation of Virulence Factor Variants in Staphylococcus aureus Biofilms." Journal of Bacteriology 189, no. 22 (August 3, 2007): 7961–67. http://dx.doi.org/10.1128/jb.00789-07.
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ABSTRACT Several serious diseases are caused by biofilm-associated Staphylococcus aureus. Colonial variants occur in biofilms of other bacterial species, and S. aureus variants are frequently isolated from biofilm-associated infections. Thus, we studied the generation of variants with altered expression of virulence factors in S. aureus biofilms. We observed that the number of variants found in biofilms, as measured by hemolytic activity, varied for different strains. Further study of hemolytic activity and signaling by the accessory gene regulator (Agr) quorum-sensing system in one S. aureus strain revealed three primary biofilm subpopulations: nonhemolytic (Agr deficient), hemolytic (Agr positive), and hyperhemolytic (also Agr positive). The nonhemolytic variant became the numerically dominant subpopulation in the biofilm. The nonhemolytic variant phenotype was stable and heritable, indicating a genetic perturbation, whereas the hyperhemolytic phenotype was unstable, suggesting a phase variation. Transcription profiling revealed that expression of the agr locus and many extracellular virulence factors was repressed in the nonhemolytic variant. Expression of the agr-activating gene, sarU, was also repressed in the nonhemolytic variant, suggesting one potential regulatory pathway responsible for the Agr-deficient phenotype. We suggest that the development of these variants in biofilms may have important clinical implications.
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Peng, Qi, Xiaohua Tang, Wanyang Dong, Ning Sun, and Wenchang Yuan. "A Review of Biofilm Formation of Staphylococcus aureus and Its Regulation Mechanism." Antibiotics 12, no. 1 (December 22, 2022): 12. http://dx.doi.org/10.3390/antibiotics12010012.
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Bacteria can form biofilms in natural and clinical environments on both biotic and abiotic surfaces. The bacterial aggregates embedded in biofilms are formed by their own produced extracellular matrix. Staphylococcus aureus (S. aureus) is one of the most common pathogens of biofilm infections. The formation of biofilm can protect bacteria from being attacked by the host immune system and antibiotics and thus bacteria can be persistent against external challenges. Therefore, clinical treatments for biofilm infections are currently encountering difficulty. To address this critical challenge, a new and effective treatment method needs to be developed. A comprehensive understanding of bacterial biofilm formation and regulation mechanisms may provide meaningful insights against antibiotic resistance due to bacterial biofilms. In this review, we discuss an overview of S. aureus biofilms including the formation process, structural and functional properties of biofilm matrix, and the mechanism regulating biofilm formation.
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Lade, Harshad, Joon Hyun Park, Sung Hee Chung, In Hee Kim, Jung-Min Kim, Hwang-Soo Joo, and Jae-Seok Kim. "Biofilm Formation by Staphylococcus aureus Clinical Isolates is Differentially Affected by Glucose and Sodium Chloride Supplemented Culture Media." Journal of Clinical Medicine 8, no. 11 (November 2, 2019): 1853. http://dx.doi.org/10.3390/jcm8111853.
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Staphylococcus aureus (S. aureus) causes persistent biofilm-related infections. Biofilm formation by S. aureus is affected by the culture conditions and is associated with certain genotypic characteristics. Here, we show that glucose and sodium chloride (NaCl) supplementation of culture media, a common practice in studies of biofilms in vitro, influences both biofilm formation by 40 S. aureus clinical isolates (methicillin-resistant and methicillin-sensitive S. aureus) and causes variations in biofilm quantification. Methicillin-resistant strains formed more robust biofilms than methicillin-sensitive strains in tryptic soy broth (TSB). However, glucose supplementation in TSB greatly promoted and stabilized biofilm formation of all strains, while additional NaCl was less efficient in this respect and resulted in significant variation in biofilm measurements. In addition, we observed that the ST239-SCCmec (Staphylococcal Cassette Chromosome mec) type III lineage formed strong biofilms in TSB supplemented with glucose and NaCl. Links between biofilm formation and accessory gene regulator (agr) status, as assessed by δ-toxin production, and with mannitol fermentation were not found. Our results show that TSB supplemented with 1.0% glucose supports robust biofilm production and reproducible quantification of S. aureus biofilm formation in vitro, whereas additional NaCl results in major variations in measurements of biofilm formation.
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Utami, Putu Sri Maharani, Noorhamdani Noorhamdani, and Masruroh Rahayu. "The extract of kemangi leaves as inhibitor of biofilm from Staphylococcus aureus in vitro." Journal of Agromedicine and Medical Sciences 6, no. 3 (October 6, 2020): 168. http://dx.doi.org/10.19184/ams.v6i3.17541.
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Biofilm is a mechanism of bacterial defense against antimicrobials that can cause resistance. Staphylococcus aureus is a biofilm-producing bacteria and the most often cause of skin and soft tissue infections. Therefore, efforts are needed to prevent the formation of Staphylococcus aureus biofilms. Basil leaves are herbal plants that contain eugenol and tannin compounds, which are thought to inhibit the formation of biofilms. This research is a laboratory experimental study that aims to prove the effect of basil leaves ethanol extract (Ocimum sanctum) on the establishment of Staphylococcus aureus biofilms with in vitro method and determine the minimum inhibitory biofilm concentration needed. In this study, the tube method with 7 different concentrations was used. The results of biofilm ring formation obtained and measured quantitatively using Mean Gray Value in Adobe Photoshop CS6. From the study’s results, is found that the increase in extract concentration is directly proportional to the thinning of the biofilm ring on the tube with a minimum inhibitory concentration of biofilm at a concentration of 30%. The Pearson correlation test showed a very strong and significant correlation (r = 0.898, p = 0,000), and the Oneway ANOVA comparison test known a significant difference among the mean of each group (p = 0,000). From these results it can be known that the ethanol extract Ocimum sanctum can inhibit the formation of Staphylococcus aureus biofilms in vitro.
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Kara Terki, I., H. Hassaine, A. Kara Terki, B. Nadira, N. Kara Terki, S. Bellifa, I. Mhamedi, and M. Lachachi. "Effects of certain disinfectants and antibiotics on biofilm formation by Staphylococcus aureus isolated from medical devices at the University Hospital Center of Sidi Bel Abbes, Algeria." African Journal of Clinical and Experimental Microbiology 21, no. 4 (August 25, 2020): 304–10. http://dx.doi.org/10.4314/ajcem.v21i4.6.
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Background: Staphylococcus aureus is one of the species of bacteria most frequently isolated from medical devices. The ability to produce biofilm is an important step in the pathogenesis of these staphylococci infection, and biofilm formation is strongly dependent on environmental conditions as well as antibiotics and disinfectants used in the treatment and prevention of infections.Methodology: In this study, 28 S. aureus isolated from medical devices at the University Hospital Center of Sidi Bel Abbes in Northwestern Algeria were tested for biofilm formation by culture on Red Congo Agar (RCA). The tube method (TM) and tissue culture plate (TCP) techniques were also used to investigate the effect of penicillin, ethanol and betadine on pre-formed biofilm.Results: Nineteen S. aureus isolates produced biofilm on the RCA and 7 produced biofilms by the tube method, 2 of which were high producer. In addition, 9 S. aureus isolates produced biofilm on polystyrene micro-plates, and in the presence of penicillin and ethanol, this number increased to 19 and 11 biofilm producing S. aureus isolates respectively. On the other hand, no biofilm was formed in the presence of betadine.Conclusion: It is important to test for biofilm formation following an imposed external constraint such as disinfectants and antibiotics in order to develop new strategies to combat bacterial biofilms but also to better control their formation.
Keywords : Staphylococcus aureus, biofilm, medical device, disinfectant, antibiotic
French Title: Effets de certains désinfectants et antibiotiques sur la formation de biofilms par Staphylococcus aureus isolé à partir de dispositifs médicaux au Centre Hospitalier Universitaire de Sidi Bel Abbès, Algérie
Contexte: Staphylococcus aureus est l'une des espèces de bactéries les plus fréquemment isolées des dispositifs médicaux. La capacité de produire du biofilm est une étape importante dans la pathogenèse de ces infections à staphylocoques, et la formation de biofilm dépend fortement des conditions environnementales ainsi que des antibiotiques et des désinfectants utilisés dans le traitement et la prévention des infections.
Méthodologie: Dans cette étude, 28 S. aureus isolés à partir de dispositifs médicaux au Centre hospitalier universitaire de Sidi Bel Abbès dans le nord-ouest de l'Algérie ont été testés pour la formation de biofilm par culture sur gélose rouge du Congo (RCA). La méthode des tubes (TM) et les techniques de plaques de culture tissulaire (TCP) ont également été utilisées pour étudier l'effet de la pénicilline, de l'éthanol et de la bétadine sur le biofilm préformé.
Résultats: Dix-neuf isolats de S. aureus ont produit un biofilm sur le RCA et 7 ont produit des biofilms par la méthode des tubes, dont 2 étaient très productifs. De plus, 9 isolats de S. aureus ont produit du biofilm sur des microplaques en polystyrène, et en présence de pénicilline et d'éthanol, ce nombre est passé à 19 et 11 isolats de S. aureus producteurs de biofilm respectivement. En revanche, aucun biofilm ne s'est formé en présence de bétadine.
Conclusion: Il est important de tester la formation de biofilm suite à une contrainte externe imposée comme les désinfectants et les antibiotiques afin de développer de nouvelles stratégies pour lutter contre les biofilms bactériens mais aussi pour mieux contrôler leur formation.
Mots-clés: Staphylococcus aureus, biofilm, dispositif médical, désinfectant, antibiotique
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Gupta, Tripti Thapa, Niraj K. Gupta, Peter Burback, and Paul Stoodley. "Free-Floating Aggregate and Single-Cell-Initiated Biofilms of Staphylococcus aureus." Antibiotics 10, no. 8 (July 21, 2021): 889. http://dx.doi.org/10.3390/antibiotics10080889.
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Periprosthetic joint infection (PJI) occurring after artificial joint replacement is a major clinical issue requiring multiple surgeries and antibiotic interventions. Staphylococcus aureus is the common bacteria responsible for PJI. Recent in vitro research has shown that staphylococcal strains rapidly form free-floating aggregates in the presence of synovial fluid (SF) with biofilm-like resistance to antimicrobial agents. However, the development of biofilms formed from these aggregates under shear have not been widely investigated. Thus, in this study, we examined the progression of attached biofilms from free-floating aggregates. Biofilms were grown for 24 h in flow cells on titanium discs after inoculation with either pre-aggregated or single planktonic cells. Image analysis showed no significant difference between the biofilm formed from aggregates vs. the planktonic cells in terms of biomass, surface area, and thickness. Regarding antibiotic susceptibility, there were 1 and 2 log reductions in biofilms formed from single cells and aggregates, respectively, when treated with vancomycin for 24 h. Thus, this study demonstrates the formation of biofilm from free-floating aggregates and follows a similar developmental time period and shows similar antibiotic tolerance to more traditionally inoculated in vitro flow cell biofilms.
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Jain, R., T. Lee, T. Hardcastle, K. Biswas, F. Radcliff, and R. Douglas. "The in vitro effect of xylitol on chronic rhinosinusitis biofilms." Rhinology journal 54, no. 4 (December 1, 2016): 323–28. http://dx.doi.org/10.4193/rhino15.380.
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Introduction: Biofilms have been implicated in chronic rhinosinusitis (CRS) and may explain the limited efficacy of antibiotics. There is a need to find more effective, non-antibiotic based therapies for CRS. This study examines the effects of xylitol on CRS biofilms and planktonic bacteria. Methods: Crystal violet assay and spectrophotometry were used to quantify the effects of xylitol (5% and 10% solutions) against Staphylococcus epidermidis, Pseudomonas aeruginosa, and Staphylococcus aureus. The disruption of established biofilms, inhibition of biofilm formation and effects on planktonic bacteria growth were investigated and compared to saline and no treatment. Results: Xylitol 5% and 10% significantly reduced biofilm biomass (S. epidermidis), inhibited biofilm formation (S. aureus and P. aeruginosa) and reduced growth of planktonic bacteria (S. epidermidis, S. aureus, and P. aeruginosa). Xylitol 5% inhibited formation of S. epidermidis biofilms more effectively than xylitol 10%. Xylitol 10% reduced S. epidermidis planktonic bacteria more effectively than xylitol 5%. Saline, xylitol 5% and 10% disrupted established biofilms of S. aureus when compared with no treatment. No solution was effective against established P. aeruginosa biofilm. Conclusions: Xylitol has variable activity against biofilms and planktonic bacteria in vitro and may have therapeutic efficacy in the management of CRS.
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Leid, Jeff G., Mark E. Shirtliff, J. W. Costerton, and and Paul Stoodley. "Human Leukocytes Adhere to, Penetrate, and Respond to Staphylococcus aureus Biofilms." Infection and Immunity 70, no. 11 (November 2002): 6339–45. http://dx.doi.org/10.1128/iai.70.11.6339-6345.2002.
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ABSTRACT Staphylococcus aureus is a common pathogen responsible for nosocomial and community infections. It readily colonizes indwelling catheters, forming microbiotic communities termed biofilms. S. aureus bacteria in biofilms are protected from killing by antibiotics and the body's immune system. For years, one mechanism behind biofilm resistance to attack from the immune system's sentinel leukocytes has been conceptualized as a deficiency in the ability of the leukocytes to penetrate the biofilm. We demonstrate here that under conditions mimicking physiological shear, leukocytes attach, penetrate, and produce cytokines in response to maturing and fully matured S. aureus biofilm.
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Pazlarová, J., S. Purkrtová, J. Babulíková, and K. Demnerová. "Effects of ampicillin and vancomycin on Staphylococcus aureus biofilms." Czech Journal of Food Sciences 32, No. 2 (April 22, 2014): 137–44. http://dx.doi.org/10.17221/156/2013-cjfs.
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The collection of 23 coagulase-positive Staphylococcus aureus strains isolated mainly from food in the Czech Republic were tested on the ability to form biofilms in the presence of ampicillin and vancomycin. The antimicrobial sensitivity (16 antibiotics) was determined in all strains by the standard disc diffusion method on Mueller-Hinton agar plates (NCCLS). The resistance to ampicillin was found in 16 strains (69.5%), all strains being susceptible to vancomycin. The formation of biofilm was conducted in 96-well, polystyrene microtiter plates COSTAR 3797 in tryptic soy broth (TSB) with 1% of glucose for 24 h at 30°C. Staining with crystal violet (0.1%) was used for biofilm quantification. Ampicillin (0.5, 2, and 4 mg/l) and vancomycin (32, 64 and 128 mg/l) were added: (i) direct addition of the agent to the well at zero time, (ii) after 24 h to washed well, (iii) after 24 h directly to well with the cell suspension. The tested types of ampicillin treatment did not confirm the impact of resistance on the biofilm production among the strains tested. The addition of vancomycin at zero time of cultivation effectively suppressed the biofilm production. Other types of treatment showed unequal strain dependent response. Planktonic cells demonstrated a higher sensitivity to antibiotics than the biofilm forming cells.
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Saginur, Raphael, Melissa StDenis, Wendy Ferris, Shawn D. Aaron, Francis Chan, Craig Lee, and Karam Ramotar. "Multiple Combination Bactericidal Testing of Staphylococcal Biofilms from Implant-Associated Infections." Antimicrobial Agents and Chemotherapy 50, no. 1 (January 2006): 55–61. http://dx.doi.org/10.1128/aac.50.1.55-61.2006.
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ABSTRACT Standardized susceptibility testing fails to predict in vivo resistance of device-related infections to antimicrobials. We assessed agents and combinations of antimicrobials against clinical isolates of Staphylococcus epidermidis and S. aureus (methicillin-resistant S. aureus and methicillin-sensitive S. aureus) retrieved from device-associated infections. Isolates were grown planktonically and as biofilms. Biofilm cultures of the organisms were found to be much more resistant to inhibitory and bactericidal effects of single and combination antibiotics than planktonic cultures (P < 0.001). Rifampin was the most common constituent of antibiotic combinations active against staphylococcal biofilms. Other frequently effective antimicrobials were vancomycin and fusidic acid. Susceptibility testing involving biofilm-associated bacteria suggests new options for combination antibiotic therapy.
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Zhao, Jianying, Jing Qian, Ji Luo, Mingming Huang, Wenjing Yan, and Jianhao Zhang. "Morphophysiological Changes in Staphylococcus aureus Biofilms Treated with Plasma-Activated Hydrogen Peroxide Solution." Applied Sciences 11, no. 24 (December 7, 2021): 11597. http://dx.doi.org/10.3390/app112411597.
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Plasma-activated solution has attracted more attention in the food industry due to no chemical residue and good bacteriostatic properties. This study aimed to evaluate the effects of plasma-activated hydrogen peroxide solution (PAH) on the morphophysiology of Staphylococcus aureus biofilms. PAH was prepared using dielectric-barrier-discharge plasma and incubated with S. aureus biofilms for 0–40 min. Changes in biofilm morphophysiology were evaluated with laser scanning confocal microscopy, electron microscopic images, reactive oxygen species (ROS) content, metabolic capacity, and 1% agarose gel. Results indicated that the population of S. aureus in the biofilms was reduced by 4.04-log after incubation with PAH for 30 min. The thickness and metabolic capacity of biofilms were decreased, the ROS content and DNA fragments of bacteria increased after PAH treatments. Data suggested that PAH treatments significantly destroyed the morphophysiology of S. aureus (ATCC 6538) biofilms and could be considered as a valuable anti-biofilm technology to reduce foodborne pathogens on food and/or in food facilities.
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Olsen, Nanna, Elowine Thiran, Tobias Hasler, Thomas Vanzieleghem, Georgios Belibasakis, Jacques Mahillon, Martin Loessner, and Mathias Schmelcher. "Synergistic Removal of Static and Dynamic Staphylococcus aureus Biofilms by Combined Treatment with a Bacteriophage Endolysin and a Polysaccharide Depolymerase." Viruses 10, no. 8 (August 18, 2018): 438. http://dx.doi.org/10.3390/v10080438.
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Staphylococcus aureus is an important pathogen and biofilm former. Biofilms cause problems in clinics and food production and are highly recalcitrant to antibiotics and sanitizers. Bacteriophage endolysins kill bacteria by degrading their cell wall and are therefore deemed promising antimicrobials and anti-biofilm agents. Depolymerases targeting polysaccharides in the extracellular matrix have been suggested as parts of a multi-enzyme approach to eradicate biofilms. The efficacy of endolysins and depolymerases against S. aureus biofilms in static models has been demonstrated. However, there is a lack of studies evaluating their activity against biofilms grown under more realistic conditions. Here, we investigated the efficacy of the endolysin LysK and the poly-N-acetylglucosamine depolymerase DA7 against staphylococcal biofilms in static and dynamic (flow cell-based) models. LysK showed activity against multiple S. aureus strains, and both LysK and DA7 removed static and dynamic biofilms from polystyrene and glass surfaces at low micromolar and nanomolar concentrations, respectively. When combined, the enzymes acted synergistically, as demonstrated by crystal violet staining of static biofilms, significantly reducing viable cell counts compared to individual enzyme treatment in the dynamic model, and confocal laser scanning microscopy. Overall, our results suggest that LysK and DA7 are potent anti-biofilm agents, alone and in combination.
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Okuda, Ken-ichi, Takeshi Zendo, Shinya Sugimoto, Tadayuki Iwase, Akiko Tajima, Satomi Yamada, Kenji Sonomoto, and Yoshimitsu Mizunoe. "Effects of Bacteriocins on Methicillin-Resistant Staphylococcus aureus Biofilm." Antimicrobial Agents and Chemotherapy 57, no. 11 (August 26, 2013): 5572–79. http://dx.doi.org/10.1128/aac.00888-13.
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ABSTRACTControl of biofilms formed by microbial pathogens is an important subject for medical researchers, since the development of biofilms on foreign-body surfaces often causes biofilm-associated infections in patients with indwelling medical devices. The present study examined the effects of different kinds of bacteriocins, which are ribosomally synthesized antimicrobial peptides produced by certain bacteria, on biofilms formed by a clinical isolate of methicillin-resistantStaphylococcus aureus(MRSA). The activities and modes of action of three bacteriocins with different structures (nisin A, lacticin Q, and nukacin ISK-1) were evaluated. Vancomycin, a glycopeptide antibiotic used in the treatment of MRSA infections, showed bactericidal activity against planktonic cells but not against biofilm cells. Among the tested bacteriocins, nisin A showed the highest bactericidal activity against both planktonic cells and biofilm cells. Lacticin Q also showed bactericidal activity against both planktonic cells and biofilm cells, but its activity against biofilm cells was significantly lower than that of nisin A. Nukacin ISK-1 showed bacteriostatic activity against planktonic cells and did not show bactericidal activity against biofilm cells. Mode-of-action studies indicated that pore formation leading to ATP efflux is important for the bactericidal activity against biofilm cells. Our results suggest that bacteriocins that form stable pores on biofilm cells are highly potent for the treatment of MRSA biofilm infections.
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KIM, SOO-HWAN, SANG-HYUN PARK, SANG-SOON KIM, and DONG-HYUN KANG. "Inactivation of Staphylococcus aureus Biofilms on Food Contact Surfaces by Superheated Steam Treatment." Journal of Food Protection 82, no. 9 (August 14, 2019): 1496–500. http://dx.doi.org/10.4315/0362-028x.jfp-18-572.
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ABSTRACT The objective of this study was to compare the inactivation efficacy of saturated steam (SS) and superheated steam (SHS) on Staphylococcus aureus biofilms on food contact surfaces, including type 304 stainless steel coupons with No. 4 finish (STS No. 4), type 304 stainless steel coupons with 2B finish (STS 2B), high-density polyethylene (HDPE), and polypropylene (PP). In addition, the effects of the surface characteristics on the inactivation efficacy were evaluated. Biofilms were formed on each food contact coupon surface using a three-strain cocktail of S. aureus. Five-day-old biofilms on STS No. 4, STS 2B, HDPE, and PP coupons were treated with SS at 100°C and SHS at 125 and 150°C for 2, 4, 7, 10, 15, and 20 s. Among all coupon types, SHS was more effective than SS in inactivating the S. aureus biofilms. S. aureus biofilms on steel coupons were more susceptible to most SS and SHS treatments than the biofilms on plastic coupons. S. aureus biofilms on HDPE and PP coupons were reduced by 4.00 and 5.22 log CFU per coupon, respectively, after SS treatment (100°C) for 20 s. SS treatment for 20 s reduced the amount of S. aureus biofilm on STS No. 4 and STS 2B coupons to below the detection limit. With SHS treatment (150°C), S. aureus biofilms on HDPE and PP needed 15 s to be inactivated to below the detection limit, while steel coupons only needed 10 s. The results of this study suggest that SHS treatment has potential as a biofilm control intervention for the food industry.
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Ellis, Jeremy R., James J. Bull, and Paul A. Rowley. "Fungal Glycoside Hydrolases Display Unique Specificities for Polysaccharides and Staphylococcus aureus Biofilms." Microorganisms 11, no. 2 (January 23, 2023): 293. http://dx.doi.org/10.3390/microorganisms11020293.
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Commercially available cellulases and amylases can disperse the pathogenic bacteria embedded in biofilms. This suggests that polysaccharide-degrading enzymes would be useful as antibacterial therapies to aid the treatment of biofilm-associated bacteria, e.g., in chronic wounds. Using a published enzyme library, we explored the capacity of 76 diverse recombinant glycoside hydrolases to disperse Staphylococcus aureus biofilms. Four of the 76 recombinant glycoside hydrolases digested purified cellulose, amylose, or pectin. However, these enzymes did not disperse biofilms, indicating that anti-biofilm activity is not general to all glycoside hydrolases and that biofilm activity cannot be predicted from the activity on pure substrates. Only one of the 76 recombinant enzymes was detectably active in biofilm dispersion, an α-xylosidase from Aspergillus nidulans. An α-xylosidase cloned subsequently from Aspergillus thermomutatus likewise demonstrated antibiofilm activity, suggesting that α-xylosidases, in general, can disperse Staphylococcus biofilms. Surprisingly, neither of the two β-xylosidases in the library degraded biofilms. Commercial preparations of amylase and cellulase that are known to be effective in the dispersion of Staphylococcus biofilms were also analyzed. The commercial cellulase contained contaminating proteins with multiple enzymes exhibiting biofilm-dispersing activity. Successfully prospecting for additional antibiofilm enzymes may thus require large libraries and may benefit from purified enzymes. The complexity of biofilms and the diversity of glycoside hydrolases continue to make it difficult to predict or understand the enzymes that could have future therapeutic applications.
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Beenken, Karen E., Paul M. Dunman, Fionnuala McAleese, Daphne Macapagal, Ellen Murphy, Steven J. Projan, Jon S. Blevins, and Mark S. Smeltzer. "Global Gene Expression in Staphylococcus aureus Biofilms." Journal of Bacteriology 186, no. 14 (July 15, 2004): 4665–84. http://dx.doi.org/10.1128/jb.186.14.4665-4684.2004.
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ABSTRACT We previously demonstrated that mutation of the staphylococcal accessory regulator (sarA) in a clinical isolate of Staphylococcus aureus (UAMS-1) results in an impaired capacity to form a biofilm in vitro (K. E. Beenken, J. S. Blevins, and M. S. Smeltzer, Infect. Immun. 71:4206-4211, 2003). In this report, we used a murine model of catheter-based biofilm formation to demonstrate that a UAMS-1 sarA mutant also has a reduced capacity to form a biofilm in vivo. Surprisingly, mutation of the UAMS-1 ica locus had little impact on biofilm formation in vitro or in vivo. In an effort to identify additional loci that might be relevant to biofilm formation and/or the adaptive response required for persistence of S. aureus within a biofilm, we isolated total cellular RNA from UAMS-1 harvested from a biofilm grown in a flow cell and compared the transcriptional profile of this RNA to RNA isolated from both exponential- and stationary-phase planktonic cultures. Comparisons were done using a custom-made Affymetrix GeneChip representing the genomic complement of six strains of S. aureus (COL, N315, Mu50, NCTC 8325, EMRSA-16 [strain 252], and MSSA-476). The results confirm that the sessile lifestyle associated with persistence within a biofilm is distinct by comparison to the lifestyles of both the exponential and postexponential phases of planktonic culture. Indeed, we identified 48 genes in which expression was induced at least twofold in biofilms over expression under both planktonic conditions. Similarly, we identified 84 genes in which expression was repressed by a factor of at least 2 compared to expression under both planktonic conditions. A primary theme that emerged from the analysis of these genes is that persistence within a biofilm requires an adaptive response that limits the deleterious effects of the reduced pH associated with anaerobic growth conditions.
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Henry-Stanley, Michelle J., Donavon J. Hess, and Carol L. Wells. "Aminoglycoside inhibition of Staphylococcus aureus biofilm formation is nutrient dependent." Journal of Medical Microbiology 63, no. 6 (June 1, 2014): 861–69. http://dx.doi.org/10.1099/jmm.0.068130-0.
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Biofilms represent microbial communities, encased in a self-produced matrix or extracellular polymeric substance. Microbial biofilms are likely responsible for a large proportion of clinically significant infections and the multicellular nature of biofilm existence has been repeatedly associated with antibiotic resistance. Classical in vitro antibiotic-susceptibility testing utilizes artificial growth media and planktonic microbes, but this method may not account for the variability inherent in environments subject to biofilm growth in vivo. Experiments were designed to test the hypothesis that nutrient concentration can modulate the antibiotic susceptibility of Staphylococcus aureus biofilms. Developing S. aureus biofilms initiated on surgical sutures, and in selected experiments planktonic cultures, were incubated for 16 h in 66 % tryptic soy broth, 0.2 % glucose (1× TSBg), supplemented with bactericidal concentrations of gentamicin, streptomycin, ampicillin or vancomycin. In parallel experiments, antibiotics were added to growth medium diluted one-third (1/3× TSBg) or concentrated threefold (3× TSBg). Following incubation, viable bacteria were enumerated from planktonic cultures or suture sonicates, and biofilm biomass was assayed using spectrophotometry. Interestingly, bactericidal concentrations of gentamicin (5 µg gentamicin ml−1) and streptomycin (32 µg streptomycin ml−1) inhibited biofilm formation in samples incubated in 1/3× or 1× TSBg, but not in samples incubated in 3× TSBg. The nutrient dependence of aminoglycoside susceptibility is not only associated with biofilm formation, as planktonic cultures incubated in 3× TSBg in the presence of gentamicin also showed antibiotic resistance. These findings appeared specific for aminoglycosides because biofilm formation was inhibited in all three growth media supplemented with bactericidal concentrations of the cell wall-active antibiotics, ampicillin and vancomycin. Additional experiments showed that the ability of 3× TSBg to overcome the antibacterial effects of gentamicin was associated with decreased uptake of gentamicin by S. aureus. Uptake is known to be decreased at low pH, and the kinetic change in pH of growth medium from biofilms incubated in 5 µg gentamicin ml−1 in the presence of 3× TSBg was decreased when compared with pH determinations from biofilms formed in 1/3× or 1× TSBg. These studies underscore the importance of environmental factors, including nutrient concentration and pH, on the antibiotic susceptibility of S. aureus planktonic and biofilm bacteria.
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Mlynek, Kevin D., Mary T. Callahan, Anton V. Shimkevitch, Jackson T. Farmer, Jennifer L. Endres, Mélodie Marchand, Kenneth W. Bayles, Alexander R. Horswill, and Jeffrey B. Kaplan. "Effects of Low-Dose Amoxicillin on Staphylococcus aureus USA300 Biofilms." Antimicrobial Agents and Chemotherapy 60, no. 5 (February 8, 2016): 2639–51. http://dx.doi.org/10.1128/aac.02070-15.
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ABSTRACTPrevious studies showed that sub-MIC levels of β-lactam antibiotics stimulate biofilm formation in most methicillin-resistantStaphylococcus aureus(MRSA) strains. Here, we investigated this process by measuring the effects of sub-MIC amoxicillin on biofilm formation by the epidemic community-associated MRSA strain USA300. We found that sub-MIC amoxicillin increased the ability of USA300 cells to attach to surfaces and form biofilms under both static and flow conditions. We also found that USA300 biofilms cultured in sub-MIC amoxicillin were thicker, contained more pillar and channel structures, and were less porous than biofilms cultured without antibiotic. Biofilm formation in sub-MIC amoxicillin correlated with the production of extracellular DNA (eDNA). However, eDNA released by amoxicillin-induced cell lysis alone was evidently not sufficient to stimulate biofilm. Sub-MIC levels of two other cell wall-active agents with different mechanisms of action—d-cycloserine and fosfomycin—also stimulated eDNA-dependent biofilm, suggesting that biofilm formation may be a mechanistic adaptation to cell wall stress. Screening a USA300 mariner transposon library for mutants deficient in biofilm formation in sub-MIC amoxicillin identified numerous known mediators ofS. aureusβ-lactam resistance and biofilm formation, as well as novel genes not previously associated with these phenotypes. Our results link cell wall stress and biofilm formation in MRSA and suggest that eDNA-dependent biofilm formation by strain USA300 in low-dose amoxicillin is an inducible phenotype that can be used to identify novel genes impacting MRSA β-lactam resistance and biofilm formation.
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Wen, Qing-Hui, Rui Wang, Si-Qi Zhao, Bo-Ru Chen, and Xin-An Zeng. "Inhibition of Biofilm Formation of Foodborne Staphylococcus aureus by the Citrus Flavonoid Naringenin." Foods 10, no. 11 (October 28, 2021): 2614. http://dx.doi.org/10.3390/foods10112614.
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Taking into consideration the importance of biofilms in food deterioration and the potential risks of antiseptic compounds, antimicrobial agents that naturally occurring are a more acceptable choice for preventing biofilm formation and in attempts to improve antibacterial effects and efficacy. Citrus flavonoids possess a variety of biological activities, including antimicrobial properties. Therefore, the anti-biofilm formation properties of the citrus flavonoid naringenin on the Staphylococcus aureus ATCC 6538 (S. aureus) were investigated using subminimum inhibitory concentrations (sub-MICs) of 5~60 mg/L. The results were confirmed using laser and scanning electron microscopy techniques, which revealed that the thick coating of S. aureus biofilms became thinner and finally separated into individual colonies when exposed to naringenin. The decreased biofilm formation of S. aureus cells may be due to a decrease in cell surface hydrophobicity and exopolysaccharide production, which is involved in the adherence or maturation of biofilms. Moreover, transcriptional results show that there was a downregulation in the expression of biofilm-related genes and alternative sigma factor sigB induced by naringenin. This work provides insight into the anti-biofilm mechanism of naringenin in S. aureus and suggests the possibility of naringenin being used in the industrial food industry for the prevention of biofilm formation.
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Rahman, Md Arifur, Ardeshir Amirkhani, Durdana Chowdhury, Maria Mempin, Mark P. Molloy, Anand Kumar Deva, Karen Vickery, and Honghua Hu. "Proteome of Staphylococcus aureus Biofilm Changes Significantly with Aging." International Journal of Molecular Sciences 23, no. 12 (June 8, 2022): 6415. http://dx.doi.org/10.3390/ijms23126415.
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Staphylococcus aureus is a notorious biofilm-producing pathogen that is frequently isolated from implantable medical device infections. As biofilm ages, it becomes more tolerant to antimicrobial treatment leading to treatment failure and necessitating the costly removal of infected devices. In this study, we performed in-solution digestion followed by TMT-based high-throughput mass spectrometry and investigated what changes occur in the proteome of S. aureus biofilm grown for 3-days and 12-days in comparison with 24 h planktonic. It showed that proteins associated with biosynthetic processes, ABC transporter pathway, virulence proteins, and shikimate kinase pathway were significantly upregulated in a 3-day biofilm, while proteins associated with sugar transporter, degradation, and stress response were downregulated. Interestingly, in a 3-day biofilm, we observed numerous proteins involved in the central metabolism pathways which could lead to biofilm growth under diverse environments by providing an alternative metabolic route to utilize energy. In 12-day biofilms, proteins associated with peptidoglycan biosynthesis, sugar transporters, and stress responses were upregulated, whereas proteins associated with ABC transporters, DNA replication, and adhesion proteins were downregulated. Gene Ontology analysis revealed that more proteins are involved in metabolic processes in 3dwb compared with 12dwb. Furthermore, we observed significant variations in the formation of biofilms resulting from changes in the level of metabolic activity in the different growth modes of biofilms that could be a significant factor in S. aureus biofilm maturation and persistence. Collectively, potential marker proteins were identified and further characterized to understand their exact role in S. aureus biofilm development, which may shed light on possible new therapeutic regimes in the treatment of biofilm-related implant-associated infections.
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Łubowska, Natalia, and Lidia Piechowicz. "Staphylococcus aureus biofilm and the role of bacteriophages in its eradication." Postępy Higieny i Medycyny Doświadczalnej 72 (January 8, 2018): 101–7. http://dx.doi.org/10.5604/01.3001.0011.5965.
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The ability to form biofilm is an important virulence factor of many microorganisms. Infections involving biofilms account for approx. 65% of all human infections. Biofilms may develop on intravascular catheters or implanted devices such as prosthetic heart valves. Implanted devices are covered by biofilm and become reservoirs of microorganisms which can be a cause of persistent infections (endocarditis, deep tissue abscesses, septic arthritis, and osteomyelitis). Treatment of infections caused by biofilm-growing cells is linked to a high risk of failure due to an extreme resistance to antimicrobial agents and increased capacity to evade the immune responses. A large number of biofilm-associated infections involve Staphylococcus aureus. Treatment of staphylococcal infections is a great challenge for clinicians because of the presence of various mechanisms of resistance to antibiotics in S. aureus, for example methicillin resistance and biofilm production. Therapeutic difficulties related with antibiotic-resistant bacteria and limitations in research on new antimicrobials were the reasons that nearly 100 years after discovery, bacteriophages caught the attention of scientists around the world as a new therapeutic option for bacterial infections. Numerous in vitro studies on S. aureus strains showed that phages can both prevent biofilm formation and contribute to the elimination of bacteria from the mature biofilm structure. The major role in biofilm eradication play depolymerases produced by some phages which facilitate their penetration into the inner layers of biofilm by disturbing the biofilm structure. This leads to the conclusion that bacteriophages treatment might become a new strategy in the prevention and eradication of infectious bacterial biofilms, including these formed by S. aureus.
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Mart’yanov, Sergey Vladislavovich, Ekaterina Alexandrovna Botchkova, Vladimir Konstantinovich Plakunov, and Andrei Vladislavovich Gannesen. "The Impact of Norepinephrine on Mono-Species and Dual-Species Staphylococcal Biofilms." Microorganisms 9, no. 4 (April 13, 2021): 820. http://dx.doi.org/10.3390/microorganisms9040820.
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The effect of norepinephrine (“NE”) on Gram-negative bacteria is well characterized; however, little is known about the impact of NE on cutaneous Gram-positive skin residents, especially staphylococci. In this study, the impact of NE on monospecies and dual-species biofilms of Staphylococcus epidermidis and S. aureus model strains was investigated for the first time. Biofilms were grown in two different models (on polytetrafluoroethylene (“PTFE”) cubes and glass microfiber filters (“GMFFs”)) and additionally kinetic measurements of bacterial growth was performed. We have shown that NE can affect the biofilm formation of both species with a strong dependence on aerobic or anaerobic culture conditions in different models. It was shown that S. epidermidis suppresses S. aureus growth in dual-species biofilms and that NE can accelerate this process, contributing to the competitive behavior of staphylococci.
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Heim, Cortney, Mark Hanke, and Tammy Kielian. "Overcoming the immune inhibitory environment associated with Staphylococcus aureus biofilms by activated macrophage transfer (166.6)." Journal of Immunology 188, no. 1_Supplement (May 1, 2012): 166.6. http://dx.doi.org/10.4049/jimmunol.188.supp.166.6.
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Abstract Staphylococcus aureus (S. aureus) can establish biofilm infections on natural and artificial surfaces, which are typically recalcitrant to antibiotic therapy. Our laboratory has shown that S. aureus biofilms evade macrophage (MΦ) anti-microbial activity, further complicating biofilm eradication. To overcome the local immune inhibitory environment created by S. aureus biofilms, we have examined whether local administration of IFN-γ and peptidoglycan activated MΦs facilitates biofilm clearance in vivo using two treatment paradigms. In a prophylactic approach, mice received activated MΦs at 12, 24, and 48 h post-infection, whereupon bacterial burdens on infected catheters and surrounding tissues were quantitated at days 3 or 14 post-infection to evaluate the longevity of MΦ-mediated biofilm clearance. For established biofilms, activated MΦs were introduced at days 7 and 9 post-infection. In both treatment paradigms, activated MΦs led to significant reductions in bacterial burdens on infected catheters and catheter-associated tissues compared to vehicle controls. In addition, many proinflammatory mediators were significantly elevated in MΦ-treated animals in both models, indicating that MΦ administration is capable of overcoming the local immune inhibitory environment created during S. aureus biofilm formation. Collectively, these findings demonstrate that the local administration of activated MΦs enhances the host immune response to facilitate S. aureus biofilm clearance.
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Singh, Rachna, Pallab Ray, Anindita Das, and Meera Sharma. "Enhanced production of exopolysaccharide matrix and biofilm by a menadione-auxotrophic Staphylococcus aureus small-colony variant." Journal of Medical Microbiology 59, no. 5 (May 1, 2010): 521–27. http://dx.doi.org/10.1099/jmm.0.017046-0.
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The role of Staphylococcus aureus small-colony variants (SCVs) in the pathogenesis of biofilm-associated infections remains unclear. This study investigated the mechanism behind increased biofilm-forming potential of a menadione-auxotrophic Staphylococcus aureus SCV compared with the wild-type parental strain, as recently reported by our laboratory. SCVs displayed an autoaggregative phenotype, with a greater amount of polysaccharide intercellular adhesin (PIA), significantly reduced tricarboxylic acid cycle activity and a decreased susceptibility to aminoglycosides and cell-wall inhibitors compared with wild-type. The biofilms formed by the SCV were highly structured, consisting of large microcolonies separated by channels, and contained more biomass as well as significantly more PIA than wild-type biofilms. The surface hydrophobicity of the two phenotypes was similar. Thus, the autoaggregation and increased biofilm-forming capacity of menadione-auxotrophic Staphylococcus aureus SCVs in this study was related to the enhanced production of PIA in these variants.
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Dong, Dong, Nicky Thomas, Mahnaz Ramezanpour, Alkis J. Psaltis, Shuman Huang, Yulin Zhao, Benjamin Thierry, Peter-John Wormald, Clive A. Prestidge, and Sarah Vreugde. "Inhibition of Staphylococcus aureus and Pseudomonas aeruginosa biofilms by quatsomes in low concentrations." Experimental Biology and Medicine 245, no. 1 (January 2020): 34–41. http://dx.doi.org/10.1177/1535370219896779.
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Staphylococcus aureus and Pseudomonas aeruginosa are primary pathogens in chronic rhinosinusitis (CRS), and the presence of S. aureus and P. aeruginosa biofilms has been associated with negative outcomes after surgery. This study investigated the inhibition effect of cetylpyridinium chloride (CPC)-quatsomes at low concentrations on both S. aureus and P. aeruginosa biofilms in vitro, as well as their toxicities towards cultured human airway epithelial (NuLi-1) cells. S. aureus ATCC 25923 and P. aeruginosa ATCC 15692 were used to establish biofilms. CPC-quatsome and CPC micelle solutions at concentrations of 0.01%, 0.025%, and 0.05% were prepared. AlamarBlue was used to test the viability of both planktonic S. aureus and P. aeruginosa and their biofilms after treatment for 5 min and 2 h, respectively. Confocal laser scanning microscopy (CLSM) was used to investigate the interactions between CPC-quatsomes and S. aureus and P. aeruginosa biofilms. A lactate dehydrogenase (LDH) assay was used to determine the toxicity of CPC-quatsomes on NuLi-1 cells. CPC-quatsome and CPC micelle solutions had significant inhibition effects at all tested concentrations on planktonic S. aureus and P. aeruginosa and their biofilms after 5-min exposure ( P < 0.05). In the CLSM study, different interactions between CPC-quatsomes and S. aureus or P. aeruginosa biofilms were observed. After 2-h treatment, the size of S. aureus biofilms decreased, while the number of dead bacteria increased in P. aeruginosa biofilms. Neither CPC-quatsomes nor CPC micelle solutions showed significant toxicity on NuLi-1 cell at all tested CPC concentrations ( P < 0.05). CPC-quatsomes at low concentrations inhibited S. aureus and P. aeruginosa in both planktonic form and biofilms. No adverse effects on NuLi-1 cells were observed, indicating their promising potential in the treatment of CRS. Impact statement Staphylococcus aureus and Pseudomonas aeruginosa biofilms are significant contributors to chronic rhinosinusitis (CRS), and are associated with poor prognosis. The killing effect of CPC-quatsomes on S. aureus biofilm at or above the CPC concentration of 0.5% (5 mg/mL) has been reported previously. This is the first study that showed the significant inhibition effect of CPC-quatsomes at low concentrations on both S. aureus and P. aeruginosa biofilms in vitro, and no adverse effects towards cultured human airway epithelial (NuLi-1) cells. In our study, CPC-quatsomes at concentrations of 0.01%, 0.025%, and 0.05% had significant inhibition effects on both planktonic and biofilms of S. aureus and P. aeruginosa. The result of this study indicates the promising potential of CPC-quatsome in the treatment of CRS.
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Gries, Casey M., Eric L. Bruger, Derek E. Moormeier, Tyler D. Scherr, Christopher M. Waters, and Tammy Kielian. "Cyclic di-AMP Released from Staphylococcus aureus Biofilm Induces a Macrophage Type I Interferon Response." Infection and Immunity 84, no. 12 (October 10, 2016): 3564–74. http://dx.doi.org/10.1128/iai.00447-16.
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Staphylococcus aureus is a leading cause of community- and nosocomial-acquired infections, with a propensity for biofilm formation. S. aureus biofilms actively skew the host immune response toward an anti-inflammatory state; however, the biofilm effector molecules and the mechanism(s) of action responsible for this phenomenon remain to be fully defined. The essential bacterial second messenger cyclic diadenylate monophosphate (c-di-AMP) is an emerging pathogen-associated molecular pattern during intracellular bacterial infections, as c-di-AMP secretion into the infected host cytosol induces a robust type I interferon (IFN) response. Type I IFNs have the potential to exacerbate infectious outcomes by promoting anti-inflammatory effects; however, the type I IFN response to S. aureus biofilms is unknown. Additionally, while several intracellular proteins function as c-di-AMP receptors in S. aureus , it has yet to be determined if any extracellular role for c-di-AMP exists and its release during biofilm formation has not yet been demonstrated. This study examined the possibility that c-di-AMP released during S. aureus biofilm growth polarizes macrophages toward an anti-inflammatory phenotype via type I interferon signaling. DacA, the enzyme responsible for c-di-AMP synthesis in S. aureus , was highly expressed during biofilm growth, and 30 to 50% of total c-di-AMP produced from S. aureus biofilm was released extracellularly due to autolytic activity. S. aureus biofilm c-di-AMP release induced macrophage type I IFN expression via a STING-dependent pathway and promoted S. aureus intracellular survival in macrophages. These findings identify c-di-AMP as another mechanism for how S. aureus biofilms promote macrophage anti-inflammatory activity, which likely contributes to biofilm persistence.
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Hrynchuk, N., L. Zelena, T. Bukhtiarova, N. Vrynchanu, L. Ishchenko, and E. Vazhnichaya. "Antibiofilm Activity of 4-(Adamantyl-1)-1-(1-Aminobutyl) Benzol against Methicillin-Resistant Staphylococcus aureus." Mikrobiolohichnyi Zhurnal 84, no. 3 (December 17, 2022): 39–50. http://dx.doi.org/10.15407/microbiolj84.03.039.
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Staphylococcus aureus is a widespread opportunistic pathogen, causing community-acquired and nosocomial infections with both acute and chronic recurrent courses. The process of chronicity of the disease is provided by biofilms. Features of the structure and functioning of biofilms, in particular the presence of matrix, quorum sensing systems, persistent cells, and efflux pumps, provide microbial communities with resistance to antimicrobial drugs under their action in therapeutic concentrations. The insufficient eff ectiveness of modern antimicrobial chemotherapy against biofi lm microorganisms indicates the urgency of the problem to search for compounds with antibiofilm activity that can affect various stages of the biofilm formation and the formed biofilm. The aim of the study is to establish the antibiofilm activity of 4-(adamantyl-1)-1-(1-aminobutyl) benzol against methicillin-resistant S. aureus (MRSA) and to determine the mechanism of its action. Methods. The ability of adamantane-containing compound 4-(adamantyl-1)-1-(1-aminobutyl) benzol (AM-166) to prevent biofilm formation and destroy the formed biofilm of S. aureus was investigated on polystyrene plates by the sorption of gentian violet on its structures followed with desorption of the dye into the organic solvent. The viability of S. aureus cells at the first stage of biofilm formation and in the composition of mature biofilms was evaluated using specific dyes for living (acridine orange) and non-viable (propidium iodide) cells. Detection of genes responsible for antibiotic resistance and biofi lm formation was performed by the polymerase chain reaction (PCR) with detection of PCR products in agarose gel. Evaluation of the effect of AM-166 on the expression of genes regulating the biofilm formation (ica, agrA, sarA, and sigB) was investigated by the real-time PCR and semi-quantitative PCR. Results. It was found that the compound AM-166 shows activity against S. aureus biofilm formation. The most pronounced effect was registered at a concentration of 5.0 minimum inhibitory concentration (MIC) (92.3%.) Under the action of AM-166 on the formed 2-day biofilms, their destruction was marked: the biomass decreases by 30.9% at 5.0 MIC. According to the results of fluorescence microscopy, the adamantane derivative at 5.0 MIC helps to reduce the number of viable cells at different stages of formation of the S. aureus biofilm. The results of molecular genetic studies indicate that the ica gene expression is significantly inhibited by the action of subinhibitory concentrations of the compound AM-116. No significant changes in the expression of sarA, agrA, and sigB genes were registered. Conclusions. Experiments on the effect of adamantane derivative on S. aureus biofilms showed that the most pronounced activity of AM-116 was observed at the stage of biofilm formation, as evidenced by the inhibition of transcriptional activity of the ica gene responsible for early stages of the biofilm formation, in particular the adhesion of planktonic cells to the substrate.
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El Haj, Cristina, Mads Lichtenberg, Karen Leth Nielsen, Thomas Bjarnsholt, and Peter Østrup Jensen. "Catalase Protects Biofilm of Staphylococcus aureus against Daptomycin Activity." Antibiotics 10, no. 5 (April 30, 2021): 511. http://dx.doi.org/10.3390/antibiotics10050511.
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Daptomycin is recommended for the treatment of Staphylococcus aureus infections due to its bactericidal activity. However, its mechanism of action is poorly understood. The involvement of reactive oxygen species (ROS) in the bactericidal activity of daptomycin has been proved against planktonic S. aureus, but not against the biofilm of S. aureus. Therefore, we evaluated if ROS contributes to the effect of daptomycin against biofilm of S. aureus. Biofilms of wild type, catalase deficient and daptomycin-resistant S. aureus strains were grown in microtiter-plates. After three days, the biofilms were exposed to daptomycin with or without thiourea in the presence of a ROS indicator. After overnight incubation, the amount of ROS and the percentage of surviving bacteria were determined. The bacterial survival was higher and the amount of ROS was lower in the wild type than in the catalase deficient biofilm, demonstrating a protective effect of catalase against daptomycin. The induction of cytotoxic ROS formation by daptomycin was verified by the addition of thiourea, which reduced the amount of ROS and protected the wild type biofilm against high concentrations of daptomycin. Accordingly, only the highest concentration of daptomycin reduced the bacterial survival and increased the ROS formation in the resistant biofilm. In conclusion, daptomycin induced the production of cytotoxic levels of endogenous ROS in S. aureus biofilm and the presence of catalase protected the biofilm against the lethality of the induced ROS.
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Gobin, Maxime, Richard Proust, Stéphane Lack, Laura Duciel, Céline Des Courtils, Emmanuel Pauthe, Adeline Gand, and Damien Seyer. "A Combination of the Natural Molecules Gallic Acid and Carvacrol Eradicates P. aeruginosa and S. aureus Mature Biofilms." International Journal of Molecular Sciences 23, no. 13 (June 27, 2022): 7118. http://dx.doi.org/10.3390/ijms23137118.
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Wound infection, especially the development of bacterial biofilms, delays wound healing and is a major public health concern. Bacteria in biofilms are more tolerant to antimicrobial agents, and new treatments to eradicate mature biofilms are needed. Combining antimicrobial molecules with different mechanisms of action is an attractive strategy to tackle the heterogeneous nature of microbial communities in biofilms. This study focused on three molecules of natural origin: gallic acid (G), carvacrol (K) and curcumin (Q). Their abilities, individually or in combination, to eradicate biofilms were quantified on mono- and dual-species mature biofilms of Pseudomonas aeruginosa and Staphylococcus aureus, the strains most commonly found in infected wounds. G presented biofilm eradicating activity on P. aeruginosa, whereas K had biofilm eradicating activity on S. aureus and P. aeruginosa. Q had no potent biofilm eradicating activity. The combination of G and K increased the effects previously observed on P. aeruginosa biofilm and led to complete eradication of S. aureus biofilm. This combination was also efficient in eradicating a dual-species biofilm of S. aureus and P. aeruginosa. This work demonstrates that K and G used in combination have a strong and synergistic eradicating activity on both mono- and dual-species mature biofilms of S. aureus and P. aeruginosa and may therefore represent an efficient alternative for the treatment of biofilms in wounds.
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Neto, Nilton A. S., Jose T. A. Oliveira, Tawanny K. B. Aguiar, Leandro P. Bezerra, Levi A. C. Branco, Felipe P. Mesquita, Cleverson D. T. Freitas, and Pedro F. N. Souza. "Synergistic Antibiofilm Activity between Synthetic Peptides and Ciprofloxacin against Staphylococcus aureus." Pathogens 11, no. 9 (August 31, 2022): 995. http://dx.doi.org/10.3390/pathogens11090995.
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Staphylococcus aureus is a human pathogen known to be resistant to antibiotics since the mid-20th century and is constantly associated with hospital-acquired infections. S. aureus forms biofilms, which are complex surface-attached communities of bacteria held together by a self-produced polymer matrix consisting of proteins, extracellular DNA, and polysaccharides. Biofilms are resistance structures responsible for increasing bacterial resistance to drugs by 1000 times more than the planktonic lifestyle. Therefore, studies have been conducted to discover novel antibacterial molecules to prevent biofilm formation and/or degrade preformed biofilms. Synthetic antimicrobial peptides (SAMPs) have appeared as promising alternative agents to overcome increasing antibiotic resistance. Here, the antibiofilm activity of eight SAMPs, in combination with the antibiotic ciprofloxacin, was investigated in vitro. Biofilm formation by S. aureus was best inhibited (76%) by the combination of Mo-CBP3-PepIII (6.2 µg mL−1) and ciprofloxacin (0.39 µg mL−1). In contrast, the highest reduction (60%) of the preformed biofilm mass was achieved with RcAlb-PepII (1.56 µg mL−1) and ciprofloxacin (0.78 µg mL−1). Fluorescence microscopy analysis reinforced these results. These active peptides formed pores in the cellular membrane of S. aureus, which may be related to the enhanced ciprofloxacin’s antibacterial activity. Our findings indicated that these peptides may act with ciprofloxacin and are powerful co-adjuvant agents for the treatment of S. aureus infections.
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Balaban, Naomi, Oscar Cirioni, Andrea Giacometti, Roberto Ghiselli, Joel B. Braunstein, Carmela Silvestri, Federico Mocchegiani, Vittorio Saba, and Giorgio Scalise. "Treatment of Staphylococcus aureus Biofilm Infection by the Quorum-Sensing Inhibitor RIP." Antimicrobial Agents and Chemotherapy 51, no. 6 (March 19, 2007): 2226–29. http://dx.doi.org/10.1128/aac.01097-06.
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ABSTRACT The quorum-sensing inhibitor RIP inhibits staphylococcal TRAP/agr systems and both TRAP- and agr-negative strains are deficient in biofilm formation in vivo, indicating the importance of quorum sensing to biofilms in the host. RIP injected systemically into rats has been found to have strong activity in preventing methicillin-resistant Staphylococcus aureus graft infections, suggesting that RIP can be used as a therapeutic agent.
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Bhattacharya, Mohini, Evelien T. M. Berends, Rita Chan, Elizabeth Schwab, Sashwati Roy, Chandan K. Sen, Victor J. Torres, and Daniel J. Wozniak. "Staphylococcus aureus biofilms release leukocidins to elicit extracellular trap formation and evade neutrophil-mediated killing." Proceedings of the National Academy of Sciences 115, no. 28 (June 25, 2018): 7416–21. http://dx.doi.org/10.1073/pnas.1721949115.
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Bacterial biofilms efficiently evade immune defenses, greatly complicating the prognosis of chronic infections. How methicillin-resistant Staphylococcus aureus (MRSA) biofilms evade host immune defenses is largely unknown. This study describes some of the major mechanisms required for S. aureus biofilms to evade the innate immune response and provides evidence of key virulence factors required for survival and persistence of bacteria during chronic infections. Neutrophils are the most abundant white blood cells in circulation, playing crucial roles in the control and elimination of bacterial pathogens. Specifically, here we show that, unlike single-celled populations, S. aureus biofilms rapidly skew neutrophils toward neutrophil extracellular trap (NET) formation through the combined activity of leukocidins Panton–Valentine leukocidin and γ-hemolysin AB. By eliciting this response, S. aureus was able to persist, as the antimicrobial activity of released NETs was ineffective at clearing biofilm bacteria. Indeed, these studies suggest that NETs could inadvertently potentiate biofilm infections. Last, chronic infection in a porcine burn wound model clearly demonstrated that leukocidins are required for “NETosis” and facilitate bacterial survival in vivo.
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Arrizubieta, María Jesús, Alejandro Toledo-Arana, Beatriz Amorena, José R. Penadés, and Iñigo Lasa. "Calcium Inhibits Bap-Dependent Multicellular Behavior in Staphylococcus aureus." Journal of Bacteriology 186, no. 22 (November 15, 2004): 7490–98. http://dx.doi.org/10.1128/jb.186.22.7490-7498.2004.
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ABSTRACT Bap (biofilm-associated protein) is a 254-kDa staphylococcal surface protein implicated in formation of biofilms by staphylococci isolated from chronic mastitis infections. The presence of potential EF-hand motifs in the amino acid sequence of Bap prompted us to investigate the effect of calcium on the multicellular behavior of Bap-expressing staphylococci. We found that addition of millimolar amounts of calcium to the growth media inhibited intercellular adhesion of and biofilm formation by Bap-positive strain V329. Addition of manganese, but not addition of magnesium, also inhibited biofilm formation, whereas bacterial aggregation in liquid media was greatly enhanced by metal-chelating agents. In contrast, calcium or chelating agents had virtually no effect on the aggregation of Bap-deficient strain M556. The biofilm elicited by insertion of bap into the chromosome of a biofilm-negative strain exhibited a similar dependence on the calcium concentration, indicating that the observed calcium inhibition was an inherent property of the Bap-mediated biofilms. Site-directed mutagenesis of two of the putative EF-hand domains resulted in a mutant strain that was capable of forming a biofilm but whose biofilm was not inhibited by calcium. Our results indicate that Bap binds Ca2+ with low affinity and that Ca2+ binding renders the protein noncompetent for biofilm formation and for intercellular adhesion. The fact that calcium inhibition of Bap-mediated multicellular behavior takes place in vitro at concentrations similar to those found in milk serum supports the possibility that this inhibition is relevant to the pathogenesis and/or epidemiology of the bacteria in the mastitis process.
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Donadu, Matthew Gavino, Marco Ferrari, Vittorio Mazzarello, Stefania Zanetti, Ivan Kushkevych, Simon K. M. R. Rittmann, Anette Stájer, et al. "No Correlation between Biofilm-Forming Capacity and Antibiotic Resistance in Environmental Staphylococcus spp.: In Vitro Results." Pathogens 11, no. 4 (April 14, 2022): 471. http://dx.doi.org/10.3390/pathogens11040471.
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The production of biofilms is a critical factor in facilitating the survival of Staphylococcus spp. in vivo and in protecting against various environmental noxa. The possible relationship between the antibiotic-resistant phenotype and biofilm-forming capacity has raised considerable interest. The purpose of the study was to assess the interdependence between biofilm-forming capacity and the antibiotic-resistant phenotype in 299 Staphylococcus spp. (S. aureus n = 143, non-aureus staphylococci [NAS] n = 156) of environmental origin. Antimicrobial susceptibility testing and detection of methicillin resistance (MR) was performed. The capacity of isolates to produce biofilms was assessed using Congo red agar (CRA) plates and a crystal violet microtiter-plate-based (CV-MTP) method. MR was identified in 46.9% of S. aureus and 53.8% of NAS isolates (p > 0.05), with resistance to most commonly used drugs being significantly higher in MR isolates compared to methicillin-susceptible isolates. Resistance rates were highest for clindamycin (57.9%), erythromycin (52.2%) and trimethoprim-sulfamethoxazole (51.1%), while susceptibility was retained for most last-resort drugs. Based on the CRA plates, biofilm was produced by 30.8% of S. aureus and 44.9% of NAS (p = 0.014), while based on the CV-MTP method, 51.7% of S. aureus and 62.8% of NAS were identified as strong biofilm producers, respectively (mean OD570 values: S. aureus: 0.779±0.471 vs. NAS: 1.053±0.551; p < 0.001). No significant differences in biofilm formation were observed based on MR (susceptible: 0.824 ± 0.325 vs. resistant: 0.896 ± 0.367; p = 0.101). However, pronounced differences in biofilm formation were identified based on rifampicin susceptibility (S: 0.784 ± 0.281 vs. R: 1.239 ± 0.286; p = 0.011). The mechanistic understanding of the mechanisms Staphylococcus spp. use to withstand harsh environmental and in vivo conditions is crucial to appropriately address the therapy and eradication of these pathogens.