Journal articles: 'Microbiology of Ps. aeruginosa'

1

Costello, Anne, F. Jerry Reen, Fergal O’Gara, Máire Callaghan, and Siobhán McClean. "Inhibition of co-colonizing cystic fibrosis-associated pathogens by Pseudomonas aeruginosa and Burkholderia multivorans." Microbiology 160, no. 7 (July 1, 2014): 1474–87. http://dx.doi.org/10.1099/mic.0.074203-0.

Full text

Abstract:

Cystic fibrosis (CF) is a recessive genetic disease characterized by chronic respiratory infections and inflammation causing permanent lung damage. Recurrent infections are caused by Gram-negative antibiotic-resistant bacterial pathogens such as Pseudomonas aeruginosa, Burkholderia cepacia complex (Bcc) and the emerging pathogen genus Pandoraea. In this study, the interactions between co-colonizing CF pathogens were investigated. Both Pandoraea and Bcc elicited potent pro-inflammatory responses that were significantly greater than Ps. aeruginosa. The original aim was to examine whether combinations of pro-inflammatory pathogens would further exacerbate inflammation. In contrast, when these pathogens were colonized in the presence of Ps. aeruginosa the pro-inflammatory response was significantly decreased. Real-time PCR quantification of bacterial DNA from mixed cultures indicated that Ps. aeruginosa significantly inhibited the growth of Burkholderia multivorans, Burkholderia cenocepacia, Pandoraea pulmonicola and Pandoraea apista, which may be a factor in its dominance as a colonizer of CF patients. Ps. aeruginosa cell-free supernatant also suppressed growth of these pathogens, indicating that inhibition was innate rather than a response to the presence of a competitor. Screening of a Ps. aeruginosa mutant library highlighted a role for quorum sensing and pyoverdine biosynthesis genes in the inhibition of B. cenocepacia. Pyoverdine was confirmed to contribute to the inhibition of B. cenocepacia strain J2315. B. multivorans was the only species that could significantly inhibit Ps. aeruginosa growth. B. multivorans also inhibited B. cenocepacia and Pa. apista. In conclusion, both Ps. aeruginosa and B. multivorans are capable of suppressing growth and virulence of co-colonizing CF pathogens.

APA, Harvard, Vancouver, ISO, and other styles

2

Nelson, Lisa K., Genevieve H. D'Amours, Kimberley M. Sproule-Willoughby, Douglas W. Morck, and Howard Ceri. "Pseudomonas aeruginosa las and rhl quorum-sensing systems are important for infection and inflammation in a rat prostatitis model." Microbiology 155, no. 8 (August 1, 2009): 2612–19. http://dx.doi.org/10.1099/mic.0.028464-0.

Full text

Abstract:

Pseudomonas aeruginosa frequently acts as an opportunistic pathogen of mucosal surfaces; yet, despite causing aggressive prostatitis in some men, its role as a pathogen in the prostate has not been investigated. Consequently, we developed a Ps. aeruginosa infection model in the rat prostate by instilling wild-type (WT) Ps. aeruginosa strain PAO1 into the rat prostate. It was found that Ps. aeruginosa produced acute and chronic infections in this mucosal tissue as determined by bacterial colonization, gross morphology, tissue damage and inflammatory markers. WT strain PAO1 and its isogenic mutant PAO-JP2, in which both the lasI and rhlI quorum-sensing signal systems have been silenced, were compared during both acute and chronic prostate infections. In acute infections, bacterial numbers and inflammatory markers were comparable between WT PA01 and PAO-JP2; however, considerably less tissue damage occurred in infections with PAO-JP2. Chronic infections with PAO-JP2 resulted in reduced bacterial colonization, tissue damage and inflammation as compared to WT PAO1 infections. Therefore, the quorum-sensing lasI and rhlI genes in Ps. aeruginosa affect acute prostate infections, but play a considerably more important role in maintaining chronic infections. We have thus developed a highly reproducible model for the study of Ps. aeruginosa virulence in the prostate.

APA, Harvard, Vancouver, ISO, and other styles

3

Irvin, Randall T., and Howard Ceri. "Immunochemical examination of the Pseudomonas aeruginosa glycocalyx: a monoclonal antibody which recognizes L-guluronic acid residues of alginic acid." Canadian Journal of Microbiology 31, no. 3 (March 1, 1985): 268–75. http://dx.doi.org/10.1139/m85-050.

Full text

Abstract:

Mice immunized with Formalin-fixed mucoid Pseudomonas aeruginosa cells developed an immune response directed, in part, towards the P. aeruginosa glycocalyx. The polyclonal mouse sera produced good immunofluorescent staining of the P. aeruginosa glycocalyx and cell surface. A library of 250 hybridoma cell lines which produced monoclonal antibodies directed against P. aeruginosa was established. Twelve clones (4.8%) produced antibody which reacted with alginate in an enzyme-linked immunosorbent assay (ELISA). Clone Ps 53 was chosen for further study, cloned, and an ascites tumor established. Clone Ps 53 was chosen for further study because the antibody produced demonstrated a specificity similar to that of a recently isolated heparin – rat-lung lectin which recognizes alginates of the Homma nontypable P. aeruginosa strains. The Ps 53 clone produced an immunoglobulin M which reacted with P. aeruginosa alginate and produced good immunofluorescent staining of the P. aeruginosa glycocalyx. The Ps 53 monoclonal antibody has an apparent specificity for L-guluronic residues in ELISA. Competitive binding studies with various alginates and monosaccharides suggest that the C6 carboxyl group of uronic acids are recognized by the antibody and that the antigen-binding site is fairly large and may recognize a particular sequence or epitope of alginic acid which is rich in L-guluronic acid. The Ps 53 monoclonal antibody did not react uniformily with all P. aeruginosa alginates but did react with all of the alginates of the Homma nontypable strains tested, suggesting that acetylation or various modifications found in P. aeruginosa alginates may interfere with antibody binding and define specific epitopes. The Ps 53 antibody also reacted with purified outer membrane, indicating that some alginate or L-guluronic acid is intimately associated with outer membrane.

APA, Harvard, Vancouver, ISO, and other styles

4

Rasmussen, Thomas Bovbjerg, Mette E. Skindersoe, Thomas Bjarnsholt, Richard K. Phipps, Kathrine Bisgaard Christensen, Peter Ostrup Jensen, Jens Bo Andersen, et al. "Identity and effects of quorum-sensing inhibitors produced by Penicillium species." Microbiology 151, no. 5 (May 1, 2005): 1325–40. http://dx.doi.org/10.1099/mic.0.27715-0.

Full text

Abstract:

Quorum sensing (QS) communication systems are thought to afford bacteria with a mechanism to strategically cause disease. One example is Pseudomonas aeruginosa, which infects immunocompromised individuals such as cystic fibrosis patients. The authors have previously documented that blockage of the QS systems not only attenuates Ps. aeruginosa but also renders biofilms highly susceptible to treatment with conventional antibiotics. Filamentous fungi produce a battery of secondary metabolites, some of which are already in clinical use as antimicrobial drugs. Fungi coexist with bacteria but lack active immune systems, so instead rely on chemical defence mechanisms. It was speculated that some of these secondary metabolites could interfere with bacterial QS communication. During a screening of 100 extracts from 50 Penicillium species, 33 were found to produce QS inhibitory (QSI) compounds. In two cases, patulin and penicillic acid were identified as being biologically active QSI compounds. Their effect on QS-controlled gene expression in Ps. aeruginosa was verified by DNA microarray transcriptomics. Similar to previously investigated QSI compounds, patulin was found to enhance biofilm susceptibility to tobramycin treatment. Ps. aeruginosa has developed QS-dependent mechanisms that block development of the oxidative burst in PMN neutrophils. Accordingly, when the bacteria were treated with either patulin or penicillic acid, the neutrophils became activated. In a mouse pulmonary infection model, Ps. aeruginosa was more rapidly cleared from the mice that were treated with patulin compared with the placebo group.

APA, Harvard, Vancouver, ISO, and other styles

5

Hemachandra, Sonali, Kulwant Kamboj, Janna Copfer, Gerald Pier, Larry L. Green, and John R. Schreiber. "Human Monoclonal Antibodies againstPseudomonas aeruginosa Lipopolysaccharide Derived from Transgenic Mice Containing Megabase Human Immunoglobulin Loci Are Opsonic and Protective against Fatal Pseudomonas Sepsis." Infection and Immunity 69, no. 4 (April 1, 2001): 2223–29. http://dx.doi.org/10.1128/iai.69.4.2223-2229.2001.

Full text

Abstract:

ABSTRACT Pseudomonas aeruginosa is a significant human pathogen, and no vaccine is commercially available. Passive antibody prophylaxis using monoclonal antibodies (MAb) against protectiveP. aeruginosa epitopes is an alternative strategy for preventing P. aeruginosa infection, but mouse MAb are not suitable for use in humans. Polyclonal human antibodies from multiple donors have variable antibody titers, and human MAb are difficult to make. We used immunoglobulin-inactivated transgenic mice reconstituted with megabase-size human immunoglobulin loci to generate a human MAb against the polysaccharide (PS) portion of the lipopolysaccharide O side chain of a common pathogenic serogroup ofP. aeruginosa, 06ad. The anti-PS human immunoglobulin G2 MAb made from mice immunized with heat-killed P. aeruginosa was specific for serogroup 06ad pseudomonas. The MAb was highly opsonic for the uptake and killing of P. aeruginosa by human polymorphonuclear leukocytes in the presence of human complement. In addition, 25 μg of the MAb protected 100% of neutropenic mice from fatal P. aeruginosasepsis. DNA sequence analysis of the genes encoding the MAb revealed VH3 and Vκ2/A2 variable-region genes, similar to variable-region genes in humans immunized with bacterial PS and associated with high-avidity anti-PS antibodies. We conclude that human MAb to P. aeruginosa made in these transgenic mice are highly protective and that these mice mimic the antibody response seen in humans immunized with T-cell-independent antigens such as bacterial PS.

APA, Harvard, Vancouver, ISO, and other styles

6

Abdelrahman, Dina N., Aya A. Taha, Mazar M. Dafaallah, Alaa Abdelgafoor Mohammed, Abdel Rahim M. El Hussein, Ahmed I. Hashim, Yousif F. Hamedelnil, and Hisham N. Altayb. "β-lactamases (bla TEM, bla SHV, bla CTXM-1, bla VEB, bla OXA-1) and class C β-lactamases gene frequency in Pseudomonas aeruginosa isolated from various clinical specimens in Khartoum State, Sudan: a cross sectional study." F1000Research 9 (April 1, 2021): 774. http://dx.doi.org/10.12688/f1000research.24818.3.

Full text

Abstract:

Background: Pseudomonas aeruginosa is a pathogenic bacterium, causing nosocomial infections with intrinsic and acquired resistance mechanisms to a large group of antibiotics, including β-lactams. This study aimed to determine the susceptibility pattern to selected antibiotics and to index the first reported β-lactamases genes frequency in Ps. aeruginosa in Khartoum State, Sudan. Methods: 121 Ps. aeruginosa clinical isolates from various clinical specimens were used in this cross sectional study conducted in Khartoum State. Eighty isolates were confirmed as Ps. aeruginosa through conventional identification methods and species specific primers. The susceptibility pattern of the confirmed isolates to selected antibiotics was done following the Kirby Bauer disk diffusion method. Multiplex PCR was used for detection of seven β-lactamase genes (blaTEM, blaSHV, blaCTXM-1, blaVEB, blaOXA-1, blaAmpC and blaDHA). Results: Of the 80 confirmed Ps. aeruginosa isolates, 8 (10%) were resistant to Imipenem while all isolates were resistant to Amoxicillin and Amoxyclav (100%). A total of 43 (54%) Ps. aeruginosa isolates were positive for blaTEM, blaSHV, blaCTXM-1, blaVEB and blaOXA-1 genes, while 27 (34%) were positive for class C β- Lactamases, and 20 (25%) were positive for both classes. Frequency of beta-lactamases genes was as follows: blaTEM, 19 (44.2%); blaSHV, 16 (37.2%); bla CTX-M1, 10 (23.3%); blaVEB, 14 (32.6%); blaOXA-1, 7 (16.3%). blaAmpC 22 (81.5%) and bla DHA 8 (29.6%). In total, 3 (11.1%) isolates were positive for both bla AmpC and blaDHA genes. Conclusion: Ps. aeruginosa isolates showed a high rate of β- lactamases production, with co-resistance to other antibiotic classes. The lowest resistance rate of Ps. aeruginosa was to Imipenem followed by Gentamicin and Ciprofloxacin. No statistically significant relationship between production of β-lactamases in Ps. aeruginosa and resistance to third generation cephalosporins was found.

APA, Harvard, Vancouver, ISO, and other styles

7

Gashaw, Getachew, Amare Fassil, and Fuad Redi. "Evaluation of the Antibacterial Activity of Pleurotus spp. Cultivated on Different Agricultural Wastes in Chiro, Ethiopia." International Journal of Microbiology 2020 (August 27, 2020): 1–9. http://dx.doi.org/10.1155/2020/9312489.

Full text

Abstract:

In the present study, mushrooms, Pleurotus ostreatus and Pleurotus florida, were cultivated on different agricultural wastes namely coffee straw (CS), pea straw (PS), Sorghum Grain Residue (SGR), and Wheat Grain (WG) for the evaluation of antibacterial activity. Antimicrobial activity evaluation was carried out against human pathogenic microorganisms, namely, Escherichia coli, Bacillus subtilis, Streptococcus faecalis, Pseudomonas aeruginosa, and Salmonella typhi by using the disc diffusion method. Methanolic extracts of P. ostreatus cultivated on a Sorghum grain residue substrate were recorded for the highest antibacterial activity against E. coli (19.8 mm) and P. aeruginosa (16.4 mm), and methanolic extracts of P. florida cultivated on a wheat grain substrate were recorded for the highest antibacterial activity against E. coli (18.6 mm) and S. faecalis (14.8 mm). Therefore, results suggested that P. ostreatus and P. florida cultivated on the coffee straw and Sorghum grain substrate were found with the highest antimicrobial activity in comparison to other substrates. The results supported that the methanolic extracts of P. ostreatus and P. florida might indeed be potential sources of antibacterial agents.

APA, Harvard, Vancouver, ISO, and other styles

8

HANIS, T., P. JELEN, P. KLÍR, J. MÑUKOVÁ, B. PÉREZ, and M. PESEK. "Poultry Meat Irradiation - Effect of Temperature on Chemical Changes and Inactivation of Microorganisms." Journal of Food Protection 52, no. 1 (January 1, 1989): 26–29. http://dx.doi.org/10.4315/0362-028x-52.1.26.

Full text

Abstract:

Chilled (10°C) and frozen (−15°C) broiler carcasses initially artificially contaminated either with Pseudomonas aeruginosa, Salmonella typhimurium or Serratia marcescens (106cfu/g) were irradiated (Co60) with doses of 0.5, 1.0, 2.5, 5.0 and 10.0 kGy. Ps. aeruginosa was eliminated by doses of 1.0 - 2.5 kGy, S. marcescens by doses of 2.5 - 5.0 kGy and S. typhimurium by a dose of 10 kGy. Characteristic radiation odor increasing with radiation dose and temperature was well removed by heat meat preparation. Radiation resulted in increase of acid and peroxide values and destruction of thiamine (up to 57%/10 kGy) and riboflavin (up to 27%/10 kGy), lower increase of fat indexes and lower destruction of vitamins was observed at lower irradiation temperature. Content of amino acids was not affected by the treatment.

APA, Harvard, Vancouver, ISO, and other styles

9

Satapute, Praveen, and Basappa Kaliwal. "Biodegradation of the fungicide propiconazole by Pseudomonas aeruginosa PS-4 strain isolated from a paddy soil." Annals of Microbiology 66, no. 4 (June 15, 2016): 1355–65. http://dx.doi.org/10.1007/s13213-016-1222-6.

Full text

APA, Harvard, Vancouver, ISO, and other styles

10

Kimura, Soichiro, Kazuhiro Tateda, Yoshikazu Ishii, Manabu Horikawa, Shinichi Miyairi, Naomasa Gotoh, Masaji Ishiguro, and Keizo Yamaguchi. "Pseudomonas aeruginosa Las quorum sensing autoinducer suppresses growth and biofilm production in Legionella species." Microbiology 155, no. 6 (June 1, 2009): 1934–39. http://dx.doi.org/10.1099/mic.0.026641-0.

Full text

Abstract:

Bacteria commonly communicate with each other by a cell-to-cell signalling mechanism known as quorum sensing (QS). Recent studies have shown that the Las QS autoinducer N-(3-oxododecanoyl)-l-homoserine lactone (3-oxo-C12-HSL) of Pseudomonas aeruginosa performs a variety of functions not only in intraspecies communication, but also in interspecies and interkingdom interactions. In this study, we report the effects of Pseudomonas 3-oxo-C12-HSL on the growth and suppression of virulence factors in other bacterial species that frequently co-exist with Ps. aeruginosa in nature. It was found that 3-oxo-C12-HSL, but not its analogues, suppressed the growth of Legionella pneumophila in a dose-dependent manner. However, 3-oxo-C12-HSL did not exhibit a growth-suppressive effect on Serratia marcescens, Proteus mirabilis, Escherichia coli, Alcaligenes faecalis and Stenotrophomonas maltophilia. A concentration of 50 μM 3-oxo-C12-HSL completely inhibited the growth of L. pneumophila. Additionally, a significant suppression of biofilm formation was demonstrated in L. pneumophila exposed to 3-oxo-C12-HSL. Our results suggest that the Pseudomonas QS autoinducer 3-oxo-C12-HSL exerts both bacteriostatic and virulence factor-suppressive activities on L. pneumophila alone.

APA, Harvard, Vancouver, ISO, and other styles

11

Sultana, Shamima, A. S. M. Shahidullah, Md Mahbubul Islam, A. F. S. A. Wasey, and Shamsun Nahar. "Antibacterial effect of Aqueous Neem (Azadirachta indica) leaf extract, crude neem leaf paste, and Ceftriaxone against Staphylococcus aureus, Escherichia coli and Pseudomonas aeruginosa." Malaysian Journal of Medical and Biological Research 3, no. 1 (June 30, 2016): 25–36. http://dx.doi.org/10.18034/mjmbr.v3i1.401.

Full text

Abstract:

The study was conducted during the period of July 2004 to June 2005 in the Department of Pharmacology & Therapeutics in collaboration of Department of Microbiology, Mymensingh Medical College, Mymensingh to determine the profile of antibacterial effect of crude neem leaf paste (CNLP), aqueous neem leaf extract (ANLE), and standard antibiotic Ceftriaxone against Staphylococcus aureus, Escherichia coli and, Pseudomonas aeruginosa. Five separate experiments were done e.g. I) Determination of inhibitory effect of crude neem leaf paste (CNLP) by incorporation into nutrient agar media (NA), against Staphylococcus aureus, Escherichia coli and, Pseudomonas aeruginosa. II) Determination of minimum inhibitory concentration (MIC) of aqueous neem leaf extract (ANLE) against that three test organisms by broth dilution technique, III) Determination of minimum inhibitory concentration (MIC) of standard antibiotic ceftriaxcone against test organisms by broth dilution technique as well as making a comparison with MIC of ANLE and IV) Subculture study of materials from effective CNLP, ANLE, NLEE and Ceftriaxone in nutrient agar medium for confirmation of respective results of different experiments conducted. Results revealed that inhibitory effects were observed against the growth of Staph. aureus, Esch. coli and Ps. aeruginosa at 15%, 20% and 25% respectively of CNLP incorporated into NA media. The broth dilution technique was followed to determine the MICs of ANLE and Ceftriaxone. The MIC of ANLE was 714 μg/ml against S. aureus and that against E. coli and P. aeruginosa was 1428 μg/ml. The MIC of Ceftriaxone was 10μg/ml against S. aureus and that against E. coli and P. aeruginosa was 25 μg/ml. The MIC of Ceftriaxone was the lowest in comparison to MICs of ANLE. The subculture study showed similar results with that of previous experiments in terms of inhibitory effects of CNLP and MICs of ANLE, Ceftriaxone against all of the organisms studied.

APA, Harvard, Vancouver, ISO, and other styles

12

Tamber, Sandeep, Elke Maier, Roland Benz, and Robert E. W. Hancock. "Characterization of OpdH, a Pseudomonas aeruginosa Porin Involved in the Uptake of Tricarboxylates." Journal of Bacteriology 189, no. 3 (November 17, 2006): 929–39. http://dx.doi.org/10.1128/jb.01296-06.

Full text

Abstract:

ABSTRACT The Pseudomonas aeruginosa outer membrane is intrinsically impermeable to many classes of antibiotics, due in part to its relative lack of general uptake pathways. Instead, this organism relies on a large number of substrate-specific uptake porins. Included in this group are the 19 members of the OprD family, which are involved in the uptake of a diverse array of metabolites. One of these porins, OpdH, has been implicated in the uptake of cis-aconitate. Here we demonstrate that this porin may also enable P. aeruginosa to take up other tricarboxylates. Isocitrate and citrate strongly and specifically induced the opdH gene via a mechanism involving derepression by the putative two-component regulatory system PA0756-PA0757. Planar bilayer analysis of purified OpdH demonstrated that it was a channel-forming protein with a large single-channel conductance (230 pS in 1 M KCl; 10-fold higher than that of OprD); however, we were unable to demonstrate the presence of a tricarboxylate binding site within the channel. Thus, these data suggest that the requirement for OpdH for efficient growth on tricarboxylates was likely due to the specific expression of this large-channel porin under particular growth conditions.

APA, Harvard, Vancouver, ISO, and other styles

13

Gupta, V., J. Chander, M. Kaur, and R. Garg. "Report of carbapenem resistant Ps. aeruginosa, isolates carrying ESBLs, AmpC and MBL enzymes based on phenotypic methodology and susceptibility to Fosfomycin." Indian Journal of Medical Microbiology 33, no. 5 (2015): 160. http://dx.doi.org/10.4103/0255-0857.150954.

Full text

APA, Harvard, Vancouver, ISO, and other styles

14

Wong, Kendy K. Y., and Robert E. W. Hancock. "Insertion Mutagenesis and Membrane Topology Model of the Pseudomonas aeruginosa Outer Membrane Protein OprM." Journal of Bacteriology 182, no. 9 (May 1, 2000): 2402–10. http://dx.doi.org/10.1128/jb.182.9.2402-2410.2000.

Full text

Abstract:

ABSTRACT Pseudomonas aeruginosa OprM is a protein involved in multiple-antibiotic resistance as the outer membrane component for the MexA-MexB-OprM efflux system. Planar lipid bilayer experiments showed that OprM had channel-forming activity with an average single-channel conductance of only about 80 pS in 1 M KCl. The gene encoding OprM was subjected to insertion mutagenesis by cloning of a foreign epitope from the circumsporozoite form of the malarial parasite Plasmodium falciparum into 11 sites. In Escherichia coli, 8 of the 11 insertion mutant genes expressed proteins at levels comparable to those obtained with the wild-type gene and the inserted malarial epitopes were surface accessible as assessed by indirect immunofluorescence. When moved to a P. aeruginosaOprM-deficient strain, seven of the insertion mutant genes expressed proteins at variable levels comparable to that of wild-type OprM and three of these reconstituted MIC profiles resembling those of the wild-type protein, while the other mutant forms showed variable MIC results. Utilizing the data from these experiments, in conjunction with multiple sequence alignments and structure predictions, an OprM topology model with 16 β strands was proposed.

APA, Harvard, Vancouver, ISO, and other styles

15

Sabbahi, Sonia, Layla Ben Ayed, and Abdellatif Boudabbous. "Cationic, anionic and neutral dyes: effects of photosensitizing properties and experimental conditions on the photodynamic inactivation of pathogenic bacteria." Journal of Water and Health 11, no. 4 (July 11, 2013): 590–99. http://dx.doi.org/10.2166/wh.2013.219.

Full text

Abstract:

The aim of this study was to evaluate the photobactericidal effect of four photosensitizers (PSs) with different structural and physico-photochemical properties, namely mesotetracationic porphyrin (T4MPyP), dianionic rose Bengal (RB), monocationic methylene blue (MB) and neutral red (NR). Their photokilling activity was tested in vitro on pathogenic bacteria such as Pseudomonas aeruginosa (P. aeruginosa) and Staphylococcus aureus (S. aureus) suspended in nutrient broth (NB) and in phosphate buffered saline (PBS) through following their influence on the PSs antimicrobial efficacy. Photodynamic inactivation (PDI) experiments were performed using visible light (L) and different PSs concentrations (20–70 μM). The ability of these PSs to mediate bacterial photodynamic inactivation was investigated as a function of type of PS and its concentrations, spectral and physico-chemical properties, bacterial strain, irradiation time and suspending medium. Indeed, they showed antibacterial effects against S. aureus and P. aeruginosa with significant difference in potency. Staphylococcus aureus suspended in NB showed 0.92 log units reduction in viable count in the presence of T4MPyP at 20 μM. Changing the suspending medium from NB to PBS, S. aureus was successfully photoinactivated by T4MPyP (20 μM) when suspended in PBS at least time exposure (10 and 30 min), followed by MB and RB.

APA, Harvard, Vancouver, ISO, and other styles

16

Poole, Keith, Thomas R. Parr Jr., and Robert E. W. Hancock. "Phosphate-selective porins from the outer membranes of fluorescent Pseudomonas sp." Canadian Journal of Microbiology 33, no. 1 (January 1, 1987): 63–69. http://dx.doi.org/10.1139/m87-011.

Full text

Abstract:

Phosphate starvation induced oligomeric proteins from the outer membranes of Pseudomonas fluorescens, Pseudomonas putida, Pseudomonas aureofaciens, and Pseudomonas chlororaphis were purified to homogeneity. The incorporation of the purified proteins into planar lipid bilayer membranes resulted in stepwise increases in membrane conductance. Single channel conductance experiments demonstrated that these proteins were all capable of forming small channels, similar to the Pseudomonas aeruginosa phosphate porin protein P, with average single channel conductances in 1 M KCl of between 233 and 252 pS. Single channel conductance measurements made in salts of varying cation or anion size indicated that the channels were uniformly anion selective. The measurement of single channel conductance as a function of KCl concentration revealed that all channels saturated at higher salt concentrations, consistent with the presence of an anion-binding site in the channel. Apparent Kd values for Cl− binding were calculated and shown to vary only twofold (180–297 mM) among all channels, including protein P channels. Phosphate competitively inhibited chloride conductance through these channels with apparent I50 values of between 0.59 and 2.5 mM phosphate at 40 mM Cl− and between 9.7 and 27 mM phosphate at 1 M Cl−. These data were consistent with the presence of a phosphate-binding site in the channels of these phosphate-regulated proteins. Furthermore, they indicated that these channels exhibit at least a 20- to 80-fold higher affinity for phosphate than for chloride.

APA, Harvard, Vancouver, ISO, and other styles

17

Saxinger, L., and G. Taylor. "P155 ESKAPE not as problematic in Canada: nosocomial bloodstream infections due to ESKAPE organisms (E. faecium, S. aureus, K. pneumoniae, A. baumannii, Ps. aeruginosa, and Enterobacter spp.) in one centre, 1999–2007." International Journal of Antimicrobial Agents 34 (July 2009): S76. http://dx.doi.org/10.1016/s0924-8579(09)70374-7.

Full text

APA, Harvard, Vancouver, ISO, and other styles

18

Levine, David, Henry Spratt, June Hanks, Charles Woods, Ledbetter Joel, Kevin Gentner, and Lindsey Brunton. "Comparison of Bacterial Contamination in a Children’s Outpatient Clinic: General Medicine Versus Pulmonary Units." Infection Control & Hospital Epidemiology 41, S1 (October 2020): s177. http://dx.doi.org/10.1017/ice.2020.708.

Full text

Abstract:

Background: The bacteria that inhabit outpatient healthcare facilities influence patient outcomes and recovery, although the diversity and quantity of these bacterial communities is largely unknown. Whether differences in bacterial presence exist in individual medical specialty units of an outpatient clinic is also largely unknown. The purpose of this study was to compare bacterial species found in the general medicine and pulmonary units of an outpatient children’s clinic associated with a teaching hospital. Methods: In total, 6 locations (4 floor sites, counters, air ducts) were sampled in 3 rooms in the pulmonary (PUL) unit and 3 rooms in the general medicine (GM) unit on 13 days over a 6-month period. Sterile double transport swabs were utilized, transported on ice to a microbiology lab, and used to inoculate Hardy Diagnostics Cdiff Banana Broth (for Clostridium difficile), CHROM MRSA agar (for methicillin-resistant Staphylococcus aureus [MRSA]), eosin methylene blue (Levine-type, for Lac+ gram negatives [GN]), and Pseudomonas isolation agar (for Pseudomonas spp and P. aeruginosa [PS and PSA]). Media were incubated for 48 hours at 37°C and were scored for bacterial presence based on colonial observation. Results: The presence of bacteria isolated from GM and PUL units differed by species and location. Based on the percentage of positive swabs, the presence of GN was widespread in both units (Fig 1). Additionally, bacterial presence was greatest on the floors (GN ranged from 72% to 85% on floors in the 2 units), whereas counters had fewer positive swabs (GN ranged from 23% to 38% on counters), and swabs from return air ducts rarely led to bacterial growth. The 1 case in which swabs from the PUL unit resulted in higher levels of bacterial growth than for the GM unit was for PSA (GM, 8%; PUL, 13%). C. difficile detection was the same on both units (ie, 35% of floor samples showed contamination). Conclusions: The levels of environmental bacterial presence observed for these clinic units differed in some cases by unit and ranged from not detectable to very high levels. Detection of C. difficile on 35% of floor samples in both units could be problematic. Additionally, for the PUL unit, contamination of 13% of floor samples by PSA should raise concerns because many patients in this clinic have cystic fibrosis (CF). Although many CF patients are colonized by PSA, others may potentially contract an infection by this pathogen from the clinical environment. This observation supports current infection control recommendations for CF patients in outpatient settings.Funding: NoneDisclosures: None

APA, Harvard, Vancouver, ISO, and other styles

19

&NA;. "Limiting wound contamination with Ps. aeruginosa." Journal of Trauma: Injury, Infection, and Critical Care 26, no. 7 (July 1986): 688. http://dx.doi.org/10.1097/00005373-198607000-00089.

Full text

APA, Harvard, Vancouver, ISO, and other styles

20

Yano, Hiromi, Yasuhiro Miyazaki, Motoko Kouno, and Masaru Ohyama. "Postoperative sinus infection with Ps. aeruginosa." Practica Oto-Rhino-Laryngologica 80, no. 3 (1987): 407–12. http://dx.doi.org/10.5631/jibirin.80.407.

Full text

APA, Harvard, Vancouver, ISO, and other styles

21

Agassandian, Marianna, Olga L. Miakotina, Matthew Andrews, Satya N. Mathur, and Rama K. Mallampalli. "Pseudomonas aeruginosa and sPLA2 IB stimulate ABCA1-mediated phospholipid efflux via ERK-activation of PPARα–RXR." Biochemical Journal 403, no. 3 (April 12, 2007): 409–20. http://dx.doi.org/10.1042/bj20061364.

Full text

Abstract:

Bacterial infection triggers an acute inflammatory response that might alter phospholipid metabolism. We have investigated the acute-phase response of murine lung epithelia to Pseudomonas aeruginosa infection. Ps. aeruginosa triggered secretion of the pro-inflammatory lipase, sPLA2 IB (phospholipase A2 IB), from lung epithelium. Ps. aeruginosa and sPLA2 IB each stimulated basolateral PtdCho (phosphatidylcholine) efflux in lung epithelial cells. Pre-treatment of cells with glyburide, an inhibitor of the lipid-export pump, ABCA1 (ATP-binding cassette transporter A1), attenuated Ps. aeruginosa and sPLA2 IB stimulation of PtdCho efflux. Effects of Ps. aeruginosa and sPLA2 IB were completely abolished in human Tangier disease fibroblasts, cells that harbour an ABCA1 genetic defect. Ps. aeruginosa and sPLA2 IB induced the heterodimeric receptors, PPARα (peroxisome-proliferator-activated receptor-α) and RXR (retinoid X receptor), factors known to modulate ABCA1 gene expression. Ps. aeruginosa and sPLA2 IB stimulation of PtdCho efflux was blocked with PD98059, a p44/42 kinase inhibitor. Transfection with MEK1 (mitogen-activated protein kinase/extracellular-signal-regulated kinase kinase 1), a kinase upstream of p44/42, increased PPARα and RXR expression co-ordinately with increased ABCA1 protein. These results suggest that pro-inflammatory effects of Ps. aeruginosa involve release of an sPLA2 of epithelial origin that, in part, via distinct signalling molecules, transactivates the ABCA1 gene, leading to export of phospholipid.

APA, Harvard, Vancouver, ISO, and other styles

22

Nur Hidayati, Dwi Yuni. "Pengaruh Induksi Bakteri Pseudomonas aeruginosa Terhadap Human Umbilical Vein Endothelial Cells (HUVECS) Culture." Jurnal Ilmiah Perikanan dan Kelautan 1, no. 1 (January 27, 2019): 1. http://dx.doi.org/10.20473/jipk.v1i1.11691.

Full text

Abstract:

Abstract One of the cause of negative gram bacteria is Pseudomonas aeruginosa (Ps. aeruginosa). It continuing become sepsis on the first step of patogenesa happen sticking between aeruginosa with endhotel cell. This sticking is mediated by adhesi molecul which have characterize same with hemaglutin protein. The main study of this research is to know the profile of endothelial cell culture within induction of Ps. aeruginosa. The methods are Ps. aeruginosa (9064) which have been isolated then processes on TCBS Media and continued with isolation terracely. The profile of weight molecule protein obtained by SDS PAGE and then conducted electroelution. The test of hemaglutinin using eritrosit mencit. The receptor cell used is endhotel cell (HUVECs) culture. The result show that dosage of hemaglutin protein of Aeruginosa bring effect to profile of HUVECs culture determined by index adhesion of Ps. aeruginosa to HUVECs culture. We conclude that protein 38,19 kDa give effect to profile of HUVECs culture in vitro.

APA, Harvard, Vancouver, ISO, and other styles

23

Abdelrahman, Dina N., Aya A. Taha, Mazar M. Dafaallah, Alaa Abdelgafoor Mohammed, Abdel Rahim M. El Hussein, Ahmed I. Hashim, Yousif F. Hamedelnil, and Hisham N. Altayb. "Extended spectrum β-lactamases and class C β-lactamases gene frequency in Pseudomonas aeruginosa isolated from various clinical specimens in Khartoum State, Sudan: a cross sectional study." F1000Research 9 (July 27, 2020): 774. http://dx.doi.org/10.12688/f1000research.24818.1.

Full text

Abstract:

Background: Pseudomonas aeruginosa is a pathogenic bacterium, causing nosocomial infections with intrinsic and acquired resistance mechanisms to a large group of antibiotics, including β-lactams. This study aimed to determine the susceptibility pattern to selected antibiotics and to index the first reported β-lactamases gene (extended spectrum β-lactamases (ESBLs) genes and class C β-lactamases genes) frequency in Ps. aeruginosa in Khartoum State, Sudan. Methods: 121 Ps. aeruginosa clinical isolates from various clinical specimens were used in this cross-sectional study conducted in Khartoum State. A total of 80 isolates were confirmed as Ps. aeruginosa through conventional identification methods and species-specific primers (the remaining 40 isolates were other bacterial species). The susceptibility pattern of the confirmed isolates to selected antibiotics was done following the Kirby Bauer disk diffusion method. Multiplex PCR was used for detection of seven β-lactamase genes (blaTEM, blaSHV, blaCTXM-1, blaVEB, blaOXA-1, blaAmpC and blaDHA). Results: Of the 80 confirmed Ps. aeruginosa isolates, 8 (10%) were resistant to Imipenem while all isolates were resistant to Amoxicillin and Amoxyclav (100%). A total of 43 (54%) Ps. aeruginosa isolates were positive for ESBLs genes, while 27 (34%) were positive for class C β-lactamases, and 20 (25%) were positive for both classes. Frequency of ESBLs genes was as follows: blaTEM, 19 (44.2%); blaSHV, 16 (37.2%); blaCTX-M1, 10 (23.3%); blaVEB, 14 (32.6%); and blaOXA-1, 7 (16.3%). Occurrence of class C β-lactamases genes was blaAmpC 22 (81.5%) and blaDHA 8 (29.6%). In total, 3 (11.1%) isolates were positive for both blaAmpC and blaDHA genes. Conclusion: Ps. aeruginosa isolates showed a high rate of β-lactamases production, with co-resistance to other antibiotic classes. The lowest resistance rate of Ps. aeruginosa was to Imipenem followed by Gentamicin and Ciprofloxacin. No statistically significant relationship between production of β-lactamases in Ps. aeruginosa and resistance to third generation cephalosporins was found.

APA, Harvard, Vancouver, ISO, and other styles

24

Abdelrahman, Dina N., Aya A. Taha, Mazar M. Dafaallah, Alaa Abdelgafoor Mohammed, Abdel Rahim M. El Hussein, Ahmed I. Hashim, Yousif F. Hamedelnil, and Hisham N. Altayb. "β-lactamases (bla TEM, bla SHV, bla CTXM-1, bla VEB, bla OXA-1) and class C β-lactamases gene frequency in Pseudomonas aeruginosa isolated from various clinical specimens in Khartoum State, Sudan: a cross sectional study." F1000Research 9 (September 15, 2020): 774. http://dx.doi.org/10.12688/f1000research.24818.2.

Full text

Abstract:

Background: Pseudomonas aeruginosa is a pathogenic bacterium, causing nosocomial infections with intrinsic and acquired resistance mechanisms to a large group of antibiotics, including β-lactams. This study aimed to determine the susceptibility pattern to selected antibiotics and to index the first reported β-lactamases gene (extended spectrum β-lactamases (ESBLs) genes and class C β-lactamases genes) frequency in Ps. aeruginosa in Khartoum State, Sudan. Methods: 121 Ps. aeruginosa clinical isolates from various clinical specimens were used in this cross-sectional study conducted in Khartoum State. A total of 80 isolates were confirmed as Ps. aeruginosa through conventional identification methods and species-specific primers (the remaining 40 isolates were other bacterial species). The susceptibility pattern of the confirmed isolates to selected antibiotics was done following the Kirby Bauer disk diffusion method. Multiplex PCR was used for detection of seven β-lactamase genes (blaTEM, blaSHV, blaCTXM-1, blaVEB, blaOXA-1, blaAmpC and blaDHA). Results: Of the 80 confirmed Ps. aeruginosa isolates, 8 (10%) were resistant to Imipenem while all isolates were resistant to Amoxicillin and Amoxyclav (100%). A total of 43 (54%) Ps. aeruginosa isolates were positive for ESBLs genes, while 27 (34%) were positive for class C β-lactamases, and 20 (25%) were positive for both classes. Frequency of ESBLs genes was as follows: blaTEM, 19 (44.2%); blaSHV, 16 (37.2%); blaCTX-M1, 10 (23.3%); blaVEB, 14 (32.6%); and blaOXA-1, 7 (16.3%). Occurrence of class C β-lactamases genes was blaAmpC 22 (81.5%) and blaDHA 8 (29.6%). In total, 3 (11.1%) isolates were positive for both blaAmpC and blaDHA genes. Conclusion: Ps. aeruginosa isolates showed a high rate of β-lactamases production, with co-resistance to other antibiotic classes. The lowest resistance rate of Ps. aeruginosa was to Imipenem followed by Gentamicin and Ciprofloxacin. No statistically significant relationship between production of β-lactamases in Ps. aeruginosa and resistance to third generation cephalosporins was found.

APA, Harvard, Vancouver, ISO, and other styles

25

Sasaki, Hiraku, Eiichi Kawamoto, Satoshi Kunita, and Ken-ichi Yagami. "Comparison of the in Vitro Susceptibility of Rodent Isolates of Pseudomonas Aeruginosa and Pasteurella Pneumotropica to Enrofloxacin." Journal of Veterinary Diagnostic Investigation 19, no. 5 (September 2007): 557–60. http://dx.doi.org/10.1177/104063870701900517.

Full text

Abstract:

The objectives of this study were to determine and compare the in vitro enrofloxacin susceptibility of 94 Pseudomonas aeruginosa isolates obtained from enrofloxacin-treated and untreated mice and that of 40 Pasteurella pneumotropica strains and also to assess the efficacy and effects of enrofloxacin treatment of laboratory mice. The minimum inhibitory concentrations (MICs) of enrofloxacin against all the Ps. aeruginosa isolates were in the range of 1 to 4 μg/ml, whereas those against all the P. pneumotropica strains were less than 0.5 μg/ml. The mutation frequency in 54% of the Ps. aeruginosa isolates on treatment with enrofloxacin ranged from 10−6 to 10−8; however, none of the P. pneumotropica strains could grow on medium containing more than 3 μg/ml enrofloxacin. Comparison of in vitro enrofloxacin susceptibilities suggested that enrofloxacin was effective for eliminating P. pneumotropica but not for eliminating Ps. aeruginosa for which the MIC of enrofloxacin was more than 1 μg/ml. These results indicated that the enrofloxacin susceptibility of P. pneumotropica was higher than that of Ps. aeruginosa, and that the enrofloxacin treatment might not affect the susceptibility of Ps. aeruginosa.

APA, Harvard, Vancouver, ISO, and other styles

26

Mihalache, Madalina, Alina Banciu, Lucian Ionescu, and Mihai Nita-Lazar. "Elisa preliminary studies of immobilization and specific detection of bacterial strains." Romanian Journal of Ecology & Environmental Chemistry 2, no. 2 (October 14, 2020): 64–69. http://dx.doi.org/10.21698/rjeec.2020.209.

Full text

Abstract:

The paper aims to emphasize the specific detection of bacterial strains using enzyme-linked immunosorbent assay. The assay is based on the specific binding of polyclonal antibody anti-E. coli tagged with FITC to E.coli and monoclonal antibody anti-Ps. aeruginosa tagged with Alexa Fluor 647 tagged to Ps. aeruginosa and on subsequent enzymatic immunological demonstration of the conjugated enzyme. In this experiment, the negative control was the Salmonella enterica strain. The two antibodies had no interaction with the negative control, instead, they were specific for E. coli and Ps. aeruginosa strains. When both strains were in the same well, the fluorescence intensity given by the presence of E. coli was 2.3 times higher than that given by Ps. aeruginosa, and the intensity of fluorescence decreased if there are both bacterial strains in the wells.

APA, Harvard, Vancouver, ISO, and other styles

27

Stravinskas Durigon, Thomas, BreAnne MacKenzie, Manoel Carneiro Oliveira-Junior, Alana Santos-Dias, Kátia De Angelis, Christiane Malfitano, Renata K. Palma, et al. "Aerobic Exercise Protects from Pseudomonas aeruginosa-Induced Pneumonia in Elderly Mice." Journal of Innate Immunity 10, no. 4 (2018): 279–90. http://dx.doi.org/10.1159/000488953.

Full text

Abstract:

Background: Pseudomonas aeruginosa (PS) infection results in severe morbidity and mortality, especially in immune-deficient populations. Aerobic exercise (AE) modulates the immune system, but its effects on the outcomes of pulmonary PS infection in elderly mice are unknown. Methods: BALB/c mice (24 weeks old) were randomized to sedentary, exercise (EX), PS, and PS + EX groups for the acute experimental setting, and PS and PS + EX groups for the chronic setting. Low-intensity AE was performed for 5 weeks, 60 min/day; 24 h after the final AE session, mice were inoculated with 5 × 104 colony-forming units (CFU) of PS, and 24 h and 14 days after PS inoculation, mice were studied. Results: AE inhibited PS colonization (p < 0.001) and lung inflammation (total cells, neutrophils, lymphocytes [p < 0.01] in bronchoalveolar lavage [BAL]), with significant differences in BAL levels of IL-1β (p < 0.001), IL-6 (p < 0.01), CXCL1 (p < 0.001), and TNF-α (p < 0.001), as well as parenchymal neutrophils (p < 0.001). AE increased BAL levels of IL-10 and parenchymal (p < 0.001) and epithelial (p < 0.001) IL-10 expression, while epithelial (p < 0.001) and parenchymal (p < 0.001) NF-κB expression was decreased. AE diminished pulmonary lipid peroxidation (p < 0.001) and increased glutathione peroxidase (p < 0.01). Pre-incubation of BEAS-2B with IL-10 inhibited PS-induced epithelial cell expression of TNF-α (p < 0.05), CD40 (p < 0.01), and dichlorodihydrofluorescein diacetate (p < 0.05). Conclusions: AE inhibits PS-induced lung inflammation and bacterial colonization in elderly mice, involving IL-10/NF-κB, and redox signaling.

APA, Harvard, Vancouver, ISO, and other styles

28

McCulloch, E., M. McMillan, C. Lucas, G. Ramage, E. Mowat, and C. William. "Molecular typing of Ps. aeruginosa direct from clinical specimens." Journal of Cystic Fibrosis 8 (June 2009): S38. http://dx.doi.org/10.1016/s1569-1993(09)60153-3.

Full text

APA, Harvard, Vancouver, ISO, and other styles

29

Huang, Chi-Ren, Chia-Yi Lien, Wan-Chen Tsai, Wei-An Lai, Che-Wei Hsu, Nai-Wen Tsai, Chiung-Chih Chang, Cheng-Hsien Lu, Chun-Chih Chien, and Wen-Neng Chang. "The clinical characteristics of adult bacterial meningitis caused by non- Pseudomonas ( Ps .) aeruginosa Pseudomonas species: A clinical comparison with Ps. aeruginosa meningitis." Kaohsiung Journal of Medical Sciences 34, no. 1 (January 2018): 49–55. http://dx.doi.org/10.1016/j.kjms.2017.08.007.

Full text

APA, Harvard, Vancouver, ISO, and other styles

30

WILSON, Emma K., Andrea BELLELLI, Francesca CUTRUZZOLÀ, Walter G. ZUMFT, Aldo GUTIERREZ, and Nigel S. SCRUTTON. "Kinetics of CO binding and CO photodissociation in Pseudomonas stutzeri cd1 nitrite reductase: probing the role of extended N-termini in fast structural relaxation upon CO photodissociation." Biochemical Journal 355, no. 1 (February 26, 2001): 39–43. http://dx.doi.org/10.1042/bj3550039.

Full text

Abstract:

cd 1 nitrite reductase from Pseudomonas stutzeri is a di-haem- containing enzyme, comprising a c-type haem and a d-type haem. Studies with the highly related cd1 nitrite reductase of Pseudomonas aeruginosahave established that this enzyme undergoes fast (microsecond) and global structural relaxation upon CO photodissociation from the reduced enzyme. A key difference between the Ps. aeruginosa and Ps. stutzerienzyme is the absence of a flexible N-terminal extension in the Ps. stutzeri enzyme. In Ps. aeruginosacd1 nitrite reductase the N-terminal extension wraps around the second subunit of the homodimer and with Tyr10 stabilizing a water molecule co-ordinated to the d1-haem. Given the intimate association of the N-terminal extension with the d1-haem, we hypothesized that the presence of the N-terminal extension likely contributes to the fast structural reorganization seen during photodissociation of CO from the reduced enzyme. In the present study we have investigated the kinetics of CO association and CO photodissociation of Ps. stutzericd1 nitrite reductase (which lacks the N-terminal arm seen in the Ps. aeruginosa enzyme) to probe the role and influence of the N-terminal arm in the fast global structural reorganization seen with Ps. aeruginosa. Surprisingly, we find that Ps. stutzericd1 nitrite reductase also undergoes fast structural reorganization during CO photodissociation. We also show, in stopped-flow experiments, that the kinetics of CO binding and dissociation with reduced Ps. stutzericd1 nitrite reductase are similar to those observed with Ps. aeruginosa enzyme, thus ruling out a major role for the N-terminal flexible arm found in Ps. aeruginosain the kinetics of these processes. Our data indicate that global structural reorganization following CO photodissociation is an intrinsic property of the haem domains in cd1 nitrite reductases. The absence of an N-terminal extension, as in the Ps. stutzericd1 nitrite reductase, does not lead to loss of global structural reorganization following CO photodissociation.

APA, Harvard, Vancouver, ISO, and other styles

31

Drinković, D. T., D. Tješić-D, J. Kelečić, A. Votava-Raić, A. Gagro, and J. Vraneš. "Efficacy of Bramitob® on eradication of Ps. aeruginosa (PA)." Journal of Cystic Fibrosis 8 (June 2009): S65. http://dx.doi.org/10.1016/s1569-1993(09)60257-5.

Full text

APA, Harvard, Vancouver, ISO, and other styles

32

Mayes, C., G. McCracken, and P. Rooney. "PC.13 Minimising risk from Ps aeruginosa using tap design." Archives of Disease in Childhood - Fetal and Neonatal Edition 99, Suppl 1 (June 2014): A40.2—A40. http://dx.doi.org/10.1136/archdischild-2014-306576.116.

Full text

APA, Harvard, Vancouver, ISO, and other styles

33

Lazarova, V. Z., B. Capdeville, and L. Nikolov. "Biofilm Performance of a Fluidized Bed Biofilm Reactor for Drinking Water Denitrification." Water Science and Technology 26, no. 3-4 (August 1, 1992): 555–66. http://dx.doi.org/10.2166/wst.1992.0435.

Full text

Abstract:

The properties of two biofilms generated with different predominant organisms were studied in a laboratory-scale fluidized bed bioreactor. Bed expansion, biofilm thickness, biofilm density, protein and polysaccharide concentrations were measured and compared. A high polysaccharide concentration was observed in the less dense and more fragile biofilm of Ps. aeruginosa. The more active biofilm of Ps. stutzeri was characterized by higher protein concentration and density. The results demonstrated that the biofilm performance mostly depended on the physiological characteristics of the preponderant organism. Complete nitrate reduction was reached in both biofilms at very low biofilm thickness. Elevated residual nitrite was observed only in the biofilm of Ps. aeruginosa.

APA, Harvard, Vancouver, ISO, and other styles

34

GODOVA, G. V., A. A. OVOD, N. V. ASTAKHOVA, and E. A. KALASHNIKOVA. "HISTOLOGICAL STUDY OF LETTUCE AND BASIL BY INFECTION WITH PS. AERUGINOSA AND PS. FLUORESCENS IN VITRO." Izvestiâ Timirâzevskoj selʹskohozâjstvennoj akademii, no. 3 (2020): 56–69. http://dx.doi.org/10.26897/0021-342x-2020-3-56-69.

Full text

Abstract:

Studies based on the use of an electronic microscope revealed ultrastructural changes in plant cells of lettuce and Basil in interaction with Ps.aeruginosa ATCC B3994, expressed in deformation and violation of the integrity of the cell wall, increasing the size of chloroplasts, sometimes full destruction accompanied by the increased number of plastoglobuli. Ps.fluorescens ATСC948 were localized in the cytoplasm and chloroplasts of cells without a cytotoxic action. Plant isolates were identified with gram staining, biochemical tests and PCR. Contamination of non-heattreated leaf vegetables with virulent strain Ps. aeruginosa is a potential threat to human health and life.

APA, Harvard, Vancouver, ISO, and other styles

35

Silvestrini, M. C., F. Cutruzzolà, R. D'Alessandro, M. Brunori, N. Fochesato, and E. Zennaro. "Expression of Pseudomonas aeruginosa nitrite reductase in Pseudomonas putida and characterization of the recombinant protein." Biochemical Journal 285, no. 2 (July 15, 1992): 661–66. http://dx.doi.org/10.1042/bj2850661.

Full text

Abstract:

Nitrite reductase from Pseudomonas aeruginosa has been successfully expressed in Pseudomonas putida. The purified recombinant enzyme contains haem c but no haem d1. Nonetheless, like the holoenzyme from Ps. aeruginosa, it is a stable dimer (molecular mass 120 kDa), and electron transfer to oxidized azurin is biphasic and follows bimolecular kinetics (k1 = 1.5 x 10(5) and k2 = 2.2 x 10(4) M-1.s-1). Unlike the chemically produced apoenzyme, recombinant nitrite reductase containing only haem c is water-soluble, stable at neutral pH and can be quantitatively reconstituted with haem d1, yielding a holoenzyme with the same properties as that expressed by Ps. aeruginosa (namely optical and c.d. spectra, molecular mass, cytochrome c551 oxidase activity and CO-binding kinetics).

APA, Harvard, Vancouver, ISO, and other styles

36

Shrestha, Rajani, N. Nayak, D. R. Bhatta, D. Hamal, S. H. Subramanya, and S. Gokhale. "Drug Resistance and Biofilm Production among Pseudomonas aeruginosa Clinical Isolates in a Tertiary Care Hospital of Nepal." Nepal Medical College Journal 21, no. 2 (August 2, 2019): 110–16. http://dx.doi.org/10.3126/nmcj.v21i2.25109.

Full text

Abstract:

Clinical isolates of Pseudomonas aeruginosa often exhibit multidrug resistance due to their inherent ability to form biofilms. Drug resistance in Ps. aeruginosa is a major clinical problem, especially in the management of patients with nosocomial infections and those admitted to ICUs with indwelling medical devices. To evaluate the biofilm forming abilities of the clinical isolates of Ps. aeruginosa and to correlate biofilm formation with antibiotic resistance. A total of 90 consecutive isolates of Ps. aeruginosa obtained from various specimens collected from patients visiting the Manipal Teaching Hospital, Pokhara, Nepal between January 2018 - October 2018 were studied. Isolates were identified by standard microbiological methods. Antibiotic susceptibility testing was performed by Kirby-Bauer disc diffusion method. All the isolates were tested for their biofilm forming abilities by employing the tissue culture plate assay. Of the 90 Ps. aeruginosa isolates, maximum i.e 42 (46.6%) were from patients in the age group of > 50 years. Majority (30; 33.3%) of the isolates were obtained from sputum samples. However, percentage isolation from other specimens like urine, endotracheal tube (ETT), pus, eye specimens and blood were 18.9%, 16.7%, 16.7%, 7.8% and 6.7% respectively. All the isolates were sensitive to polymixin B and colistin, 91.1% of the organisms were sensitive to imipenem, and more than 80% to aminoglycosides (80% to gentamicin, 83.3% to amikacin). A total of 29 (32.2%) organisms were biofilm producers. Maximum numbers of biofilm producing strains were obtained from ETT (8 of 15; 53.3%), pus (8 of 15; 53.3%) and blood (2 of 6; 33.3%) i.e from all invasive sites. None of the isolates from noninvasive specimens such as conjunctival swabs were biofilm positive. Significantly higher numbers of biofilm producers (23 of 29; 79.3%) were found to be multidrug resistant as compared to non-biofilm (6 of 61; 9.8%) producers (p=0.000). Ps. aeruginosa colonization leading to biofilm formation in deep seated tissues and on indwelling devices is a therapeutic challenge as majority of the isolates would be recalcitrant to commonly used antipseudomonal drugs. Effective monitoring of drug resistance patterns in all Pseudomonas clinical isolates should be a prerequisite for successful patient management.

APA, Harvard, Vancouver, ISO, and other styles

37

Papaioannidou, Paraskevi, Vassilios Nitsas, and Vassiliki Mirtsou-Fidani. "Hydrolysis of cefazolin by enzymes produced by Pseudomonas aeruginosa after exposure to ceftazidime in vitro." Vojnosanitetski pregled 66, no. 10 (2009): 785–90. http://dx.doi.org/10.2298/vsp0910785p.

Full text

Abstract:

Background/Aim. Sometimes resistance of Pseudomonas aeruginosa (Ps. aeruginosa) is developed during antibiotic treatment, in spite of the initial susceptibility in vitro. The aim of this study was to use an in vitro model for the study of the development of resistant strains of Ps. aeruginosa after a short exposure to ceftazidime, and to study the hydrolysing capacity of ?-lactamases produced by the resistant strains. Methods. Among 563 clinical strains of Ps. aeruginosa, 37 multisensitive strains were collected for the study. After being identified, strains with simultaneous sensitivity to 5 expanded spectrum cephalosporins were chosen. For each strain, the minimal inhibitory concentration (MIC) of the 5 expanded spectrum cephalosporins was determined, and the production of extended spectrum ?-lactamases (ESBL) was excluded by the double-disc synergy diffusion test. Strains non producing ESBL were cultivated in concentrations of ceftazidime equal to MIC?2 and MIC?4. After 24 hours of culture, the development of resistant strains was estimated and the cephalosporinase activity of the produced ?-lactamases was determined by their ability to hydrolyse cefazolin. Hydrolysis of cefazolin was studied by measuring the change of its absorbance on 272 nm using a Shimadzu 160A spectrophotometer. The hydrolyzing capacity of the enzymes was expressed as the percentage of the antibiotic, which was hydrolysed in 10 sec. Results. A total of 60% and 50% of strains developed resistant strains after exposure to ceftazidime in concentration MIC?2 and MIC?4, respectively. The hydrolyzing capacity of the original strains was 15-36% while the hydrolyzing capacity of the resistant strains was 10-73%. Totally 64% of the resistant strains expressed higher hydrolyzing capacity than the original strains. Conclusion. Regardless of the susceptibility test results, Ps. aeruginosa presented a high tendency to develop resistant strains after a short exposure to ceftazidime in vitro. In most cases the resistant strains expressed higher cephalosporinase activity than the original strains, suggesting derepression of chromosomal ?-lactamases. Our model offers a simple, inexpensive and rapid method for detecting resistance of Ps. aeruginosa developed due to derepression of ?-lactamases, and for discriminating resistant strains with derepressed ?-lactamases from strains that developed other mechanisms of resistance.

APA, Harvard, Vancouver, ISO, and other styles

38

Pennington, James E. "Pseudomonas aeruginosa." Infectious Disease Clinics of North America 4, no. 2 (June 1990): 259–70. http://dx.doi.org/10.1016/s0891-5520(20)30340-8.

Full text

APA, Harvard, Vancouver, ISO, and other styles

39

Chioroglo, E., S. Sciuca, and O. Turcu. "The sensibility of Ps. aeruginosa isolates in children with cystic fibrosis." Journal of Cystic Fibrosis 7 (June 2008): S35. http://dx.doi.org/10.1016/s1569-1993(08)60133-2.

Full text

APA, Harvard, Vancouver, ISO, and other styles

40

Orlov, Aleksandr V., Viktor N. Kovalev, Marina N. Ignatieva, Lubov A. Antipova, Ekaterina A. Egorova, and Marina O. Volkova. "The technical aspects of collecting and transporting the sputum cystic fibrosis patients." Pediatrician (St. Petersburg) 7, no. 2 (June 15, 2016): 92–95. http://dx.doi.org/10.17816/ped7292-95.

Full text

Abstract:

Timely diagnosis of infection in cystic fibrosis patients is a major aim. This is especially important for timely treatment in primary seed Ps. aeruginosa and Burkholderia cepacia. Early treatment allows in most cases to prevent the formation of chronic Pseudomonas aeruginosa infection. This also applies to re-sowing Ps. aeruginosa after the previous eradication. However, not all cities and small towns have laboratories equipped sufficiently to do bacteriological analysis of cystic fibrosis patients sputum, especially for the allocation of Ps. aeruginosa and Burkholderia cepacia. In this regard, the choice of methods of collecting material and its storage and transportation to specialized laboratories is very relevant. In 5 cities of the North-West region of Russia in 51 patients with cystic fibrosis conducted fences sputum and its subsequent delivery and carrying out of sowing in NIIDA FMBA of Russia in St Petersburg. Five patients extract sputum by coughing, 12 - induced sputum, 24 - were held flush with the posterior wall of the pharynx, 8 - swab from posterior pharyngeal wall, the parents of 2 patients brought the sputum coughed in previous day at house. As the result of bacteriologic test in 15 children certain pathogens were detected for the first time: Staphylococcus in 10 patients, Pseudomonas aeruginosa in 4 patients, Achromobacter in 1 person. Pathogens are well preserved during transportation of specimens to the laboratory in transport medium in the cold, which allows the use of bacteriological laboratories of large cities for carrying out sputum cultures of patients from other regions.

APA, Harvard, Vancouver, ISO, and other styles

41

PRESSLER, T., S. S. PEDERSEN, F. ESPERSEN, N. HØIBY, and C. KOCH. "IgG subclass antibodies to Pseudomonas aeruginosa in sera from patients with chronic Ps. aeruginosa infection investigated by ELISA." Clinical & Experimental Immunology 81, no. 3 (June 28, 2008): 428–34. http://dx.doi.org/10.1111/j.1365-2249.1990.tb05351.x.

Full text

APA, Harvard, Vancouver, ISO, and other styles

42

Hazlett, Linda. "Pseudomonas aeruginosa: my research passion." Future Microbiology 8, no. 7 (July 2013): 833–34. http://dx.doi.org/10.2217/fmb.13.49.

Full text

APA, Harvard, Vancouver, ISO, and other styles

43

LI, L., X. L. PAN, and G. J. MU. "Toxic effects of potassium permanganate on photosystem II activity of cyanobacteria Microcystis aeruginosa." Photosynthetica 58, no. 1 (March 10, 2020): 54–60. http://dx.doi.org/10.32615/ps.2019.155.

Full text

APA, Harvard, Vancouver, ISO, and other styles

44

Vallés, Jordi, and Dolors Mariscal. "Neumonía por Pseudomonas aeruginosa." Enfermedades Infecciosas y Microbiología Clínica 23 (December 2005): 30–36. http://dx.doi.org/10.1157/13091218.

Full text

APA, Harvard, Vancouver, ISO, and other styles

45

Cornaglia, G. "Pseudomonas aeruginosa." International Journal of Infectious Diseases 14 (March 2010): e24. http://dx.doi.org/10.1016/j.ijid.2010.02.1541.

Full text

APA, Harvard, Vancouver, ISO, and other styles

46

Monteiro, Rosana, Andreia Patrícia Magalhães, Maria Olivia Pereira, and Ana Margarida Sousa. "Long-term coexistence of Pseudomonas aeruginosa and Staphylococcus aureus using an in vitro cystic fibrosis model." Future Microbiology 16, no. 12 (August 2021): 879–93. http://dx.doi.org/10.2217/fmb-2021-0025.

Full text

Abstract:

Aim: To investigate the role of pre-established Staphylococcus aureus on Pseudomonas aeruginosa adaptation and antibiotic tolerance. Materials & methods: Bacteria were cultured mimicking the sequential pattern of lung colonization and exposure to ciprofloxacin. Results: In the absence of ciprofloxacin exposure, S. aureus and P. aeruginosa coexisted supported by the physicochemical characteristics of the artificial sputum medium. S. aureus had no role in P. aeruginosa tolerance against ciprofloxacin and did not select P. aeruginosa small-colony variants during antibiotic treatment. rhlR and psqE were downregulated after the contact with S. aureus indicating that P. aeruginosa attenuated its virulence potential. Conclusion: P. aeruginosa and S. aureus can cohabit in cystic fibrosis airway environment for long-term without significant impact on P. aeruginosa adaptation and antibiotic tolerance.

APA, Harvard, Vancouver, ISO, and other styles

47

Eckweiler, Denitsa, and Susanne Häussler. "Antisense transcription in Pseudomonas aeruginosa." Microbiology 164, no. 6 (June 1, 2018): 889–95. http://dx.doi.org/10.1099/mic.0.000664.

Full text

APA, Harvard, Vancouver, ISO, and other styles

48

Mochalkin, Igor, John D. Knafels, and Sandra Lightle. "Crystal structure of LpxC from Pseudomonas aeruginosa complexed with the potent BB-78485 inhibitor." Protein Science 17, no. 3 (March 2008): 450–57. http://dx.doi.org/10.1110/ps.073324108.

Full text

APA, Harvard, Vancouver, ISO, and other styles

49

Shimpi, Navinchandra, Mahesh Borane, Satyendra Mishra, and Meghraj Kadam. "Biodegradation of polystyrene (PS)-poly(lactic acid) (PLA) nanocomposites using Pseudomonas aeruginosa." Macromolecular Research 20, no. 2 (January 11, 2012): 181–87. http://dx.doi.org/10.1007/s13233-012-0026-1.

Full text

APA, Harvard, Vancouver, ISO, and other styles

50

Garau, Javier, and Lucia Gomez. "Pseudomonas aeruginosa pneumonia." Current Opinion in Infectious Diseases 16, no. 2 (April 2003): 135–43. http://dx.doi.org/10.1097/00001432-200304000-00010.

Full text

APA, Harvard, Vancouver, ISO, and other styles

Journal articles on the topic 'Microbiology of Ps. aeruginosa'

Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles