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Khalid, Kanwal, e Chit Laa Poh. "The Promising Potential of Reverse Vaccinology-Based Next-Generation Vaccine Development over Conventional Vaccines against Antibiotic-Resistant Bacteria". Vaccines 11, n. 7 (20 luglio 2023): 1264. http://dx.doi.org/10.3390/vaccines11071264.
Abstract (sommario):
The clinical use of antibiotics has led to the emergence of multidrug-resistant (MDR) bacteria, leading to the current antibiotic resistance crisis. To address this issue, next-generation vaccines are being developed to prevent antimicrobial resistance caused by MDR bacteria. Traditional vaccine platforms, such as inactivated vaccines (IVs) and live attenuated vaccines (LAVs), were effective in preventing bacterial infections. However, they have shown reduced efficacy against emerging antibiotic-resistant bacteria, including MDR M. tuberculosis. Additionally, the large-scale production of LAVs and IVs requires the growth of live pathogenic microorganisms. A more promising approach for the accelerated development of vaccines against antibiotic-resistant bacteria involves the use of in silico immunoinformatics techniques and reverse vaccinology. The bioinformatics approach can identify highly conserved antigenic targets capable of providing broader protection against emerging drug-resistant bacteria. Multi-epitope vaccines, such as recombinant protein-, DNA-, or mRNA-based vaccines, which incorporate several antigenic targets, offer the potential for accelerated development timelines. This review evaluates the potential of next-generation vaccine development based on the reverse vaccinology approach and highlights the development of safe and immunogenic vaccines through relevant examples from successful preclinical and clinical studies.
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Benmhidi, Messaoud, Sana Boukhalf, Sonia Benammar, Meriem Makhlouf, Asma Lounis e Chahinez Khernane. "emerging highly resistant bacteria data at the University Hospital of Batna". Batna Journal of Medical Sciences (BJMS) 7, n. 2 (9 novembre 2020): 134–36. http://dx.doi.org/10.48087/bjmsoa.2020.7215.
Abstract (sommario):
Les Bactéries multi résistantes posent un problème de santé publique, Thérapeutique, de Pronostic et de Prise en charge. Actuellement, la diffusion de carbapénèmases constitue le problème clinique le plus important en matière de résistance aux antibiotiques chez les Gram négatifs, en particulier chez les entérobactéries et le risque de transmission entre patients et élevé. Cette étude a pour objectifs de donner une répartition des BHRe isolées par service et par prélèvements et de sensibiliser aux risques de l'antibiorésistance Il s’agit d’une étude rétrospective avisée descriptive des BHRe isolées des prélèvements pathologiques provenant des différents services du CHU de Batna. Notre enquête a porté sur une année. Tous les prélèvements ont été traités au niveau du laboratoire de bactériologie par un examen microscopique, une culture sur milieux gélosés spécifiques et un antibiogramme selon les normes CLSI. Ces examens ont abouti à un taux de BHRe de 2,20% pour les EPC et 0,5% pour les ERV. Seulement deux espèces sont considérées comme BHRe et qui sont Enterococcus faecium résistants aux glycopeptides quelques soit le mécanisme de résistance (ERV) et Entérobactéries résistantes aux carbapénèmes par production de carbapénèmases (EPC).
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Saleem, Mehwish, Farzana Rashid e Mariam Faiz. "Genomic Analysis of Highly Virulent blaCTX-M, blaSHV and blaTEM Genes in Resistant Strains of E.coli and Klebsiella: an emerging threat". Pakistan Journal of Medical and Health Sciences 16, n. 1 (18 gennaio 2022): 186–88. http://dx.doi.org/10.53350/pjmhs22161186.
Abstract (sommario):
Background: The term antimicrobial resistance refers to the ability to resists the effects of drugs formally used to treat them and this term relates only to bacteria becoming resistant. Microorganisms that are resistant to multiple drugs are known as multidrug-resistant bacteria. Aim: To investigate the prevalence of SHV, TEM and CTXm genes from E.coli and Klebsiella isolated from patients of Lahore, Pakistan. Methods: Patients with prolonged hospital stay were enrolled in this cross-sectional study with 60 samples comprising Klebsiella pneumoniae and Escherichia coli (Ctx, Cro, Caz resistant) were identified in clinical specimens. To assess susceptibility, the disc diffusion method was applied with eight antibiotic panel of cephalosporin 3rd generation. A Double disc, combined disc test was used to identify the ESBL-producing bacteria. By real - time PCR, The presence of the genes encoding blaTEM, blaSHV, and blaCTXm was tested in ESBL positive isolates as well as additional isolates with MICs of less than 4g/mL for ceftazidime, cefotaxime, ceftriaxone, and aztreonam (PCR). Results: The frequency of E. coli and Klebsiella bacteria was found in 59% and 41% of the 60 samples, respectively. According to the data, 23 isolates (16.37%) were multidrug resistant, and 7(6.89%) were ESBL-positive. At least one of the antibiotics ceftazidime, ceftriaxone, or cefotaxime was resistant to 30(25.86%) of the isolates. The ESBL genes were sequenced to corroborate the PCR result. Conclusions: Among E. coli and Klebsiella bacteria obtained from patients, blaTEM-116 was the most frequently isolated ESBL gene, followed by Shv and Ctxm. Keywords: Antibiotic Resistance, Beta- Lactamases, E. coli, Klebsiella pneumonia
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L, Krishna, Sindhu bala e Mahesh Chandra. N. "Review Article -Antibiotics Resistant to Different Microorganisms". International Journal of Scientific Research and Management 10, n. 12 (29 dicembre 2022): 768–80. http://dx.doi.org/10.18535/ijsrm/v10i12.mp04.
Abstract (sommario):
Over a years, people mostly who were struggled with primary cause of infection and diseases by microorganisms, and utmost care has been taken that some antibiotics are highly resistant to bac- terial species and emergence of broad-range of antibiotic therapy. Broad-spectrum antibiotics have widely emerged in various ways to kill microorganisms that tend to cause illness and diseases in the human era. New resistance mechanisms are emerging and spreading worldwide. However, some bacteria may become resistant to commonly used antibiotics. Antibiotic-resistant bacteria are bacteria that are inhibited or killed by antibiotics as they can able to survive and even rapidly spread by multiplying in the human system in the presence of antibiotics. The major mechanisms interrupted in bacterial resistance are limitation of drug uptake, modification of a drug target, in- activation of a drug, and active efflux of a drug. Those bacteria are resistant to many antibiotics and they are termed Multi-resistant organisms. For example, benzylpenicillin has very little effect on most organisms in the human digestive system. Staphylococcus aureus and Neisseria gonor- rhoeae are resistant to benzylpenicillin, Methicillin-resistant Staphylococcus aureus, Vancomycin- resistant Enterococcus, Multi-drug-resistant Mycobacterium tuberculosis, Carbapenem-resistant Enterobacteriaceae. Different methods were used for detecting the antibiotic resistance to different microorganisms mainly Gram-negative bacilli, and Gram-positive bacteria. The common ways that antibiotic-resistant bacteria can be transmission in hospitals from person to person is through contact with contaminated hands of hospital staff, door handles, hospital beds, and equipment. Important ways can be followed to prevent antibiotic resistance by minimizing unnecessary over- prescribing of antibiotics by medical practitioners and maintaining proper hygiene such as hand washing by use of regular infection control.
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Williams, Caitlin L., Heather M. Neu, Jeremy J. Gilbreath, Sarah L. J. Michel, Daniel V. Zurawski e D. Scott Merrell. "Copper Resistance of the Emerging Pathogen Acinetobacter baumannii". Applied and Environmental Microbiology 82, n. 20 (12 agosto 2016): 6174–88. http://dx.doi.org/10.1128/aem.01813-16.
Abstract (sommario):
ABSTRACTAcinetobacter baumanniiis an important emerging pathogen that is capable of causing many types of severe infection, especially in immunocompromised hosts. SinceA. baumanniican rapidly acquire antibiotic resistance genes, many infections are on the verge of being untreatable, and novel therapies are desperately needed. To investigate the potential utility of copper-based antibacterial strategies againstAcinetobacterinfections, we characterized copper resistance in a panel of recent clinicalA. baumanniiisolates. Exposure to increasing concentrations of copper in liquid culture and on solid surfaces resulted in dose-dependent and strain-dependent effects; levels of copper resistance varied broadly across isolates, possibly resulting from identified genotypic variation among strains. Examination of the growth-phase-dependent effect of copper onA. baumanniirevealed that resistance to copper increased dramatically in stationary phase. Moreover,A. baumanniibiofilms were more resistant to copper than planktonic cells but were still susceptible to copper toxicity. Exposure of bacteria to subinhibitory concentrations of copper allowed them to better adapt to and grow in high concentrations of copper; this copper tolerance response is likely achieved via increased expression of copper resistance mechanisms. Indeed, genomic analysis revealed numerous putative copper resistance proteins that share amino acid homology to known proteins inEscherichia coliandPseudomonas aeruginosa. Transcriptional analysis revealed significant upregulation of these putative copper resistance genes following brief copper exposure. Future characterization of copper resistance mechanisms may aid in the search for novel antibiotics againstAcinetobacterand other highly antibiotic-resistant pathogens.IMPORTANCEAcinetobacter baumanniicauses many types of severe nosocomial infections; unfortunately, some isolates have acquired resistance to almost every available antibiotic, and treatment options are incredibly limited. Copper is an essential nutrient but becomes toxic at high concentrations. The inherent antimicrobial properties of copper give it potential for use in novel therapeutics against drug-resistant pathogens. We show thatA. baumanniiclinical isolates are sensitive to copperin vitro, both in liquid and on solid metal surfaces. Since bacterial resistance to copper is mediated though mechanisms of efflux and detoxification, we identified genes encoding putative copper-related proteins inA. baumanniiand showed that expression of some of these genes is regulated by the copper concentration. We propose that the antimicrobial effects of copper may be beneficial in the development of future therapeutics that target multidrug-resistant bacteria.
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Dash, Rachita, e Surajit Bhattacharjya. "Thanatin: An Emerging Host Defense Antimicrobial Peptide with Multiple Modes of Action". International Journal of Molecular Sciences 22, n. 4 (3 febbraio 2021): 1522. http://dx.doi.org/10.3390/ijms22041522.
Abstract (sommario):
Antimicrobial peptides (AMPs) possess great potential for combating drug-resistant bacteria. Thanatin is a pathogen-inducible single-disulfide-bond-containing β-hairpin AMP which was first isolated from the insect Podisus maculiventris. The 21-residue-long thanatin displays broad-spectrum activity against both Gram-negative and Gram-positive bacteria as well as against various species of fungi. Remarkably, thanatin was found to be highly potent in inhibiting the growth of bacteria and fungi at considerably low concentrations. Although thanatin was isolated around 25 years ago, only recently has there been a pronounced interest in understanding its mode of action and activity against drug-resistant bacteria. In this review, multiple modes of action of thanatin in killing bacteria and in vivo activity, therapeutic potential are discussed. This promising AMP requires further research for the development of novel molecules for the treatment of infections caused by drug resistant pathogens.
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Nepal, Suruchi, Sandra Maaß, Stefano Grasso, Francis M. Cavallo, Jürgen Bartel, Dörte Becher, Erik Bathoorn e Jan Maarten van Dijl. "Proteomic Charting of Imipenem Adaptive Responses in a Highly Carbapenem Resistant Clinical Enterobacter roggenkampii Isolate". Antibiotics 10, n. 5 (28 aprile 2021): 501. http://dx.doi.org/10.3390/antibiotics10050501.
Abstract (sommario):
Gram-negative bacteria belonging to the Enterobacter cloacae complex are increasingly implicated in difficult-to-treat nosocomial infections, as exemplified by a recently characterized highly carbapenem-resistant clinical Enterobacter roggenkampii isolate with sequence type (ST) 232. While mechanisms of carbapenem resistance are well-understood, little is known about the responses of highly drug-resistant bacteria to these antibiotics. Our present study was therefore aimed at charting the responses of the E. roggenkampii ST232 isolate to the carbapenem imipenem, using a ‘stable isotope labeling of amino acids in cell culture’ approach for quantitative mass spectrometry. This unveiled diverse responses of E. roggenkampii ST232 to imipenem, especially altered levels of proteins for cell wall biogenesis, central carbon metabolism, respiration, iron–sulfur cluster synthesis, and metal homeostasis. These observations suggest a scenario where imipenem-challenged bacteria reduce metabolic activity to save resources otherwise used for cell wall biogenesis, and to limit formation of detrimental reactive oxygen species at the cytoplasmic membrane due to respiration and Fenton chemistry. We consider these observations important, because knowing the adaptive responses of a highly resistant bacterium of the E. cloacae complex to last-resort antibiotics, such as imipenem, provides a ‘sneak preview’ into the future development of antibiotic resistance in this emerging group of pathogens.
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Lemay-St-Denis, Claudèle, Sarah-Slim Diwan e Joelle N. Pelletier. "The Bacterial Genomic Context of Highly Trimethoprim-Resistant DfrB Dihydrofolate Reductases Highlights an Emerging Threat to Public Health". Antibiotics 10, n. 4 (13 aprile 2021): 433. http://dx.doi.org/10.3390/antibiotics10040433.
Abstract (sommario):
Type B dihydrofolate reductase (dfrb) genes were identified following the introduction of trimethoprim in the 1960s. Although they intrinsically confer resistance to trimethoprim (TMP) that is orders of magnitude greater than through other mechanisms, the distribution and prevalence of these short (237 bp) genes is unknown. Indeed, this knowledge has been hampered by systematic biases in search methodologies. Here, we investigate the genomic context of dfrbs to gain information on their current distribution in bacterial genomes. Upon searching publicly available databases, we identified 61 sequences containing dfrbs within an analyzable genomic context. The majority (70%) of those sequences also harbor virulence genes and 97% of the dfrbs are found near a mobile genetic element, representing a potential risk for antibiotic resistance genes. We further identified and confirmed the TMP-resistant phenotype of two new members of the family, dfrb10 and dfrb11. Dfrbs are found both in Betaproteobacteria and Gammaproteobacteria, a majority (59%) being in Pseudomonas aeruginosa. Previously labelled as strictly plasmid-borne, we found 69% of dfrbs in the chromosome of pathogenic bacteria. Our results demonstrate that the intrinsically TMP-resistant dfrbs are a potential emerging threat to public health and justify closer surveillance of these genes.
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Bonko, Massa dit Achille, Palpouguini Lompo, Marc Christian Tahita, Francois Kiemde, Ibrahima Karama, Athanase M. Somé, Petra F. Mens, Sandra Menting, Halidou Tinto e Henk D. F. H. Schallig. "Antibiotic Susceptibility of Staphylococcus aureus and Streptococcus pneumoniae Isolates from the Nasopharynx of Febrile Children under 5 Years in Nanoro, Burkina Faso". Antibiotics 10, n. 4 (15 aprile 2021): 444. http://dx.doi.org/10.3390/antibiotics10040444.
Abstract (sommario):
(1) Background: nasopharynx colonization by resistant Staphylococcus aureus and Streptococcus pneumoniae can lead to serious diseases. Emerging resistance to antibiotics commonly used to treat infections due to these pathogens poses a serious threat to the health system. The present study aimed to determine the antibiotic susceptibility of S. aureus and S. pneumoniae isolates from the febrile children’s nasopharynx under 5 years in Nanoro (Burkina Faso). (2) Methods: bacterial isolates were identified from nasopharyngeal swabs prospectively collected from 629 febrile children. Antibiotic susceptibility of S. aureus and S. pneumoniae isolates was assessed by Kirby–Bauer method and results were interpreted according to the Clinical and Laboratory Standard Institute guidelines. (3) Results: bacterial colonization was confirmed in 154 (24.5%) of children of whom 96.1% carried S. aureus, 3.2% had S. pneumoniae, and 0.6% carried both bacteria. S. aureus isolates showed alarming resistance to penicillin (96.0%) and S. pneumoniae was highly resistant to tetracycline (100%) and trimethoprim–sulfamethoxazole (83.3%), and moderately resistant to penicillin (50.0%). Furthermore, 4.0% of S. aureus identified were methicillin resistant. (4) Conclusion: this study showed concerning resistance rates to antibiotics to treat suspected bacterial respiratory tract infections. The work highlights the necessity to implement continuous antibiotic resistance surveillance.
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József, Sóki, e és Székely Edit. "The clinically important anaerobic, human pathogenic Bacteroides species and their antibiotic resistance levels in Central and Southeast Europe". Bulletin of Medical Sciences 91, n. 1 (1 luglio 2018): 19–25. http://dx.doi.org/10.2478/orvtudert-2018-0003.
Abstract (sommario):
Abstract The Bacteroides and Parabacteroides species are important obligate anaerobic bacteria that are significant constituents of normal flora (microbiota), and opportunistic pathogens with special biological background. They are highly resistant to antibiotics and monitoring their resistance levels is important for their empiric therapy. Several antibiotic resistance studies were conducted in the USA and Europe and we have data for the region involved in this study showing comparable trends. Multidrug-resistant strains are emerging among Bacteroides too, where the proper antibiotic tests and treatments may be life-saving.
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Millar, Jess A., e Rahul Raghavan. "Accumulation and expression of multiple antibiotic resistance genes in Arcobacter cryaerophilus that thrives in sewage". PeerJ 5 (25 aprile 2017): e3269. http://dx.doi.org/10.7717/peerj.3269.
Abstract (sommario):
We explored the bacterial diversity of untreated sewage influent samples of a wastewater treatment plant in Tucson, AZ and discovered that Arcobacter cryaerophilus, an emerging human pathogen of animal origin, was the most dominant bacterium. The other highly prevalent bacteria were members of the phyla Bacteroidetes and Firmicutes, which are major constituents of human gut microbiome, indicating that bacteria of human and animal origin intermingle in sewage. By assembling a near-complete genome of A. cryaerophilus, we show that the bacterium has accumulated a large number of antibiotic resistance genes (ARGs) probably enabling it to thrive in the wastewater. We also determined that a majority of ARGs was being expressed in sewage, suggestive of trace levels of antibiotics or other stresses that could act as a selective force that amplifies multidrug resistant bacteria in municipal sewage. Because all bacteria are not eliminated even after several rounds of wastewater treatment, ARGs in sewage could affect public health due to their potential to contaminate environmental water.
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Gottlieb, Tom, e Elaine Cheong. "An overview of emerging community based antimicrobial resistance". Microbiology Australia 28, n. 4 (2007): 186. http://dx.doi.org/10.1071/ma07186.
Abstract (sommario):
The development of community antimicrobial resistance should not surprise any budding microbiologist. Bacteria are highly adaptable and mutations are acquired or selected in response to any number of stresses. In the 21st century the major ?stressor? is profligate human and veterinary antibiotic use, and inappropriate antimicrobial use in food and agricultural sectors. Worldwide, resistance in the community has been well described in many bacterial species. In this overview, we focus on community resistance in three bacterial species ? Streptococcus pneumoniae, Staphylococcus aureus and Neisseria gonorrhoeae. In all three human antibiotic use provides the greatest selection pressure.
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Koulenti, Xu, Mok, Song, Karageorgopoulos, Armaganidis, Lipman e SotiriosTsiodras. "Novel Antibiotics for Multidrug-Resistant Gram-Positive Microorganisms". Microorganisms 7, n. 8 (18 agosto 2019): 270. http://dx.doi.org/10.3390/microorganisms7080270.
Abstract (sommario):
Increasing multidrug-resistance to Gram-positive pathogens, particularly to staphylococci, enterococci and streptococci, is a major problem, resulting in significant morbidity, mortality and healthcare costs. In recent years, only a small number of novel antibiotics effective against Gram-positive bacteria has been approved. This review will discuss the current evidence for novel branded antibiotics that are highly effective in the treatment of multidrug-resistant infections by Gram-positive pathogens, namely ceftobiprole, ceftaroline, telavancin, oritavancin, dalbavancin, tedizolid, besifloxacin, delafloxacin, ozenoxacin, and omadacycline. The mechanism of action, pharmacokinetics, microbiological spectrum, efficacy and safety profile will be concisely presented. As for any emerging antibiotic agent, resistance is likely to develop against these highly effective antibiotics. Only through appropriate dosing, utilization and careful resistance development monitoring will these novel antibiotics continue to treat Gram-positive pathogens in the future.
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dos Santos, Sandie Bispo, Miguel Fernandez Alarcon, Anelise Stella Ballaben, Ricardo Harakava, Renata Galetti, Mateus Cardoso Guimarães, Mariene Miyoko Natori, Leonardo Susumu Takahashi, Ricardo Ildefonso e Marco Rozas-Serri. "First Report of Aeromonas veronii as an Emerging Bacterial Pathogen of Farmed Nile Tilapia (Oreochromis niloticus) in Brazil". Pathogens 12, n. 8 (8 agosto 2023): 1020. http://dx.doi.org/10.3390/pathogens12081020.
Abstract (sommario):
Brazil is one of the world’s leading producers of Nile tilapia, Oreochromis niloticus. However, the industry faces a major challenge in terms of infectious diseases, as at least five new pathogens have been formally described in the last five years. Aeromonas species are Gram-negative anaerobic bacteria that are often described as fish pathogens causing Motile Aeromonas Septicemia (MAS). In late December 2022, an epidemic outbreak was reported in farmed Nile tilapia in the state of São Paulo, Brazil, characterized by clinical signs and gross pathology suggestive of MAS. The objective of this study was to isolate, identify, and characterize in vitro and in vivo the causative agent of this epidemic outbreak. The bacterial isolates were identified as Aeromonas veronii based on the homology of 16S rRNA (99.9%), gyrB (98.9%), and the rpoB gene (99.1%). A. veronii showed susceptibility only to florfenicol, while it was resistant to the other three antimicrobials tested, oxytetracycline, enrofloxacin, and amoxicillin. The lowest florfenicol concentration capable of inhibiting bacterial growth was ≤0.5 µg/mL. The phenotypic resistance of the A. veronii isolate observed for quinolones and tetracycline was genetically confirmed by the presence of the qnrS2 (colE plasmid) and tetA antibiotic-resistant genes, respectively. A. veronii isolate was highly pathogenic in juvenile Nile tilapia tested in vivo, showing a mortality rate ranging from 3 to 100% in the lowest (1.2 × 104) and highest (1.2 × 108) bacterial dose groups, respectively. To our knowledge, this study would constitute the first report of highly pathogenic and multidrug-resistant A. veronii associated with outbreaks and high mortality rates in tilapia farmed in commercial net cages in Brazil.
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Sharma, Sonika, Sibnarayan Datta, Soumya Chatterjee, Mohan G. Vairale e S. K. Dwivedi. "Potential Application of Bacteriophage in Decontaminating Biothreat Agents". Defence Life Science Journal 6, n. 1 (23 febbraio 2021): 70–84. http://dx.doi.org/10.14429/dlsj.6.15537.
Abstract (sommario):
Multidrug resistant bacterial infections have become a potent risk, globally and there is an urgent need to phage and phage-derived enzymes as a therapeutic agent. The risk is more prominent in underdeveloped nations, where high population density, poor drinking water, inadequate sanitary and health care facilities ease the spread of infection. Bacteriophages (or ‘phages’) are abundant in nature and highly specific in their infection and pathogenicity, allowing their isolation, enrichment and use against specific bacteria. Employing bacteriophages as a tool for neutralizing potential biological threat agents can thus be an effective approach towards preparedness for biothreat mitigation. Unlike chemical antibiotics, phages are self-propagating, i.e., starting with a small number they can sustain their population, do not affect non-target/ beneficial bacterial populations. The tremendous potential of bacteriophages has recently been shown in treating multidrug resistant bacterial infections in terminally ill human subjects with unprecedented success. The natural anti-bacterial properties can be harnessed for decontamination of food, water, crops and for many other purposes including pathogen reduction in wastewater etc. Additionally, with the advancement in genetic engineering, deliberate use of such engineered multidrug resistant bacteria by state/non-state players has also become a reality. Owing to their resistance to several of the available antibiotics, control and mitigation of emerging pathogens is going to be great challenge. In this context, bacteriophages could be of potential use, since these viruses specifically infect bacterial hosts, often leading to their destruction.
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Borelli, Tiago Cabral, Gabriel Lencioni Lovate, Ana Flavia Tonelli Scaranello, Lucas Ferreira Ribeiro, Livia Zaramela, Felipe Marcelo Pereira-dos-Santos, Rafael Silva-Rocha e María-Eugenia Guazzaroni. "Combining Functional Genomics and Whole-Genome Sequencing to Detect Antibiotic Resistance Genes in Bacterial Strains Co-Occurring Simultaneously in a Brazilian Hospital". Antibiotics 10, n. 4 (11 aprile 2021): 419. http://dx.doi.org/10.3390/antibiotics10040419.
Abstract (sommario):
(1) Background: The rise of multi-antibiotic resistant bacteria represents an emergent threat to human health. Here, we investigate antibiotic resistance mechanisms in bacteria of several species isolated from an intensive care unit in Brazil. (2) Methods: We used whole-genome analysis to identify antibiotic resistance genes (ARGs) and plasmids in 34 strains of Gram-negative and Gram-positive bacteria, providing the first genomic description of Morganella morganii and Ralstonia mannitolilytica clinical isolates from South America. (3) Results: We identified a high abundance of beta-lactamase genes in resistant organisms, including seven extended-spectrum beta-lactamases (OXA-1, OXA-10, CTX-M-1, KPC, TEM, HYDRO, BLP) shared between organisms from different species. Additionally, we identified several ARG-carrying plasmids indicating the potential for a fast transmission of resistance mechanism between bacterial strains. Furthermore, we uncovered two pairs of (near) identical plasmids exhibiting multi-drug resistance. Finally, since many highly resistant strains carry several different ARGs, we used functional genomics to investigate which of them were indeed functional. In this sense, for three bacterial strains (Escherichia coli, Klebsiella pneumoniae, and M. morganii), we identified six beta-lactamase genes out of 15 predicted in silico as those mainly responsible for the resistance mechanisms observed, corroborating the existence of redundant resistance mechanisms in these organisms. (4) Conclusions: Systematic studies similar to the one presented here should help to prevent outbreaks of novel multidrug-resistant bacteria in healthcare facilities.
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La Rosa, Ruggero, Helle Krogh Johansen e Søren Molin. "Persistent Bacterial Infections, Antibiotic Treatment Failure, and Microbial Adaptive Evolution". Antibiotics 11, n. 3 (21 marzo 2022): 419. http://dx.doi.org/10.3390/antibiotics11030419.
Abstract (sommario):
Antibiotic resistance is expected by the WHO to be the biggest threat to human health before 2050. In this overview, we argue that this prediction may in fact be too optimistic because it is often overlooked that many bacterial infections frequently ‘go under the radar’ because they are difficult to diagnose and characterize. Due to our lifestyle, persistent infections caused by opportunistic bacteria—well-known or emerging—show increasing success of infecting patients with reduced defense capacity, and often antibiotics fail to be sufficiently effective, even if the bacteria are susceptible, leaving small bacterial populations unaffected by treatment in the patient. The mechanisms behind infection persistence are multiple, and therefore very difficult to diagnose in the laboratory and to treat. In contrast to antibiotic resistance associated with acute infections caused by traditional bacterial pathogens, genetic markers associated with many persistent infections are imprecise and mostly without diagnostic value. In the absence of effective eradication strategies, there is a significant risk that persistent infections may eventually become highly resistant to antibiotic treatment due to the accumulation of genomic mutations, which will transform colonization into persistence.
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Alqarni, Mohammed H., Ahmed I. Foudah, Aftab Alam, Mohammad A. Salkini, Magdy M. Muharram, Nikolaos E. Labrou e Pinki Rawat. "Coumarin-Encapsulated Solid Lipid Nanoparticles as an Effective Therapy against Methicillin-Resistant Staphylococcus aureus". Bioengineering 9, n. 10 (20 settembre 2022): 484. http://dx.doi.org/10.3390/bioengineering9100484.
Abstract (sommario):
Bacterial infections caused by antibiotic-resistant pathogens are a significant public health problem. This is because the transmission of infectious diseases is shifting, and new antibiotic-resistant strains of bacteria are emerging. The development of biofilms that are resistant to antibiotics poses another hurdle to drugs and treatment alternatives. Therefore, there is an urgent need to develop innovative strategies to effectively eliminate antibiotic-resistant microorganisms effectively. Natural coumarins have broad spectrum bioactivity and the potential for lower resistance. Coumarin is a secondary metabolite found in certain plants, fungi, and bacteria. It is highly effective against methicillin-resistant Staphylococcus aureus (MRSA). Therefore, coumarin can be used as an alternative to combat MRSA. However, most antibacterial agents lack selective targeting of pathological sites, limiting the efficacy of their antibacterial activity. Efficient MRSA treatments can be achieved through nanoparticle (NPs)-based targeted therapies. To address this challenge, a novel coumarin-loaded solid lipid nanocarrier for MRSA was developed to overcome this challenge. The developed systems exhibited a particle size of 138.5 ± 76.06 nm and a polydispersity index (PDI) of 0.245 ± 0.00. The zeta potential of coumarin-loaded SLNs was reported to be −22.2 ± 8.15 mV with a spherical shape. The encapsulation efficiency of coumarin was reported to be 63.09 ± 3.46% in the final formulation. The developed formulation was biocompatible with a minimum inhibitory concentration (MIC) of 1.08 µg/mL. This study suggests that coumarin-loaded SLNs can effectively treat MRSA infections.
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Critchley, Ian A., Casey L. Young, Kimberley C. Stone, Urs A. Ochsner, Joseph Guiles, Ted Tarasow e Nebojsa Janjic. "Antibacterial Activity of REP8839, a New Antibiotic for Topical Use". Antimicrobial Agents and Chemotherapy 49, n. 10 (ottobre 2005): 4247–52. http://dx.doi.org/10.1128/aac.49.10.4247-4252.2005.
Abstract (sommario):
ABSTRACT REP8839 is a novel methionyl-tRNA synthetase (MetS) inhibitor with potent antibacterial activity against clinical isolates of Staphylococcus aureus, Streptococcus pyogenes, and other clinically important gram-positive bacteria but little activity against gram-negative bacteria. All isolates of S. aureus, including strains resistant to methicillin, mupirocin, vancomycin, and linezolid were susceptible to REP8839 at concentrations of ≤0.5 μg/ml. REP8839 was also active against Staphylococcus epidermidis, including multiply resistant strains (MIC, ≤0.25 μg/ml). All S. pyogenes isolates were susceptible to REP8839 at concentrations of ≤0.25 μg/ml, suggesting that MetS2, a second enzyme previously identified in Streptococcus pneumoniae, was not present in this organism. REP8839 was highly bound to the protein of human serum, and activity was not greatly influenced by inoculum size but was affected by pH, exhibiting optimal antibacterial activity in a neutral medium rather than a weak acidic medium. Like mupirocin, REP8839 exhibited bacteriostatic activity against key pathogens. The emergence of mupirocin resistance in S. aureus highlights the need for a new topical antibiotic with the ability to inhibit high-level mupirocin-resistant strains and other emerging phenotypes, such as vancomycin-resistant and community-acquired methicillin-resistant isolates.
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Ben Ashur, Abir, Hamida El Magrahi, Asma Elkammoshi e Hiba Alsharif. "Prevalence and Antibiotics Susceptibility Pattern of Urine Bacterial Isolates from Tripoli Medical Center (TMC), Tripoli, Libya". Iberoamerican Journal of Medicine 3, n. 3 (4 giugno 2021): 221–26. http://dx.doi.org/10.53986/ibjm.2021.0035.
Abstract (sommario):
Introduction: Urinary tract infections (UTI) are one of the most common human bacterial infections encountered by physicians. The risk of resistant microbes is emerging as a result of the overuse of antibiotics treatments. The presence of pathogens with increased resistance to antimicrobial agents makes UTIs difficult to treat. This study was aimed at determining the prevalence of the pathogens that cause UTIs, as well as the antibiotic susceptibility of these isolates. Materials and methods: This prospective study was conducted from February 2020 to April 2020; a total number of 200 urine samples were collected from patients who daily attended TMC Libya. Bacterial pathogens were determined by bacteriological culture methods and Antimicrobial susceptibility testing was done by using the disc diffusion method. Results: Out of 200 samples, 110 cases had a positive culture. The dominant bacterial pathogens were Gram-negative that being with Escherichia coli (49, 55.68%), followed by Klebsiella pneumonia (18, 20.46%), Pseudomona aeruginosa (9, 10.23%), Proteus mirabilis (8, 9.09%), Enterobacter aerogenes (2, 2.27%), Citrobacter freundii (2, 2.27%). Gram-positive bacteria were Staphylococcus aureus 20 (90.91%) followed by S. saprophyticus (2, 9.01%) of the isolate’s strains. The isolated uropathogen showed increased levels of resistance to antibiotics. Where the Escherichia coli, Klebsiella pneumoniae, Staphylococcus aureus indicated the highest antibiotic resistance to Nitrofurantoin, Sulfamethoxazole/trimethoprim, Tetracycline, Ciprofloxacin, Metronidazole and also revealed the most sensitivity to Cefixime followed by doxycycline and ceftriaxone. Conclusions: The obtained results emphasized the emergence of highly resistant bacteria to most of the tested antimicrobials and propose the need for physicians to change their treatment pattern depending on antimicrobial susceptibility results.
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Puvabanditsin, Surasak, Marianne Jacob, Maaz Jalil, Samhita Bhattarai, Qaiser Patel, Mehrin Sadiq e Rajeev Mehta. "Extended-Spectrum Beta-Lactamase-Producing Escherichia coli Meningitis and Cerebral Abscess in a Neonate: Therapeutic Challenge". Case Reports in Infectious Diseases 2019 (28 marzo 2019): 1–5. http://dx.doi.org/10.1155/2019/6874192.
Abstract (sommario):
We report a case of a 12-day-old term neonate with extended-spectrum beta-lactamase (ESBL) producing Escherichia coli (E. coli) meningitis and cerebral abscess. The patient received a 7-day course of antibiotics just few days prior to the infection. The incidence of infections from ESBL-producing E. coli is increasingly emerging. Antimicrobial agents must be vigilantly utilized to prevent the new highly resistant bacteria.
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Borges, Vítor, Andrea Santos, Cristina Belo Correia, Margarida Saraiva, Armelle Ménard, Luís Vieira, Daniel A. Sampaio, Miguel Pinheiro, João Paulo Gomes e Mónica Oleastro. "Helicobacter pullorum Isolated from Fresh Chicken Meat: Antibiotic Resistance and Genomic Traits of an Emerging Foodborne Pathogen". Applied and Environmental Microbiology 81, n. 23 (18 settembre 2015): 8155–63. http://dx.doi.org/10.1128/aem.02394-15.
Abstract (sommario):
ABSTRACTMeat and meat products are important sources of human intestinal infections. We report the isolation ofHelicobacter pullorumstrains from chicken meat. Bacteria were isolated from 4 of the 17 analyzed fresh chicken meat samples, using a membrane filter method. MIC determination revealed that the four strains showed acquired resistance to ciprofloxacin; one was also resistant to erythromycin, and another one was resistant to tetracycline. Whole-genome sequencing of the four strains and comparative genomics revealed important genetic traits within theH. pullorumspecies, such as 18 highly polymorphic genes (including a putative new cytotoxin gene), plasmids, prophages, and a complete type VI secretion system (T6SS). The T6SS was found in three out of the four isolates, suggesting that it may play a role inH. pullorumpathogenicity and diversity. This study suggests that the emerging pathogenH. pullorumcan be transmitted to humans by chicken meat consumption/contact and constitutes an important contribution toward a better knowledge of the genetic diversity within theH. pullorumspecies. In addition, some genetic traits found in the four strains provide relevant clues to how this species may promote adaptation and virulence.
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von Ambüren, Julia, Fynn Schreiber, Julia Fischer, Sandra Winter, Edeltraud van Gumpel, Alexander Simonis e Jan Rybniker. "Comprehensive Host Cell-Based Screening Assays for Identification of Anti-Virulence Drugs Targeting Pseudomonas aeruginosa and Salmonella Typhimurium". Microorganisms 8, n. 8 (22 luglio 2020): 1096. http://dx.doi.org/10.3390/microorganisms8081096.
Abstract (sommario):
The prevalence of bacterial pathogens being resistant to antibiotic treatment is increasing worldwide, leading to a severe global health challenge. Simultaneously, the development and approval of new antibiotics stagnated in the past decades, leading to an urgent need for novel approaches to avoid the spread of untreatable bacterial infections in the future. We developed a highly comprehensive screening platform based on quantification of pathogen driven host-cell death to detect new anti-virulence drugs targeting Pseudomonas aeruginosa (Pa) and Salmonella enterica serovar Typhimurium (ST), both known for their emerging antibiotic resistance. By screening over 10,000 small molecules we could identify several substances showing promising effects on Pa and ST pathogenicity in our in vitro infection model. Importantly, we could detect compounds potently inhibiting bacteria induced killing of host cells and one novel comipound with impact on the function of the type 3 secretion system (T3SS) of ST. Thus, we provide proof of concept data of rapid and feasible medium- to high-throughput drug screening assays targeting virulence mechanisms of two major Gram-negative pathogens.
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Diacon, Andreas H., Carlos A. Guerrero-Bustamante, Bernd Rosenkranz, Francisco J. Rubio Pomar, Naadira Vanker e Graham F. Hatfull. "Mycobacteriophages to Treat Tuberculosis: Dream or Delusion?" Respiration 101, n. 1 (23 novembre 2021): 1–15. http://dx.doi.org/10.1159/000519870.
Abstract (sommario):
Rates of antimicrobial resistance are increasing globally while the pipeline of new antibiotics is drying up, putting patients with disease caused by drug-resistant bacteria at increased risk of complications and death. The growing costs for diagnosis and management of drug resistance threaten tuberculosis control where the disease is endemic and resources limited. Bacteriophages are viruses that attack bacteria. Phage preparations served as anti-infective agents long before antibiotics were discovered. Though small in size, phages are the most abundant and diverse biological entity on earth. Phages have co-evolved with their hosts and possess all the tools needed to infect and kill bacteria, independent of drug resistance. Modern biotechnology has improved our understanding of the biology of phages and their possible uses. Phage preparations are available to treat meat, fruit, vegetables, and dairy products against parasites or to prevent contamination with human pathogens, such as Listeria monocytogenes, Escherichia coli, or Staphylococcus aureus. Such phage-treated products are considered fit for human consumption. A number of recent case reports describe in great detail the successful treatment of highly drug-resistant infections with individualized phage preparations. Formal clinical trials with standardized products are slowly emerging. With its highly conserved genome and relative paucity of natural phage defence mechanisms Mycobacterium tuberculosis appears to be a suitable target for phage treatment. A phage cocktail with diverse and strictly lytic phages that kill all lineages of M. tuberculosis, and can be propagated on Mycobacterium smegmatis, has been assembled and is available for the evaluation of optimal dosage and suitable routes of administration for tuberculosis in humans. Phage treatment can be expected to be safe and active on extracellular organisms, but phage penetration to intracellular and granulomatous environments as well as synergistic effects with antibiotics are important questions to address during further evaluation.
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Gupta, R., T. Kumar e A. Mittal. "Bioremediation of Cadmium Contaminated Effluent by Sporosarcina luteola: A Bacterium Isolated from Soil near Wazirpur Industrial Area, New Delhi, India". Asian Journal of Chemistry 31, n. 11 (28 settembre 2019): 2642–46. http://dx.doi.org/10.14233/ajchem.2019.22285.
Abstract (sommario):
Heavy metals pollution is emerging as a threat to ecological systems causing various problems to mankind, plants and animals. Aim of the present study was to isolate and identify cadmium tolerant bacteria from the soil of Wazirpur industrial area of New Delhi (India). The study involved physico-chemical characterization of the polluted soil which was found to contain high concentration of iron, manganese and cadmium at 352, 15.3 g/kg soil and 3.16 ppm, respectively. One bacterial strain was identified as Sporosarcina luteola on the basis of morphological, biochemical and phylogeny analysis. Strain Sporosarcina luteola was highly resistant to Cd up to 5mM (mM= millimolar) when cultured in solidified nutrient agar plates and 7.2 mM in nutrient broth. Sporosarcina luteola has also showed substantial growth in presence of Co, Pb, Fe and Mn upto 2.0, 2.0, 3.5 and 4.0 mM, respectively in liquid medium. Optimum growth of identified bacteria was shown at 37 ºC, 7.0 pH and it tolerated up to 3 % sodium chloride (w/v). This is reported for the first time that Sporosarcina luteola (metal-tolerant bacteria) has potential of removal of cadmium from industrially contaminated soil.
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VRANCIANU, CORNELIU OVIDIU, ROXANA-ELENA CRISTIAN, IRINA GHEORGHE-BARBU, ILDA BARBU CZOBOR, MARIAN CONSTANTIN, IOANA CRUNTEANU e SORIN IOAN TUDORACHE. "Emerging antimicrobial susceptibility methods in monitoring colistin-resistant Enterobacteriaceae". Romanian Biotechnological Letters 27, n. 6/2022 (23 aprile 2023): 3758–62. http://dx.doi.org/10.25083/rbl/27.6/3758.3762.
Abstract (sommario):
One of the most important essential pillars in the fight against antibiotic resistance is to optimize antibiotic treatment by developing and optimizing appropriate methods to establish the antibiotic susceptibility profiles of a specific microbial strain. Moreover, this will contribute to the suveillance and limitation of antimicrobial resistance transmission and spread. Therefore, it is also imperative to harmonize different approaches and techniques and to perform suitable antimicrobial susceptibility tests in microbiology laboratories to achieve precise, reproducible, and comparable results. However, the conventional methods for antimicrobial susceptibility testing are usually based on bacterial culture methods, which are time-consuming, complicated, and labor-intensive. Therefore, other approaches are needed to address these issues. In this mini-review, we will present the common and future perspectives in antimicrobial susceptibility testing. Microfluidic technology and electrochemical devices have recently gained significant attention in infection management. These advantages include rapid detection, high sensitivity and specificity, highly automated assay, simplicity, low cost, and potential for point-of-care testing in low-resource areas.
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Nekahiwot, Solome, e Negeri Debela. "Multi-Drug Resistant Gonorrhea: An Emerging Global Threat". International Journal of Infectious Diseases and Therapy 9, n. 1 (2 aprile 2024): 17–25. http://dx.doi.org/10.11648/j.ijidt.20240901.13.
Abstract (sommario):
<i>Neisseria gonorrhoeae</i> is the bacterial culprit behind gonorrhea, a highly prevalent sexually transmitted infection (STI) found worldwide. Despite over 1 million daily cases, many infections are asymptomatic, contributing to its widespread transmission. The emergence of multidrug-resistant strains poses a significant challenge to public health, limiting treatment options and increasing the risk of complications. Key aspects covered include the bacterium's transmission dynamics, pathogenesis, clinical manifestations, laboratory diagnosis methods, and epidemiology. Transmission primarily occurs through sexual contact, with the bacterium thriving on mucous membranes in various parts of the body. Clinical presentations range from urethritis and cervicitis to more severe complications such as pelvic inflammatory disease and disseminated gonococcal infection. Laboratory diagnosis relies on culture, nucleic acid amplification tests (NAATs), and Gram staining, with NAATs offering high sensitivity. However, antimicrobial susceptibility testing is essential to guide treatment decisions, given the rapid emergence of resistance. Gonorrhea's epidemiology varies globally, with higher prevalence rates in low- and middle-income countries. Surveillance programs play a crucial role in monitoring antimicrobial resistance trends and informing treatment guidelines. The economic burden of gonorrhea is substantial, with potential increases in medical expenses and the challenge of managing outbreaks. Despite these challenges, there is hope for the development of new treatments and vaccines. Promising candidates such as zoliflodacin and solithromycin have shown efficacy in clinical trials, while vaccine development faces obstacles due to the bacterium's antigenic variation. The paper provides a comprehensive overview of <i>N. gonorrhoeae,</i> covering its basic features, transmission, pathogenesis, clinical presentation, laboratory diagnosis, epidemiology, challenges of drug-resistant gonorrhea, and prospects for the development of new treatments and vaccines. The paper underscores the urgent need for continued research, surveillance, and development of effective strategies to combat drug-resistant gonorrhea. Investment in new treatments and vaccines is crucial to mitigate the spread of the infection and its associated complications.
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Dezanet, Clément, Julie Kempf, Marie-Paule Mingeot-Leclercq e Jean-Luc Décout. "Amphiphilic Aminoglycosides as Medicinal Agents". International Journal of Molecular Sciences 21, n. 19 (8 ottobre 2020): 7411. http://dx.doi.org/10.3390/ijms21197411.
Abstract (sommario):
The conjugation of hydrophobic group(s) to the polycationic hydrophilic core of the antibiotic drugs aminoglycosides (AGs), targeting ribosomal RNA, has led to the development of amphiphilic aminoglycosides (AAGs). These drugs exhibit numerous biological effects, including good antibacterial effects against susceptible and multidrug-resistant bacteria due to the targeting of bacterial membranes. In the first part of this review, we summarize our work in identifying and developing broad-spectrum antibacterial AAGs that constitute a new class of antibiotic agents acting on bacterial membranes. The target-shift strongly improves antibiotic activity against bacterial strains that are resistant to the parent AG drugs and to antibiotic drugs of other classes, and renders the emergence of resistant Pseudomonas aeruginosa strains highly difficult. Structure–activity and structure–eukaryotic cytotoxicity relationships, specificity and barriers that need to be crossed in their development as antibacterial agents are delineated, with a focus on their targets in membranes, lipopolysaccharides (LPS) and cardiolipin (CL), and the corresponding mode of action against Gram-negative bacteria. At the end of the first part, we summarize the other recent advances in the field of antibacterial AAGs, mainly published since 2016, with an emphasis on the emerging AAGs which are made of an AG core conjugated to an adjuvant or an antibiotic drug of another class (antibiotic hybrids). In the second part, we briefly illustrate other biological and biochemical effects of AAGs, i.e., their antifungal activity, their use as delivery vehicles of nucleic acids, of short peptide (polyamide) nucleic acids (PNAs) and of drugs, as well as their ability to cleave DNA at abasic sites and to inhibit the functioning of connexin hemichannels. Finally, we discuss some aspects of structure–activity relationships in order to explain and improve the target selectivity of AAGs.
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Eger, Elias, Marielle Domke, Stefan E. Heiden, Madeleine Paditz, Veronika Balau, Christiane Huxdorff, Dirk Zimmermann, Timo Homeier-Bachmann e Katharina Schaufler. "Highly Virulent and Multidrug-Resistant Escherichia coli Sequence Type 58 from a Sausage in Germany". Antibiotics 11, n. 8 (26 luglio 2022): 1006. http://dx.doi.org/10.3390/antibiotics11081006.
Abstract (sommario):
Studies have previously described the occurrence of multidrug-resistant (MDR) Escherichia coli in human and veterinary medical settings, livestock, and, to a lesser extent, in the environment and food. While they mostly analyzed foodborne E. coli regarding phenotypic and sometimes genotypic antibiotic resistance and basic phylogenetic classification, we have limited understanding of the in vitro and in vivo virulence characteristics and global phylogenetic contexts of these bacteria. Here, we investigated in-depth an E. coli strain (PBIO3502) isolated from a pork sausage in Germany in 2021. Whole-genome sequence analysis revealed sequence type (ST)58, which has an internationally emerging high-risk clonal lineage. In addition to its MDR phenotype that mostly matched the genotype, PBIO3502 demonstrated pronounced virulence features, including in vitro biofilm formation, siderophore secretion, serum resilience, and in vivo mortality in Galleria mellonella larvae. Along with the genomic analysis indicating close phylogenetic relatedness of our strain with publicly available, clinically relevant representatives of the same ST, these results suggest the zoonotic and pathogenic character of PBIO3502 with the potential to cause infection in humans and animals. Additionally, our study highlights the necessity of the One Health approach while integrating human, animal, and environmental health, as well as the role of meat products and food chains in the putative transmission of MDR pathogens.
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Hernandez, Rafael J., Elze Hesse, Andrea J. Dowling, Nicola M. Coyle, Edward J. Feil, Will H. Gaze e Michiel Vos. "Using the wax moth larvaGalleria mellonellainfection model to detect emerging bacterial pathogens". PeerJ 6 (4 gennaio 2019): e6150. http://dx.doi.org/10.7717/peerj.6150.
Abstract (sommario):
Climate change, changing farming practices, social and demographic changes and rising levels of antibiotic resistance are likely to lead to future increases in opportunistic bacterial infections that are more difficult to treat. Uncovering the prevalence and identity of pathogenic bacteria in the environment is key to assessing transmission risks. We describe the first use of the Wax moth larvaGalleria mellonella, a well-established model for the mammalian innate immune system, to selectively enrich and characterize pathogens from coastal environments in the South West of the UK. Whole-genome sequencing of highly virulent isolates revealed amongst others aProteus mirabilisstrain carrying theSalmonellaSGI1 genomic island not reported from the UK before and the recently described speciesVibrio injenensishitherto only reported from human patients in Korea. Our novel method has the power to detect bacterial pathogens in the environment that potentially pose a serious risk to public health.
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Alsalmi, Asma Ahmed Sulaiman, Said A. Al-Busafi, Ruwaida Naseer Abdullah AL-Lamki e Mohamed Mabruk. "The Ecology and Antibiotic Resistance Patterns of Gastrointestinal Tract Infections in A Tertiary Care Hospital in Oman". Journal of Pure and Applied Microbiology 15, n. 3 (26 agosto 2021): 1634–42. http://dx.doi.org/10.22207/jpam.15.3.60.
Abstract (sommario):
A wide range of gastrointestinal (GI) illnesses is caused by foodborne bacteria that can arise from either a direct bacterial infection or bacterial toxin ingestion. The treatment of these infections has been hampered by the appearance of resistant strains. This current study aims to investigate the prevalence of Gastrointestinal tract (GIT) infections in Omani patients and their resistance pattern against commonly used antibiotics. Seven hundred and ninety fresh stool samples were obtained from Omani patients attending Sultan Qaboos University Hospital with GI manifestation from the 1st of June to the 30th of November 2019. Bacterial identification in stool samples was carried out by inoculation in culture media, microscopical examination and biochemical tests confirmed by MALDI. BD PhoenixTM. The antibiotics sensitivity testing was carried out by the Manual disk diffusion method and by MALDI. BD PhoenixTM. Out of 790 stool samples, 49 samples were positive for GIT bacterial infections. Salmonella spp. was the most prevalent isolate and more associated with children less than ten years old. Out of the 49 bacterial isolates, 3 (6.1%) were Clostridium difficili, 4 (8.2%) were Shigella flexneri, 5 (10.2%) were Campylobacter jejuni, and different Salmonella spp. serotypes were detected such as Salmonella Kentucky (8.2%), Salmonella enteritidis (6.1%), Salmonella infantis (4.1%), Salmonella welteverden (4.1%), Salmonella typhimurium (4.1%), Salmonella anatum (2.0%), Salmonella tesvia (2.0%), Salmonella Uganda (2.0%), Salmonella Arizona (2.0%) and (40.8%) of other Salmonella spp. serotypes. Eighty percent of isolated Campylobacter jejuni were resistant to Ciprofloxacin and Tetracycline. Salmonella spp. and Shigella flexneri were highly resistant to Amikacin, Gentamicin, and Cefuroxime. The low level of bacterial infection detected among screened patients in the present study indicates the excellent hand washing hygiene practice in reducing GIT infections among patients in Oman. This good hand washing hygiene practice is of great help in the efforts of controlling the spread of other severe diseases like COVID-19. However, detecting the emerging of antibiotic-resistant of GIT bacterial pathogens among patients in Oman, such as Salmonella and Shigella to a commonly used antibiotic such as Gentamicin, is alarming.
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Gallagher, Larry A., Elizabeth Ramage, Eli J. Weiss, Matthew Radey, Hillary S. Hayden, Kiara G. Held, Holly K. Huse, Daniel V. Zurawski, Mitchell J. Brittnacher e Colin Manoil. "Resources for Genetic and Genomic Analysis of Emerging Pathogen Acinetobacter baumannii". Journal of Bacteriology 197, n. 12 (6 aprile 2015): 2027–35. http://dx.doi.org/10.1128/jb.00131-15.
Abstract (sommario):
ABSTRACTAcinetobacter baumanniiis a Gram-negative bacterial pathogen notorious for causing serious nosocomial infections that resist antibiotic therapy. Research to identify factors responsible for the pathogen's success has been limited by the resources available for genome-scale experimental studies. This report describes the development of several such resources forA. baumanniistrain AB5075, a recently characterized wound isolate that is multidrug resistant and displays robust virulence in animal models. We report the completion and annotation of the genome sequence, the construction of a comprehensive ordered transposon mutant library, the extension of high-coverage transposon mutant pool sequencing (Tn-seq) to the strain, and the identification of the genes essential for growth on nutrient-rich agar. These resources should facilitate large-scale genetic analysis of virulence, resistance, and other clinically relevant traits that makeA. baumanniia formidable public health threat.IMPORTANCEAcinetobacter baumanniiis one of six bacterial pathogens primarily responsible for antibiotic-resistant infections that have become the scourge of health care facilities worldwide. Eliminating such infections requires a deeper understanding of the factors that enable the pathogen to persist in hospital environments, establish infections, and resist antibiotics. We present a set of resources that should accelerate genome-scale genetic characterization of these traits for a reference isolate ofA. baumanniithat is highly virulent and representative of current outbreak strains.
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Laverde-Rojas, Valentina, Yamil Liscano, Sandra Patricia Rivera-Sánchez, Ivan Darío Ocampo-Ibáñez, Yeiston Betancourt, Maria José Alhajj, Cristhian J. Yarce, Constain H. Salamanca e Jose Oñate-Garzón. "Antimicrobial Contribution of Chitosan Surface-Modified Nanoliposomes Combined with Colistin against Sensitive and Colistin-Resistant Clinical Pseudomonas aeruginosa". Pharmaceutics 13, n. 1 (30 dicembre 2020): 41. http://dx.doi.org/10.3390/pharmaceutics13010041.
Abstract (sommario):
Colistin is a re-emergent antibiotic peptide used as a last resort in clinical practice to overcome multi-drug resistant (MDR) Gram-negative bacterial infections. Unfortunately, the dissemination of colistin-resistant strains has increased in recent years and is considered a public health problem worldwide. Strategies to reduce resistance to antibiotics such as nanotechnology have been applied successfully. In this work, colistin was characterized physicochemically by surface tension measurements. Subsequently, nanoliposomes coated with highly deacetylated chitosan were prepared with and without colistin. The nanoliposomes were characterized using dynamic light scattering and zeta potential measurements. Both physicochemical parameters fluctuated relatively to the addition of colistin and/or polymer. The antimicrobial activity of formulations increased by four-fold against clinical isolates of susceptible Pseudomona aeruginosa but did not have antimicrobial activity against multidrug-resistant (MDR) bacteria. Interestingly, the free coated nanoliposomes exhibited the same antibacterial activity in both sensitive and MDR strains. Finally, the interaction of colistin with phospholipids was characterized using molecular dynamics (MD) simulations and determined that colistin is weakly associated with micelles constituted by zwitterionic phospholipids.
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Gallardo-Godoy, Alejandra, Karl Hansford, Craig Muldoon, Bernd Becker, Alysha Elliott, Johnny Huang, Ruby Pelingon, Mark Butler, Mark Blaskovich e Matthew Cooper. "Structure-Function Studies of Polymyxin B Lipononapeptides". Molecules 24, n. 3 (2 febbraio 2019): 553. http://dx.doi.org/10.3390/molecules24030553.
Abstract (sommario):
The emerging threat of infections caused by highly drug-resistant bacteria has prompted a resurgence in the use of the lipodecapeptide antibiotics polymyxin B and colistin as last resort therapies. Given the emergence of resistance to these drugs, there has also been a renewed interest in the development of next generation polymyxins with improved therapeutic indices and spectra of action. We report structure-activity studies of 36 polymyxin lipononapeptides structurally characterised by an exocyclic FA-Thr2-Dab3 lipodipeptide motif instead of the native FA-Dab1-Thr2-Dab3 tripeptide motif found in polymyxin B, removing one of the positively charged residues believed to contribute to nephrotoxicity. The compounds were prepared by solid phase synthesis using an on-resin cyclisation approach, varying the fatty acid and the residues at position 2 (P2), P3 and P4, then assessing antimicrobial potency against a panel of Gram-negative bacteria, including polymyxin-resistant strains. Pairwise comparison of N-acyl nonapeptide and decapeptide analogues possessing different fatty acids demonstrated that antimicrobial potency is strongly influenced by the N-terminal L-Dab-1 residue, contingent upon the fatty acid. This study highlights that antimicrobial potency may be retained upon truncation of the N-terminal L-Dab-1 residue of the native exocyclic lipotripeptide motif found in polymyxin B. The strategy may aid in the design of next generation polymyxins.
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SIKDER, SUCHANDAN, TURFATUL JANNAT, NAHIDA JAMAN SMRITY, SHARNALIKA KARMAKAR, NUSRAT ZAHAN SRABONI, MOHAMMAD REDWANUR RAHMAN, NAJIAH MUSA, ETI RANI SARKAR e HELENA KHATOON. "THE ANTIBACTERIAL POTENTIAL OF EUKARYOTIC MARINE MICROALGAE AGAINST PATHOGENS FROM CHICKEN, DOG AND AQUACULTURE". JOURNAL OF SUSTAINABILITY SCIENCE AND MANAGEMENT 19, n. 1 (31 gennaio 2024): 74–86. http://dx.doi.org/10.46754/jssm.2024.01.007.
Abstract (sommario):
Antibiotic resistance is an emerging concern, leading to the search for alternative antibacterial agents. Scientists looking for potential alternatives to antibiotics see promise in the antimicrobial propensity of microalgae. We investigated the antibacterial potentials of Tetraselmis, Chlorella, and Nannochloropsis against pathogenic bacteria from chicken, dogs, and fish. We identified E. coli, Stenotrophomonas sp., Streptococcus sp., Staphylococcus sp., Aeromonas sp. and Lysinibacillus sp. by colony characteristics, Gram staining and VITEK-2 tests. Results demonstrated that Tetraselmis was highly sensitive against Stenotrophomonas sp. (p < 0.0001) and E. coli (p < 0.001) from chicken, and Staphylococcus sp. (p < 0.01) from dogs. Moreover, Chlorella was highly sensitive against E. coli (p < 0.0001) from dogs. All the bacteria isolated from chicken were moderate to highly sensitive to Chlorella. Nannochloropsis was marginally sensitive to all the bacteria isolated from chickens and dogs. The minimum inhibitory concentration values indicate that a minimum of 10 mg/ml of Tetraselmis can suppress the growth of Aeromonas sp. from fish and Chlorella can suppress E. coli and Stenotrophomonas sp. from chicken. Results indicate that native microalgae may have an active somatic or secretory components that prevent bacterial cell division and/or induce lysis. Advanced studies should be performed to identify the active component for the development of newer and sustainable antimicrobial drugs.
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Vanzolini, Tania, Michela Bruschi, Andrea C. Rinaldi, Mauro Magnani e Alessandra Fraternale. "Multitalented Synthetic Antimicrobial Peptides and Their Antibacterial, Antifungal and Antiviral Mechanisms". International Journal of Molecular Sciences 23, n. 1 (4 gennaio 2022): 545. http://dx.doi.org/10.3390/ijms23010545.
Abstract (sommario):
Despite the great strides in healthcare during the last century, some challenges still remained unanswered. The development of multi-drug resistant bacteria, the alarming growth of fungal infections, the emerging/re-emerging of viral diseases are yet a worldwide threat. Since the discovery of natural antimicrobial peptides able to broadly hit several pathogens, peptide-based therapeutics have been under the lenses of the researchers. This review aims to focus on synthetic peptides and elucidate their multifaceted mechanisms of action as antiviral, antibacterial and antifungal agents. Antimicrobial peptides generally affect highly preserved structures, e.g., the phospholipid membrane via pore formation or other constitutive targets like peptidoglycans in Gram-negative and Gram-positive bacteria, and glucan in the fungal cell wall. Additionally, some peptides are particularly active on biofilm destabilizing the microbial communities. They can also act intracellularly, e.g., on protein biosynthesis or DNA replication. Their intracellular properties are extended upon viral infection since peptides can influence several steps along the virus life cycle starting from viral receptor-cell interaction to the budding. Besides their mode of action, improvements in manufacturing to increase their half-life and performances are also taken into consideration together with advantages and impairments in the clinical usage. Thus far, the progress of new synthetic peptide-based approaches is making them a promising tool to counteract emerging infections.
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Rahman, Mohammad Anisur, AKM Anisur Rahman, Md Ariful Islam e Md Mahbub Alam. "Multi–drug resistant Staphylococcus aureus isolated from milk, chicken meat, beef and egg in Bangladesh". Research in Agriculture Livestock and Fisheries 5, n. 2 (9 settembre 2018): 175–83. http://dx.doi.org/10.3329/ralf.v5i2.38055.
Abstract (sommario):
Staphylococcal infection is one of the most common food-borne diseases in the world. Moreover, antimicrobial resistance of pathogenic bacteria, including Staphylococcus (S.) aureus is an emerging problem of food safety. This study was conducted to investigate the prevalence of S. aureus in milk, chicken meat, egg and beef; and to determine the multi-drug resistance (MDR) profile of S. aureus in Mymensingh and Gazipur districts, Bangladesh. A total of 189 samples of milk (n=108), chicken meat (n=51), egg (n=20) and beef (n=10) were collected from Bangladesh Agricultural University dairy farm, American dairy farm, Gazipur and different dairy farms of municipal area and retail shops during July 2016 to June 2018. S. aureus were isolated and identified by conventional methods and polymerase chain reaction (PCR). Antimicrobial susceptibility tests were done through disc diffusion test using 10 commonly used antibiotics. The overall prevalence of S. aureus in all food samples was 43.39%. A total of 39 (76.47%) chicken meat, 25 (23.15%) milk, 11(55%) egg and 07 (70%) beef samples were S. aureus positive through conventional method. Among 82 culture positive samples only 39 samples (47.56%) were confirmed by PCR. Antibiogram study showed that S. aureus isolated from chicken meat were mostly resistant to oxytetracycline (71.79%); and highly sensitive to amikacin (100%) and neomycin (100%). S. aureus isolated from milk samples were highly sensitive to neomycin (100%), and resistant to amikacin (56%). Only 28.57% isolates of S. aureus originated from beef samples were resistant to oxytetracycline and 100 % isolates were sensitive to ciprofloxacin, gentamicin, erythromycin, azithromycin, doxycycline. Similarly, S. aureus isolated from egg samples were resistant to erythromycin (81.82%) and 100% sensitive to amikacin. Out of 41.46% MDR isolates 12%, 53.85%, 90.91% and 0% of the S. aureus originated from milk, chicken meat, egg and beef respectively. The higher prevalence of S. aureus in chicken meat, beef, egg and milk indicates unhygienic production, marketing and processing of these foods. Presence of MDR S. aureus in these foods might pose serious public health threats. Rational use of antibiotics with higher sensitivity should be prescribed in managing poultry diseases to reduce re-emerging MDR in Bangladesh.Res. Agric., Livest. Fish.5(2): 175-183, August 2018
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DeNegre, Ashley A., Kellen Myers e Nina H. Fefferman. "Impact of Strain Competition on Bacterial Resistance in Immunocompromised Populations". Antibiotics 9, n. 3 (7 marzo 2020): 114. http://dx.doi.org/10.3390/antibiotics9030114.
Abstract (sommario):
Despite the risk of emerging drug resistance that occurs with the frequent use of antimicrobial agents, targeted and prophylactic antibiotics have been considered crucial to opportunistic infection management among the HIV/AIDS-immunocompromised. As we recently demonstrated, the disrupted selective pressures that occur in AIDS-prevalent host populations increase the probability of novel emergence. This effect is concerning, given that bacterial strains unresponsive to first-line antibiotics can be particularly dangerous to hosts whose immune response is insufficient to fight infection in the absence of antibiotic support. While greater host susceptibility within a highly immunocompromised population may offer a fitness advantage to drug-resistant bacterial strains, this advantage could be mitigated by increased morbidity and mortality among the AIDS-immunocompromised. Using a Susceptible-Exposed-Infectious-Recovered (SEIR) epidemiological model parameterized to reflect conditions in an AIDS-prevalent host population, we examine the evolutionary relationship between drug-sensitive and -resistant strains of Mycobacterium tuberculosis. We explore this relationship when the fitness of the resistant strain is varied relative to that of the sensitive strain to investigate the likely long-term multi-strain dynamics of the AIDS-mediated increased emergence of drug resistance.
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Schrag, Stephanie J., Lesley McGee, Cynthia G. Whitney, Bernard Beall, Allen S. Craig, Miriam E. Choate, James H. Jorgensen, Richard R. Facklam e Keith P. Klugman. "Emergence of Streptococcus pneumoniae with Very-High-Level Resistance to Penicillin". Antimicrobial Agents and Chemotherapy 48, n. 8 (agosto 2004): 3016–23. http://dx.doi.org/10.1128/aac.48.8.3016-3023.2004.
Abstract (sommario):
ABSTRACT Penicillin resistance threatens the treatment of pneumococcal infections. We used sentinel hospital surveillance (1978 to 2001) and population-based surveillance (1995 to 2001) in seven states in the Active Bacterial Core surveillance of the Emerging Infections Program Network to document the emergence in the United States of invasive pneumococcal isolates with very-high-level penicillin resistance (MIC ≥ 8 μg/ml). Very-high-level penicillin resistance was first detected in 1995 in multiple pneumococcal serotypes in three regions of the United States. The prevalence increased from 0.56% (14 of 2,507) of isolates in 1995 to 0.87% in 2001 (P = 0.03), with peaks in 1996 and 2000 associated with epidemics in Georgia and Maryland. For a majority of the strains the MICs of amoxicillin (91%), cefuroxime (100%), and cefotaxime (68%), were ≥8 μg/ml and all were resistant to at least one other drug class. Pneumonia (50%) and bacteremia (36%) were the most common clinical presentations. Factors associated with very highly resistant infections included residence in Tennessee, age of <5 or ≥65 years, and resistance to at least three drug classes. Hospitalization and case fatality rates were not higher than those of other pneumococcal infection patients; length of hospital stay was longer, controlling for age. Among the strains from 2000 and 2001, 39% were related to Tennessee23F-4 and 35% were related to England14-9. After the introduction of the pneumococcal conjugate vaccine, the incidence of highly penicillin resistant infections decreased by 50% among children <5 years of age. The emergence, clonality, and association of very-high-level penicillin resistance with multiple drug resistance requires further monitoring and highlights the need for novel agents active against the pneumococcus.
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Rebecca Annisha, Owassa Dza, Zifu Li, Xiaoqin Zhou, Ngomah Madgil Don Stenay e Oscar Omondi Donde. "Performance evaluation of combined ultraviolet-ultrasonic technologies in removal of sulfonamide and tetracycline resistant Escherichia coli from domestic effluents". Journal of Water, Sanitation and Hygiene for Development 10, n. 2 (6 marzo 2020): 276–85. http://dx.doi.org/10.2166/washdev.2020.144.
Abstract (sommario):
Abstract Proper treatment of wastewater is key to the achievement of sustainable environmental management. The use of ultraviolet radiation and ultrasound have continued to be considered as some of the best sustainable practices in wastewater purification. However, despite the suitability of the two emerging techniques in sustainably increasing the purification efficiencies of wastewater, their application has not been fully understood, especially in eliminating faecal pathogenic microorganisms. Moreover, their combined potential in the elimination of Escherichia coli resistant genes from wastewater has not been adequately explored. This study was designed to evaluate the potential of individual and combined/integrated ultraviolet radiation and ultrasonic technologies in the removal of antibiotic-resistant E. coli from domestic effluents. There was a statistical difference in the mean log units of sulfonamide resistant E. coli between the different ultraviolet radiation and ultrasonic dosages (P < 0.05), showing that ultraviolet radiation technology was more effective in the removal of both sulfonamide and tetracycline resistant E. coli from the wastewater. However, the integrated ultraviolet radiation-ultrasonic technique was highly efficient and is recommended in the removal of antibiotic resistant E. coli from wastewater. Nonetheless, further studies also need to be performed to further evaluate the disinfection effectiveness on a different bacteria species under continuous operation.
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Naveed, Muhammad, Jawad-ul Hassan, Muneeb Ahmad, Nida Naeem, Muhammad Saad Mughal, Ali A. Rabaan, Mohammed Aljeldah et al. "Designing mRNA- and Peptide-Based Vaccine Construct against Emerging Multidrug-Resistant Citrobacter freundii: A Computational-Based Subtractive Proteomics Approach". Medicina 58, n. 10 (27 settembre 2022): 1356. http://dx.doi.org/10.3390/medicina58101356.
Abstract (sommario):
Background and Objectives: Citrobacter freundii (C. freundii) is an emerging and opportunistic Gram-negative bacteria of the human gastrointestinal tract associated with nosocomial and severe respiratory tract infections. It has also been associated with pneumonia, bloodstream, and urinary tract infections. Intrinsic and adaptive virulence characteristics of C. freundii have become a significant source of diarrheal infections and food poisoning among immune-compromised patients and newborns. Impulsive usage of antibiotics and these adaptive virulence characteristics has modulated the C. freundii into multidrug-resistant (MDR) bacteria. Conventional approaches are futile against MDR C. freundii. Materials and Methods: The current study exploits the modern computational-based vaccine design approach to treat infections related to MDR C. freundii. A whole proteome of C. freundii (strain: CWH001) was retrieved to screen pathogenic and nonhomologous proteins. Six proteins were shortlisted for the selection of putative epitopes for vaccine construct. Highly antigenic, nonallergen, and nontoxic eleven B-cell, HTL, and TCL epitopes were selected for mRNA- and peptide-based multi-epitope vaccine construct. Secondary and tertiary structures of the multi-epitope vaccine (MEVC) were designed, refined, and validated. Results: Evaluation of population coverage of MHC-I and MHC-II alleles were 72% and 90%, respectively. Docking MEVC with TLR-3 receptor with the binding affinity of 21.46 (kcal/mol) occurred through the mmGBSA process. Further validations include codon optimization with an enhanced CAI value of 0.95 and GC content of about 51%. Immune stimulation and molecular dynamic simulation ensure the antibody production upon antigen interaction with the host and stability of the MEVC construct, respectively. Conclusions: These interpretations propose a new strategy to combat MDR C. freundii. Further, in vivo and in vitro trials of this vaccine will be valuable in combating MDR pathogens.
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Drees, Marci, Lisa Pineles, Anthony D. Harris e Daniel J. Morgan. "Variation in Definitions and Isolation Procedures for Multidrug-Resistant Gram-Negative Bacteria: A Survey of the Society for Healthcare Epidemiology of America Research Network". Infection Control & Hospital Epidemiology 35, n. 4 (aprile 2014): 362–66. http://dx.doi.org/10.1086/675600.
Abstract (sommario):
Objective.To assess definitions, experience, and infection control practices for multidrug-resistant gram-negative bacteria (MDR-GNB), including Enterobacteriaceae, Acinetobacter, and Pseudomonas species, in acute care hospitals.Design.Cross-sectional survey.Participants.US and international members of the Society for Healthcare Epidemiology of America (SHEA) Research Network.Methods.Online survey that included definitions, infection control procedures, and microbiology capability related to MDR-GNB and other MDR bacteria.Results.From November 2012 through February 2013, 66 of 170 SHEA Research Network members responded (39% response rate), representing 26 states and 15 countries. More than 80% of facilities reported experience with each MDR-GNB isolate, and 78% had encountered GNB resistant to all antibiotics except colistin (62% Acinetobacter, 59% Pseudomonas, and 52% Enterobacteriaceae species). Participants varied regarding their definitions of “multidrug resistant,” with 14 unique definitions for Acinetobacter, 18 for Pseudomonas, and 22 for Enterobacteriaceae species. Substantial variation also existed in isolation practices. Although isolation was commonly used for methicillin-resistant Staphylococcus aureus (MRSA), vancomycin-resistant enterococci (VRE), and carbapenem-resistant Enterobacteriaceae (CRE), approximately 20% of facilities did not isolate for MDR Pseudomonas or Acinetobacter. The majority of those that isolated MDR organisms also removed isolation using a wide variety of criteria.Conclusion.Facilities vary significantly in their approach to preventing MDR-GNB transmission. Although practices for MRSA and VRE are relatively standardized, emerging pathogens CRE and other MDR-GNB have highly varied definitions and management. This confusion makes communication difficult, and varied use of isolation may contribute to emergence of these organisms. Public health agencies need to promote standard definitions and management to enable broader initiatives to limit emergence of MDR-GNB.
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Shafeeq, Ali, Hisham Ahmed Imad, Ahmed Azhad, Migdhaadh Shareef, Mohamed Shaneez Najmy, Mohamed Mausool Siraj, Mohamed Sunil et al. "A Fatal Case of Native Valve Endocarditis with Multiple Embolic Phenomena and Invasive Methicillin-Resistant Staphylococcus aureus Bacteremia: A Case Report from the Maldives". Tropical Medicine and Infectious Disease 8, n. 1 (10 gennaio 2023): 53. http://dx.doi.org/10.3390/tropicalmed8010053.
Abstract (sommario):
Infective endocarditis (IE) is a life-threatening condition caused by infection within the endocardium of the heart and commonly involves the valves. The subsequent cascading inflammation leads to the appearance of a highly friable thrombus that is large enough to become lodged within the heart chambers. As a result, fever, fatigue, heart murmurs, and embolization phenomena may be seen in patients with IE. Embolization results in the seeding of bacteria and obstruction of circulation, causing cell ischemia. Of concern, bacteria with the potential to gain pan-drug resistance, such as methicillin-resistant Staphylococcus aureus (MRSA), are increasingly being identified as the causative agent of IE in hospitals and among intravenous drug abusers. We retrospectively reviewed de-identified clinical data to summarize the clinical course of a patient with MRSA isolated using an automated blood culture system. At the time of presentation, the patient showed a poor consciousness level, and the calculated Glasgow scale was 10/15. A high-grade fever with circulatory shock indicated an occult infection, and a systolic murmur was observed with peripheral signs of embolization. This case demonstrated the emerging threat of antimicrobial resistance in the community and revealed clinical findings of IE that may be helpful to clinicians for the early recognition of the disease. The management of such cases requires a multi-specialty approach, which is not widely available in small-island developing states such as the Maldives.
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Abbasi, Nazia Bashir, Nighat Jabeen e Shafat Khatoon. "NEONATAL SEPSIS;". Professional Medical Journal 24, n. 10 (6 ottobre 2017): 1455–60. http://dx.doi.org/10.29309/tpmj/2017.24.10.709.
Abstract (sommario):
Introduction: Neonatal sepsis is a systemic condition characterized bybacteremia that occurs in the first month of life. It is a fatal condition and need to be treatedpromptly. Bacterial isolates include both gram positive and negative bacteria and the cureof condition is highly dependent on antimicrobial drug sensitivity and resistant patterns. It isthere for utmost important to known commonly occurring bacteria in neonatal septic statesand their drug sensitivity patterns. Objectives: To determine the frequency of the bacterialisolates in blood and their sensitivity patterns to commonly used antibiotics in neonatal sepsis.Setting: Neonatal intensive care unit(NICU), Department of Shifa International Hospital. (SIH),Islamabad. Study Design: Cross sectional. Duration: This study was conducted between 6 1stJune 2013 to 30th November 2013. Subject and Methods: A total of 180 neonates, admittedin NICU with evidence of clinical sepsis i.e. with signs and symptoms suggestive of septicemia(fever, lethargy, reluctance to feed, seizures, and irritability) were included in this study. Thesamples for blood cultures were taken. Identification of bacterial isolates was carried out by thestandard bacteriological techniques, which include gram staining and bacterial cultures andantimicrobial sensitivity patterns which was performed by modified Kirby and Bauer disc diffusemethod as per CLSI (Clinical and Laboratory StandardsInstitute)guidelines.A predesignedPerforma was filled. Results: Culture revealed bacterial growth in 7.2% samples. Gram negativeorganisms were observed in 6.67% and only 1 were gram positive. In this study, 50% and 100%of E-coli were sensitive to ampicillin, meropenem and amikacin, gentamycin respectively. Sixtyto 100% of pseudomonas was sensitive to ceftazidime, tazobactum, meropenem and 100%of enterococcus was sensitive to ampicillin and vancomycin. Conclusion: Antimicrobial drugresistance and constantly changing resistance patterns is emerging issues in various groupsof infections and septic states, especially for routinely used antibiotics as found in our study.Thus by prescribing rational use of antimicrobial as per bactriogram, It‘ll be easier totreat sepsiseffectively and economically and reduce the mortality and morbidity related to neonatal sepsis.
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Tsay, Sharon, Rory M. Welsh, Eleanor H. Adams, Nancy A. Chow, Lalitha Gade, Elizabeth L. Berkow, Emily Lutterloh et al. "Public Health Response to US Cases of Candida auris, a Globally Emerging, Multidrug-Resistant Yeast, 2013–2017". Open Forum Infectious Diseases 4, suppl_1 (2017): S72—S73. http://dx.doi.org/10.1093/ofid/ofx163.002.
Abstract (sommario):
Abstract Background Candida auris is an often multidrug-resistant yeast that causes invasive infections and, unlike most Candida species, spreads in healthcare facilities. CDC released a clinical alert in June 2016 requesting reporting of C. auris cases. We investigated cases to contain transmission and inform prevention measures for this novel organism. Methods Clinical cases were defined as C. auris from any clinical specimen from a patient in the United States. Response to cases included implementation of infection control measures, enhanced cleaning and disinfection, and testing of close contacts for C. auris colonisation (isolation from a person’s axilla or groin was defined as a screening case). Microbiology records were reviewed at reporting facilities for missed cases. All isolates were forwarded to CDC for confirmation, antifungal susceptibility testing, and whole-genome sequencing (WGS). Results As of April 13, 2017, 61 clinical cases of C. auris were reported from six states: New York (39), New Jersey (15), Illinois (4), Indiana (1), Maryland (1), and Massachusetts (1). All but two occurred since 2016 (Figure). An additional 32 screening cases were identified among contacts. Median age of clinical case-patients was 70 years (range 21–96); 56% were male. Nearly, all had underlying medical conditions and extensive exposure to healthcare facilities before infection. Most clinical isolates were from blood (38, 62%), followed by urine (8, 13%) and respiratory tract (5, 8%). Among the first 35 isolates, 30 (86%) were resistant to fluconazole, 15 (43%) to amphotericin B, and one (3%) to caspofungin. No isolate was resistant to all three. WGS revealed isolates from each state were highly related and different from other states, suggestive of transmission. Microbiology record reviews did not identify additional cases before 2016. Conclusion C. auris is an emerging pathogen, with similarities to multidrug-resistant bacteria, that has been transmitted in US healthcare settings. CDC and public health partners are committed to prompt and aggressive action through investigation of cases and heightened infection control practices to halt its spread. Disclosures All authors: No reported disclosures.
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Shrestha, Sachet Prabhat, Jagat Khadka, Amod K. Pokhrel e Brijesh Sathian. "Acute bacterial conjunctivitis – antibiotic susceptibility and resistance to commercially available topical antibiotics in Nepal". Nepalese Journal of Ophthalmology 8, n. 1 (12 dicembre 2016): 23–35. http://dx.doi.org/10.3126/nepjoph.v8i1.16153.
Abstract (sommario):
Introduction: There is a shifting trend in susceptibility and resistance of the bacteria towards available antibiotics in the last decade. Therefore, periodic studies to monitor the emerging trends in antibiotic susceptibility and resistance are crucial in guiding antibiotic selection. Objectives: The aim of this study was to determine the most common pathogens causing bacterial conjunctivitis, and to find the in vitro susceptibility and resistance of these pathogens to commercially available topical antibiotic eye drops in Nepal. Subjects and methods: Conjunctival smears and antibiotic sensitivity tests were performed for 308 patients presenting to the Eye Care Center, Padma Nursing Home, Pokhara, Nepal from 11th December 1012 to 4th October 2013 with clinical signs and symptoms of acute infective conjunctivitisin in a hospital based cross-sectional study. Antibiotic sensitivity tests were performed for thirteen commercially available topical antibiotics- Chloroamphenicol, Moxifloxacin, Ofloxacin, Ciprofloxacin, Gentamycin, Tobramycin, Neomycin, Bacitracin, Polymyxin-B, Methicillin, Cephazoline, Amikacin and Vancomycin. Results: Acute infective conjunctivitis and viral conjunctivitis was more common in adults and in males. Bacterial conjunctivitis was present in about one third (32.47% to 36.04%) of the patients with acute infective conjunctivitis, and it was more common in children. Bacteria were highly sensitive (93-98%) to most commercially available antibiotics but significant resistance was found against three antibiotics-Bacitracin (9.0%), Neomycin (16.0%) and Polymyxin-B (24.0%). MRSA infection was found in 7.0% of the bacterial isolates. Rest of antibiotics, showed variable resistance (14.3% to 100.0%). All cases of Ophthalmia neonatorum were bacterial. Conclusion: The best commercially available antibiotic for bacterial conjunctivitis was Moxifloxacin. Nepal J Ophthalmol 2016; 8(15): 23-35
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Asma, Syeda Tasmia, Kálmán Imre, Adriana Morar, Mirela Imre, Ulas Acaroz, Syed Rizwan Ali Shah, Syed Zajif Hussain et al. "Natural Strategies as Potential Weapons against Bacterial Biofilms". Life 12, n. 10 (17 ottobre 2022): 1618. http://dx.doi.org/10.3390/life12101618.
Abstract (sommario):
Microbial biofilm is an aggregation of microbial species that are either attached to surfaces or organized into an extracellular matrix. Microbes in the form of biofilms are highly resistant to several antimicrobials compared to planktonic microbial cells. Their resistance developing ability is one of the major root causes of antibiotic resistance in health sectors. Therefore, effective antibiofilm compounds are required to treat biofilm-associated health issues. The awareness of biofilm properties, formation, and resistance mechanisms facilitate researchers to design and develop combating strategies. This review highlights biofilm formation, composition, major stability parameters, resistance mechanisms, pathogenicity, combating strategies, and effective biofilm-controlling compounds. The naturally derived products, particularly plants, have demonstrated significant medicinal properties, producing them a practical approach for controlling biofilm-producing microbes. Despite providing effective antibiofilm activities, the plant-derived antimicrobial compounds may face the limitations of less bioavailability and low concentration of bioactive molecules. The microbes-derived and the phytonanotechnology-based antibiofilm compounds are emerging as an effective approach to inhibit and eliminate the biofilm-producing microbes.
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Drawz, Sarah M., e James R. Johnson. "Pokes, Pathogens, and Primum Non Nocere: Prudent Prophylaxis Protocols for Prostate Biopsy". Infection Control & Hospital Epidemiology 34, n. 9 (settembre 2013): 977–79. http://dx.doi.org/10.1086/671937.
Abstract (sommario):
Infectious complications following transrectal ultrasound-guided biopsy of the prostate (TRUBP)—including urinary tract infections, prostatitis, epididymo-orchitis, and bacteremia—have increased dramatically in recent years. Traditionally, fluoroquinolones have been the mainstay for perioperative prophylaxis. Likely as a result of a combination of this selective pressure and temporal shifts in the clonal composition of the rectal microbiota, most post-TRUBP infections today are caused by fluoroquinolone-resistant Escherichia coli, especially those from sequence type 131 (ST131), an emerging multidrug-resistant strain that is highly prevalent among pre-TRUBP rectal isolates. Clinicians need improved approaches for preventing these complications. Fortunately, helpful guidance is beginning to appear.
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Kosmeri, Chrysoula, Vasileios Giapros, Anastasios Serbis, Foteini Balomenou e Maria Baltogianni. "Antibiofilm Strategies in Neonatal and Pediatric Infections". Antibiotics 13, n. 6 (30 maggio 2024): 509. http://dx.doi.org/10.3390/antibiotics13060509.
Abstract (sommario):
Biofilm-related infections pose significant challenges in neonatal and pediatric care, contributing to increased morbidity and mortality rates. These complex microbial communities, comprising bacteria and fungi, exhibit resilience against antibiotics and host immune responses. Bacterial species such as Enterococcus faecalis, Pseudomonas aeruginosa, Staphylococcus aureus, and Staphylococcus epidermidis commonly form biofilms on medical devices, exacerbating infection risks. Neonates and children, particularly those in intensive care units, are highly susceptible to biofilm-associated infections due to the prolonged use of invasive devices, such as central lines and endotracheal tubes. Enteral feeding tubes, crucial for neonatal nutritional support, also serve as potential sites for biofilm formation, contributing to recurrent microbial contamination. Moreover, Candida species, including Candida pelliculosa, present emerging challenges in neonatal care, with multi-drug resistant strains posing treatment complexities. Current antimicrobial therapies, while important in managing infections, often fall short in eradicating biofilms, necessitating alternative strategies. The aim of this review is to summarize current knowledge regarding antibiofilm strategies in neonates and in children. Novel approaches focusing on biofilm inhibition and dispersal show promise, including surface modifications, matrix-degrading enzymes, and quorum-sensing inhibitors. Prudent use of medical devices and exploration of innovative antibiofilm therapies are imperative in mitigating neonatal and pediatric biofilm infections.
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Caragata, E. P., S. Dong, Y. Dong, M. L. Simões, C. V. Tikhe e G. Dimopoulos. "Prospects and Pitfalls: Next-Generation Tools to Control Mosquito-Transmitted Disease". Annual Review of Microbiology 74, n. 1 (8 settembre 2020): 455–75. http://dx.doi.org/10.1146/annurev-micro-011320-025557.
Abstract (sommario):
Mosquito-transmitted diseases, including malaria and dengue, are a major threat to human health around the globe, affecting millions each year. A diverse array of next-generation tools has been designed to eliminate mosquito populations or to replace them with mosquitoes that are less capable of transmitting key pathogens. Many of these new approaches have been built on recent advances in CRISPR/Cas9-based genome editing. These initiatives have driven the development of pathogen-resistant lines, new genetics-based sexing methods, and new methods of driving desirable genetic traits into mosquito populations. Many other emerging tools involve microorganisms, including two strategies involving Wolbachia that are achieving great success in the field. At the same time, other mosquito-associated bacteria, fungi, and even viruses represent untapped sources of new mosquitocidal or antipathogen compounds. Although there are still hurdles to be overcome, the prospect that such approaches will reduce the impact of these diseases is highly encouraging.