Multidrug resistance efflux pump expression in uropathogenic Gram-negative bacteria in organ transplant recipients. - Related Documents




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488401.0000Multidrug resistance efflux pump expression in uropathogenic Gram-negative bacteria in organ transplant recipients. Urinary tract infections (UTIs) are common in healthcare settings and communities; and are predominantly caused by Gram-negative bacteria, which account for > 70% of UTI cases. Escherichia coli, Klebsiella pneumoniae, and Pseudomonas aeruginosa are the most common bacterial agents responsible for UTIs. The emergence of antibiotic resistance poses a challenge for UTI treatment; and efflux pump overexpression contributes to Gram-negative bacterial resistance. This comprehensive review summarizes the current understanding of multidrug resistance (MDR) efflux pump expression in prevalent Gram-negative bacteria that demonstrate resistance to antibiotics predominantly used for UTI treatment. This review examines the available data, and offers insights into the role of efflux pumps in conferring MDR to UTI-causing bacteria. Understanding these resistance mechanisms is crucial for developing effective strategies to combat antibiotic resistance in UTI management. Furthermore, this review emphasizes the need to characterize efflux pump-mediated antimicrobial resistance in solid organ transplantation cases. Solid organ transplant recipients are particularly vulnerable to UTIs caused by MDR bacteria, posing a serious threat to their health and recovery. Identifying the efflux pump profiles of these bacterial strains can guide appropriate antibiotic choices and optimize treatment outcomes in transplant recipients. By consolidating existing knowledge on efflux pump expression in antibiotic-resistant Gram-negative bacteria associated with UTIs, this review acknowledges gaps and identifies the future scope of research that should address the growing challenge of MDR UTIs, particularly in high-risk populations such as solid organ transplant recipients.202540452526
488010.9999Molecular mechanisms of tigecycline-resistance among Enterobacterales. The global emergence of antimicrobial resistance to multiple antibiotics has recently become a significant concern. Gram-negative bacteria, known for their ability to acquire mobile genetic elements such as plasmids, represent one of the most hazardous microorganisms. This phenomenon poses a serious threat to public health. Notably, the significance of tigecycline, a member of the antibiotic group glycylcyclines and derivative of tetracyclines has increased. Tigecycline is one of the last-resort antimicrobial drugs used to treat complicated infections caused by multidrug-resistant (MDR) bacteria, extensively drug-resistant (XDR) bacteria or even pan-drug-resistant (PDR) bacteria. The primary mechanisms of tigecycline resistance include efflux pumps' overexpression, tet genes and outer membrane porins. Efflux pumps are crucial in conferring multi-drug resistance by expelling antibiotics (such as tigecycline by direct expelling) and decreasing their concentration to sub-toxic levels. This review discusses the problem of tigecycline resistance, and provides important information for understanding the existing molecular mechanisms of tigecycline resistance in Enterobacterales. The emergence and spread of pathogens resistant to last-resort therapeutic options stands as a major global healthcare concern, especially when microorganisms are already resistant to carbapenems and/or colistin.202438655285
488320.9999New tools to mitigate drug resistance in Enterobacteriaceae - Escherichia coli and Klebsiella pneumoniae. Treatment to common bacterial infections are becoming ineffective of late, owing to the emergence and dissemination of antibiotic resistance globally. Escherichia coli and Klebsiella pneumoniae are the most notorious microorganisms and are among the critical priority pathogens listed by WHO in 2017. These pathogens are the predominant cause of sepsis, urinary tract infections (UTIs), pneumonia, meningitis and pyogenic liver abscess. Concern arises due to the resistance of bacteria to most of the beta lactam antibiotics like penicillin, cephalosporin, monobactams and carbapenems, even to the last resort antibiotics like colistin. Preventing influx by modulation of porins, extruding the antibiotics by overexpression of efflux pumps, mutations of drug targets/receptors, biofilm formation, altering the drug molecules and rendering them ineffective are few resistance mechanisms that are adapted by Enterobacteriaeceae upon exposure to antibiotics. The situation is exacerbated due to the process of horizontal gene transfer (HGT), wherein the genes encoding resistance mechanisms are transferred to the neighbouring bacteria through plasmids/phages/uptake of free DNA. Carbapenemases, other beta lactamases and mcr genes coding for colistin resistance are widely disseminated leading to limited/no therapeutic options against those infections. Development of new antibiotics can be viewed as a possible solution but it involves major investment, time and labour despite which, the bacteria can easily adapt to the new antibiotic and evolve resistance in a relatively short time. Targeting the resistance mechanisms can be one feasible alternative to tackle these multidrug resistant (MDR) pathogens. Removal of plasmid (plasmid curing) causing resistance, use of bacteriophages and bacteriotherapy can be other potential approaches to combat infections caused by MDR E. coli and K. pneumoniae. The present review discusses the efficacies of these therapies in mitigating these infections, which can be potentially used as an adjuvant therapy along with existing antibiotics.202335649163
979230.9998Emergence of antibiotic resistance Pseudomonas aeruginosa in intensive care unit; a critical review. The emergence of antibiotic resistant bacteria in the healthcare is a serious concern. In the Healthcare premises precisely intensive care unit are major sources of microbial diversity. Recent findings have demonstrated not only microbial diversity but also drug resistant microbes largely habitat in ICU. Pseudomonas aeruginosa found as a part of normal intestinal flora and a significant pathogen responsible for wide range of ICU acquired infection in critically ill patients. Nosocomial infection associated with this organism including gastrointestinal infection, urinary tract infections and blood stream infection. Infection caused by this organism are difficult to treat because of the presence of its innate resistance to many antibiotics (β-lactam and penem group of antibiotics), and its ability to acquire further resistance mechanism to multiple class of antibiotics, including Beta-lactams, aminoglycosides and fluoroquinolones. In the molecular evolution microbes adopted several mechanism to maintain genomic plasticity. The tool microbe use for its survival is mainly biofilm formation, quorum sensing, and horizontal gene transfer and enzyme promiscuity. Such genomic plasticity provide an ideal habitat to grow and survive in hearse environment mainly antibiotics pressure. This review focus on infection caused by Pseudomonas aeruginosa, its mechanisms of resistance and available treatment options. The present study provides a systemic review on major source of Pseudomonas aeruginosa in ICU. Further, study also emphasizes virulence gene/s associated with Pseudomonas aeruginosa genome for extended drug resistance. Study gives detailed overview of antibiotic drug resistance mechanism.201931194018
488940.9998The Challenge of Overcoming Antibiotic Resistance in Carbapenem-Resistant Gram-Negative Bacteria: "Attack on Titan". The global burden of bacterial resistance remains one of the most serious public health concerns. Infections caused by multidrug-resistant (MDR) bacteria in critically ill patients require immediate empirical treatment, which may not only be ineffective due to the resistance of MDR bacteria to multiple classes of antibiotics, but may also contribute to the selection and spread of antimicrobial resistance. Both the WHO and the ECDC consider carbapenem-resistant Enterobacteriaceae (CRE), carbapenem-resistant Pseudomonas aeruginosa (CRPA), and carbapenem-resistant Acinetobacter baumannii (CRAB) to be the highest priority. The ability to form biofilm and the acquisition of multiple drug resistance genes, in particular to carbapenems, have made these pathogens particularly difficult to treat. They are a growing cause of healthcare-associated infections and a significant threat to public health, associated with a high mortality rate. Moreover, co-colonization with these pathogens in critically ill patients was found to be a significant predictor for in-hospital mortality. Importantly, they have the potential to spread resistance using mobile genetic elements. Given the current situation, it is clear that finding new ways to combat antimicrobial resistance can no longer be delayed. The aim of this review was to evaluate the literature on how these pathogens contribute to the global burden of AMR. The review also highlights the importance of the rational use of antibiotics and the need to implement antimicrobial stewardship principles to prevent the transmission of drug-resistant organisms in healthcare settings. Finally, the review discusses the advantages and limitations of alternative therapies for the treatment of infections caused by these "titans" of antibiotic resistance.202337630472
488750.9998Mechanisms of Bacterial Drug Resistance with Special Emphasis on Phenotypic and Molecular Characterization of Extended Spectrum Beta-lactamase. Antibiotics are designed to effectively treat bacterial infections while minimizing harm to the human body. They work by targeting specific components of bacteria or by disrupting essential processes such as cell wall synthesis, membrane function, protein production, and metabolic pathways. However, the misuse and overuse of antibiotics have led to the emergence of drug resistance in humans, animals, and agriculture, contributing to the global spread of this problem. Drug resistance can be either innate or acquired, with acquired resistance involving changes in the bacterial chromosomes or transferable elements. Bacterial species employ various mechanisms of drug resistance, including modifying the antibiotic targets, inactivating the drug, reducing uptake or increasing efflux, overexpressing the target, utilizing alternative pathways, and forming biofilms. One significant concern in the realm of drug resistance revolves around the emergence and proliferation of extended-spectrum beta-lactamases (ESBLs), a gene that is found in most gram-negative bacteria, primarily carried by Escherichia coli and Klebsiella pneumoniae in healthcare settings. ESBL-mediated resistance poses challenges for diagnosis, treatment, infection control, and antibiotic stewardship. Accurate detection of ESBL genes is crucial, and phenotypic methods are commonly used for initial screening. However, these methods have limitations, and confirmatory molecular techniques such as PCR and DNA sequencing are employed to accurately identify ESBL genes. Despite the significant global concerns surrounding ESBLs, they have spread worldwide, mainly facilitated by healthcare settings, inappropriate antimicrobial use, and host susceptibility. Addressing this issue requires implementing comprehensive measures, including enhanced surveillance, strict infection control practices, antibiotic stewardship programs, rapid diagnostic methods, alternative therapies, public education initiatives, and research focused on developing new drugs. Furthermore, collaboration among the healthcare, public health, and research sectors is pivotal in effectively combating the escalating threat posed by ESBL-mediated resistance. Antibiotics have revolutionized medical care by effectively treating bacterial infections. However, the emergence of ESBL gene resistance poses a global challenge that requires an integrated approach to prevent a threatening future.202438700878
488260.9998Molecular Factors and Mechanisms Driving Multidrug Resistance in Uropathogenic Escherichia coli-An Update. The rapid emergence of multidrug-resistant (MDR) bacteria indisputably constitutes a major global health problem. Pathogenic Escherichia coli are listed among the most critical group of bacteria that require fast development of new antibiotics and innovative treatment strategies. Among harmful extraintestinal Enterobacteriaceae strains, uropathogenic E. coli (UPEC) pose a significant health threat. UPEC are considered the major causative factor of urinary tract infection (UTI), the second-most commonly diagnosed infectious disease in humans worldwide. UTI treatment places a substantial financial burden on healthcare systems. Most importantly, the misuse of antibiotics during treatment has caused selection of strains with the ability to acquire MDR via miscellaneous mechanisms resulting in gaining resistance against many commonly prescribed antibiotics like ampicillin, gentamicin, cotrimoxazole and quinolones. Mobile genetic elements (MGEs) such as transposons, integrons and conjugative plasmids are the major drivers in spreading resistance genes in UPEC. The co-occurrence of various bacterial evasion strategies involving MGEs and the SOS stress response system requires further research and can potentially lead to the discovery of new, much-awaited therapeutic targets. Here, we analyzed and summarized recent discoveries regarding the role, mechanisms, and perspectives of MDR in the pathogenicity of UPEC.202236011308
486570.9998Molecular mechanisms related to colistin resistance in Enterobacteriaceae. Colistin is an effective antibiotic for treatment of most multidrug-resistant Gram-negative bacteria. It is used currently as a last-line drug for infections due to severe Gram-negative bacteria followed by an increase in resistance among Gram-negative bacteria. Colistin resistance is considered a serious problem, due to a lack of alternative antibiotics. Some bacteria, including Pseudomonas aeruginosa, Acinetobacter baumannii, Enterobacteriaceae members, such as Escherichia coli, Salmonella spp., and Klebsiella spp. have an acquired resistance against colistin. However, other bacteria, including Serratia spp., Proteus spp. and Burkholderia spp. are naturally resistant to this antibiotic. In addition, clinicians should be alert to the possibility of colistin resistance among multidrug-resistant bacteria and development through mutation or adaptation mechanisms. Rapidly emerging bacterial resistance has made it harder for us to rely completely on the discovery of new antibiotics; therefore, we need to have logical approaches to use old antibiotics, such as colistin. This review presents current knowledge about the different mechanisms of colistin resistance.201931190901
487580.9998An Overview of the Genetic Mechanisms of Colistin-Resistance in Bacterial Pathogens: An Indian Perspective. Colistin resistance in bacteria is a growing global issue, given its role as a critical last-resort antibiotic, particularly for treating Gram-negative bacterial infections. Pathogens adopt multiple resistance mechanisms, mediated either by plasmids or chromosomal changes. Some of the most frequently observed strategies include the occurrence of plasmid-borne mobile colistin resistance (mcr) genes, enhanced efflux pump activity, mutations in the regulatory systems, and alterations in the lipid A structure. This article provides an overview of the studies investigating the genetic mechanisms underlying colistin resistance in nosocomial Gram-negative bacteria from India. A total of 37 studies were identified through online searches across various databases, including PubMed, ScienceDirect, and Web of Science. These studies were reviewed to examine bacterial species and their mechanisms of colistin resistance. Over 26 (70.27%) studies were focused on Klebsiella pneumoniae. The most commonly reported mechanism of colistin resistance involved mutations in the two-component systems pmrAB and phoPQ. Plasmid-mediated colistin-resistant mcr genes were identified in 22 studies (18.18%). Four studies reported the overexpression of efflux pump genes as a mechanism of colistin resistance. This article provides a comprehensive summary of these studies, emphasizing the presence of diverse resistance mechanisms across various pathogens. It underscores the necessity for future genomic research on a broader range of pathogens to investigate the prevalence of different mechanisms of colistin resistance in the various regions of India.202540078264
979090.9998Emerging antibiotic resistance: carbapenemase-producing enterobacteria. Bad new bugs, still no new drugs. Antimicrobial resistance (AMR) is a global health security threat requiring actions across government sectors and society. Many factors are involved in this phenomenon, being overuse of antibiotics, incorrect antibiotic prophylaxis, and use of antibiotics for zootechnic reasons the main causes of the increasing rate of multi-drug resistant (MDR) bacteria. The impact of resistance to antimicrobials is an important threat due also to the emergence of MDR Gram-negative bacteria resistant to carbapenems, and the lack of the research for new active molecules. The production of extended spectrum beta-lactamase enzymes has been the first threatening mechanism for Gram-negative resistance to antibiotics, which prompted the development of new classes of antibiotics such as carbapenems. Unfortunately, resistance to carbapenems developed because of multiple mechanisms including efflux pumps, porin mutations and enzyme production, being the latter particularly relevant in terms of diffusion due to the genes located within plasmids that drive their horizontal diffusion. In this scenario, antimicrobial stewardship programs (ASP) are a mandatory resource in fighting the resistance spread. The reduction of total amount of antibiotics administration in the hospital setting and guiding prescribers in the correct administration of antibiotics for the smallest period possible, at the correct dosage, can be defined as the first goals of an ASP. Anyway, in an efficacious ASP, apart from antibiotic administration, efforts must been made in ensuring the lowest probability of spreading of MDR by efficacious measures of isolation of carriers, and by offering tools for a rapid diagnosis of viral infections avoiding the administration of unnecessary antibiotics. A continuous audit of the ASP programs and a correct assessment of the allergy to drugs such as penicillin have to complete the program. Currently, only a few options are available for patients with an infection sustained by Gram-negative MDR bacteria. All the options actually available are based on the administration of colystin, an old drug whose real efficacy is reduced due to its relevant toxicity, or on the administration of recently proposed drugs such as ceftolozane-tazobactam, ceftazidime-avibactam and meropenem-vaborbactam. All these new drugs do not have a novel mechanism of action and have limited spectrum in term of activity against MDR bacteria. In conclusion, antimicrobial resistance is a global emergence and AMP is the most powerful tool actually available. Few limited options are available to treat infections due to Carbapenem Resistant Enterobacteria. Antimicrobial molecules with true novel mechanism of action are needed to win the fight against antimicrobial resistance.201931846984
4862100.9998Genetic Factors That Contribute to Antibiotic Resistance through Intrinsic and Acquired Bacterial Genes in Urinary Tract Infections. The overprescribing and misuse of antibiotics have led to the rapid development of multidrug-resistant bacteria, such as those that cause UTIs. UTIs are the most common outpatient infections and are mainly caused by Escherichia coli and Klebsiella spp., although some Gram-positive bacteria, such as Pseudomonas aeruginosa, have been isolated in many cases. The rise of antimicrobial-resistant bacteria is a major public health concern, as it is predicted to lead to increased healthcare costs and poor patient outcomes and is expected to be the leading cause of global mortality by 2050. Antibiotic resistance among bacterial species can arise from a myriad of factors, including intrinsic and acquired resistance mechanisms, as well as mobile genetic elements, such as transposons, integrons, and plasmids. Plasmid-mediated resistance is of major concern as drug-resistance genes can quickly and efficiently spread across bacterial species via horizontal gene transfer. The emergence of extended-spectrum β-lactamases (ESBLs) such as NDM-1, OXA, KPC, and CTX-M family members has conferred resistance to many commonly used antibiotics in the treatment of UTIs, including penicillins, carbapenems, cephalosporins, and sulfamethoxazole. This review will focus on plasmid-mediated bacterial genes, especially those that encode ESBLs, and how they contribute to antibiotic resistance. Early clinical detection of these genes in patient samples will provide better treatment options and reduce the threat of antibiotic resistance.202337374909
4866110.9998Resistance to polymyxins in Gram-negative organisms. Polymyxins have recently been re-introduced into the therapeutic arsenal to combat infections caused by multidrug-resistant Gram-negative bacteria. However, the emergence of strains resistant to these last-resort drugs is becoming a critical issue in a growing number of countries. Both intrinsic and transferable mechanisms of polymyxin resistance have been characterised. These mechanisms as well as the epidemiological data regarding four relevant bacterial pathogens (Escherichia coli, Klebsiella pneumoniae, Acinetobacter baumannii and Pseudomonas aeruginosa) are considered in this review. A special focus is made on plasmid-mediated resistance and the spread of mcr genes.201728163137
4870120.9998Emergent Polymyxin Resistance: End of an Era? Until recently, the polymyxin antibiotics were sparingly used due to dose limiting toxicities. However, the lack of therapeutic alternatives for infections caused by highly resistant Gram-negative bacteria has led to the increased use of the polymyxins. Unfortunately, in the last decade the world has witnessed increased rates of polymyxin resistance, which is likely in part due to its irrational use in human and veterinary medicine. The spread of polymyxin-resistance has been aided by the dissemination of the transferable polymyxin-resistance gene, mcr, in humans and the environment. The mortality of colistin-resistant bacteria infections varies in different reports. However, poor clinical outcome was associated with prior colistin treatment, illness severity, complications and multidrug resistance. Detection of polymyxin-resistance in the clinic is possible through multiple robust and practical tests including broth microdilution susceptibility testing, chromogenic agar testing, and molecular biology assays. There are multiple risk factors that increase a person's risk for infection with a polymyxin-resistant bacteria including age, prior colistin treatment, hospitalization and ventilator support. For patients that are determined to be infected by polymyxin-resistant bacteria, various antibiotic treatment options currently exist. The rising trend of polymyxin-resistance threatens patient care and warrants an effective control.201931420655
4881130.9998Investigating colistin drug resistance: The role of high-throughput sequencing and bioinformatics. Bacterial infections involving antibiotic-resistant gram-negative bacteria continue to increase and represent a major global public health concern. Resistance to antibiotics in these bacteria is mediated by chromosomal and/or acquired resistance mechanisms, these give rise to multi-drug resistant (MDR), extensive-drug resistant (XDR) or pan-drug resistant (PDR) bacterial strains. Most recently, plasmid-mediated resistance to colistin, an antibiotic that had been set apart as the last resort antibiotic in the treatment of infections involving MDR, XDR and PDR gram-negative bacteria has been reported. Plasmid-mediated colistin resistant gram-negative bacteria have been described to be PDR, implying a state devoid of alternative antibiotic therapeutic options. This review concisely describes the evolution of antibiotic resistance to plasmid-mediated colistin resistance and discusses the potential role of high-throughput sequencing technologies, genomics, and bioinformatics towards improving antibiotic resistance surveillance, the search for novel drug targets and precision antibiotic therapy focused at combating colistin resistance, and antibiotic resistance as a whole.201931354944
9791140.9998Beta-lactam resistance and the effectiveness of antimicrobial peptides against KPC-producing bacteria. Bacterial resistance is a problem that is giving serious cause for concern because bacterial strains such as Acinetobacter baumannii and Pseudomonas aeruginosa are difficult to treat and highly opportunistic. These bacteria easily acquire resistance genes even from other species, which confers greater persistence and tolerance towards conventional antibiotics. These bacteria have the highest death rate in hospitalized intensive care patients, so strong measures must be taken. In this review, we focus on the use of antimicrobial peptides (AMPs) as an alternative to traditional drugs, due to their rapid action and lower risk of generating resistance by microorganisms. We also present an overview of beta-lactams and explicitly explain the activity of AMPs against carbapenemase-producing bacteria as potential alternative agents for infection control.202236042694
4890150.9998Understanding of Colistin Usage in Food Animals and Available Detection Techniques: A Review. Progress in the medical profession is determined by the achievements and effectiveness of new antibiotics in the treatment of microbial infections. However, the development of multiple-drug resistance in numerous bacteria, especially Gram-negative bacteria, has limited the treatment options. Due to this resistance, the resurgence of cyclic polypeptide drugs like colistin remains the only option. The drug, colistin, is a well-known growth inhibitor of Gram-negative bacteria like Acinetobacter baumanni, Enterobacter cloacae, Klebsiella pneumoniae, and Pseudomonas aeruginosa. Technological advancements have uncovered the role of the mcr-1(mobilized colistin resistance) gene, which is responsible for the development of resistance in Gram-negative bacteria, which make them distinct from other bacteria without this gene. Additionally, food animals have been determined to be the reservoir for colistin resistance microbes, from which they spread to other hosts. Due to the adverse effects of colistin, many developed countries have prohibited its usage in animal foods, but developing countries are still using colistin in animal food production, thereby imposing a major risk to the public health. Therefore, there is a need for implementation of sustainable measures in livestock farms to prevent microbial infection. This review highlights the negative effects (increased resistance) of colistin consumption and emphasizes the different approaches used for detecting colistin in animal-based foods as well as the challenges associated with its detection.202033081121
4856160.9998An Overview on Phenotypic and Genotypic Characterisation of Carbapenem-Resistant Enterobacterales. Improper use of antimicrobials has resulted in the emergence of antimicrobial resistance (AMR), including multi-drug resistance (MDR) among bacteria. Recently, a sudden increase in Carbapenem-resistant Enterobacterales (CRE) has been observed. This presents a substantial challenge in the treatment of CRE-infected individuals. Bacterial plasmids include the genes for carbapenem resistance, which can also spread to other bacteria to make them resistant. The incidence of CRE is rising significantly despite the efforts of health authorities, clinicians, and scientists. Many genotypic and phenotypic techniques are available to identify CRE. However, effective identification requires the integration of two or more methods. Whole genome sequencing (WGS), an advanced molecular approach, helps identify new strains of CRE and screening of the patient population; however, WGS is challenging to apply in clinical settings due to the complexity and high expense involved with this technique. The current review highlights the molecular mechanism of development of Carbapenem resistance, the epidemiology of CRE infections, spread of CRE, treatment options, and the phenotypic/genotypic characterisation of CRE. The potential of microorganisms to acquire resistance against Carbapenems remains high, which can lead to even more susceptible drugs such as colistin and polymyxins. Hence, the current study recommends running the antibiotic stewardship programs at an institutional level to control the use of antibiotics and to reduce the spread of CRE worldwide.202236422214
4879170.9998Prevalence of polymyxin resistance through the food chain, the global crisis. Antimicrobial resistance is one of the vital challenges facing global health today. Multi-drug resistant (MDR) infections are often treated with the narrow-spectrum drugs, colistin (polymyxin E) or polymyxin B, which are last-resort antibiotics for human therapeutics that are effective against Gram-negative bacteria. Unfortunately, resistance to these polymyxins has occurred because of selective pressure caused by the inappropriate use of those antibiotics, especially in farming. The mechanisms of resistance to polymyxins are mediated through intrinsic, mutational, or genetic alteration in chromosomal genes. The mechanism includes the regulatory network controlling chemical modifications of lipid A moiety of lipopolysaccharide, reducing the negative charge of lipid A and its affinity for polymyxins. Additionally, the unique mobile colistin/polymyxin B resistance (mcr) gene reported in Enterobacteriales is responsible for the horizontal dissemination of resistance to polymyxins via the food chain. There is now an urgent need to increase surveillance for detecting resistance to polymyxins. Therefore, this review presents an overview of presently available scientific literature on the mechanism of resistance to polymyxins, with their associated gene variants, evaluation methods, resistance transmission through the food chain via food bacteria, and related risk factors. We further focus on the significant implications of polymyxins usage in India and future views for food safety to preserve polymyxin activity.202235079146
4878180.9998Bacteria carrying mobile colistin resistance genes and their control measures, an updated review. The plasmid encoded mobile colistin resistance (MCRs) enzyme poses a significant challenge to the clinical efficacy of colistin, which is frequently employed as a last resort antibiotic for treating infections caused by multidrug resistant bacteria. This transferase catalyzes the addition of positively charged phosphoethanolamine to lipid A of the outer membrane of gram-negative bacteria, thereby facilitating the acquired colistin resistance. This review aims to summarize and critically discuss recent advancements in the distribution and pathogenesis of mcr-positive bacteria, as well as the various control measures available for treating these infections. In addition, the ecology of mcr genes, colistin-resistance mechanism, co-existence with other antibiotic resistant genes, and their impact on clinical treatment are also analyzed to address the colistin resistance crisis. These insights provide a comprehensive perspective on MCRs and serve as a valuable reference for future therapeutic approaches to effectively combat mcr-positive bacterial infections.202439516398
4864190.9998Colistin resistance mechanisms in Gram-negative bacteria: a Focus on Escherichia coli. Multidrug-resistant (MDR) Escherichia coli strains have rapidly increased worldwide, and effective antibiotic therapeutic options are becoming more restricted. As a polymyxin antibiotic, colistin has a long history of usage, and it is used as a final line of treatment for severe infections by Gram-negative bacteria (GNB) with high-level resistance. However, its application has been challenged by the emergence of E. coli colistin resistance. Hence, determining the mechanism that confers colistin resistance is crucial for monitoring and controlling the dissemination of colistin-resistant E. coli strains. This comprehensive review summarizes colistin resistance mechanisms in E. coli strains and concentrates on the history, mode of action, and therapeutic implications of colistin. We have mainly focused on the fundamental mechanisms of colistin resistance that are mediated by chromosomal or plasmid elements and discussed major mutations in the two-component systems (TCSs) genes and plasmids that transmit the mobilized colistin resistance resistant genes in E. coli strains.202336754367