Mobile Tigecycline Resistance: An Emerging Health Catastrophe Requiring Urgent One Health Global Intervention. - Related Documents




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249201.0000Mobile Tigecycline Resistance: An Emerging Health Catastrophe Requiring Urgent One Health Global Intervention. Mobile tigecycline resistance (MTR) threatens the clinical efficacy of the salvage antibiotic, tigecycline (TIG) used in treating deadly infections in humans caused by superbugs (multidrug-, extensively drug-, and pandrug-resistant bacteria), including carbapenem- and colistin-resistant bacteria. Currently, non-mobile tet(X) and mobile plasmid-mediated transmissible tet(X) and resistance-nodulation-division (RND) efflux pump tmexCD-toprJ genes, conferring high-level TIG (HLT) resistance have been detected in humans, animals, and environmental ecosystems. Given the increasing rate of development and spread of plasmid-mediated resistance against the two last-resort antibiotics, colistin (COL) and TIG, there is a need to alert the global community on the emergence and spread of plasmid-mediated HLT resistance and the need for nations, especially developing countries, to increase their antimicrobial stewardship. Justifiably, MTR spread projects One Health ramifications and portends a monumental threat to global public and animal health, which could lead to outrageous health and economic impact due to limited options for therapy. To delve more into this very important subject matter, this current work will discuss why MTR is an emerging health catastrophe requiring urgent One Health global intervention, which has been constructed as follows: (a) antimicrobial activity of TIG; (b) mechanism of TIG resistance; (c) distribution, reservoirs, and traits of MTR gene-harboring isolates; (d) causes of MTR development; (e) possible MTR gene transfer mode and One Health implication; and (f) MTR spread and mitigating strategies.202235979498
488010.9992Molecular 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
661520.9992Is Africa ready for mobile colistin resistance threat? Antimicrobial resistance is a growing public health problem and a threat to effective treatment and prevention of an array of infections caused by bacteria. Africa is already faced with many socio-economic and health crises. Many countries in Africa can seldom boast of a standardized health care facility comparable to those in developed countries. Yet, the non-therapeutic use of COL has been banned in developed countries. However, in Africa, except for South Africa, COL is an over-the-counter (OTC) medication sold and dispensed by non-professionals/without a veterinarian's supervision. The ban of non-therapeutic COL in developed countries has proven to reduce the development of mobile colistin resistance (MCR) in humans and animals. The unregulated use of COL has been proven to select pathogenic and commensal bacteria resistance. A transmissible plasmid-mediated colistin determinant, mobile COL resistance (mcr) gene, which is rapidly transferred/acquired horizontally or laterally intra/inter-species/genera, has been reported. A highly promiscuous mobile genetic element like plasmids containing transposons, insertion sequences, and integrons aid the carriage/rapid transfer and acquisition of these mcr genes. Hence, we highlight the danger posed by escalating colistin (COL) resistance in the continent and the impetus to halt the indiscriminate and non-therapeutic use of COL to protect public health.202134377360
661630.9992The menace of colistin resistance across globe: Obstacles and opportunities in curbing its spread. Colistin-resistance in bacteria is a big concern for public health, since it is a last resort antibiotic to treat infectious diseases of multidrug resistant and carbapenem resistant Gram-negative pathogens in clinical settings. The emergence of colistin resistance in aquaculture and poultry settings has escalated the risks associated with colistin resistance in environment as well. The staggering number of reports pertaining to the rise of colistin resistance in bacteria from clinical and non-clinical settings is disconcerting. The co-existence of colistin resistant genes with other antibiotic resistant genes introduces new challenges in combatting antimicrobial resistance. Some countries have banned the manufacture, sale and distribution of colistin and its formulations for food producing animals. However, to tackle the issue of antimicrobial resistance, a one health approach initiative, inclusive of human, animal, and environmental health needs to be developed. Herein, we review the recent reports in colistin resistance in bacteria of clinical and non-clinical settings, deliberating on the new findings obtained regarding the development of colistin resistance. This review also discusses the initiatives implemented globally in mitigating colistin resistance, their strength and weakness.202336812837
661740.9992Mechanisms in colistin-resistant superbugs transmissible from veterinary, livestock and animal food products to humans. In the era of antibiotic resistance, where multidrug-resistant (MDR), extensively drug resistant (XDR), and pan-drug resistant (PDR) Gram-negative infections are prevalent, it is crucial to identify the primary sources of antibiotic resistance, understand resistant mechanisms, and develop strategies to combat these mechanisms. The emergence of resistance to last-resort antibiotics like colistin has sparked a war between humanity and resistant bacteria, leaving humanity struggling to find effective countermeasures. Although colistin is used as a highly toxic antibiotic in infections that are not treated with routine antibiotics, its widespread use in animal breeding and veterinary medicine has contributed to the spread of colistin-resistant bacteria, plasmid-borne colistin resistance genes (mcr), and antibiotic residues in livestock and animal-derived foods. These sources can potentially transmit colistin resistance to humans through various routes. Therefore, managing the use of colistin in livestock and animal foods, implementing strict monitoring, and establishing guidelines for its proper use are essential to prevent the escalation of colistin resistance. This review article discusses the latest mechanisms of colistin antibiotic resistance, particularly biofilm production as a public health threat, the livestock and animal food sources of this resistance, and the routes of transmission to humans.202540386099
487350.9991Farm animals and aquaculture: significant reservoirs of mobile colistin resistance genes. Colistin resistance has attracted substantial attention after colistin was considered as a last-resort drug for the treatment of infections caused by carbapenem-resistant and/or multidrug-resistant (MDR) Gram-negative bacteria in clinical settings. However, with the discovery of highly mobile colistin resistance (mcr) genes, colistin resistance has become an increasingly urgent issue worldwide. Despite many reviews, which summarized the prevalence, mechanisms, and structures of these genes in bacteria of human and animal origin, studies on the prevalence of mobile colistin resistance genes in aquaculture and their transmission between animals and humans remain scarce. Herein, we review recent reports on the prevalence of colistin resistance genes in animals, especially wildlife and aquaculture, and their possibility of transmission to humans via the food chain. This review also gives some insights into the routine surveillance, changing policy and replacement of polymyxins by polymyxin derivatives, molecular inhibitors, and traditional Chinese medicine to tackle colistin resistance.202032114703
250060.9991The crisis of carbapenemase-mediated carbapenem resistance across the human-animal-environmental interface in India. Carbapenems are the decision-making antimicrobials used to combat severe Gram-negative bacterial infections in humans. Carbapenem resistance poses a potential public health emergency, especially in developing countries such as India, accounting for high morbidity, mortality, and healthcare cost. Emergence and transmission of plasmid-mediated "big five" carbapenemase genes including KPC, NDM, IMP, VIM and OXA-48-type among Gram-negative bacteria is spiralling the issue. Carbapenemase-producing carbapenem-resistant organisms (CP-CRO) cause multi- or pan-drug resistance by co-harboring several antibiotic resistance determinants. In addition of human origin, animals and even environmental sites are also the reservoir of CROs. Spillage in food-chains compromises food safety and security and increases the chance of cross-border transmission of these superbugs. Metallo-β-lactamases, mainly NDM-1 producing CROs, are commonly shared between human, animal and environmental interfaces worldwide, including in India. Antimicrobial resistance (AMR) surveillance using the One Health approach has been implemented in Europe, the United-Kingdom and the United-States to mitigate the crisis. This concept is still not implemented in most developing countries, including India, where the burden of antibiotic-resistant bacteria is high. Lack of AMR surveillance in animal and environmental sectors underestimates the cumulative burden of carbapenem resistance resulting in the silent spread of these superbugs. In-depth indiscriminate AMR surveillance focusing on carbapenem resistance is urgently required to develop and deploy effective national policies for preserving the efficacy of carbapenems as last-resort antibiotics in India. Tracking and mapping of international high-risk clones are pivotal for containing the global spread of CP-CRO.202336241158
487270.9991A Review on Colistin Resistance: An Antibiotic of Last Resort. Antibiotic resistance has emerged as a significant global public health issue, driven by the rapid adaptation of microorganisms to commonly prescribed antibiotics. Colistin, previously regarded as a last-resort antibiotic for treating infections caused by Gram-negative bacteria, is increasingly becoming resistant due to chromosomal mutations and the acquisition of resistance genes carried by plasmids, particularly the mcr genes. The mobile colistin resistance gene (mcr-1) was first discovered in E. coli from China in 2016. Since that time, studies have reported different variants of mcr genes ranging from mcr-1 to mcr-10, mainly in Enterobacteriaceae from various parts of the world, which is a major concern for public health. The co-presence of colistin-resistant genes with other antibiotic resistance determinants further complicates treatment strategies and underscores the urgent need for enhanced surveillance and antimicrobial stewardship efforts. Therefore, understanding the mechanisms driving colistin resistance and monitoring its global prevalence are essential steps in addressing the growing threat of antimicrobial resistance and preserving the efficacy of existing antibiotics. This review underscores the critical role of colistin as a last-choice antibiotic, elucidates the mechanisms of colistin resistance and the dissemination of resistant genes, explores the global prevalence of mcr genes, and evaluates the current detection methods for colistin-resistant bacteria. The objective is to shed light on these key aspects with strategies for combating the growing threat of resistance to antibiotics.202438674716
661080.9991The Gut Microbiome and Colistin Resistance: A Hidden Driver of Antimicrobial Failure. Colistin, a polymyxin antibiotic reintroduced as a last-resort therapy against multidrug-resistant Gram-negative bacteria, is increasingly being compromised by the emergence of plasmid-mediated colistin resistance genes (mcr-1 to mcr-10). The human gut microbiota serves as a major reservoir and transmission hub for these resistance determinants, even among individuals without prior colistin exposure. This review explores the mechanisms, dissemination, and clinical implications of mcr-mediated colistin resistance within the gut microbiota, highlighting its role in horizontal gene transfer, colonization, and environmental persistence. A comprehensive synthesis of the recent literature was conducted, focusing on epidemiological studies, molecular mechanisms, neonatal implications and decolonization strategies. The intestinal tract supports the enrichment and exchange of mcr genes among commensal and pathogenic bacteria, especially under antibiotic pressure. Colistin use in agriculture has amplified gut colonization with resistant strains in both animals and humans. Surveillance gaps remain, particularly in neonatal populations, where colonization may occur early and persist silently. Promising interventions, such as fecal microbiota transplantation and phage therapies, are under investigation but lack large-scale clinical validation. The gut microbiome plays a central role in the global spread of colistin resistance. Mitigating this threat requires integrated One Health responses, improved diagnostics for gut colonization, and investment in microbiome-based therapies. A proactive, multisectoral approach is essential to safeguard colistin efficacy and address the expanding threat of mcr-mediated resistance.202541009471
487490.9991Mobilized colistin resistance (mcr) genes from 1 to 10: a comprehensive review. At the present time, the polymyxin antibiotic colistin is considered a last-line treatment option for severe human infections caused by multi-drug and carbapenem-resistant Gram-negative bacteria. Lately, the vast spread of colistin resistance among bacteria has got great attention worldwide due to its significant role as the last refuge in treating diseases caused by the resistant infectious agents. Therefore, the discovery of plasmid-mediated mobile colistin resistance (mcr) genes raised global public health concerns as they can spread by horizontal transfer and have chances of global dissemination. To date, ten slightly different variants of the mcr-1 gene (mcr-1 to mcr-10) have been identified in different bacteria isolated from animals, foods, farms, humans, and the environment. Therefore, the issue of mcr spread is growing and worsening day after day. In this backdrop, the current article presents an overview of mcr variants, their spread, and the resistance mechanisms they confer. Hence, this paper will advance our knowledge about colistin resistance while supporting the efforts toward better stewardship and proper usage of antimicrobials.202133839987
9793100.9991Recent Review on Subclass B1 Metallo-β-lactamases Inhibitors: Sword for Antimicrobial Resistance. An emerging crisis of antibiotic resistance for microbial pathogens is alarming all the nations, posing a global threat to human health. The production of the metalloβ-lactamase enzyme is the most powerful strategy of bacteria to produce resistance. An efficient way to combat this global health threat is the development of broad/non-specific type of metalloβ-lactamase inhibitors, which can inhibit the different isoforms of the enzyme. Till date, there are no clinically active drugs against metallo- β-lactamase. The lack of efficient drug molecules against MBLs carrying bacteria requires continuous research efforts to overcome the problem of multidrug-resistance bacteria. The present review will discuss the clinically potent molecules against different variants of B1 metalloβ-lactamase.201930556502
6625110.9991The ecological threat posed by invasive species as silent carriers of global priority bacteria to wildlife. •Invasive species can act as silent carriers of multidrug-resistant bacterial species.•Invasive species in natural environments without predators can amplify the spread of antimicrobial resistance.•Global data on WHO priority bacteria and antimicrobial resistance in invasive species are provided.•Epidemiological surveillance of antimicrobial resistance in invasive species is discussed.202540331078
4871120.9990Colistin: from the shadows to a One Health approach for addressing antimicrobial resistance. Antimicrobial resistance (AMR) poses a serious threat to human, animal and environmental health worldwide. Colistin has regained importance as a last-resort treatment against multi-drug-resistant Gram-negative bacteria. However, colistin resistance has been reported in various Enterobacteriaceae species isolated from several sources. The 2015 discovery of the plasmid-mediated mcr-1 (mobile colistin resistance) gene conferring resistance to colistin was a major concern within the scientific community worldwide. The global spread of this plasmid - as well as the subsequent identification of 10 MCR-family genes and their variants that catalyse the addition of phosphoethanolamine to the phosphate group of lipid A - underscores the urgent need to regulate the use of colistin, particularly in animal production. This review traces the history of colistin resistance and mcr-like gene identification, and examines the impact of policy changes regarding the use of colistin on the prevalence of mcr-1-positive Escherichia coli and colistin-resistant E. coli from a One Health perspective. The withdrawal of colistin as a livestock growth promoter in several countries reduced the prevalence of colistin-resistant bacteria and its resistance determinants (e.g. mcr-1 gene) in farm animals, humans and the environment. This reduction was certainly favoured by the significant fitness cost associated with acquisition and expression of the mcr-1 gene in enterobacterial species. The success of this One Health intervention could be used to accelerate regulation of other important antimicrobials, especially those associated with bacterial resistance mechanisms linked to high fitness cost. The development of global collaborations and the implementation of sustainable solutions like the One Health approach are essential to manage AMR.202336640846
4332130.9990Development and transmission of antimicrobial resistance among Gram-negative bacteria in animals and their public health impact. Gram-negative bacteria are known to cause severe infections in both humans and animals. Antimicrobial resistance (AMR) in Gram-negative bacteria is a major challenge in the treatment of clinical infections globally due to the propensity of these organisms to rapidly develop resistance against antimicrobials in use. In addition, Gram-negative bacteria possess highly efficient mechanisms through which the AMR can be disseminated between pathogenic and commensal bacteria of the same or different species. These unique traits of Gram-negative bacteria have resulted in evolution of Gram-negative bacterial strains demonstrating resistance to multiple classes of antimicrobials. The evergrowing resistance issue has not only resulted in limitation of treatment options but also led to increased treatment costs and mortality rates in humans and animals. With few or no new antimicrobials in production to combat severe life-threatening infections, AMR has been described as the one of the most severe, long-term threats to human health. Aside from overuse and misuse of antimicrobials in humans, another factor that has exacerbated the emergence of AMR in Gram-negative bacteria is the veterinary use of antimicrobials that belong to the same classes considered to be critically important for treating serious life-threatening infections in humans. Despite the fact that development of AMR dates back to before the introduction of antimicrobials, the recent surge in the resistance towards all available critically important antimicrobials has emerged as a major public health issue. This review thus focuses on discussing the development, transmission and public health impact of AMR in Gram-negative bacteria in animals.201728258227
4185140.9990Containment of antimicrobial resistance due to use of antimicrobial agents in animals intended for food: WHO perspective. The use of antimicrobial agents in humans and food-producing animals has important consequences for human and animal health, as it can lead to the development of resistant bacteria (pathogens and/or commensals with resistance genes). Moreover, resistant bacteria in animals can be transferred to people--usually through the consumption of food, but also through direct contact with food-producing animals or through environmental spread. Ultimately, this can result in human infections with bacteria that are resistant to antimicrobial agents and that can therefore be difficult or impossible to cure. Of special concern is resistance to antimicrobial agents classified by the World Health Organization (WHO) as critically important for human medicine, such as fluoroquinolones, third- and fourth-generation cephalosporins, and macrolides. WHO encourages the agricultural, food, veterinary and health sectors to work together to eliminate the burden of antimicrobial resistance arising from the use of antimicrobial agents in food-producing animals. Joint efforts should be made to reduce the inappropriate use of antimicrobial agents (e.g. the use of antimicrobials as growth promoters) and limit the spread of bacteria resistant to antimicrobial agents. WHO will continueto address this issue in conjunction with the Food and Agriculture Organization of the United Nations, the World Organisation for Animal Health, the animal health/production industry and other important stakeholders. It will also continue to enhance the capacity of its Member States (through training courses and sentinel studies), particularly developing countries, to conduct integrated surveillance of antimicrobial use and resistance, to carry out risk assessments to support the selection of risk management options and to implement strategies for the containment of antimicrobial resistance.201222849282
4881150.9990Investigating 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
4876160.9990Epidemiology of mobile colistin resistance (mcr) genes in aquatic environments. Colistin is one of the last-line therapies against multidrug-resistant Gram-negative pathogens, especially carbapenemase-producing isolates, making resistance to this compound a major global public-health crisis. Until recently, colistin resistance in Gram-negative bacteria was known to arise only by chromosomal mutations. However, a plasmid-mediated colistin resistance mechanism was described in late 2015. This mechanism is encoded by different mobile colistin resistance (mcr) genes that encode phosphoethanolamine (pEtN) transferases. These enzymes catalyse the addition of a pEtN moiety to lipid A in the bacterial outer membrane leading to colistin resistance. MCR-producing Gram-negative bacteria have been largely disseminated worldwide. However, their environmental dissemination has been underestimated. Indeed, water environments act as a connecting medium between different environments, allowing them to play a crucial role in the spread of antibiotic resistance between the natural environment and humans and other animals. For a better understanding of the role of such environments as reservoirs and/or dissemination routes of mcr genes, this review discusses primarily the various water habitats contributing to the spread of antibiotic resistance. Thereafter, we provide an overview of existing knowledge regarding the global epidemiology of mcr genes in water environments. This review confirms the global distribution of mcr genes in several water environments, including wastewater from different origins, surface water and tap water, making these environments reservoirs and dissemination routes of concern for this resistance mechanism.202134438108
4878170.9990Bacteria 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
4887180.9990Mechanisms 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
4868190.9990Extended spectrum β-lactamases, carbapenemases and mobile genetic elements responsible for antibiotics resistance in Gram-negative bacteria. Infectious diseases due to Gram-negative bacteria are a leading cause of morbidity and mortality worldwide. Antimicrobial agents represent one major therapeutic tools implicated to treat these infections. The misuse of antimicrobial agents has resulted in the emergence of resistant strains of Gram-negatives in particular Enterobacteriaceae and non-fermenters; they have an effect not only on a human but on the public health when bacteria use the resistance mechanisms to spread in the hospital environment and to the community outside the hospitals by means of mobile genetic elements. Gram-negative bacteria have become increasingly resistant to antimicrobial agents. They have developed several mechanisms by which they can withstand to antimicrobials, these mechanisms include the production of Extended-spectrum β-lactamases (ESBLs) and carbapenemases, furthermore, Gram-negative bacteria are now capable of spreading such resistance between members of the family Enterobacteriaceae and non-fermenters using mobile genetic elements as vehicles for such resistance mechanisms rendering antibiotics useless. Therefore, addressing the issue of mechanisms of antimicrobial resistance is considered one of most urgent priorities. This review will help to illustrate different resistance mechanisms; ESBLs, carbapenemases encoded by genes carried by mobile genetic elements, which are used by Gram-negative bacteria to escape antimicrobial effect.201322667455