# | Rank | Similarity | Title + Abs. | Year | PMID |
|---|---|---|---|---|---|
| 0 | 1 | 2 | 3 | 4 | 5 |
| 4156 | 0 | 1.0000 | Antibiotic resistance genes in Escherichia coli - literature review. Antimicrobial resistance threatens humans and animals worldwide and is recognized as one of the leading global public health issues. Escherichia coli (E. coli) has an unquestionable role in carrying and transmitting antibiotic resistance genes (ARGs), which in many cases are encoded on plasmids or phage, thus creating the potential for horizontal gene transfer. In this literature review, the authors summarize the major antibiotic resistance genes occurring in E. coli bacteria, through the major antibiotic classes. The aim was not only listing the resistance genes against the clinically relevant antibiotics, used in the treatment of E. coli infections, but also to cover the entire resistance gene carriage in E. coli, providing a more complete picture. We started with the long-standing antibiotic groups (beta-lactams, aminoglycosides, tetracyclines, sulfonamides and diaminopyrimidines), then moved toward the newer groups (phenicols, peptides, fluoroquinolones, nitrofurans and nitroimidazoles), and in every group we summarized the resistance genes grouped by the mechanism of their action (enzymatic inactivation, antibiotic efflux, reduced permeability, etc.). We observed that the frequency of antibiotic resistance mechanisms changes in the different groups. | 2025 | 40249005 |
| 4157 | 1 | 0.9999 | Antimicrobial drug resistance against Escherichia coli and its harmful effect on animal health. Multidrug resistance among pathogenic bacteria is imperilling the worth of antibiotic infection, which has become an emerging problem, which previously transformed the veterinary sciences. Since its discovery, many antibiotics have been effective in treating bacterial infections in animals. Escherichia coli, a bacterium, is one of the reservoirs of antibiotic resistance genes in a community. The current use of antibiotics and demographic factors usually increase multidrug resistance. Genetically, the continuous adoption of environmental changes by E. coli allows it to acquire many multidrug resistance. During the host's life, antimicrobial resistance rarely poses a threat to the E. coli strain and pressure, similar to that of a flexible animal lower intestine. In this review, we describe the E. coli antibiotic drug-resistance mechanism driving transmission, the causes of transmission and the harmful effects on animal health. | 2022 | 35608149 |
| 4240 | 2 | 0.9999 | Genetics of antimicrobial resistance. Antimicrobial resistant strains of bacteria are an increasing threat to animal and human health. Resistance mechanisms to circumvent the toxic action of antimicrobials have been identified and described for all known antimicrobials currently available for clinical use in human and veterinary medicine. Acquired bacterial antibiotic resistance can result from the mutation of normal cellular genes, the acquisition of foreign resistance genes, or a combination of these two mechanisms. The most common resistance mechanisms employed by bacteria include enzymatic degradation or alteration of the antimicrobial, mutation in the antimicrobial target site, decreased cell wall permeability to antimicrobials, and active efflux of the antimicrobial across the cell membrane. The spread of mobile genetic elements such as plasmids, transposons, and integrons has greatly contributed to the rapid dissemination of antimicrobial resistance among several bacterial genera of human and veterinary importance. Antimicrobial resistance genes have been shown to accumulate on mobile elements, leading to a situation where multidrug resistance phenotypes can be transferred to a susceptible recipient via a single genetic event. The increasing prevalence of antimicrobial resistant bacterial pathogens has severe implications for the future treatment and prevention of infectious diseases in both animals and humans. The versatility with which bacteria adapt to their environment and exchange DNA between different genera highlights the need to implement effective antimicrobial stewardship and infection control programs in both human and veterinary medicine. | 2006 | 17127523 |
| 4140 | 3 | 0.9999 | Use of antimicrobials in veterinary medicine and mechanisms of resistance. This review deals with the application of antimicrobial agents in veterinary medicine and food animal production and the possible consequences arising from the widespread and multipurpose use of antimicrobials. The various mechanisms that bacteria have developed to escape the inhibitory effects of the antimicrobials most frequently used in the veterinary field are reported in detail. Resistance of bacteria to tetracyclines, macrolide-lincosamide-streptogramin antibiotics, beta-lactam antibiotics, aminoglycosides, sulfonamides, trimethoprim, fluoroquinolones and chloramphenicol/florfenicol is described with regard to enzymatic inactivation, decreased intracellular drug accumulation and modification/protection/replacement of the target sites. In addition, basic information is given about mobile genetic elements which carry the respective resistance genes, such as plasmids, transposons, and gene cassettes/integrons, and their ways of spreading via conjugation, mobilisation, transduction, and transformation. | 2001 | 11432414 |
| 4326 | 4 | 0.9999 | Antibiotic resistance in oral/respiratory bacteria. In the last 20 years, changes in world technology have occurred which have allowed for the rapid transport of people, food, and goods. Unfortunately, antibiotic residues and antibiotic-resistant bacteria have been transported as well. Over the past 20 years, the rise in antibiotic-resistant gene carriage in virtually every species of bacteria, not just oral/respiratory bacteria, has been documented. In this review, the main mechanisms of resistance to the important antibiotics used for treatment of disease caused by oral/respiratory bacteria--including beta-lactams, tetracycline, and metronidazole--are discussed in detail. Mechanisms of resistance for macrolides, lincosamides, streptogramins, trimethoprim, sulfonamides, aminoglycosides, and chloramphenicol are also discussed, along with the possible role that mercury resistance may play in the bacterial ecology. | 1998 | 9825225 |
| 4155 | 5 | 0.9999 | Resistance to tetracycline, macrolide-lincosamide-streptogramin, trimethoprim, and sulfonamide drug classes. The discovery and use of antimicrobial agents in the last 50 yr has been one of medicine's greatest achievements. These agents have reduced morbidity and mortality of humans and animals and have directly contributed to human's increased life span. However, bacteria are becoming increasingly resistant to these agents by mutations, which alter existing bacterial proteins, and/or acquisition of new genes, which provide new proteins. The latter are often associated with mobile elements that can be exchanged quickly across bacterial populations and may carry multiple antibiotic genes for resistance. In some case, virulence factors are also found on these same mobile elements. There is mounting evidence that antimicrobial use in agriculture, both plant and animal, and for environmental purposes does influence the antimicrobial resistant development in bacteria important in humans and in reverse. In this article, we will examine the genes which confer resistance to tetracycline, macrolide-lincosamide-streptogramin (MLS), trimethoprim, and sulfonamide. | 2002 | 11936257 |
| 4314 | 6 | 0.9999 | Cephalosporin resistance among animal-associated Enterobacteria: a current perspective. Beta-lactam antimicrobials are an important class of drugs used for the treatment of infection. Resistance can arise by several mechanisms, including the acquisition of genes encoding beta-lactamases from other bacteria, alterations in cell membrane permeability and over expression of endogenous beta-lactamases. The acquisition of beta-lactamase resistance genes by both Salmonella and Escherichia coli appears to be on the rise, which may pose potential problems for the treatment of infections in both human and animal medicine. The prudent use of clinically important antimicrobials is therefore critical to maintain their effectiveness. Where possible, the use of newer generation cephalosporins should be limited in veterinary medicine. | 2005 | 15954857 |
| 4046 | 7 | 0.9999 | Horizontal Gene Transfer and Its Association with Antibiotic Resistance in the Genus Aeromonas spp. The evolution of multidrug resistant bacteria to the most diverse antimicrobials known so far pose a serious problem to global public health. Currently, microorganisms that develop resistant phenotypes to multiple drugs are associated with high morbidity and mortality. This resistance is encoded by a group of genes termed 'bacterial resistome', divided in intrinsic and extrinsic resistome. The first one refers to the resistance displayed on an organism without previous exposure to an antibiotic not involving horizontal genetic transfer, and it can be acquired via mutations. The latter, on the contrary, is acquired exclusively via horizontal genetic transfer involving mobile genetic elements that constitute the 'bacterial mobilome'. This transfer is mediated by three different mechanisms: transduction, transformation, and conjugation. Recently, a problem of public health due to implications in the emergence of multi-drug resistance in Aeromonas spp. strains in water environments has been described. This is derived from the genetic material transfer via conjugation events. This is important, since bacteria that have acquired antibiotic resistance in natural environments can cause infections derived from their ingestion or direct contact with open wounds or mucosal tissue, which in turn, by their resistant nature, makes their eradication complex. Implications of the emergence of resistance in Aeromonas spp. by horizontal gene transfer on public health are discussed. | 2019 | 31540466 |
| 4154 | 8 | 0.9999 | Resistance to the tetracyclines and macrolide-lincosamide-streptogramin group of antibiotics and its genetic linkage - a review. An excessive use of antimicrobial agents poses a risk for the selection of resistant bacteria. Of particular interest are antibiotics that have large consumption rates in both veterinary and human medicine, such as the tetracyclines and macrolide-lincosamide-streptogramin (MLS) group of antibiotics. A high load of these agents increases the risk of transmission of resistant bacteria and/or resistance determinants to humans, leading to a subsequent therapeutic failure. An increasing incidence of bacteria resistant to both tetracyclines and MLS antibiotics has been recently observed. This review summarizes the current knowledge on different tetracycline and MLS resistance genes that can be linked together on transposable elements. | 2017 | 28664720 |
| 4043 | 9 | 0.9999 | Mobile antibiotic resistance - the spread of genes determining the resistance of bacteria through food products. In recent years, more and more antibiotics have become ineffective in the treatment of bacterial nfections. The acquisition of antibiotic resistance by bacteria is associated with circulation of genes in the environment. Determinants of antibiotic resistance may be transferred to pathogenic bacteria. It has been shown that conjugation is one of the key mechanisms responsible for spread of antibiotic resistance genes, which is highly efficient and allows the barrier to restrictions and modifications to be avoided. Some conjugative modules enable the transfer of plasmids even between phylogenetically distant bacterial species. Many scientific reports indicate that food is one of the main reservoirs of these genes. Antibiotic resistance genes have been identified in meat products, milk, fruits and vegetables. The reason for such a wide spread of antibiotic resistance genes is the overuse of antibiotics by breeders of plants and animals, as well as by horizontal gene transfer. It was shown, that resistance determinants located on mobile genetic elements, which are isolated from food products, can easily be transferred to another niche. The antibiotic resistance genes have been in the environment for 30 000 years. Their removal from food products is not possible, but the risks associated with the emergence of multiresistant pathogenic strains are very large. The only option is to control the emergence, selection and spread of these genes. Therefore measures are sought to prevent horizontal transfer of genes. Promising concepts involve the combination of developmental biology, evolution and ecology in the fight against the spread of antibiotic resistance. | 2016 | 27383577 |
| 4152 | 10 | 0.9999 | Quinolone resistance: much more than predicted. Since quinolones are synthetic antibiotics, it was predicted that mutations in target genes would be the only mechanism through which resistance could be acquired, because there will not be quinolone-resistance genes in nature. Contrary to this prediction, a variety of elements ranging from efflux pumps, target-protecting proteins, and even quinolone-modifying enzymes have been shown to contribute to quinolone resistance. The finding of some of these elements in plasmids indicates that quinolone resistance can be transferable. As a result, there has been a developing interest on the reservoirs for quinolone-resistance genes and on the potential risks associated with the use of these antibiotics in non-clinical environments. As a matter of fact, plasmid-encoded, quinolone-resistance qnr genes originated in the chromosome of aquatic bacteria. Thus the use of quinolones in fish-farming might constitute a risk for the emergence of resistance. Failure to predict the development of quinolone resistance reinforces the need of taking into consideration the wide plasticity of biological systems for future predictions. This plasticity allows pathogens to deal with toxic compounds, including those with a synthetic origin as quinolones. | 2011 | 21687414 |
| 4423 | 11 | 0.9999 | Inactivation of antibiotics and the dissemination of resistance genes. The emergence of multidrug-resistant bacteria is a phenomenon of concern to the clinician and the pharmaceutical industry, as it is the major cause of failure in the treatment of infectious diseases. The most common mechanism of resistance in pathogenic bacteria to antibiotics of the aminoglycoside, beta-lactam (penicillins and cephalosporins), and chloramphenicol types involves the enzymic inactivation of the antibiotic by hydrolysis or by formation of inactive derivatives. Such resistance determinants most probably were acquired by pathogenic bacteria from a pool of resistance genes in other microbial genera, including antibiotic-producing organisms. The resistance gene sequences were subsequently integrated by site-specific recombination into several classes of naturally occurring gene expression cassettes (typically "integrons") and disseminated within the microbial population by a variety of gene transfer mechanisms. Although bacterial conjugation once was believed to be restricted in host range, it now appears that this mechanism of transfer permits genetic exchange between many different bacterial genera in nature. | 1994 | 8153624 |
| 3897 | 12 | 0.9998 | The use of aminoglycosides in animals within the EU: development of resistance in animals and possible impact on human and animal health: a review. Aminoglycosides (AGs) are important antibacterial agents for the treatment of various infections in humans and animals. Following extensive use of AGs in humans, food-producing animals and companion animals, acquired resistance among human and animal pathogens and commensal bacteria has emerged. Acquired resistance occurs through several mechanisms, but enzymatic inactivation of AGs is the most common one. Resistance genes are often located on mobile genetic elements, facilitating their spread between different bacterial species and between animals and humans. AG resistance has been found in many different bacterial species, including those with zoonotic potential such as Salmonella spp., Campylobacter spp. and livestock-associated MRSA. The highest risk is anticipated from transfer of resistant enterococci or coliforms (Escherichia coli) since infections with these pathogens in humans would potentially be treated with AGs. There is evidence that the use of AGs in human and veterinary medicine is associated with the increased prevalence of resistance. The same resistance genes have been found in isolates from humans and animals. Evaluation of risk factors indicates that the probability of transmission of AG resistance from animals to humans through transfer of zoonotic or commensal foodborne bacteria and/or their mobile genetic elements can be regarded as high, although there are no quantitative data on the actual contribution of animals to AG resistance in human pathogens. Responsible use of AGs is of great importance in order to safeguard their clinical efficacy for human and veterinary medicine. | 2019 | 31002332 |
| 4040 | 13 | 0.9998 | Molecular Insights into Antimicrobial Resistance Traits of Commensal Human Gut Microbiota. Antimicrobial resistance (AMR) among bacterial species that resides in complex ecosystems is a natural phenomenon. Indiscriminate use of antimicrobials in healthcare, livestock, and agriculture provides an evolutionary advantage to the resistant variants to dominate the ecosystem. Ascendency of resistant variants threatens the efficacy of most, if not all, of the antimicrobial drugs commonly used to prevent and/or cure microbial infections. Resistant phenotype is very common in enteric bacteria. The most common mechanisms of AMR are enzymatic modifications to the antimicrobials or their target molecules. In enteric bacteria, most of the resistance traits are acquired by horizontal gene transfer from closely or distantly related bacterial population. AMR traits are generally linked with mobile genetic elements (MGEs) and could rapidly disseminate to the bacterial species through horizontal gene transfer (HGT) from a pool of resistance genes. Although prevalence of AMR genes among pathogenic bacteria is widely studied in the interest of infectious disease management, the resistance profile and the genetic traits that encode resistance to the commensal microbiota residing in the gut of healthy humans are not well-studied. In the present study, we have characterized AMR phenotypes and genotypes of five dominant commensal enteric bacteria isolated from the gut of healthy Indians. Our study revealed that like pathogenic bacteria, enteric commensals are also multidrug-resistant. The genes encoding antibiotic resistance are physically linked with MGEs and could disseminate vertically to the progeny and laterally to the distantly related microbial species. Consequently, the AMR genes present in the chromosome of commensal gut bacteria could be a potential source of resistance functions for other enteric pathogens. | 2019 | 30009332 |
| 3819 | 14 | 0.9998 | Enhancement of bacterial competitive fitness by apramycin resistance plasmids from non-pathogenic Escherichia coli. The study of antibiotic resistance has in the past focused on organisms that are pathogenic to humans or animals. However, the development of resistance in commensal organisms is of concern because of possible transfer of resistance genes to zoonotic pathogens. Conjugative plasmids are genetic elements capable of such transfer and are traditionally thought to engender a fitness burden on host bacteria. In this study, conjugative apramycin resistance plasmids isolated from newborn calves were characterized. Calves were raised on a farm that had not used apramycin or related aminoglycoside antibiotics for at least 20 months prior to sampling. Of three apramycin resistance plasmids, one was capable of transfer at very high rates and two were found to confer fitness advantages on new Escherichia coli hosts. This is the first identification of natural plasmids isolated from commensal organisms that are able to confer a fitness advantage on a new host. This work indicates that reservoirs of antibiotic resistance genes in commensal organisms might not decrease if antibiotic usage is halted. | 2006 | 17148431 |
| 4149 | 15 | 0.9998 | Antibiotic resistance genes from the environment: a perspective through newly identified antibiotic resistance mechanisms in the clinical setting. Soil bacteria may contain antibiotic resistance genes responsible for different mechanisms that permit them to overcome the natural antibiotics present in the environment. This gene pool has been recently named the 'resistome', and its components can be mobilized into the microbial community affecting humans because of the participation of genetic platforms that efficiently facilitate the mobilization and maintenance of these resistance genes. Evidence for this transference has been suggested or demonstrated with newly identified widespread genes in multidrug-resistant bacteria. These resistance genes include those responsible for ribosomal methylases affecting aminoglycosides (armA, rtmB), methyltransferases affecting linezolid (cfr) or plasmid-mediated efflux pumps conferring low-level fluoroquinolone resistance (qepA), all of which are associated with antibiotic-producing bacteria. In addition, resistance genes whose ancestors have been identified in environmental isolates that are not recognized as antibiotic producers have also been recently detected. These include the qnr and the bla(CTX) genes compromising the activity of fluoroquinolones and extended-spectrum cephalosporins, respectively. The application of metagenomic tools and phylogenetic analysis will facilitate future identification of other new resistance genes and their corresponding ancestors in environmental bacteria, and will enable further exploration of the concept of the resistome as being a unique reservoir of antibiotic resistance genes and genetic elements participating in resistance gene transfer. | 2009 | 19220348 |
| 4146 | 16 | 0.9998 | Aquatic Environments as Hotspots of Transferable Low-Level Quinolone Resistance and Their Potential Contribution to High-Level Quinolone Resistance. The disposal of antibiotics in the aquatic environment favors the selection of bacteria exhibiting antibiotic resistance mechanisms. Quinolones are bactericidal antimicrobials extensively used in both human and animal medicine. Some of the quinolone-resistance mechanisms are encoded by different bacterial genes, whereas others are the result of mutations in the enzymes on which those antibiotics act. The worldwide occurrence of quinolone resistance genes in aquatic environments has been widely reported, particularly in areas impacted by urban discharges. The most commonly reported quinolone resistance gene, qnr, encodes for the Qnr proteins that protect DNA gyrase and topoisomerase IV from quinolone activity. It is important to note that low-level resistance usually constitutes the first step in the development of high-level resistance, because bacteria carrying these genes have an adaptive advantage compared to the highly susceptible bacterial population in environments with low concentrations of this antimicrobial group. In addition, these genes can act additively with chromosomal mutations in the sequences of the target proteins of quinolones leading to high-level quinolone resistance. The occurrence of qnr genes in aquatic environments is most probably caused by the release of bacteria carrying these genes through anthropogenic pollution and maintained by the selective activity of antimicrobial residues discharged into these environments. This increase in the levels of quinolone resistance has consequences both in clinical settings and the wider aquatic environment, where there is an increased exposure risk to the general population, representing a significant threat to the efficacy of quinolone-based human and animal therapies. In this review the potential role of aquatic environments as reservoirs of the qnr genes, their activity in reducing the susceptibility to various quinolones, and the possible ways these genes contribute to the acquisition and spread of high-level resistance to quinolones will be discussed. | 2022 | 36358142 |
| 4084 | 17 | 0.9998 | Bacteriophages Contribute to the Spread of Antibiotic Resistance Genes among Foodborne Pathogens of the Enterobacteriaceae Family - A Review. Foodborne illnesses continue to have an economic impact on global health care systems. There is a growing concern regarding the increasing frequency of antibiotic resistance in foodborne bacterial pathogens and how such resistance may affect treatment outcomes. In an effort to better understand how to reduce the spread of resistance, many research studies have been conducted regarding the methods by which antibiotic resistance genes are mobilized and spread between bacteria. Transduction by bacteriophages (phages) is one of many horizontal gene transfer mechanisms, and recent findings have shown phage-mediated transduction to be a significant contributor to dissemination of antibiotic resistance genes. Here, we review the viability of transduction as a contributing factor to the dissemination of antibiotic resistance genes in foodborne pathogens of the Enterobacteriaceae family, including non-typhoidal Salmonella and Shiga toxin-producing Escherichia coli, as well as environmental factors that increase transduction of antibiotic resistance genes. | 2017 | 28676794 |
| 6631 | 18 | 0.9998 | Antibiotic Resistance in Escherichia coli from Farm Livestock and Related Analytical Methods: A Review. The indiscriminate use of antibiotics for the treatment of human and animal infections has led to the rise of resistance in pathogens and in commensal bacteria. In particular, farm animals may act as vectors for the dissemination of drug-resistant genes because of the intensive use of antibiotics in animal production, enabling resistance to a wide range of antimicrobial agents, including those normally used in human medicine. Escherichia coli, being a widespread commensal, is considered a good indicator of antibiotic use. Ultimately, it is emerging as a global threat, developing dramatically high levels of antibiotic resistance to multiple classes of drugs. Its prevalence in food animals is hence alarming, and more studies are needed in order to ascertain the spread dynamics between the food chain and humans. In this context, great attention should be paid to the accurate detection of resistance by conventional and molecular methods. In this review, a comprehensive list of the most widely used testing methods is also addressed. | 2018 | 29554996 |
| 3896 | 19 | 0.9998 | Antimicrobial resistance genes in bacteria from animal-based foods. Antimicrobial resistance is a worldwide public health threat. Farm animals are important sources of bacteria containing antimicrobial resistance genes (ARGs). Although the use of antimicrobials in aquaculture and livestock has been reduced in several countries, these compounds are still routinely applied in animal production, and contribute to ARGs emergence and spread among bacteria. ARGs are transmitted to humans mainly through the consumption of products of animal origin (PAO). Bacteria can present intrinsic resistance, and once antimicrobials are administered, this resistance may be selected and multiply. The exchange of genetic material is another mechanism used by bacteria to acquire resistance. Some of the main ARGs found in bacteria present in PAO are the bla, mcr-1, cfr and tet genes, which are directly associated to antibiotic resistance in the human clinic. | 2020 | 32762867 |