# | Rank | Similarity | Title + Abs. | Year | PMID |
|---|---|---|---|---|---|
| 0 | 1 | 2 | 3 | 4 | 5 |
| 4088 | 0 | 1.0000 | Expanding the soil antibiotic resistome: exploring environmental diversity. Antibiotic resistance has largely been studied in the context of failure of the drugs in clinical settings. There is now growing evidence that bacteria that live in the environment (e.g. the soil) are multi-drug-resistant. Recent functional screens and the growing accumulation of metagenomic databases are revealing an unexpected density of resistance genes in the environment: the antibiotic resistome. This challenges our current understanding of antibiotic resistance and provides both barriers and opportunities for antimicrobial drug discovery. | 2007 | 17951101 |
| 4087 | 1 | 0.9999 | Next-generation approaches to understand and combat the antibiotic resistome. Antibiotic resistance is a natural feature of diverse microbial ecosystems. Although recent studies of the antibiotic resistome have highlighted barriers to the horizontal transfer of antibiotic resistance genes between habitats, the rapid global spread of genes that confer resistance to carbapenem, colistin and quinolone antibiotics illustrates the dire clinical and societal consequences of such events. Over time, the study of antibiotic resistance has grown from focusing on single pathogenic organisms in axenic culture to studying antibiotic resistance in pathogenic, commensal and environmental bacteria at the level of microbial communities. As the study of antibiotic resistance advances, it is important to incorporate this comprehensive approach to better inform global antibiotic resistance surveillance and antibiotic development. It is increasingly becoming apparent that although not all resistance genes are likely to geographically and phylogenetically disseminate, the threat presented by those that are is serious and warrants an interdisciplinary research focus. In this Review, we highlight seminal work in the resistome field, discuss recent advances in the studies of resistomes, and propose a resistome paradigm that can pave the way for the improved proactive identification and mitigation of emerging antibiotic resistance threats. | 2017 | 28392565 |
| 4086 | 2 | 0.9999 | Insights into antibiotic resistance through metagenomic approaches. The consequences of bacterial infections have been curtailed by the introduction of a wide range of antibiotics. However, infections continue to be a leading cause of mortality, in part due to the evolution and acquisition of antibiotic-resistance genes. Antibiotic misuse and overprescription have created a driving force influencing the selection of resistance. Despite the problem of antibiotic resistance in infectious bacteria, little is known about the diversity, distribution and origins of resistance genes, especially for the unculturable majority of environmental bacteria. Functional and sequence-based metagenomics have been used for the discovery of novel resistance determinants and the improved understanding of antibiotic-resistance mechanisms in clinical and natural environments. This review discusses recent findings and future challenges in the study of antibiotic resistance through metagenomic approaches. | 2012 | 22191448 |
| 4070 | 3 | 0.9999 | Antibiotic Resistance Mechanisms in Bacteria: Relationships Between Resistance Determinants of Antibiotic Producers, Environmental Bacteria, and Clinical Pathogens. Emergence of antibiotic resistant pathogenic bacteria poses a serious public health challenge worldwide. However, antibiotic resistance genes are not confined to the clinic; instead they are widely prevalent in different bacterial populations in the environment. Therefore, to understand development of antibiotic resistance in pathogens, we need to consider important reservoirs of resistance genes, which may include determinants that confer self-resistance in antibiotic producing soil bacteria and genes encoding intrinsic resistance mechanisms present in all or most non-producer environmental bacteria. While the presence of resistance determinants in soil and environmental bacteria does not pose a threat to human health, their mobilization to new hosts and their expression under different contexts, for example their transfer to plasmids and integrons in pathogenic bacteria, can translate into a problem of huge proportions, as discussed in this review. Selective pressure brought about by human activities further results in enrichment of such determinants in bacterial populations. Thus, there is an urgent need to understand distribution of resistance determinants in bacterial populations, elucidate resistance mechanisms, and determine environmental factors that promote their dissemination. This comprehensive review describes the major known self-resistance mechanisms found in producer soil bacteria of the genus Streptomyces and explores the relationships between resistance determinants found in producer soil bacteria, non-producer environmental bacteria, and clinical isolates. Specific examples highlighting potential pathways by which pathogenic clinical isolates might acquire these resistance determinants from soil and environmental bacteria are also discussed. Overall, this article provides a conceptual framework for understanding the complexity of the problem of emergence of antibiotic resistance in the clinic. Availability of such knowledge will allow researchers to build models for dissemination of resistance genes and for developing interventions to prevent recruitment of additional or novel genes into pathogens. | 2018 | 30555448 |
| 4004 | 4 | 0.9999 | Diverse Distribution of Resistomes in the Human and Environmental Microbiomes. The routine therapeutic use of antibiotics has caused resistance genes to be disseminated across microbial populations. In particular, bacterial strains having antibiotic resistance genes are frequently observed in the human microbiome. Moreover, multidrug-resistant pathogens are now widely spread, threatening public health. Such genes are transferred and spread among bacteria even in different environments. Advances in high throughput sequencing technology and computational algorithms have accelerated investigation into antibiotic resistance genes of bacteria. Such studies have revealed that the antibiotic resistance genes are located close to the mobility-associated genes, which promotes their dissemination. An increasing level of information on genomic sequences of resistome should expedite research on drug-resistance in our body and environment, thereby contributing to the development of public health policy. In this review, the high prevalence of antibiotic resistance genes and their exchange in the human and environmental microbiome is discussed with respect to the genomic contents. The relationships among diverse resistomes, related bacterial species, and the antibiotics are reviewed. In addition, recent advances in bioinformatics approaches to investigate such relationships are discussed. | 2018 | 30532649 |
| 4022 | 5 | 0.9999 | Antibiotic resistance in the environment. Antibiotic resistance is a global health challenge, involving the transfer of bacteria and genes between humans, animals and the environment. Although multiple barriers restrict the flow of both bacteria and genes, pathogens recurrently acquire new resistance factors from other species, thereby reducing our ability to prevent and treat bacterial infections. Evolutionary events that lead to the emergence of new resistance factors in pathogens are rare and challenging to predict, but may be associated with vast ramifications. Transmission events of already widespread resistant strains are, on the other hand, common, quantifiable and more predictable, but the consequences of each event are limited. Quantifying the pathways and identifying the drivers of and bottlenecks for environmental evolution and transmission of antibiotic resistance are key components to understand and manage the resistance crisis as a whole. In this Review, we present our current understanding of the roles of the environment, including antibiotic pollution, in resistance evolution, in transmission and as a mere reflection of the regional antibiotic resistance situation in the clinic. We provide a perspective on current evidence, describe risk scenarios, discuss methods for surveillance and the assessment of potential drivers, and finally identify some actions to mitigate risks. | 2022 | 34737424 |
| 4101 | 6 | 0.9999 | What Is the Role of the Environment in the Emergence of Novel Antibiotic Resistance Genes? A Modeling Approach. It is generally accepted that intervention strategies to curb antibiotic resistance cannot solely focus on human and veterinary medicine but must also consider environmental settings. While the environment clearly has a role in transmission of resistant bacteria, its role in the emergence of novel antibiotic resistance genes (ARGs) is less clear. It has been suggested that the environment constitutes an enormous recruitment ground for ARGs to pathogens, but its extent is practically unknown. We have constructed a model framework for resistance emergence and used available quantitative data on relevant processes to identify limiting steps in the appearance of ARGs in human pathogens. We found that in a majority of possible scenarios, the environment would only play a minor role in the emergence of novel ARGs. However, the uncertainty is enormous, highlighting an urgent need for more quantitative data. Specifically, more data is most needed on the fitness costs of ARG carriage, the degree of dispersal of resistant bacteria from the environment to humans, and the rates of mobilization and horizontal transfer of ARGs. This type of data is instrumental to determine which processes should be targeted for interventions to curb development and transmission of ARGs in the environment. | 2021 | 34792330 |
| 4068 | 7 | 0.9999 | Co-selection for antibiotic resistance by environmental contaminants. The environment is increasingly recognised as a hotspot for the selection and dissemination of antibiotic resistant bacteria and antibiotic resistance genes. These can be selected for by antibiotics and non-antibiotic agents (such as metals and biocides), with the evidence to support this well established by observational and experimental studies. However, there is emerging evidence to suggest that plant protection products (such as herbicides), and non-antibiotic drugs (such as chemotherapeutic agents), can also co-select for antibiotic resistance. This review aims to provide an overview of four classes of non-antibiotic agents (metals, biocides, plant protection products, and non-antibiotic drugs) and how they may co-select for antibiotic resistance, with a particular focus on the environment. It also aims to identify key knowledge gaps that should be addressed in future work, to better understand these potential co-selective agents. | 2024 | 39843965 |
| 4035 | 8 | 0.9999 | Discovery of novel antibiotic resistance genes through metagenomics. Antibiotic resistance (AR) represents a challenge for the treatment of infectious diseases. Traditionally, antibiotic resistance determinants have been retrieved from culturable bacteria which represent a minor fraction of the total microbial diversity found in natural environments such as soils. In this review, we summarize recent advances in the study of antibiotic resistance using two main culture-independent approaches: sequence-based metagenomics and functional metagenomics. | 2014 | 25564024 |
| 4071 | 9 | 0.9999 | Antibiotic resistance in the environment: a link to the clinic? The emergence of resistance to all classes of antibiotics in previously susceptible bacterial pathogens is a major challenge to infectious disease medicine. The origin of the genes associated with resistance has long been a mystery. There is a growing body of evidence that is demonstrating that environmental microbes are highly drug resistant. The genes that make up this environmental resistome have the potential to be transferred to pathogens and indeed there is some evidence that at least some clinically relevant resistance genes have originated in environmental microbes. Understanding the extent of the environmental resistome and its mobilization into pathogenic bacteria is essential for the management and discovery of antibiotics. | 2010 | 20850375 |
| 4102 | 10 | 0.9999 | Forces shaping the antibiotic resistome. Antibiotic resistance has become a problem of global scale. Resistance arises through mutation or through the acquisition of resistance gene(s) from other bacteria in a process called horizontal gene transfer (HGT). While HGT is recognized as an important factor in the dissemination of resistance genes in clinical pathogens, its role in the environment has been called into question by a recent study published in Nature. The authors found little evidence of HGT in soil using a culture-independent functional metagenomics approach, which is in contrast to previous work from the same lab showing HGT between the environment and human microbiome. While surprising at face value, these results may be explained by the lack of selective pressure in the environment studied. Importantly, this work suggests the need for careful monitoring of environmental antibiotic pollution and stringent antibiotic stewardship in the fight against resistance. | 2014 | 25213620 |
| 4026 | 11 | 0.9999 | Gut microbiome in the emergence of antibiotic-resistant bacterial pathogens. The human gastrointestinal tract is home to a complex and dynamic community of microorganisms known as gut microbiota, which provide the host with important metabolic, signaling, and immunomodulatory functions. Both the commensal and pathogenic members of the gut microbiome serve as reservoirs of antimicrobial-resistance genes (ARG), which can cause potential health threats to the host and can transfer the ARGs to the susceptible microbes and into the environment. Antimicrobial resistance is becoming a major burden on human health and is widely recognized as a global challenge. The diversity and abundance of ARGs in the gut microbiome are variable and depend on the exposure to healthcare-associated antibiotics, usage of antibiotics in veterinary and agriculture, and the migration of the population. The transfer frequency of the ARGs through horizontal gene transfer (HGT) with the help of mobile genetic elements (MGEs) like plasmids, transposons, or phages is much higher among bacteria living in the GI tract compared to other microbial ecosystems. HGT in gut bacteria is facilitated through multiple gene transfer mechanisms, including transformation, conjugation, transduction, and vesicle fusion. It is the need of the hour to implement strict policies to limit indiscriminate antibiotic usage when needed. Developing rapid diagnostic tests for resistance determination and alternatives to antibiotics like vaccination, probiotics, and bacteriophage therapy should have the highest priority in the research and development sectors. Collective actions for sustainable development against resistant pathogens by promoting endogenous gut microbial growth and diversity through interdisciplinary research and findings are key to overcoming the current antimicrobial resistance crisis. | 2022 | 36280316 |
| 4015 | 12 | 0.9999 | Bacteriophages as Environmental Reservoirs of Antibiotic Resistance. Although antibiotic resistance represents a significant and growing public health concern, the contribution of bacteriophages (phages) to the mobilization of antibiotic resistance genes (ARGs) in the environment has not been extensively studied. Recent studies, however, suggest that phages play an important role in the acquisition, maintenance, and spread of ARGs than previously expected. This Opinion article offers an update on the contribution of phages to environmental antibiotic resistance. A better understanding of the mechanisms and factors that promote antibiotic resistance may significantly contribute to the implementation of control strategies. | 2019 | 30905524 |
| 9702 | 13 | 0.9999 | The role of natural environments in the evolution of resistance traits in pathogenic bacteria. Antibiotics are among the most valuable compounds used for fighting human diseases. Unfortunately, pathogenic bacteria have evolved towards resistance. One important and frequently forgotten aspect of antibiotics and their resistance genes is that they evolved in non-clinical (natural) environments before the use of antibiotics by humans. Given that the biosphere is mainly formed by micro-organisms, learning the functional role of antibiotics and their resistance elements in nature has relevant implications both for human health and from an ecological perspective. Recent works have suggested that some antibiotics may serve for signalling purposes at the low concentrations probably found in natural ecosystems, whereas some antibiotic resistance genes were originally selected in their hosts for metabolic purposes or for signal trafficking. However, the high concentrations of antibiotics released in specific habitats (for instance, clinical settings) as a consequence of human activity can shift those functional roles. The pollution of natural ecosystems by antibiotics and resistance genes might have consequences for the evolution of the microbiosphere. Whereas antibiotics produce transient and usually local challenges in microbial communities, antibiotic resistance genes present in gene-transfer units can spread in nature with consequences for human health and the evolution of environmental microbiota that are largely ignored. | 2009 | 19364732 |
| 4090 | 14 | 0.9999 | Ancient Resistome. Antibiotic resistance is an ancient biological mechanism in bacteria, although its proliferation in our contemporary world has been amplified through antimicrobial therapy. Recent studies conducted on ancient environmental and human samples have uncovered numerous antibiotic-resistant bacteria and resistance genes. The resistance genes that have been reported from the analysis of ancient bacterial DNA include genes coding for several classes of antibiotics, such as glycopeptides, β-lactams, tetracyclines, and macrolides. The investigation of the resistome of ancient bacteria is a recent and emerging field of research, and technological advancements such as next-generation sequencing will further contribute to its growth. It is hoped that the knowledge gained from this research will help us to better understand the evolution of antibiotic resistance genes and will also be used in drug design as a proactive measure against antibiotic resistance. | 2016 | 27726801 |
| 4018 | 15 | 0.9999 | Mobile elements, zoonotic pathogens and commensal bacteria: conduits for the delivery of resistance genes into humans, production animals and soil microbiota. Multiple antibiotic resistant pathogens represent a major clinical challenge in both human and veterinary context. It is now well-understood that the genes that encode resistance are context independent. That is, the same gene is commonly present in otherwise very disparate pathogens in both humans and production and companion animals, and among bacteria that proliferate in an agricultural context. This can be true even for pathogenic species or clonal types that are otherwise confined to a single host or ecological niche. It therefore follows that mechanisms of gene flow must exist to move genes from one part of the microbial biosphere to another. It is widely accepted that lateral (or horizontal) gene transfer (L(H)GT) drives this gene flow. LGT is relatively well-understood mechanistically but much of this knowledge is derived from a reductionist perspective. We believe that this is impeding our ability to deal with the medical ramifications of LGT. Resistance genes and the genetic scaffolds that mobilize them in multiply drug resistant bacteria of clinical significance are likely to have their origins in completely unrelated parts of the microbial biosphere. Resistance genes are increasingly polluting the microbial biosphere by contaminating environmental niches where previously they were not detected. More attention needs to be paid to the way that humans have, through the widespread application of antibiotics, selected for combinations of mobile elements that enhance the flow of resistance genes between remotely linked parts of the microbial biosphere. Attention also needs to be paid to those bacteria that link human and animal ecosystems. We argue that multiply antibiotic resistant commensal bacteria are especially important in this regard. More generally, the post genomics era offers the opportunity for understanding how resistance genes are mobilized from a one health perspective. In the long term, this holistic approach offers the best opportunity to better manage what is an enormous problem to humans both in terms of health and food security. | 2013 | 23641238 |
| 9686 | 16 | 0.9999 | Selective pressures for public antibiotic resistance. The rapid increase of antibiotic-resistant pathogens is severely limiting our current treatment possibilities. An important subset of the resistance mechanisms conferring antibiotic resistance have public effects, allowing otherwise susceptible bacteria to also survive antibiotic treatment. As susceptible bacteria can survive treatment without bearing the metabolic cost of producing the resistance mechanism, there is potential to increase their relative frequency in the population and, as such, select against resistant bacteria. Multiple studies showed that this altered selection for resistance is dependent on various environmental and treatment parameters. In this review, we provide a comprehensive overview of their most important findings and describe the main factors impacting the selection for resistance. In-depth understanding of the driving forces behind selection can aid in the design and implementation of alternative treatments which limit the risk of resistance development. | 2025 | 39158370 |
| 4085 | 17 | 0.9999 | The antibiotic resistome. IMPORTANCE OF THE FIELD: Antibiotics are essential for the treatment of bacterial infections and are among our most important drugs. Resistance has emerged to all classes of antibiotics in clinical use. Antibiotic resistance has, proven inevitable and very often it emerges rapidly after the introduction of a drug into the clinic. There is, therefore, a great interest in understanding the origins, scope and evolution of antibiotic resistance. AREAS COVERED IN THIS REVIEW: The review discusses the concept of the antibiotic resistome, which is the collection of all genes that directly or indirectly contribute to antibiotic resistance. WHAT THE READER WILL GAIN: The review seeks to assemble current knowledge of the resistome concept as a means of understanding the totality of resistance and not just resistance in pathogenic bacteria. TAKE HOME MESSAGE: The concept of the antibiotic resistome provides a framework for the study and understanding of how resistance emerges and evolves. Furthermore, the study of the resistome reveals strategies that can be applied in new antibiotic discoveries. | 2010 | 22827799 |
| 9701 | 18 | 0.9999 | Environmental factors influencing the development and spread of antibiotic resistance. Antibiotic resistance and its wider implications present us with a growing healthcare crisis. Recent research points to the environment as an important component for the transmission of resistant bacteria and in the emergence of resistant pathogens. However, a deeper understanding of the evolutionary and ecological processes that lead to clinical appearance of resistance genes is still lacking, as is knowledge of environmental dispersal barriers. This calls for better models of how resistance genes evolve, are mobilized, transferred and disseminated in the environment. Here, we attempt to define the ecological and evolutionary environmental factors that contribute to resistance development and transmission. Although mobilization of resistance genes likely occurs continuously, the great majority of such genetic events do not lead to the establishment of novel resistance factors in bacterial populations, unless there is a selection pressure for maintaining them or their fitness costs are negligible. To enable preventative measures it is therefore critical to investigate under what conditions and to what extent environmental selection for resistance takes place. In addition, understanding dispersal barriers is not only key to evaluate risks, but also to prevent resistant pathogens, as well as novel resistance genes, from reaching humans. | 2018 | 29069382 |
| 4096 | 19 | 0.9999 | Environmental hotspots for antibiotic resistance genes. Bacterial resistance toward broad-spectrum antibiotics has become a major concern in recent years. The threat posed by the infectious bacteria and the pace with which resistance determinants are transmitted needs to be deciphered. Soil and water contain unique and diverse microbial communities as well as pools of naturally occurring antibiotics resistant genes. Overuse of antibiotics along with poor sanitary practices expose these indigenous microbial communities to antibiotic resistance genes from other bacteria and accelerate the process of acquisition and dissemination. Clinical settings, where most antibiotics are prescribed, are hypothesized to serve as a major hotspot. The predisposition of the surrounding environments to a pool of antibiotic-resistant bacteria facilitates rapid antibiotic resistance among the indigenous microbiota in the soil, water, and clinical environments via horizontal gene transfer. This provides favorable conditions for the development of more multidrug-resistant pathogens. Limitations in detecting gene transfer mechanisms have likely left us underestimating the role played by the surrounding environmental hotspots in the emergence of multidrug-resistant bacteria. This review aims to identify the major drivers responsible for the spread of antibiotic resistance and hotspots responsible for the acquisition of antibiotic resistance genes. | 2021 | 34180594 |