ENCOMPASSES - Word Related Documents




#
Rank
Similarity
Title + Abs.
Year
PMID
012345
650800.9844Synergizing Ecotoxicology and Microbiome Data Is Key for Developing Global Indicators of Environmental Antimicrobial Resistance. The One Health concept recognises the interconnectedness of humans, plants, animals and the environment. Recent research strongly supports the idea that the environment serves as a significant reservoir for antimicrobial resistance (AMR). However, the complexity of natural environments makes efforts at AMR public health risk assessment difficult. We lack sufficient data on key ecological parameters that influence AMR, as well as the primary proxies necessary for evaluating risks to human health. Developing environmental AMR 'early warning systems' requires models with well-defined parameters. This is necessary to support the implementation of clear and targeted interventions. In this review, we provide a comprehensive overview of the current tools used globally for environmental AMR human health risk assessment and the underlying knowledge gaps. We highlight the urgent need for standardised, cost-effective risk assessment frameworks that are adaptable across different environments and regions to enhance comparability and reliability. These frameworks must also account for previously understudied AMR sources, such as horticulture, and emerging threats like climate change. In addition, integrating traditional ecotoxicology with modern 'omics' approaches will be essential for developing more comprehensive risk models and informing targeted AMR mitigation strategies.202439611949
836210.9843Lifestyle evolution in symbiotic bacteria: insights from genomics. Bacteria that live only in eukaryotic cells and tissues, including chronic pathogens and mutualistic bacteriocyte associates, often possess a distinctive set of genomic traits, including reduced genome size, biased nucleotide base composition and fast polypeptide evolution. These phylogenetically diverse bacteria have lost certain functional categories of genes, including DNA repair genes, which affect mutational patterns. However, pathogens and mutualistic symbionts retain loci that underlie their unique interaction types, such as genes enabling nutrient provisioning by mutualistic bacteria-inhabiting animals. Recent genomic studies suggest that many of these bacteria are irreversibly specialized, precluding shifts between pathogenesis and mutualism.200010884696
678720.9843Impact of chlorine disinfection on intracellular and extracellular antimicrobial resistance genes in wastewater treatment and water reclamation. Wastewater treatment plants and water reclamation facilities are reservoirs of antimicrobial resistance genes (ARGs). These ARGs are not limited solely to intracellular DNA (inARGs) but include extracellular DNA (exARGs) present in wastewater. The release of exARGs from cells can be exacerbated by treatment processes, including chlorine disinfection, which disrupts bacterial cells. Given the potential for exARGs to drive horizontal gene transfer and contribute to the proliferation of antimicrobial resistance, it is imperative to recognize these fractions as emerging environmental pollutants. In this study, we conducted a comprehensive year-long assessment of both inARGs and exARGs, further differentiating between dissolved exARGs (Dis_exARGs) and exARGs adsorbed onto particulate matter (Ads_exARGs), within a full-scale wastewater treatment and water reclamation facility. The results revealed that Ads_exARGs comprised up to 30 % of the total ARGs in raw sewage with high biomass content. Generally, treatments at low and high doses of chlorine increased the abundance of Dis_exARGs and Ads_exARGs. The fate of ARG levels that varied depending on the type of ARGs suggested variations in the susceptibility of the host bacteria to chlorination. Moreover, co-occurrence of several potential opportunistic pathogenic bacteria and ARGs were observed. Therefore, we propose higher doses of chlorination as a prerequisite for the effective removal of inARGs and exARGs.202439067603
746130.9842Human- and infrastructure-associated bacteria in greywater. Greywater, the wastewater from sinks, showers and laundry, is an understudied environment for bacterial communities. Most greywater studies focus on quantifying pathogens, often via proxies used in other wastewater, like faecal indicator bacteria; there is a need to identify more greywater-appropriate surrogates, like Staphylococcus sp. Sequencing-based studies have revealed distinct communities in different types of greywater as well as in different parts of greywater infrastructure, including biofilms on pipes, holding tanks and filtration systems. The use of metagenomic sequencing provides high resolution on both the taxa and genes present, which may be of interest in cases like identifying pathogens and surrogates relevant to different matrices, monitoring antibiotic resistance genes and understanding metabolic processes occurring in the system. Here, we review what is known about bacterial communities in different types of greywater and its infrastructure. We suggest that wider adoption of environmental sequencing in greywater research is important because it can describe the entire bacterial community along with its metabolic capabilities, including pathways for removal of nutrients and organic materials. We briefly describe a metagenomic dataset comparing different types of greywater samples in a college dormitory building to highlight the type of questions these methods can address. Metagenomic sequencing can help further the understanding of greywater treatment for reuse because it allows for identification of new pathogens or genes of concern.202133905584
958140.9842Lateral gene transfer, bacterial genome evolution, and the Anthropocene. Lateral gene transfer (LGT) has significantly influenced bacterial evolution since the origins of life. It helped bacteria generate flexible, mosaic genomes and enables individual cells to rapidly acquire adaptive phenotypes. In turn, this allowed bacteria to mount strong defenses against human attempts to control their growth. The widespread dissemination of genes conferring resistance to antimicrobial agents has precipitated a crisis for modern medicine. Our actions can promote increased rates of LGT and also provide selective forces to fix such events in bacterial populations. For instance, the use of selective agents induces the bacterial SOS response, which stimulates LGT. We create hotspots for lateral transfer, such as wastewater systems, hospitals, and animal production facilities. Conduits of gene transfer between humans and animals ensure rapid dissemination of recent transfer events, as does modern transport and globalization. As resistance to antibacterial compounds becomes universal, there is likely to be increasing selection pressure for phenotypes with adverse consequences for human welfare, such as enhanced virulence, pathogenicity, and transmission. Improved understanding of the ecology of LGT could help us devise strategies to control this fundamental evolutionary process.201727706829
667050.9842Ecology of antimicrobial resistance: humans, animals, food and environment. Antimicrobial resistance is a major health problem. After decades of research, numerous difficulties in tackling resistance have emerged, from the paucity of new antimicrobials to the inefficient contingency plans to reduce the use of antimicrobials; consequently, resistance to these drugs is out of control. Today we know that bacteria from the environment are often at the very origin of the acquired resistance determinants found in hospitals worldwide. Here we define the genetic components that flow from the environment to pathogenic bacteria and thereby confer a quantum increase in resistance levels, as resistance units (RU). Environmental bacteria as well as microbiomes from humans, animals, and food represent an infinite reservoir of RU, which are based on genes that have had, or not, a resistance function in their original bacterial hosts. This brief review presents our current knowledge of antimicrobial resistance and its consequences, with special focus on the importance of an ecologic perspective of antimicrobial resistance. This discipline encompasses the study of the relationships of entities and events in the framework of curing and preventing disease, a definition that takes into account both microbial ecology and antimicrobial resistance. Understanding the flux of RU throughout the diverse ecosystems is crucial to assess, prevent and eventually predict emerging scaffolds before they colonize health institutions. Collaborative horizontal research scenarios should be envisaged and involve all actors working with humans, animals, food and the environment.201223847814
644360.9842Understanding bacterial ecology to combat antibiotic resistance dissemination. The dissemination of antibiotic resistance from environmental sources is a growing concern. Despite the widespread occurrence of antibiotic resistance transmission events, there are actually multiple obstacles in the ecosystem that restrict the flow of bacteria and genes, in particular nonnegligible biological barriers. How these ecological factors help combat the dissemination of antibiotic resistance and relevant antibiotic resistance-diminishing organisms (ARDOs) deserves further exploration. This review summarizes the factors that influence the growth, metabolism, and environmental adaptation of antibiotic-resistant bacteria (ARB) and restrict the horizontal gene transfer (HGT) of antibiotic resistance genes (ARGs). Additionally, this review discusses the achievements in the application of ARDOs to improve biotechnology for wastewater and solid waste remediation while highlighting current challenges limiting their broader implementation.202539855970
645270.9842Megacities as sources for pathogenic bacteria in rivers and their fate downstream. Poor sanitation, poor treatments of waste water, as well as catastrophic floods introduce pathogenic bacteria into rivers, infecting and killing many people. The goal of clean water for everyone has to be achieved with a still growing human population and their rapid concentration in large cities, often megacities. How long introduced pathogens survive in rivers and what their niches are remain poorly known but essential to control water-borne diseases in megacities. Biofilms are often niches for various pathogens because they possess high resistances against environmental stress. They also facilitate gene transfers of antibiotic resistance genes which become an increasing health problem. Beside biofilms, amoebae are carriers of pathogenic bacteria and niches for their survival. An overview about our current understanding of the fate and niches of pathogens in rivers, the multitude of microbial community interactions, and the impact of severe flooding, a prerequisite to control pathogens in polluted rivers, is given.201120885968
969280.9841Host ecology regulates interspecies recombination in bacteria of the genus Campylobacter. Horizontal gene transfer (HGT) can allow traits that have evolved in one bacterial species to transfer to another. This has potential to rapidly promote new adaptive trajectories such as zoonotic transfer or antimicrobial resistance. However, for this to occur requires gaps to align in barriers to recombination within a given time frame. Chief among these barriers is the physical separation of species with distinct ecologies in separate niches. Within the genus Campylobacter, there are species with divergent ecologies, from rarely isolated single-host specialists to multihost generalist species that are among the most common global causes of human bacterial gastroenteritis. Here, by characterizing these contrasting ecologies, we can quantify HGT among sympatric and allopatric species in natural populations. Analyzing recipient and donor population ancestry among genomes from 30 Campylobacter species, we show that cohabitation in the same host can lead to a six-fold increase in HGT between species. This accounts for up to 30% of all SNPs within a given species and identifies highly recombinogenic genes with functions including host adaptation and antimicrobial resistance. As described in some animal and plant species, ecological factors are a major evolutionary force for speciation in bacteria and changes to the host landscape can promote partial convergence of distinct species through HGT.202235191377
410390.9841Aeromonas: the multifaceted middleman in the One Health world. Aeromonas is at the interface of all the One Health components and represents an amazingly sound test case in the One Health approach, from economic loss in aquaculture tochallenges related to antibiotic-resistant bacteria selected from the environment. In human health, infections following leech therapy is an outstanding example of such One Health challenges. Aeromonads are not only ubiquitous environmental bacteria, able to rapidly colonize and cause opportunistic infections in humans and animals, they are also capable of promoting interactions and gene exchanges between the One Health components. This makes this genus a key amplifier of genetic transfer, especially of antibiotic resistance genes.202234717260
8625100.9841Marine viruses: truth or dare. Over the past two decades, marine virology has progressed from a curiosity to an intensely studied topic of critical importance to oceanography. At concentrations of approximately 10 million viruses per milliliter of surface seawater, viruses are the most abundant biological entities in the oceans. The majority of these viruses are phages (viruses that infect bacteria). Through lysing their bacterial hosts, marine phages control bacterial abundance, affect community composition, and impact global biogeochemical cycles. In addition, phages influence their hosts through selection for resistance, horizontal gene transfer, and manipulation of bacterial metabolism. Recent work has also demonstrated that marine phages are extremely diverse and can carry a variety of auxiliary metabolic genes encoding critical ecological functions. This review is structured as a scientific "truth or dare," revealing several well-established "truths" about marine viruses and presenting a few "dares" for the research community to undertake in future studies.201222457982
9719110.9841Dynamics of antibiotic resistance genes in plasmids and bacteriophages. This brief review explores the intricate interplay between bacteriophages and plasmids in the context of antibiotic resistance gene (ARG) dissemination. Originating from studies in the late 1950s, the review traces the evolution of knowledge regarding extrachromosomal factors facilitating horizontal gene transfer and adaptation in bacteria. Analyzing the gene repertoires of plasmids and bacteriophages, the study highlights their contributions to bacterial evolution and adaptation. While plasmids encode essential and accessory genes influencing host characteristics, bacteriophages carry auxiliary metabolic genes (AMGs) that augment host metabolism. The debate on phages carrying ARGs is explored through a critical evaluation of various studies, revealing contrasting findings from researchers. Additionally, the review addresses the interplay between prophages and plasmids, underlining their similarities and divergences. Based on the available literature evidence, we conclude that plasmids generally encode ARGs while bacteriophages typically do not contain ARGs. But extra-chromosomaly present prophages with plasmid characteristics can encode and disseminate ARGs.202538651513
9668120.9840Genomic and functional techniques to mine the microbiome for novel antimicrobials and antimicrobial resistance genes. Microbial communities contain diverse bacteria that play important roles in every environment. Advances in sequencing and computational methodologies over the past decades have illuminated the phylogenetic and functional diversity of microbial communities from diverse habitats. Among the activities encoded in microbiomes are the abilities to synthesize and resist small molecules, yielding antimicrobial activity. These functions are of particular interest when viewed in light of the public health emergency posed by the increase in clinical antimicrobial resistance and the dwindling antimicrobial discovery and approval pipeline, and given the intimate ecological and evolutionary relationship between antimicrobial biosynthesis and resistance. Here, we review genomic and functional methods that have been developed for accessing the antimicrobial biosynthesis and resistance capacity of microbiomes and highlight outstanding examples of their applications.201727768825
8359130.9840Comparative Genomic Analysis of Acanthamoeba Endosymbionts Highlights the Role of Amoebae as a "Melting Pot" Shaping the Rickettsiales Evolution. Amoebae have been considered as a genetic "melting pot" for its symbionts, facilitating genetic exchanges of the bacteria that co-inhabit the same host. To test the "melting pot" hypothesis, we analyzed six genomes of amoeba endosymbionts within Rickettsiales, four of which belong to Holosporaceae family and two to Candidatus Midichloriaceae. For the first time, we identified plasmids in obligate amoeba endosymbionts, which suggests conjugation as a potential mechanism for lateral gene transfers (LGTs) that underpin the "melting pot" hypothesis. We found strong evidence of recent LGTs between the Rickettsiales amoeba endosymbionts, suggesting that the LGTs are continuous and ongoing. In addition, comparative genomic and phylogenomic analyses revealed pervasive and recurrent LGTs between Rickettsiales and distantly related amoeba-associated bacteria throughout the Rickettsiales evolution. Many of these exchanged genes are important for amoeba-symbiont interactions, including genes in transport system, antibiotic resistance, stress response, and bacterial virulence, suggesting that LGTs have played important roles in the adaptation of endosymbionts to their intracellular habitats. Surprisingly, we found little evidence of LGTs between amoebae and their bacterial endosymbionts. Our study strongly supports the "melting pot" hypothesis and highlights the role of amoebae in shaping the Rickettsiales evolution.201729177480
3785140.9840A network approach to decipher the dynamics of Lysobacteraceae plasmid gene sharing. Plasmids provide an efficient vehicle for gene sharing among bacterial populations, playing a key role in bacterial evolution. Network approaches are particularly suitable to represent multipartite relationships and are useful tools to characterize plasmid-mediated gene sharing events. The bacterial family Lysobacteraceae includes plant commensal, plant pathogenic and opportunistic human pathogens for which plasmid-mediated adaptation has been reported. We searched for homologues of plasmid gene sequences from this family in the entire diversity of available bacterial genome sequences and built a network of plasmid gene sharing from the results. While plasmid genes are openly shared between the bacteria of the family Lysobacteraceae, taxonomy strongly defined the boundaries of these exchanges, which only barely reached other families. Most inferred plasmid gene sharing events involved a few genes only, and evidence of full plasmid transfers were restricted to taxonomically closely related taxa. We detected multiple plasmid-chromosome gene transfers, including the known sharing of a heavy metal resistance transposon. In the network, bacterial lifestyles shaped substructures of isolates colonizing specific ecological niches and harbouring specific types of resistance genes. Genes associated with pathogenicity or antibiotic and metal resistance were among those that most importantly structured the network, highlighting the imprints of human-mediated selective pressure on pathogenic populations. A massive sequencing effort on environmental Lysobacteraceae is therefore required to refine our understanding of how this reservoir fuels the emergence and the spread of genes among this family and its potential impact on plant, animal and human health.202335593155
9838150.9839Interactions between plasmids and other mobile genetic elements affect their transmission and persistence. Plasmids are genetic elements that play a role in bacterial evolution by providing new genes that promote adaptation to diverse conditions. Plasmids are also known to reduce bacterial competitiveness in the absence of selection for plasmid-encoded traits. It is easier to understand plasmid persistence when considering the evidence that plasmid maintenance can improve during co-evolution with the bacterial host, i.e. the chromosome. However, bacteria isolated from nature often harbor diverse mobile elements: phages, transposons, genomic islands and even other plasmids. Recent interest has emerged on the role such elements play on the persistence and evolution of plasmids. Here, we mainly review interactions between different plasmids, but also discuss their interactions with other genetic elements. We focus on interactions that impact fundamental plasmid traits, such as the fitness effect imposed on their hosts and the transfer efficiency into new host cells. We illustrate these phenomena with examples concerning clinically relevant organisms and the spread of plasmids carrying antibiotic resistance genes and virulence factors.201930771401
9837160.9839Mobilizable genomic islands, different strategies for the dissemination of multidrug resistance and other adaptive traits. Mobile genetic elements are near ubiquitous DNA segments that revealed a surprising variety of strategies for their propagation among prokaryotes and between eukaryotes. In bacteria, conjugative elements were shown to be key drivers of evolution and adaptation by efficiently disseminating genes involved in pathogenicity, symbiosis, metabolic pathways, and antibiotic resistance. Conjugative plasmids of the incompatibility groups A and C (A/C) are important vehicles for the dissemination of antibiotic resistance and the consequent global emergence and spread of multi-resistant pathogenic bacteria. Beyond their own mobility, A/C plasmids were also shown to drive the mobility of unrelated non-autonomous mobilizable genomic islands, which may also confer further advantageous traits. In this commentary, we summarize the current knowledge on different classes of A/C-dependent mobilizable genomic islands and we discuss other DNA hitchhikers and their implication in bacterial evolution. Furthermore, we glimpse at the complex genetic network linking autonomous and non-autonomous mobile genetic elements, and at the associated flow of genetic information between bacteria.201728439449
9691170.9839Defining pathogenic bacterial species in the genomic era. Actual definitions of bacterial species are limited due to the current criteria of definition and the use of restrictive genetic tools. The 16S ribosomal RNA sequence, for example, has been widely used as a marker for phylogenetic analyses; however, its use often leads to misleading species definitions. According to the first genetic studies, removing a certain number of genes from pathogenic bacteria removes their capacity to infect hosts. However, more recent studies have demonstrated that the specialization of bacteria in eukaryotic cells is associated with massive gene loss, especially for allopatric endosymbionts that have been isolated for a long time in an intracellular niche. Indeed, sympatric free-living bacteria often have bigger genomes and exhibit greater resistance and plasticity and constitute species complexes rather than true species. Specialists, such as pathogenic bacteria, escape these bacterial complexes and colonize a niche, thereby gaining a species name. Their specialization allows them to become allopatric, and their gene losses eventually favor reductive genome evolution. A pathogenic species is characterized by a gene repertoire that is defined not only by genes that are present but also by those that are lacking. It is likely that current bacterial pathogens will disappear soon and be replaced by new ones that will emerge from bacterial complexes that are already in contact with humans.201021687765
3783180.9839Ecology drives a global network of gene exchange connecting the human microbiome. Horizontal gene transfer (HGT), the acquisition of genetic material from non-parental lineages, is known to be important in bacterial evolution. In particular, HGT provides rapid access to genetic innovations, allowing traits such as virulence, antibiotic resistance and xenobiotic metabolism to spread through the human microbiome. Recent anecdotal studies providing snapshots of active gene flow on the human body have highlighted the need to determine the frequency of such recent transfers and the forces that govern these events. Here we report the discovery and characterization of a vast, human-associated network of gene exchange, large enough to directly compare the principal forces shaping HGT. We show that this network of 10,770 unique, recently transferred (more than 99% nucleotide identity) genes found in 2,235 full bacterial genomes, is shaped principally by ecology rather than geography or phylogeny, with most gene exchange occurring between isolates from ecologically similar, but geographically separated, environments. For example, we observe 25-fold more HGT between human-associated bacteria than among ecologically diverse non-human isolates (P = 3.0 × 10(-270)). We show that within the human microbiome this ecological architecture continues across multiple spatial scales, functional classes and ecological niches with transfer further enriched among bacteria that inhabit the same body site, have the same oxygen tolerance or have the same ability to cause disease. This structure offers a window into the molecular traits that define ecological niches, insight that we use to uncover sources of antibiotic resistance and identify genes associated with the pathology of meningitis and other diseases.201122037308
6646190.9839Food animals and antimicrobials: impacts on human health. Antimicrobials are valuable therapeutics whose efficacy is seriously compromised by the emergence and spread of antimicrobial resistance. The provision of antibiotics to food animals encompasses a wide variety of nontherapeutic purposes that include growth promotion. The concern over resistance emergence and spread to people by nontherapeutic use of antimicrobials has led to conflicted practices and opinions. Considerable evidence supported the removal of nontherapeutic antimicrobials (NTAs) in Europe, based on the "precautionary principle." Still, concrete scientific evidence of the favorable versus unfavorable consequences of NTAs is not clear to all stakeholders. Substantial data show elevated antibiotic resistance in bacteria associated with animals fed NTAs and their food products. This resistance spreads to other animals and humans-directly by contact and indirectly via the food chain, water, air, and manured and sludge-fertilized soils. Modern genetic techniques are making advances in deciphering the ecological impact of NTAs, but modeling efforts are thwarted by deficits in key knowledge of microbial and antibiotic loads at each stage of the transmission chain. Still, the substantial and expanding volume of evidence reporting animal-to-human spread of resistant bacteria, including that arising from use of NTAs, supports eliminating NTA use in order to reduce the growing environmental load of resistance genes.201121976606