Metagenomic analysis of bacterial fitness and plasmids carrying bla(TEM-1) and virulence genes before and after cleaning and disinfection in pig slaughterhouses. - Related Documents




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318201.0000Metagenomic analysis of bacterial fitness and plasmids carrying bla(TEM-1) and virulence genes before and after cleaning and disinfection in pig slaughterhouses. The identification of antibiotic resistance genes (ARGs), virulence genes, and pathogens in animal slaughterhouses poses a major threat to human health. However, limited data is available about the contamination and dissemination of ARGs in commercial pig slaughterhouses before and after disinfectant application. In this study, we used metagenomics and plasmid profiling to analys ethe effect of quaternary-ammonium-based cleaning and disinfection (C&D) on the microbiota, antibiotic resistance genes (ARGs), and virulence genes (VFs) in a pig slaughterhouse. According to results C&D effectively reduced the total microbial population and abundance of ARGs. However, the prevalence of disinfectant-resistant bacteria, particularly Escherichia coli, increased dramatically from 5.9 % to 14.9 %. Additionally, the clinically significant β-lactamase gene bla(TEM-1) remained intact throughout C&D process. The persistence of bla(TEM-1) is primarily facilitated by low-fitness-cost IncR-type plasmids (pTZ17 and pSB24), which are characterised by their simplified structures that have no effect on bacterialgrowth or motility and exhibit stability in the absence of antibiotics. On the other hand, the high-virulence IncFIB plasmid (pYA21) harbors numerous ARGs and VFs. Despite their low survival rate after C&D, the remaining bacteria may pose an even greater risk. The results suggest that current disinfection protocols may unintentionally promote the persistence and dissemination of resistance plasmids with potential fitness or economic advantages. Our findings highlight the need of integrating plasmid ecology and virulence profiling into standard surveillance practices, which will enhance disinfection strategies and help to mitigate the spread of antimicrobial resistance.202541124743
345610.9998Phage particles harboring antibiotic resistance genes in fresh-cut vegetables and agricultural soil. Bacteriophages are ubiquitously distributed prokaryotic viruses that are more abundant than bacteria. As a consequence of their life cycle, phages can kidnap part of their host's genetic material, including antibiotic resistance genes (ARGs), which released phage particles transfer in a process called transduction. The spread of ARGs among pathogenic bacteria currently constitutes a serious global health problem. In this study, fresh vegetables (lettuce, spinach and cucumber), and cropland soil were screened by qPCR for ten ARGs (bla(TEM), bla(CTX-M-1) group, bla(CTX-M-9) group, bla(OXA-48), bla(VIM), mecA, sul1, qnrA, qnrS and armA) in their viral DNA fraction. The presence of ARGs in the phage DNA was analyzed before and after propagation experiments in an Escherichia coli host strain to evaluate the ability of the phage particles to infect a host. ARGs were found in the phage DNA fraction of all matrices, although with heterogeneous values. ARG prevalence was significantly higher in lettuce and soil, and the most common overall were β-lactamases. After propagation experiments, an increase in ARG densities in phage particles was observed in samples of all four matrices, confirming that part of the isolated phage particles were infectious. This study reveals the abundance of free, replicative ARG-containing phage particles in vegetable matrices and cropland soil. The particles are proposed as vehicles for resistance transfer in these environments, where they can persist for a long time, with the possibility of generating new resistant bacterial strains. Ingestion of these mobile genetic elements may also favor the emergence of new resistances, a risk not previously considered.201829567433
346620.9998Behavior of last resort antibiotic resistance genes (mcr-1 and bla(NDM-1)) in a drinking water supply system and their possible acquisition by the mouse gut flora. Mcr-1 and bla(NDM-1) antibiotic resistance genes (ARGs) confer resistance to colistins and carbapenems, which are often antibiotics used as a last resort in tertiary care hospitals. Dissemination of these two ARGs in drinking water supply systems and their effect on healthy gut bacteria are poorly studied. In this study, the dissemination of mcr-1 and bla(NDM-1) in a drinking water supply system, and their effect on the antibiotic resistance of mouse gut bacteria are explored. Metagenome analysis revealed that source water (Taipu river and Jinze reservoir) was polluted with ARGs. Mcr-1 and bla(NDM-1) can be disseminated through the water distribution system. Even advanced water treatments (ozone and biological activated carbon (BAC)) could not effectively remove mcr-1 and bla(NDM-1). Low concentrations of chloramine disinfectants in the water distribution system were not effective at limiting ARG abundance. Mobile genetic elements were also found to play a major role in the dissemination of ARGs via horizontal gene transfer (HGT) throughout the water supply system. Statistical analysis revealed that there was no effect of temperature on the abundance of mcr-1 and bla(NDM-1) throughout the water supply system. A last resort ARG, mcr-1 can disseminate from drinking water to the healthy mouse gut. The presence of mcr-1 in a strain belonging to Enterococcus hirae, which is different from the strain belonging to the Bacillus cereus group isolated from drinking water, strongly supports the phenomena of HGT inside the gut. This research provides novel insights into the role of drinking water in disseminating ARGs to the gut and strongly suggests that drinking water may also play a major role apart from other factors known to be involved in the prevalence of last resort ARGs in the gut.202031896482
346730.9998Epidemiological characteristics of antibiotic resistance genes in various bacteria worldwide. OBJECTIVES: This study aims to investigate the epidemiological characteristics of various bacteria carrying ARGs on a global scale over extended time periods. METHODS: A total of 25,285 globally isolated bacteria's genomes were analyzed to explore ARGs. The analysis focused on temporal, geographic, and species distribution, including pathogenic and non-pathogenic bacteria, intracellular parasitic states, ARG types, and their association with MGEs. Multiple linear regression was employed to identify ARG risk factors in bacteria. RESULTS: The overall prevalence of bacteria with ARGs was 64.2%, indicating that at least one ARG was present in 64.2% (16,243/25,285) of the included bacterial, with an average of 14.4 ARGs per bacterium. ARGs have been increasing globally, averaging one additional ARG every three years, closely linked to rising antibiotic consumption. Pathogenic bacteria harbored more ARGs than non-pathogenic ones. Intracellular parasitic bacteria still carry specific types of ARGs despite being less likely to generate ARGs. Clinical and human-associated bacteria showed higher ARG counts, and bacteria isolated from humans had the highest number of disinfectant-resistant genes. The average number of ARGs in bacteria isolated from high-middle-income and lower-middle-income countries is higher. Factors like motility, non-sporulation, Gram-positive staining, extracellular parasitism, and human pathogenicity are linked to higher ARGs levels. CONCLUSIONS: An increasing number of bacteria carrying ARGs pose a significant challenge to the control of antibiotics-resistant pathogens worldwide. The issue of bacteria carrying more ARGs requires greater global attention.202540147137
325440.9998Temporal trends of antibiotic resistance in culturable bacteria reveal the role of potential pathogens as pioneering carriers and resistance accumulators. Understanding the occurrence and temporal trends of antibiotic resistance genes (ARGs) within bacteria is crucial for controlling and predicting the proliferation of antibiotic-resistant bacteria. However, gaps remain in understanding the long-term trends across different bacterial species and in assessing related health risks. We collected 22,360 bacterial complete genome sequences with collection time and compiled a temporal dataset of ARGs in culturable bacteria. Our results revealed the widespread presence of ARGs among culturable bacterial species, with potential pathogens carrying significantly more ARGs than non-pathogenic species. Temporal trend analysis revealed that only 11.0 % of bacterial species experienced an increase of more than one unit in ARG quantity and diversity over one century, with 83.3 % of them being potential pathogenic species. The temporal accumulation of ARGs in many potential pathogenic species is influenced by the abundance of mobile genetic elements, with several species also exhibiting temporal accumulation of plasmid-borne ARGs. Notably, Shigella flexneri and Klebsiella pneumoniae exhibited an accumulation of high-risk ARGs associated with at least five antibiotic types over at least 40 years. Furthermore, the distribution of ARG-carrying strains before the use of antibiotics revealed a wide range of bacterial species and antibiotic types for intrinsic resistance, including some synthetic antibiotics. This work reveals the significant role of potential pathogens in the expansion of antibiotic resistance and highlights the importance of strengthening vigilance against the emergence of novel multidrug-resistant pathogens.202540712179
328350.9998Prevalence of diverse antimicrobial resistance genes and bacteria in sewage treatment plant-derived sludge environment. Antimicrobial resistance (AMR) contamination in the environment is one of the most significant worldwide threats of the 21(st) century. Since sludge is heavily exposed to diverse contaminants, including pharmaceuticals, the inhabitant bacterial population is expected to exhibit resistance to antimicrobial agents. In this study, sewage treatment plant (STP) sludge samples were analyzed to assess the antibiotic-resistant bacterial population, abundance of AMR genes (ermF, qnrS, Sul1, blaGES, blaCTX-M, and blaNDM), and mobile genetic elements (intl1 and IS26). Out of 16, six bacterial isolates exhibited resistance to 13 antibiotics with a high multiple antibiotic resistance index (MARI) (0.93) and high metal tolerance. Quantitative polymerase chain reaction showed the abundance of target genes ranging from 6.6 × 10(3) to 6.5 × 10(8) copies g(-1) sludge. The overall outcome reveals that STP sludge comprised varied multidrug-resistant bacterial populations. It will give insights into the functions of heavy metals and biofilm development in the selection and spread of AMR genes and the associated bacteria. Therefore, the application of sludge needs proper screening for AMR and metal contamination prior to its countless applications. This study will contribute immensely to the risk analysis of STP effluents on environmental health, including control of AMR transmission.202438463555
710660.9998The swine waste resistome: Spreading and transfer of antibiotic resistance genes in Escherichia coli strains and the associated microbial communities. The overuse of antimicrobials in livestock farming has led to the development of resistant bacteria and the spread of antibiotic-resistant genes (ARGs) among animals. When manure containing these antibiotics is applied to agricultural fields, it creates a selective pressure that promotes the acquisition of ARGs by bacteria, primarily through horizontal gene transfer. Most research on ARGs focuses on their role in clinical antibiotic resistance and their transfer from environmental sources to bacteria associated with humans, such as Escherichia coli. The study investigates the spread of antibiotic-resistant genes (ARGs) through class 1 integrons in 27 Escherichia coli strains from pig manure. It focuses on six common ARGs (ermB, cmlA, floR, qnrS, tetA, and TEM) and the class 1 integron gene, assessing their prevalence in manure samples from three pig farms. The study found correlations and anticorrelations among these genes, indicating a predisposition of the integron in spreading certain ARGs. Specifically, cmlA and tetA genes were positively correlated with each other and negatively with int1, suggesting they are not transferred via Int1. Farm B had the highest int1 counts and a higher abundance of the TEM gene, but lower levels of cmlA and tetA genes. The results underscore the complexity of predicting ARG spread in agricultural environments and the associated health risks to humans through the food chain. The study's results offer valuable insights into the antibiotic-resistant genes (ARGs) profile in swine livestock, potentially aiding in the development of methods to trace ARGs in the environment.202439053184
711070.9998The "best practices for farming" successfully contributed to decrease the antibiotic resistance gene abundances within dairy farms. INTRODUCTION: Farms are significant hotspots for the dissemination of antibiotic-resistant bacteria and genes (ARGs) into the environment and directly to humans. The prevalence of ARGs on farms underscores the need for effective strategies to reduce their spread. This study aimed to evaluate the impact of a guideline on "best practices for farming" aimed at reducing the dissemination of antibiotic resistance. METHODS: A guideline focused on prudent antibiotic use, selective therapy, and hygienic and immune-prophylactic practices was developed and provided to the owners of 10 selected dairy farms and their veterinarians. Fecal samples were collected from lactating cows, dry cows, and calves both before and after the implementation of the guideline. ARGs (bla (TEM), ermB, sul2, and tetA) were initially screened by end-point PCR, followed by quantification using digital droplet PCR. ARG abundance was expressed in relative terms by dividing the copy number of ARGs by the copy number of the 16S rRNA gene. RESULTS: The ARG abundances were higher in lactating cows compared to other categories. Despite similar levels of antibiotic administration (based on veterinary prescription data from the sampled farms) in both sampling campaigns, the total abundance of selected ARGs, particularly bla (TEM) and tetA, significantly decreased after the adoption of the farming guidelines. DISCUSSION: This study highlights the positive impact of prudent antibiotic use and the implementation of farming best practices in reducing the abundance of ARGs. The lactating cow category emerged as a crucial point of intervention for reducing the spread of antibiotic resistance. These findings contribute to ongoing efforts to address antibiotic resistance in farm environments and strengthen the evidence supporting the adoption of good farming practices.202439840338
320880.9998Effects of Antibiotic Residues on Fecal Microbiota Composition and Antimicrobial Resistance Gene Profiles in Cattle from Northwestern China. Grazing is a free-range farming model commonly practiced in low-external-input agricultural systems. The widespread use of veterinary antibiotics in livestock farming has led to significant environmental accumulation of antibiotic residues and antibiotic resistance genes (ARGs), posing global health risks. This study investigated the antibiotic residues, bacterial community, ARG profiles, and mobile genetic elements (MGEs) in cattle feces from three provinces in western China (Ningxia, Xinjiang, and Inner Mongolia) under grazing modes. The HPLC-MS detection showed that the concentration of tetracycline antibiotics was the highest in all three provinces. Correlation analysis revealed a significant negative correlation between antibiotic residues and the diversity and population abundance of intestinal microbiota. However, the abundance of ARGs was directly proportional to antibiotic residues. Then, the Sankey analysis revealed that the ARGs in the cattle fecal samples were concentrated in 15 human pathogenic bacteria (HPB) species, with 9 of these species harboring multiple drug resistance genes. Metagenomic sequencing revealed that carbapenemase-resistant genes (bla(KPC) and bla(VIM)) were also present in considerable abundance, accounting for about 10% of the total ARGs detected in three provinces. Notably, Klebsiella pneumoniae strains carrying bla(CTX-M-55) were detected, which had a possibility of IncFII plasmids harboring transposons and IS19, indicating the risk of horizontal transfer of ARGs. This study significantly advances the understanding of the impact of antibiotic residues on the fecal microbiota composition and ARG profiles in grazing cattle from northwestern China. Furthermore, it provides critical insights for the development of rational antibiotic usage strategies and comprehensive public health risk assessments.202540732167
710790.9998A Comprehensive Study of the Microbiome, Resistome, and Physical and Chemical Characteristics of Chicken Waste from Intensive Farms. The application of chicken waste to farmland could be detrimental to public health. It may contribute to the dissemination of antibiotic-resistance genes (ARGs) and antibiotic-resistant bacteria (ARB) from feces and their subsequent entry into the food chain. The present study analyzes the metagenome and resistome of chicken manure and litter obtained from a commercial chicken farm in Poland. ARB were isolated, identified, and screened for antibiogram fingerprints using standard microbiological and molecular methods. The physicochemical properties of the chicken waste were also determined. ARGs, integrons, and mobile genetic elements (MGE) in chicken waste were analyzed using high-throughput SmartChip qPCR. The results confirm the presence of many ARGs, probably located in MGE, which can be transferred to other bacteria. Potentially pathogenic or opportunistic microorganisms and phytopathogens were isolated. More than 50% of the isolated strains were classified as being multi-drug resistant, and the remainder were resistant to at least one antibiotic class; these pose a real risk of entering the groundwater and contaminating the surrounding environment. Our results indicate that while chicken manure can be sufficient sources of the nutrients essential for plant growth, its microbiological aspects make this material highly dangerous to the environment.202236009027
7105100.9998Estimating the contribution of bacteriophage to the dissemination of antibiotic resistance genes in pig feces. The transfer of antibiotic resistance genes (ARGs) in the environment is a threat to both human and animal health. However, the contribution of bacteriophages to the dissemination of resistance genes via transduction is rarely explored. In this study, we screened pig feces from three commercial farms in China for 32 clinically relevant ARG types to assess the presence of the ARG population in bacteria and bacteriophage and further to estimate the contribution of bacteriophages to the dissemination of antibiotic resistance. We found that bacteriophage DNA contained 35.5% of the target ARG types and sul1, bla(TEM) and ermB were found in 100% of the phage DNA samples. The most abundant genes in the bacterial population were ermB and fexA whereas ermB was the most abundant in bacteriophage. In contrast, floR was the least abundant ARG in both populations. Also, the ratio index of the abundance of ARGs in bacteriophage and bacteria was firstly used in this study as an estimator of bacteriophage ability to transmit ARGs. The ratio for qnrA was the greatest (about 10(-1)) and differed from the most abundant bacteriophage ARG ermB. In addition, fexA had the lowest ratio value (about 10(-6)) and not floR. These results illustrate that ARGs abundance and detection rates used alone probably be not suitable for comprehensively judging the contribution of bacteriophage to the dissemination of antibiotic resistance. A more suitable model is the application of three indices; occurrence rate, absolute abundance in bacteriophage and the ratio value as warning and monitoring tools for environmental ARG assessments in bacteriophages.201829573711
3192110.9998Metagenome-Wide Analysis of Rural and Urban Surface Waters and Sediments in Bangladesh Identifies Human Waste as a Driver of Antibiotic Resistance. In many low- and middle-income countries, antibiotic-resistant bacteria spread in the environment due to inadequate treatment of wastewater and the poorly regulated use of antibiotics in agri- and aquaculture. Here, we characterized the abundance and diversity of antibiotic-resistant bacteria and antibiotic resistance genes in surface waters and sediments in Bangladesh through quantitative culture of extended-spectrum beta-lactamase (ESBL)-producing coliforms and shotgun metagenomics. Samples were collected from highly urbanized settings (n = 7), rural ponds with a history of aquaculture-related antibiotic use (n = 11), and rural ponds with no history of antibiotic use (n = 6). ESBL-producing coliforms were found to be more prevalent in urban samples than in rural samples. Shotgun sequencing showed that sediment samples were dominated by the phylum Proteobacteria (on average, 73.8% of assigned reads), while in the water samples, Cyanobacteria were the predominant phylum (on average, 60.9% of assigned reads). Antibiotic resistance genes were detected in all samples, but their abundance varied 1,525-fold between sites, with the highest levels of antibiotic resistance genes being present in urban surface water samples. The abundance of antibiotic resistance genes was significantly correlated (R(2) = 0.73; P = 8.9 × 10(-15)) with the abundance of bacteria originating from the human gut, which suggests that the release of untreated sewage is a driver for the spread of environmental antibiotic resistance genes in Bangladesh, particularly in highly urbanized settings. IMPORTANCE Low- and middle-income countries (LMICs) have higher burdens of multidrug-resistant infections than high-income countries, and there is thus an urgent need to elucidate the drivers of the spread of antibiotic-resistant bacteria in LMICs. Here, we study the diversity and abundance of antibiotic resistance genes in surface water and sediments from rural and urban settings in Bangladesh. We found that urban surface waters are particularly rich in antibiotic resistance genes, with a higher number of them associated with plasmids, indicating that they are more likely to spread horizontally. The abundance of antibiotic resistance genes was strongly correlated with the abundance of bacteria that originate from the human gut, suggesting that uncontrolled release of human waste is a major driver for the spread of antibiotic resistance in the urban environment. Improvements in sanitation in LMICs may thus be a key intervention to reduce the dissemination of antibiotic-resistant bacteria.202134254820
6594120.9998An omics-based framework for assessing the health risk of antimicrobial resistance genes. Antibiotic resistance genes (ARGs) are widespread among bacteria. However, not all ARGs pose serious threats to public health, highlighting the importance of identifying those that are high-risk. Here, we developed an 'omics-based' framework to evaluate ARG risk considering human-associated-enrichment, gene mobility, and host pathogenicity. Our framework classifies human-associated, mobile ARGs (3.6% of all ARGs) as the highest risk, which we further differentiate as 'current threats' (Rank I; 3%) - already present among pathogens - and 'future threats' (Rank II; 0.6%) - novel resistance emerging from non-pathogens. Our framework identified 73 'current threat' ARG families. Of these, 35 were among the 37 high-risk ARGs proposed by the World Health Organization and other literature; the remaining 38 were significantly enriched in hospital plasmids. By evaluating all pathogen genomes released since framework construction, we confirmed that ARGs that recently transferred into pathogens were significantly enriched in Rank II ('future threats'). Lastly, we applied the framework to gut microbiome genomes from fecal microbiota transplantation donors. We found that although ARGs were widespread (73% of genomes), only 8.9% of genomes contained high-risk ARGs. Our framework provides an easy-to-implement approach to identify current and future antimicrobial resistance threats, with potential clinical applications including reducing risk of microbiome-based interventions.202134362925
3458130.9998MinION Nanopore Sequencing Enables Correlation between Resistome Phenotype and Genotype of Coliform Bacteria in Municipal Sewage. Wastewater treatment plants (WWTPs) functioned as the intersection between the human society and nature environment, are receiving increasingly more attention on risk assessment of the acquisition of environmental antibiotic resistance genes (ARGs) by pathogenetic populations during treatment. However, because of the general lack of robust resistome profiling methods, genotype, and resistance phenotype is still poorly correlated in human pathogens of sewage samples. Here we applied MinION sequencing to quantify the resistance genes of multiple antibiotic resistant (MAR) coliform bacteria, a common indicator for human enteric pathogens in sewage samples. Our pipeline could deliver the results within 30 h from sample collection and the resistome quantification was consistent to that based on the Illumina platform. Additionally, the long nanopore reads not only enabled a simultaneous identification of the carrier populations of ARGs detected, but also facilitated the genome reconstruction of a representative MAR strain, from which we identified an instance of chromosomal integration of environmental resistance gene obtained by plasmid exchange with a porcine pathogen. This study demonstrated the utilization of MinION sequencing in quick monitoring and simultaneous phylogenetic tracking of environmental ARGs to address potential health risk associated with them.201729163399
7323140.9997Identification and quantification of bacterial genomes carrying antibiotic resistance genes and virulence factor genes for aquatic microbiological risk assessment. Aquatic ecosystems have been increasingly threatened by anthropogenic activities, e.g., wastewater discharge and farm operation. Several methods are adopted to evaluate the effects of anthropogenic activities on biological risk in the environment, such as qPCR and amplicon next-generation sequencing. However, these methods fall short of providing genomic information of target species, which is vital for risk assessment from genomic aspect. Here, we developed a novel approach integrating metagenomic analysis and flow cytometry to identify and quantify potential pathogenic antibiotic resistant bacteria (PARB; carrying both antibiotic resistance genes (ARGs) and virulence factor genes (VFGs)) in the environment, which are of particular concern due to their infection ability and antibiotic resistance. Based on the abundance/density of PARB, we evaluated microbiological risk in a river impacted by both municipal drainage and agriculture runoff. We collected samples upstream (mountainous area) as the control. Results showed that 81.8% of dominant PARB (33) recovered using our approach were related to known pathogenic taxa. In addition, intragenomic ARGs-VFGs coexistence patterns in the dominant Pseudomonas genomes (20 out of 71 PARB) showed high similarity with the most closely related Pseudomonas genomes from the NCBI RefSeq database. These results reflect acceptable reliability of the approach for (potential) pathogen identification in environmental samples. According to the PARB density, microbiological risk in samples from the agricultural area was significantly higher than in samples from the urban area. We speculated that this was due to the higher antibiotic usage in agriculture as well as intragenomic ARGs-VFGs co-evolution under antibiotic selective pressure. This study provides an alternative approach for the identification and quantification of PARB in aquatic environments, which can be applied for microbiological risk assessment.202031614233
3465150.9997Role of Flies in the Maintenance of Antimicrobial Resistance in Farm Environments. Flies play an important role as vectors in the transmission of antimicrobial-resistant bacteria (ARB) and are hypothesized to transfer ARB between internal and external livestock housing areas. The aim of this study was to understand the role that flies may play in the maintenance of ARB in the farm environment. We first evaluated the fate of ingested antimicrobial-resistant Escherichia coli harboring a plasmid containing antimicrobial-resistance genes (ARGs) throughout the housefly (Musca domestica) life cycle, from adult to the subsequent F1 generation. Antimicrobial-resistant E. coli was isolated from different life cycle stages and ARG carriage quantified. The ingested E. coli persisted throughout the fly life cycle, and ARG carriage was maintained at a constant level in the housefly microbiota. To clarify the transmission of ARB from flies to livestock, 30-day-old chickens were inoculated with maggots containing antimicrobial-resistant E. coli. Based on the quantification of bacteria isolated from cecal samples, antimicrobial-resistant E. coli persisted in these chickens for at least 16 days. These results suggest that flies act as a reservoir of ARB throughout their life cycle and may therefore be involved in the maintenance and circulation of ARB in the farm environment.201929708845
3145160.9997Preventive antibiotic treatment of calves: emergence of dysbiosis causing propagation of obese state-associated and mobile multidrug resistance-carrying bacteria. In agriculture, antibiotics are used for the treatment and prevention of livestock disease. Antibiotics perturb the bacterial gut composition but the extent of these changes and potential consequences for animal and human health is still debated. Six calves were housed in a controlled environment. Three animals received an injection of the antibiotic florfenicol (Nuflor), and three received no treatment. Faecal samples were collected at 0, 3 and 7 days, and bacterial communities were profiled to assess the impact of a therapy on the gut microbiota. Phylogenetic analysis (16S-rDNA) established that at day 7, antibiotic-treated microbiota showed a 10-fold increase in facultative anaerobic Escherichia spp, a signature of imbalanced microbiota, dysbiosis. The antibiotic resistome showed a high background of antibiotic resistance genes, which did not significantly change in response to florfenicol. However, the maintenance of Escherichia coli plasmid-encoded quinolone, oqxB and propagation of mcr-2, and colistin resistance genes were observed and confirmed by Sanger sequencing. The microbiota of treated animals was enriched with energy harvesting bacteria, common to obese microbial communities. We propose that antibiotic treatment of healthy animals leads to unbalanced, disease- and obese-related microbiota that promotes growth of E. coli carrying resistance genes on mobile elements, potentially increasing the risk of transmission of antibiotic resistant bacteria to humans.202031663669
3238170.9997Extensive metagenomic analysis of the porcine gut resistome to identify indicators reflecting antimicrobial resistance. BACKGROUND: Antimicrobial resistance (AMR) has been regarded as a major threat to global health. Pigs are considered an important source of antimicrobial resistance genes (ARGs). However, there is still a lack of large-scale quantitative data on the distribution of ARGs in the pig production industry. The bacterial species integrated ARGs in the gut microbiome have not been clarified. RESULTS: In the present study, we used deep metagenomic sequencing data of 451 samples from 425 pigs including wild boars, Tibetan pigs, and commercial or cross-bred experimental pigs under different rearing modes, to comprehensively survey the diversity and distribution of ARGs and detect the bacteria integrated in these ARGs. We identified a total of 1295 open reading frames (ORFs) recognized as antimicrobial resistance protein-coding genes. The ORFs were clustered into 349 unique types of ARGs, and these could be further classified into 69 drug resistance classes. Tetracycline resistance was most enriched in pig feces. Pigs raised on commercial farms had a significantly higher AMR level than pigs under semi-free ranging conditions or wild boars. We tracked the changes in the composition of ARGs at different growth stages and gut locations. There were 30 drug resistance classes showing significantly different abundances in pigs between 25 and 240 days of age. The richness of ARGs and 41 drug resistance classes were significantly different between cecum lumen and feces in pigs from commercial farms, but not in wild boars. We identified 24 bacterial species that existed in almost all tested samples (core bacteria) and were integrated 128 ARGs in their genomes. However, only nine ARGs of these 128 ARGs were core ARGs, suggesting that most of the ARGs in these bacterial species might be acquired rather than constitutive. We selected three subsets of ARGs as indicators for evaluating the pollution level of ARGs in samples with high accuracy (r = 0.73~0.89). CONCLUSIONS: This study provides a primary overview of ARG profiles in various farms under different rearing modes, and the data serve as a reference for optimizing the use of antimicrobials and evaluating the risk of pollution by ARGs in pig farms. Video abstract.202235246246
3469180.9997Antibiotic resistance genes of emerging concern in municipal and hospital wastewater from a major Swedish city. The spread of antibiotic resistance among bacterial pathogens is to a large extent mediated by mobile antibiotic resistance genes (ARGs). The prevalence and geographic distribution of several newly discovered ARGs, as well as some clinically important ARGs conferring resistance to last resort antibiotics, are largely unknown. Targeted analysis of wastewater samples could allow estimations of carriage in the population connected to the sewers as well as release to the environment. Here we quantified ARGs conferring resistance to linezolid (optrA and cfr(A)) and colistin (mcr-1, -2, -3, -4 and -5) and the recently discovered gar (aminoglycoside ARG) and sul4 (sulphonamide ARG) in raw hospital and municipal wastewater as well as treated municipal wastewater during five years in a low antibiotic resistance prevalence setting (Gothenburg, Sweden). Additionally, variations in bacterial composition of the wastewaters characterized by 16S rRNA sequencing were related to the variations of the ARGs in an attempt to reveal if the presence of known or suspected bacterial host taxa could explain the presence of the ARGs in wastewater. The mcr-1, mcr-3, mcr-4, mcr-5, sul4 and gar genes were detected regularly in all types of wastewater samples while optrA and cfr(A) were detected only in hospital wastewater. The most abundant genes were mcr-3 and mcr-5, especially in municipal wastewater. The detection of optrA was restricted to a peak during one year. Most of the ARGs correlated with taxa previously described as bacterial hosts and associated with humans. Although some of the tentative hosts may include bacteria also thriving in wastewater environments, detection of the ARGs in the wastewaters could reflect their presence in the gut flora of the contributing populations. If so, they could already today or in the near future hinder treatment of bacterial infections in a setting where they currently are rarely targeted/detected during clinical surveillance.202234748849
4980190.9997Co-selection of antibiotic and disinfectant resistance in environmental bacteria: Health implications and mitigation strategies. BACKGROUND: The rapid emergence of co-selection between antimicrobials, including antibiotics and disinfectants, presents a significant challenge to healthcare systems. This phenomenon exacerbates contamination risks and limits the effectiveness of strategies to combat antibiotic resistance in clinical settings. This study aimed to investigate the prevalence and characteristics of bacteria in hospital environments that exhibit co-selection mechanisms and their potential implications for patient health, framed within the One Health perspective. METHODS: Air and surface samples were collected from seven large hospitals and analyzed to detect antibiotic-resistant bacteria (ARB). The resistance profiles of isolated ARB to various disinfectants were determined. Bacterial species were identified using 16S rRNA gene sequencing, and the presence of antibiotic resistance genes (ARGs) and class 1 integrons (intI1) was investigated. RESULTS: A high percentage (85%) of samples contained ARB, with β-lactam resistance being the most frequently observed. Alarmingly, 94% of isolated ARB exhibited resistance to at least one disinfectant, and 91% demonstrated resistance to three or more disinfectants. Staphylococcus and Bacillus emerged as the dominant genera displaying co-selection. The presence of ARGs, including mecA (associated with methicillin resistance) and qacB (associated with disinfectant resistance), along with intI1, provided further evidence supporting co-selection mechanisms. CONCLUSION: These findings underscore the critical need for robust antimicrobial resistance surveillance and the prudent use of disinfectants in healthcare settings. Further research into co-selection mechanisms is essential to inform the development of effective infection control strategies and minimize the spread of resistant bacteria.202539732420