Occurrence of integrons and antibiotic resistance genes in cryoconite and ice of Svalbard, Greenland, and the Caucasus glaciers. - Related Documents




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527901.0000Occurrence of integrons and antibiotic resistance genes in cryoconite and ice of Svalbard, Greenland, and the Caucasus glaciers. The prevalence of integrons and antibiotic resistance genes (ARGs) is a serious threat for public health in the new millennium. Although commonly detected in sites affected by strong anthropogenic pressure, in remote areas their occurrence, dissemination, and transfer to other ecosystems is poorly recognized. Remote sites are considered as a benchmark for human-induced contamination on Earth. For years glaciers were considered pristine, now they are regarded as reservoirs of contaminants, thus studies on contamination of glaciers, which may be released to other ecosystems, are highly needed. Therefore, in this study we evaluated the occurrence and frequency of clinically relevant ARGs and resistance integrons in the genomes of culturable bacteria and class 1 integron-integrase gene copy number in the metagenome of cryoconite, ice and supraglacial gravel collected on two Arctic (South-West Greenland and Svalbard) and two High Mountain (the Caucasus) glaciers. Altogether, 36 strains with intI1 integron-integrase gene were isolated. Presence of class 1 integron-integrase gene was also recorded in metagenomic DNA from all sampling localities. The mean values of relative abundance of intI1 gene varied among samples and ranged from 0.7% in cryoconite from Adishi Glacier (the Caucasus) to 16.3% in cryoconite from Greenland. Moreover, antibiotic-resistant strains were isolated from all regions. Genes conferring resistance to β-lactams (bla(SHV), bla(TEM), bla(OXA), bla(CMY)), fluoroquinolones (qepA, qnrC), and chloramphenicol (cat, cmr) were detected in the genomes of bacterial isolates.202032059297
536210.9995Cross-environmental cycling of antimicrobial resistance in agricultural areas fertilized with poultry litter: A one health approach. Poultry litter, commonly used as an organic fertilizer, can contain antimicrobial residues, resistant bacteria, and/or antimicrobial resistance genes. After application to soil, these contaminants can reach crops and be transported to aquatic systems through leaching and runoff. Once in water bodies, they can return to soil and crops through irrigation, establishing a cycle that promotes the selection, spread and persistence of antimicrobial resistance. To investigate the hypothesis of a cyclical event, samples of poultry litter, cultivable soil fertilized with this organic residue, rhizosphere soil from Sechium edule (chayote), water, and sediments from irrigation ponds were collected across two agricultural and poultry-producing areas during the dry and rainy seasons. Clinically significant bacteria, especially bacteria belonging to the Enterobacteriaceae family, were isolated. Fifty-three strains exhibited one or more antimicrobial resistance genes, as detected by PCR amplification, including those conferring resistance to sulfonamides (sul1 and sul2), fluoroquinolones (qnrB, qnrA, and qnrS), and β-lactams (bla(GES), bla(TEM), bla(SHV), bla(CTX-M-1/2,)bla(CTX-M-8), and bla(CTX-M-14)). Genes encoding integrases related to class-1 and 2 integrons (intI1 and intI2) were also observed. A rare occurrence of the bla(GES) gene was observed in Stenotrophomonas sp. and Brevundimonas sp. Strains of Escherichia sp. were multidrug resistant. Sequencing of the 16S rRNA encoding gene indicated unique operational taxonomic units (OTUs) originating from poultry litter and found in the soil, rhizosphere, water, and sediment, highlighting the dissemination of this material across agricultural substrates. These findings strongly suggest the spread of antimicrobial-resistant bacteria in agricultural environments, posing potential risks to both human and animal health.202439447633
326220.9995Characteristics of Wild Bird Resistomes and Dissemination of Antibiotic Resistance Genes in Interconnected Bird-Habitat Systems Revealed by Similarity of bla(TEM) Polymorphic Sequences. Wild birds are known to harbor and discharge antibiotic-resistant bacteria (ARB) and their associated antibiotic resistance genes (ARGs). However, assessments of their contribution to the dissemination of antibiotic resistance in the environment are limited to culture-dependent bacterial snapshots. Here, we present a high-throughput sequencing study that corroborates extensive ARG exchange between wild bird feces and their habitats and implies the need to scrutinize high-mobility birds as potential vectors for global propagation of ARGs. We characterized the resistome (281 ARGs) and microbiome of seven wild bird species and their terrestrial and aquatic habitats. The resistomes of bird feces were influenced by the microbial community structure, mobile genetic elements (MGEs), and residual antibiotics. We designated 33 ARGs found in more than 90% of the bird fecal samples as core ARGs of wild bird feces, among which 16 ARGs were shared as core ARGs in both wild bird feces and their habitats; these genes represent a large proportion of both the bird feces (35.0 ± 15.9%) and the environmental resistome (29.9 ± 21.4%). One of the most detected β-lactam resistance genes (bla(TEM), commonly harbored by multidrug resistant "superbugs") was used as molecular marker to demonstrate the high interconnectivity of ARGs between the microbiomes of wild birds and their habitats. Overall, this work provides a comprehensive analysis of the wild bird resistome and underscores the importance to consider genetic exchange between animals and the environment in the One Health approach.202235700319
532030.9995Antimicrobial resistance genes in microbiota associated with sediments and water from the Akaki river in Ethiopia. The spread of antimicrobial-resistant pathogens is a global health concern. Most studies report high levels of antimicrobial resistance genes (ARGs) in the aquatic environment; however, levels associated with sediments are limited. This study aimed to investigate the distribution of ARGs in the sediments and water of the Akaki river in Addis Ababa, Ethiopia. The diversity and abundance of 84 ARGs and 116 clinically important bacteria were evaluated from the sediments and water collected from five sites in the Akaki river. Most of the ARGs were found in the city close to anthropogenic activities. Water samples collected in the middle catchment of the river contained 71-75% of targeted ARGs, with genes encoding aminoglycoside acetyltransferase (aac(6)-Ib-cr), aminoglycoside adenylyl transferase (aadA1), β-lactamase (bla(OXA-10))(,) quinolone resistance S (qnrS), macrolide efflux protein A (mefA), and tetracycline resistance (tetA), were detected at all sampling sites. Much fewer ARGs were detected in all sediments, and those near the hospitals had the highest diversity and level. Despite the lower levels and diversity, there were no unique ARGs detected in the sediments that were also not detected in the waters. A wide range of clinically relevant pathogens were also detected in the Akaki river. The findings suggest that the water phase, rather than the sediments in the Akaki river, is a potential conduit for the spread of ARGs and antibiotic-resistant bacteria.202235583762
347340.9995Distribution of antibiotic resistance genes in glacier environments. Antibiotic resistance genes are biologically transmitted from microorganism to microorganism in particular micro-environments where dense microbial communities are often exposed to an intensive use of antibiotics, such as intestinal microflora, and the soil microflora of agricultural fields. However, recent studies have detected antibiotic-resistant bacteria and/or antibiotic resistance genes in the natural environment geographically isolated from such areas. Here we sought to examine the prevalence of antibiotic resistance genes in 54 snow and ice samples collected from the Arctic, Antarctic, Central Asia, North and South America and Africa, to evaluate the level of these genes in environments supposedly not affected by anthropogenic factors. We observed a widespread distribution of antibiotic resistance genes in samples from various glaciers in Central Asia, North and South America, Greenland and Africa. In contrast, Antarctic glaciers were virtually free from these genes. Antibiotic resistance genes, of both clinical (i.e. aac(3), blaIMP) and agricultural (i.e. strA and tetW) origin, were detected. Our results show regional geographical distribution of antibiotic resistance genes, with the most plausible modes of transmission through airborne bacteria and migrating birds.201323757141
284250.9995Assessing antimicrobial and metal resistance genes in Escherichia coli from domestic groundwater supplies in rural Ireland. Natural ecosystems can become significant reservoirs and/or pathways for antimicrobial resistance (AMR) dissemination, with the potential to affect nearby microbiological, animal, and ultimately human communities. This is further accentuated in environments that provide direct human exposure, such as drinking water. To date, however, few studies have investigated AMR dissemination potential and the presence of co-selective stressors (e.g., metals/metalloids) in groundwater environments of human health significance. Accordingly, the present study analysed samples from rural (drinking) groundwater supplies (i.e., private wells) in the Republic of Ireland, where land use is dominated by livestock grazing activities. In total, 48 Escherichia coli isolates tested phenotypically for antimicrobial susceptibility in an earlier study were further subject to whole genome sequencing (WGS) and corresponding water samples were further analysed for trace metal/metalloid concentrations. Eight isolates (i.e., 16.7%) were genotypically resistant to antimicrobials, confirming prior phenotypic results through the identification of ten antimicrobial resistance genes (ARGs); namely: aph(3″)-lb (strA; n=7), aph(6)-Id (strA; n = 6), blaTEM (n = 6), sul2 (n = 6), tetA (n = 4), floR (n = 2), dfrA5 (n = 1), tetB (n = 1), and tetY (n = 1). Additional bioinformatic analysis revealed that all ARGs were plasmid-borne, except for two of the six sul2 genes, and that 31.2% of all tested isolates (n = 15) and 37.5% of resistant ones (n = 3) carried virulence genes. Study results also found no significant relationships between metal concentrations and ARG abundance. Additionally, just one genetic linkage was identified between ARGs and a metal resistance gene (MRG), namely merA, a mercury-resistant gene found on the same plasmid as blaTEM, dfrA5, strA, strB, and sul2 in the only isolate of inferred porcine (as opposed to bovine) origin. Overall, findings suggest that ARG (and MRG) acquisition may be occurring prior to groundwater ingress, and are likely a legacy issue arising from agricultural practices.202337343911
330760.9995Diversity of β-lactamase-encoding genes in wastewater: bacteriophages as reporters. A reservoir of antibiotic resistance genes (ARGs) is present in pathogenic, commensal, and environmental bacteria as well as in mobile genetic elements, including bacteriophages. Wastewater treatment plants (WWTPs) are considered hotspots for the spread of ARGs. The aim of this work was to analyze the diversity of the highly prevalent ARGs bla(CTX-M) and bla(TEM) in bacterial and bacteriophage fractions associated with human and animal environments through the study of urban waste and animal residues discharged into WWTPs to provide information about the composition and maintenance of the current resistome in Buenos Aires, Argentina. The results showed that a putative extended-spectrum variant of the bla(TEM) gene was the most frequently detected, with bla(TEM-116) being the most prevalent, while a recently described type, bla(TEM-229), was also found. In the bacteriophage fraction, we detected bla(CTX-M) genes from four out of the five clusters described. The detection of bla(CTX- M-9)-like and bla(CTX-M-25)-like genes was unexpected based on surveys of the ARGs from clinical pathogens circulating regionally. The finding of divergent bla(CTX-M) sequences associated with previously reported environmental genes argues in favor of the natural environment as a reservoir of resistance genes. ARGs were detected in bacteriophages as frequently as in bacterial communities, and furthermore, the bla(CTX-M) genes were more diverse in the bacteriophage fraction. Bacteriophages might therefore play a role in the spread of ARGs in the environment, but they might also be used as "reporters" for monitoring circulating ARGs.202133683473
314070.9995Uncovering the diversity and contents of gene cassettes in class 1 integrons from the endophytes of raw vegetables. Rapid spread of antibiotic resistance genes (ARGs) in pathogens is threatening human health. Integrons allow bacteria to integrate and express foreign genes, facilitating horizontal transfer of ARGs in environments. Consumption of raw vegetables represents a pathway for human exposure to environmental ARGs. However, few studies have focused on integron-associated ARGs in the endophytes of raw vegetables. Here, based on the approach of qPCR and clone library, we quantified the abundance of integrase genes and analyzed the diversity and contents of resistance gene cassettes in class 1 integrons from the endophytes of six common raw vegetables. The results revealed that integrase genes for class 1 integron were most prevalent compared with class 2 and class 3 integron integrase genes (1-2 order magnitude, P < 0.05). The cucumber endophytes harbored a higher absolute abundance of integrase genes than other vegetables, while the highest bacterial abundance was detected in cabbage and cucumber endophytes. Thirty-two unique resistance gene cassettes were detected, the majority of which were associated with the genes encoding resistance to beta-lactam and aminoglycoside. Antibiotic resistance gene cassettes accounted for 52.5 % of the functionally annotated gene cassettes, and bla(TEM-157) and aadA2 were the most frequently detected resistance cassettes. Additionally, carrot endophytes harbored the highest proportion of antibiotic resistance gene cassettes in the class 1 integrons. Collectively, these results provide an in-depth view of acquired resistance genes by integrons in the raw vegetable endophytes and highlight the potential health risk of the transmission of ARGs via the food chain.202236371907
282580.9994Taxonomic diversity of antimicrobial-resistant bacteria and genes in the Red Sea coast. Despite development of a record number of recreational sites and industrial zones on the Red Sea coast in the last decade, antibiotic-resistant bacteria in this environment remain largely unexplored. In this study, 16S rDNA sequencing was used to identify bacteria isolated from 12 sediment samples collected from the Red Sea coastal, offshore, and mangroves sites. Quantitative PCR was used to estimate the quantity of antimicrobial resistance genes (ARGs) in genomic DNA in the samples. A total of 470 bacteria were isolated and classified into 137 distinct species, including 10 candidate novel species. Site-specific bacterial communities inhabiting the Red Sea were apparent. Relatively, more resistant isolates were recovered from the coast, and samples from offshore locations contained the most multidrug-resistant bacteria. Eighteen ARGs were detected in this study encoding resistance to aminoglycoside, beta-lactam, sulfonamide, macrolide, quinolone, and tetracycline antibiotics. The qnrS, aacC2, ermC, and bla(TEM-1) genes were commonly found in coastal and offshore sites. Relatively higher abundance of ARGs, including aacC2 and aacC3, were found in the apparently anthropogenically contaminated (beach) samples from coast compared to other collected samples. In conclusion, a relative increase in antimicrobial-resistant isolates was found in sediment samples from the Red Sea, compared to other studies. Anthropogenic activities likely contribute to this increase in bacterial diversity and ARGs.201931063890
330490.9994Antibiotic resistance profiles and mutations that might affect drug susceptibility in metagenome-assembled genomes of Legionella pneumophila and Aeromonas species from municipal wastewater. Antibiotic resistance (AR) has emerged as a significant global health issue. Wastewater treatment plants (WWTPs) contain diverse bacterial communities, including pathogens, and have been identified as crucial reservoirs for the emergence and dissemination of AR. The present study aimed to identify antibiotic resistance genes (ARGs) and screen for the presence of mutations associated with AR in Legionella pneumophila and Aeromonas spp. from municipal wastewater. Metagenome-assembled genomes (MAGs) of L. pneumophila and Aeromonas spp. were reconstructed to investigate the molecular mechanisms of AR in these organisms. A total of 138 nonsynonymous single nucleotide variants (SNVs) in seven genes associated with AR and one deletion mutation in the lpeB gene were identified in L. pneumophila. In Aeromonas spp., two (aph(6)-Id and aph(3'')-Ib) and five (bla(MOX-4), bla(OXA-1143), bla(OXA-724), cepH, and imiH) ARGs conferring resistance to aminoglycosides and β-lactams were identified, respectively. Moreover, this study presents β-lactam resistance genes, bla(OXA-1143) and bla(OXA-724), for the first time in Aeromonas spp. from a municipal WWTP. In conclusion, these findings shed light on the molecular mechanisms through which clinically relevant pathogenic bacteria such as L. pneumophila and Aeromonas spp. found in natural environments like municipal wastewater acquire AR.202540269715
3380100.9994Antimicrobial Resistance Linked to Septic System Contamination in the Indiana Lake Michigan Watershed. Extended-spectrum β-lactamases confer resistance to a variety of β-lactam antimicrobials, and the genes for these enzymes are often found on plasmids that include additional antimicrobial resistance genes (ARG). We surveyed aquatic environments in the Indiana Lake Michigan watershed in proximity to areas with high densities of residential septic systems to determine if human fecal contamination from septic effluent correlated with the presence of antimicrobial resistance genes and phenotypically resistant bacteria. Of the 269 E. coli isolated from environmental samples and one septic source, 97 isolates were resistant to cefotaxime, a third-generation cephalosporin. A subset of those isolates showed phenotypic resistance to other β-lactams, fluoroquinolones, sulfonamides, and tetracyclines. Quantitative PCR was used to quantify human-associated Bacteroides dorei gene copies (Human Bacteroides) from water samples and to identify the presence of ARG harbored on plasmids from E. coli isolates or in environmental DNA. We found a strong correlation between the presence of ARG and human fecal concentrations, which supports our hypothesis that septic effluent is a source of ARG and resistant organisms. The observed plasmid-based resistance adds an additional level of risk, as human-associated bacteria from septic systems may expand the environmental resistome by acting as a reservoir of transmissible resistance genes.202336978436
5366110.9994Fresh produce as a reservoir of antimicrobial resistance genes: A case study of Switzerland. Antimicrobial resistance (AMR) can be transferred to humans through food and fresh produce can be an ideal vector as it is often consumed raw or minimally processed. The production environment of fresh produce and the agricultural practices and regulations can vary substantially worldwide, and consequently, the contamination sources of AMR. In this study, 75 imported and 75 non-imported fresh produce samples purchased from Swiss retailers were tested for the presence of antimicrobial resistant bacteria (ARB) and antimicrobial resistance genes (ARGs). Moreover, the plasmidome of 4 selected samples was sequenced to have an insight on the diversity of mobile resistome. In total, 91 ARB were isolated from fresh produce, mainly cephalosporin-resistant Enterobacterales (n = 64) and carbapenem-resistant P. aeruginosa (n = 13). All P. aeruginosa, as well as 16 Enterobacterales' isolates were multidrug-resistant. No differences between imported and Swiss fresh produce were found regarding the number of ARB. In 95 % of samples at least one ARG was detected, being the most frequent sul1, bla(TEM), and ermB. Abundance of sul1 and intI1 correlated strongly with the total amount of ARGs, suggesting they could be good indicators for AMR in fresh produce. Furthermore, sul1 correlated with the fecal marker yccT, indicating that fecal contamination could be one of the sources of AMR. The gene sulI was significantly higher in most imported samples, suggesting higher anthropogenic contamination in the food production chain of imported produce. The analyses of the plasmidome of coriander and carrot samples revealed the presence of several ARGs as well as genes conferring resistance to antiseptics and disinfectants in mobile genetic elements. Overall, this study demonstrated that fresh produce contributes to the dissemination of ARGs and ARB.202437813266
1818120.9994Importance of anthropogenic sources at shaping the antimicrobial resistance profile of a peri-urban mesocarnivore. Anthropogenically derived antimicrobial-resistant bacteria (ARB) and antimicrobial resistance genes (ARG) have been detected in wildlife. The likelihood of detecting ARB and ARG in wildlife increases with wildlife exposure to anthropogenic sources of antimicrobial resistance (AMR). Whether anthropogenic sources also increase the risk for AMR to spread in bacteria of wildlife is not well understood. The spread of AMR in bacteria of wildlife can be estimated by examining the richness of ARB and ARG, and the prevalence of ARB that have mobilizable ARG (i.e., ARG that can be transferred across bacteria via plasmids). Here, we investigated whether raccoons (Procyon lotor), with different exposures to anthropogenic sources, differed in prevalence and richness of extended-spectrum cephalosporin-resistant (ESC-R) Escherichia coli, richness of ARG present in ESC-R E. coli, and prevalence of ESC-R E. coli with plasmid-associated ARG. Sampling took place over the course of 10 months at seven sites in Chicago, USA. ESC-R E. coli were isolated from over half of the 211 raccoons sampled and were more likely to be isolated from urban than suburban raccoons. When examining the whole-genome sequences of ESC-R E. coli, 56 sequence types were identified, most of which were associated with the ARG bla(CMY) and bla(CTX-M). A greater richness of ESC-R E. coli sequence types was found at sites with a wastewater treatment plant (WWTP) than without, but no difference was detected based on urban context. ARG richness in ESC-R E. coli did not significantly vary by urban context nor with presence of a WWTP. Importantly, ESC-R E. coli carrying plasmid-associated bla(CTX-M) and bla(CMY) ARG were more likely to be isolated from raccoons sampled at sites with a WWTP than without. Our findings indicate that anthropogenic sources may shape the AMR profile of wildlife, reinforcing the need to prevent dissemination of AMR into the environment.202133401044
5363130.9994Irrigation Ponds as Sources of Antimicrobial-Resistant Bacteria in Agricultural Areas with Intensive Use of Poultry Litter. Poultry litter is widely used worldwide as an organic fertilizer in agriculture. However, poultry litter may contain high concentrations of antibiotics and/or antimicrobial-resistant bacteria (ARB), which can be mobilized through soil erosion to water bodies, contributing to the spread of antimicrobial resistance genes (ARGs) in the environment. To better comprehend this kind of mobilization, the bacterial communities of four ponds used for irrigation in agricultural and poultry production areas were determined in two periods of the year: at the beginning (low volume of rainfall) and at the end of the rainy season (high volume of rainfall). 16S rRNA gene sequencing revealed not only significantly different bacterial community structures and compositions among the four ponds but also between the samplings. When the DNA obtained from the water samples was PCR amplified using primers for ARGs, those encoding integrases (intI1) and resistance to sulfonamides (sul1 and sul2) and β-lactams (bla(GES), bla(TEM) and bla(SHV)) were detected in three ponds. Moreover, bacterial strains were isolated from CHROMagar plates supplemented with sulfamethoxazole, ceftriaxone or ciprofloxacin and identified as belonging to clinically important Enterobacteriaceae. The results presented here indicate a potential risk of spreading ARB through water resources in agricultural areas with extensive fertilization with poultry litter.202236421294
5341140.9994Occurrence of Bacterial Markers and Antibiotic Resistance Genes in Sub-Saharan Rivers Receiving Animal Farm Wastewaters. Antibiotic resistant bacteria and genes which confer resistance to antibiotics from human/animal sources are currently considered a serious environmental and a public health concern. This problem is still little investigated in aquatic environment of developing countries according to the different climatic conditions. In this research, the total bacterial load, the abundance of relevant bacteria (Escherichia coli (E. coli), Enterococcus (Ent), and Pseudomonas), and antibiotic resistance genes (ARGs: bla(OXA-48), bla(CTX-M), sul1, sul2, sul3, and tet(B)) were quantified using Quantitative Polymerase Chain Reaction (qPCR) in sediments from two rivers receiving animal farming wastewaters under tropical conditions in Kinshasa, capital city of the Democratic Republic of the Congo. Human and pig host-specific markers were exploited to examine the sources of contamination. The total bacterial load correlated with relevant bacteria and genes bla(OXA-48), sul3, and tet(B) (P value < 0.01). E. coli strongly correlated with 16s rDNA, Enterococcus, Pseudomonas spp., bla(OXA-48), sul3, and tet(B) (P value < 0.01) and with bla(CTX-M), sul1, and sul2 at a lower magnitude (P value < 0.05). The most abundant and most commonly detected ARGs were sul1, and sul2. Our findings confirmed at least two sources of contamination originating from pigs and anthropogenic activities and that animal farm wastewaters didn't exclusively contribute to antibiotic resistance profile. Moreover, our analysis sheds the light on developing countries where less than adequate infrastructure or lack of it adds to the complexity of antibiotic resistance proliferation with potential risks to the human exposure and aquatic living organisms. This research presents useful tools for the evaluation of emerging microbial contaminants in aquatic ecosystems which can be applied in the similar environment.201931619758
5296150.9994Occurrence of sul and tet(M) genes in bacterial community in Japanese marine aquaculture environment throughout the year: Profile comparison with Taiwanese and Finnish aquaculture waters. The use of antibiotics in aquaculture causes selection pressure for antibiotic-resistant bacteria (ARB). Antibiotic resistance genes (ARGs) may persist in ARB and the environment for long time even after stopping drug administration. Here we show monthly differences in the occurrences of genes conferring resistance to sulfonamides (i.e. sul1, sul2, sul3), and tetracyclines (tet(M)) in Japanese aquaculture seawater accompanied by records of drug administration. sul2 was found to persist throughout the year, whereas the occurrences of sul1, sul3, and tet(M) changed month-to-month. sul3 and tet(M) were detected in natural bacterial assemblages in May and July, but not in colony-forming bacteria, thus suggesting that the sul3 was harbored by the non-culturable fraction of the bacterial community. Comparison of results from Taiwanese, Japanese, and Finnish aquaculture waters reveals that the profile of sul genes and tet(M) in Taiwan resembles that in Japan, but is distinct from that in Finland. To our knowledge, this work represents the first report to use the same method to compare the dynamics of sul genes and tet(M) in aquaculture seawater in different countries.201930889452
5339160.9994Metal impacts on the persistence and proliferation of β-lactam resistance genes in Xiangjiang River, China. Currently, the emergence of clinically relevant multi-resistant bacteria and the associated β-lactamases resistance genes which threaten the last frontier for antibiotics presents a major challenge for medical treatment. Xiangjiang River is typically contaminated with heavy metals due to the intensive metal mining activities within this watershed. The occurrence and distribution of several β-lactam antibiotics and ten β-lactam resistance genes (bla(TEM), bla(VIM), bla(SHV), bla(GES), bla(DHA), bla(OXA-1), bla(OXA-2), bla(OXA-10), bla(CMY-2), and bla(ampC)) were investigated in the Xiangjiang River, China. The absolute abundance of bla genes was as high as (7.0 ± 0.6) × 10(6) copies/mL for surface water and (2.3 ± 0.7) × 10(8) copies/g for sediment. In contrast, all the detected β-lactam antibiotic compounds were below the detection limit. The distribution of individual bla gene subtypes was correlated with speciation of heavy metals which might affect the bacterial community structure. The principal coordinate analysis (PCoA) and Mantal test reconfirmed that the heavy metals had a correlation with the bla genes and the bla genes were correlated with bacterial community structure, suggesting that heavy metals impacted on the distribution of the bla genes by shifting bacterial community structure under the long-term selective pressure. The microcosm experiments indicated metal-induced persistence of bla genes in the resistant bacteria (Bacillus megaterium, Staphylococcus epidermidis). The persistence of β-lactam resistance under metal selective pressure is beneficial to the survival of resistant bacteria, thereby contributing to the shift of the bacterial community structure, consequently impacts on the distribution of bla genes.201931256402
1807170.9994Do Microorganisms in Bathing Water in Guadeloupe (French West Indies) Have Resistance Genes? Waterborne faecal contamination is a major public health concern. The main objectives of this study were to investigate faecal contamination and Escherichia coli (E. coli) antibiotic resistance in recreational fresh water from Guadeloupe and to characterise the microbiome and resistome composition in biofilms from submerged rocks. Significant faecal contamination was observed at 14 freshwater sites. E. coli predominated (62%), followed by Enterobacter cloacae (11%) and Acinetobacter spp. (11%). Of 152 E. coli isolated, none produced extended-spectrum beta-lactamases (ESBLs), but 7% showed resistance to streptomycin and 4% to tetracycline. Biofilm resistome analysis revealed clinically significant antibiotic-resistance genes (ARGs), including those coding for resistance to sulfonamides (sul1), carbapenems (bla(KPC)), and third-generation cephalosporins (bla(CTX-M)). Mobile genetic elements (MGEs) (intI1, intI2, intI3) linked to resistance to aminoglycosides, beta-lactams, tetracycline, as well as heavy metal resistance determinants (copA, cusF, czcA, merA) conferring resistance to copper, silver, cadmium, and mercury were also detected. Diverse bacterial phyla were found in biofilm samples, of which Proteobacteria, Bacteroidetes, Planctonomycetes, and Cyanobacteria were predominant. Despite the frequent presence of E. coli exceeding regulatory standards, the low levels of antibiotic-resistant bacteria in freshwater and of ARGs and MGEs in associated biofilms suggest limited antibiotic resistance in Guadeloupean recreational waters.202438247646
5365180.9994Drinking Water and Biofilm as Sources of Antimicrobial Resistance in Free-Range Organic Broiler Farms. Drinking water distribution systems (DWDSs) represent an ideal environment for biofilm formation, which can harbor pathogenic and antimicrobial-resistant bacteria. This study aimed to assess longitudinally the microbial community composition and antimicrobial resistance (AMR), as determined by 16S rRNA NGS and qPCR, respectively, in drinking water (DW) and biofilm from DWDSs, as well as faeces, of free-range organic broiler farms. The role of DWDSs in AMR gene (ARG) dissemination within the farm environment and transmission to animals, was also assessed. DW and biofilm microbial communities differed from those of faecal samples. Moreover, potentially pathogenic and opportunistic bacteria (e.g., Staphylococcaceae) were identified in water and biofilms. High prevalence and abundance of ARGs conferring resistance to carbapenems (i.e., bla(NDM)), 3rd and 4th generation cephalosporins (i.e., bla(CMY-2)), (fluoro)quinolones (i.e., qnrS), and polymyxins (i.e., mcr-3 and mcr-5) were detected in DW, biofilm, and faecal samples, which is of concern for both animal and human health. Although other factors (e.g., feed, pests, and wildlife) may contribute to the dissemination of AMR in free-range organic poultry farms, this study indicates that DWDSs can also play a role.202439334983
3075190.9994Comparison of environmental microbiomes in an antibiotic resistance-polluted urban river highlights periphyton and fish gut communities as reservoirs of concern. Natural waterways near urban areas are heavily impacted by anthropogenic activities, including their microbial communities. A contaminant of growing public health concern in rivers is antibiotic resistant genes (ARGs), which can spread between neighboring bacteria and increase the potential for transmission of AR bacteria to animals and humans. To identify the matrices of most concern for AR, we compared ARG burdens and microbial community structures between sample types from the Scioto River Watershed, Ohio, the United States, from 2017 to 2018. Five environmental matrices (water, sediment, periphyton, detritus, and fish gut) were collected from 26 river sites. Due to our focus on clinically relevant ARGs, three carbapenem resistance genes (bla(KPC), bla(NDM), and bla(OXA-48)) were quantified via DropletDigital™ PCR. At a subset of nine urbanized sites, we conducted16S rRNA gene sequencing and functional gene predictions. Carbapenem resistance genes were quantified from all matrices, with bla(KPC) being the most detected (88 % of samples), followed by bla(NDM) (64 %) and bla(OXA-48) (23 %). Fish gut samples showed higher concentrations of bla(KPC) and bla(NDM) than any other matrix, indicating potential ARG bioaccumulation, and risk of broader dissemination through aquatic and nearshore food webs. Periphyton had higher concentrations of bla(NDM) than water, sediment, or detritus. Microbial community analysis identified differences by sample type in community diversity and structure. Sediment samples had the most diverse microbial communities, and detritus, the least. Spearman correlations did not reveal significant relationships between the concentrations of the monitored ARGs and microbial community diversity. However, several differentially abundant taxa and microbial functions were identified by sample type that is definitive of these matrices' roles in the river ecosystem and habitat type. In summary, the fish gut and periphyton are a concern as AR reservoirs due to their relatively high concentration of carbapenem resistance genes, diverse microbial communities, and natural functions that promote AR.202235973543