# | Rank | Similarity | Title + Abs. | Year | PMID |
|---|---|---|---|---|---|
| 0 | 1 | 2 | 3 | 4 | 5 |
| 3108 | 0 | 1.0000 | Amoxicillin and thiamphenicol treatments may influence the co-selection of resistance genes in the chicken gut microbiota. The aim of this study was to assess the dynamics of microbial communities and antimicrobial resistance genes (ARGs) in the chicken gut following amoxicillin and thiamphenicol treatments and potential co-selection of ARGs. To this purpose, the microbial community composition, using 16S rRNA NGS, and the abundance of ARGs conferring resistance to β-lactams and phenicols, using qPCRs, were determined. Results revealed that the administered antimicrobials did not significantly reduce the gut microbiota diversity, but changed its composition, with taxa (e.g. Gallibacterium and Megamonas) being enriched after treatment and replacing other bacteria (e.g. Streptococcus and Bifidobacterium). Positive correlations were found between ARGs (e.g. cmlA, bla(CMY-2), and bla(SHV)) and the relative abundance of specific taxa (e.g. Lactobacillus and Subdoligranulum). The selective pressure exerted by both amoxicillin and thiamphenicol resulted in an increased abundance of ARGs conferring resistance to β-lactams (e.g. bla(TEM-1), bla(SHV,) and bla(CTX-M1-like)) and phenicols (e.g. floR and cmlA). These findings, together with the co-occurrence of genes conferring resistance to the two antimicrobial classes (e.g. bla(TEM-1) and cmlA), suggest a possible interaction among antimicrobials on resistance emergence, possibly due to the presence of mobile genetic elements (MGEs) carrying multiple resistance determinants. | 2022 | 36437351 |
| 5300 | 1 | 0.9998 | From Pig Breeding Environment to Subsequently Produced Pork: Comparative Analysis of Antibiotic Resistance Genes and Bacterial Community Composition. It is well verified that pig farms are an important reservoir and supplier of antibiotic resistance genes (ARGs). However, little is known about the transmission of ARGs between the breeding environment and subsequently produced pork. This study was conducted to investigate if ARGs and associated host bacteria spread from the breeding environment onto the meat through the food production chain. We thus analyzed the occurrence and abundance of ARGs, as well as comparing both ARG and bacterial community compositions in farm soil, pig feces and pork samples from a large-scale pig farm located in Xiamen, People's Republic of China. Among the 26 target ARGs, genes conferring resistance to sulfonamide, trimethoprim, aminoglycoside, chloramphenicol, macrolide, florfenicol, and tetracycline were observed at high frequency in both the pig breeding environment and pork. The prevalence of ARGs in pork was surprisingly consistent with breeding environments, especially between the pork and feces. The relative abundance of 10 representative ARGs conferring resistance to six classes of antibiotics ranged from 3.01 × 10(-1) to 1.55 × 10(-6) copies/16S rRNA copies. The ARGs conferring resistance to sulfanilamide (sulI and sulII), aminoglycoside (aadA), and tetracycline [tet(A) and tet(M)] were most highly abundant across most samples. Samples from feces and meat possessed a higher similarity in ARG compositions than samples from the farms soil. Enterobacteriaceae found on the meat samples were further identical with previously isolated multidrug-resistant bacteria from the same pig farm. Our results strongly indicate that ARGs can be potentially spreading from pig breeding environment to meat via the pork industry chain, such as feed supply, pig feeding and pork production. | 2019 | 30761096 |
| 5301 | 2 | 0.9998 | High levels of antibiotic resistance genes and opportunistic pathogenic bacteria indicators in urban wild bird feces. This study analyzed fresh feces from three common bird species that live in urban environments and interact with human communities. Antibiotic resistance genes (ARGs) encoding resistance to three major classes of antibiotics (i.e., tetracyclines, β-lactams, and sulfonamides) and the mobile genetic element integrase gene (intI1) were abundant (up to 10(9), 10(8), 10(9), and 10(10) copies/g dry feces for tetW, bla(TEM), sul1, and intI1, respectively), with relative concentrations surprisingly comparable to that in poultry and livestock that are occasionally fed antibiotics. Biomarkers for opportunistic pathogens were also abundant (up to 10(7) copies/g dry feces) and the dominant isolates (i.e., Enterococcus spp. and Pseudomonas aeruginosa) harbored both ARGs and virulence genes. ARGs in bird feces followed first-order attenuation with half-lives ranging from 1.3 to 11.1 days in impacted soil. Although residual antibiotics were detected in the feces, no significant correlation was observed between fecal antibiotic concentrations and ARG relative abundance. Thus, other unaccounted factors likely contributed selective pressure for ARG maintenance. These findings highlight the contribution of wild urban bird feces to the maintenance and dissemination of ARGs, and the associated health risks. | 2020 | 32663725 |
| 3109 | 3 | 0.9998 | Metagenomic characterization of bacterial community and antibiotic resistance genes in representative ready-to-eat food in southern China. Ready-to-eat (RTE) foods have been considered to be reservoirs of antibiotic resistance bacteria, which constitute direct threat to human health, but the potential microbiological risks of RTE foods remain largely unexplored. In this study, the metagenomic approach was employed to characterize the comprehensive profiles of bacterial community and antibiotic resistance gene (ARG) in 18 RTE food samples (8 RTE meat, 7 RTE vegetables and 3 RTE fruit) in southern China. In total, the most abundant phyla in RTE foods were Proteobacteria, Firmicutes, Cyanobacteria, Bacteroidetes and Actinobacteria. 204 ARG subtypes belonging to 18 ARG types were detected with an abundance range between 2.81 × 10(-5) and 7.7 × 10(-1) copy of ARG per copy of 16S rRNA gene. Multidrug-resistant genes were the most predominant ARG type in the RTE foods. Chloramphenicol, macrolide-lincosamide-streptogramin, multidrug resistance, aminoglycoside, bacitracin, tetracycline and β-lactam resistance genes were dominant, which were also associated with antibiotics used extensively in human medicine or veterinary medicine/promoters. Variation partitioning analysis indicated that the join effect of bacterial community and mobile genetic elements (MGEs) played an important role in the resistome alteration. This study further deepens the comprehensive understanding of antibiotic resistome and the correlations among the antibiotic resistome, microbiota, and MGEs in the RTE foods. | 2020 | 33093543 |
| 5373 | 4 | 0.9998 | Impact of soil supplemented with pig manure on the abundance of antibiotic resistant bacteria and their associated genes. This study was conducted to evaluate the abundance of antibiotic resistant bacteria and their resistance genes from agriculture soil supplemented with pig manure. Uncultivable soil sample was supplemented with pig manure samples under microcosm experimental conditions and plated on Luria-Bertani (LB) agar incorporated with commercial antibiotics. The supplementation of soil with 15% pig manure resulted in the highest increase in the population of antibiotic resistant bacteria (ARB)/multiple antibiotic resistant bacteria (MARB). Seven genera that included Pseudomonas, Escherichia, Providencia, Salmonella, Bacillus, Alcaligenes and Paenalcaligenes were the cultivable ARB identified. A total of ten antibiotic resistant bacteria genes (ARGs) frequently used in clinical or veterinary settings and two mobile genetic elements (MGEs) (Class 1 and Class 2 integrons) were detected. Eight heavy metal, copper, cadmium, chromium, manganese, lead, zinc, iron, and cobalt were found in all of the manure samples at different concentrations. Tetracycline resistance genes were widely distributed with prevalence of 50%, while aminoglycoside and quinolone-resistance gene had 16% and 13%, respectively. Eighteen ARB isolates carried more than two ARGs in their genome. Class 1 integron was detected among all the 18 ARB with prevalence of 90-100%, while Class 2 integron was detected among 11 ARB. The two classes of integron were found among 10 ARB. Undoubtedly, pig manure collected from farms in Akure metropolis are rich in ARB and their abundance might play a vital role in the dissemination of resistance genes among clinically-relevant pathogens. | 2023 | 37308603 |
| 3139 | 5 | 0.9998 | Sulfonamide-resistant bacteria and their resistance genes in soils fertilized with manures from Jiangsu Province, Southeastern China. Antibiotic-resistant bacteria and genes are recognized as new environmental pollutants that warrant special concern. There were few reports on veterinary antibiotic-resistant bacteria and genes in China. This work systematically analyzed the prevalence and distribution of sulfonamide resistance genes in soils from the environments around poultry and livestock farms in Jiangsu Province, Southeastern China. The results showed that the animal manure application made the spread and abundance of antibiotic resistance genes (ARGs) increasingly in the soil. The frequency of sulfonamide resistance genes was sul1 > sul2 > sul3 in pig-manured soil DNA and sul2 > sul1 > sul3 in chicken-manured soil DNA. Further analysis suggested that the frequency distribution of the sul genes in the genomic DNA and plasmids of the SR isolates from manured soil was sul2 > sul1 > sul3 overall (p<0.05). The combination of sul1 and sul2 was the most frequent, and the co-existence of sul1 and sul3 was not found either in the genomic DNA or plasmids. The sample type, animal type and sampling time can influence the prevalence and distribution pattern of sulfonamide resistance genes. The present study also indicated that Bacillus, Pseudomonas and Shigella were the most prevalent sul-positive genera in the soil, suggesting a potential human health risk. The above results could be important in the evaluation of antibiotic-resistant bacteria and genes from manure as sources of agricultural soil pollution; the results also demonstrate the necessity and urgency of the regulation and supervision of veterinary antibiotics in China. | 2014 | 25405870 |
| 5295 | 6 | 0.9998 | Occurrence of (fluoro)quinolones and (fluoro)quinolone resistance in soil receiving swine manure for 11 years. Because of the widespread use of antibiotics in animal breeding, the agricultural application of animal manure can lead to the introduction of antibiotics, antibiotic-resistant bacteria and antibiotic resistance genes to the soil and surrounding environment, which may pose a threat to public health. In this study, we investigated the status of (fluoro)quinolone (FQ) residues and FQ resistance levels in soil with and without receiving long-term swine manure. Six FQs (pipemidic acid, lomefloxacin, enrofloxacin, norfloxacin, ciprofloxacin, and ofloxacin) were only detected in manured soil, with individual concentrations ranging from below the detection limit to 27.2 μg kg(-1) and increasing with the increase in swine manure application rates. Higher load rates of swine manure yielded a higher number of ciprofloxacin-resistant (CIPr) bacteria after spreading. A total of 24 CIPr bacterial isolates were obtained from the tested soil, which belonged to four phyla (Proteobacteria, Firmicutes, Actinobacteria, and Bacteroidetes) or were related to nine different genera. Only 18 isolates from manured soil were positive for five plasmid-mediated quinolone resistance (PMQR) genes (aac(6')-Ib-cr, qnrD, qepA, oqxA, and oqxB). To our knowledge, this study is the first to examine the occurrence of PMQR genes in FQ-resistant bacteria from the soil environment. A similar result was observed for the total DNA from soil, with the exception of aac(6')-Ib being detected in the control sample. The absolute and relative abundances of total PMQR genes also increased with fertilization quantity. Significant correlations were observed between FQ resistance levels and FQ concentrations. These results indicated that the agricultural application of swine manure led to FQ residues and enhanced FQ resistance. This investigation provides baseline data on FQ resistance profiles in soils receiving long-term swine manure. | 2015 | 26042895 |
| 5355 | 7 | 0.9998 | Impact of wastewater treatment processes on antimicrobial resistance genes and their co-occurrence with virulence genes in Escherichia coli. An increase in the frequency of antimicrobial resistance genes (ARGs) in bacteria including Escherichia coli could be a threat to public health. This study investigated the impact of activated sludge and physicochemical wastewater treatment processes on the prevalence of ARGs in E. coli isolates. In total, 719 E. coli were isolated from the influent and effluent (prior to disinfection) of two activated sludge and two physicochemical municipal treatment plants, and genotyped using DNA microarrays. Changes in the abundance of ARGs in the E. coli population were different for the two treatment processes. Activated sludge treatment did not change the prevalence of ARG-possessing E. coli but increased the abundance of ARGs in the E. coli genome while physicochemical treatment reduced both the prevalence of ARG-carrying E. coli as well as the frequency of ARGs in the E. coli genome. Most E. coli isolates from the four treatment plants possessed ARGs of multiple antimicrobial classes, mainly aminoglycoside, β-lactams, quinolone and tetracyclines. In addition these isolates harboured DNA insertion sequence elements including integrase and transposase. A significant positive association was found between the occurrence of ARGs and virulence genotypes. | 2014 | 24380739 |
| 5365 | 8 | 0.9998 | Drinking 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. | 2024 | 39334983 |
| 5354 | 9 | 0.9998 | Cultivation-dependent and high-throughput sequencing approaches studying the co-occurrence of antibiotic resistance genes in municipal sewage system. During the past years, antibiotic-resistant bacteria (ARB) leading for the spreading of antibiotic resistance genes (ARGs) became a global problem, especially multidrug-resistant (MDR) bacteria are considered the prime culprit of antibiotic resistance. However, the correlation between the antibiotic-resistant phenotype and the ARG profiles remains poorly understood. In the present study, metagenomic functional screening and metagenomic analysis of coliforms were combined to explore the phenotype and genotype of the ARBs from municipal sewage. Our results showed that the ARG co-occurrence was widespread in the municipal sewage. The present study also highlighted the high abundance of ARGs from antibiotic resistance coliforms especially the MDR coliforms with ARG level of 33.8 ± 4.2 copies per cell. The ARG profiles and the antibiotic resistance phenotypes of the isolated antibiotic resistant coliforms were also correlated and indicated that the resistance to the related antibiotic (ampicillin, kanamycin, erythromycin, chloramphenicol, and tetracycline) was mostly contributed by the ARGs belonging to the subtypes of β-lactamase, aminoglycoside 3-phosphotransferase, phosphotransferase type 2, chloramphenicol acetyltransferase, tetA, etc. | 2017 | 29034431 |
| 5299 | 10 | 0.9998 | Macrolide resistance genes and mobile genetic elements in waterways from pig farms to the sea in Taiwan. OBJECTIVES: Macrolides have a long history of use in animals and humans. Dynamics of macrolide-antibiotic resistance genes (ARGs) in waterways from the origin to the sea has not been reported. METHODS: Resistant bacterial rate was measured by culture method, and copy numbers of macrolide-ARGs, mef(A), erm(B), mph(B), mef(C)-mph(G), and mobile genetic elements (MGEs) traI and IntI1 were quantitated in environmental DNA. Community composition in each site was investigated by 16S rRNA gene metagenomic sequencing. In Yilan area, antibiotics were quantitated. RESULTS: Surface water samples from pig farms to the sea in southern and northern areas in Taiwan were monitored. Macrolide-resistant bacteria accounted for 3%-28% of total colony-forming bacteria in aquaculture ponds and rivers, whereas in pig farm wastewater it was 26%-100%. Three common macrolide-ARGs mef(A), erm(B), and mph(B) and the relatively new mef(C)-mph(G) were frequently detected in pig farms, but not in aquaculture ponds and the sea. Rivers receiving pig wastewater showed ARG contamination similar to the pig farms. Among the MGEs, IntI1 was frequently distributed in all sites and was positively related to mef(A), erm(B), and mph(B) but not to mef(C)-mph(G). CONCLUSION: Pig farms are the origin of macrolide-ARGs, although macrolide contamination is low. Since lincomycin was detected in pig farms in the northern area, the increase of macrolide-ARGs is a future concern due to cross-resistance to lincomycin. ARGs abundance in aquaculture ponds was low, though MGEs were detected. Relation of IntI1 to ARG suggests convergence of ARGs to specific MGEs might be time/history dependent. | 2022 | 35533984 |
| 5294 | 11 | 0.9998 | Association of florfenicol residues with the abundance of oxazolidinone resistance genes in livestock manures. Livestock and poultry manures are major reservoirs of antibiotic-resistant bacteria and antibiotic resistance genes (ARGs). Linezolid is a clinical medicine for humans and has never been approved for use in livestock. Interestingly, three linezolid resistance genes (cfr, optrA, and poxtA) have been detected in bacteria of animal origin, arousing public concern. This study investigated the abundance of three ARGs, cfr, optrA, and poxtA, in manures from 157 large-scale farms in China using real-time quantitative polymerase chain reaction. The residual concentrations of linezolid, florfenicol, tiamulin, and valnemulin were determined using ultra-high performance liquid chromatography-tandem mass spectrometry. A total of 140 livestock farms were tested positive for ARGs, and the positive detection rate was 89.17 %. OptrA was the most commonly detected ARG. The diversity and abundance of ARGs were significantly higher in poultry and swine manure than in bovine manure. Redundancy analysis presented a strong association between florfenicol and all the three ARGs targeted in the study, and tiamulin showed a significant correlation with optrA. Our results indicated that the residual concentration of florfenicol had a major effect on the distribution of the three ARGs in livestock manures, and extensive use of florfenicol may lead to the production of linezolid resistance genes. | 2020 | 32516648 |
| 5359 | 12 | 0.9998 | Metagenomic insights into plasmid-mediated antimicrobial resistance in poultry slaughterhouse wastewater: antibiotics occurrence and genetic markers. Slaughterhouse wastewater represents important convergence and concentration points for antimicrobial residues, bacteria, and antibiotic resistance genes (ARG), which can promote antimicrobial resistance propagation in different environmental compartments. This study reports the assessment of the metaplasmidome-associated resistome in poultry slaughterhouse wastewater treated by biological processes, employing metagenomic sequencing. Antimicrobial residues from a wastewater treatment plant (WWTP) that treats poultry slaughterhouse influents and effluents were investigated through high-performance liquid chromatography coupled to tandem mass spectrometry (HPLC-MS/MS). Residues from the macrolide, sulfonamide, and fluoroquinolone classes were detected, the latter two persisting after the wastewater treatment. The genetic markers 16S rRNA rrs (bacterial community) and uidA (Escherichia coli) were investigated by RT-qPCR and the sul1 and int1 genes by qPCR. After treatment, the 16S rRNA rrs, uidA, sul1, and int1 markers exhibited reductions of 0.67, 1.07, 1.28, and 0.79 genes copies, respectively, with no statistical significance (p > 0.05). The plasmidome-focused metagenomics sequences (MiSeq platform (Illumina®)) revealed more than 100 ARG in the WWTP influent, which can potentially confer resistance to 14 pharmacological classes relevant in the human and veterinary clinical contexts, in which the qnr gene (resistance to fluoroquinolones) was the most prevalent. Only 7.8% of ARG were reduced after wastewater treatment, and the remaining 92.2% were associated with an increase in the prevalence of ARG linked to multidrug efflux pumps, substrate-specific for certain classes of antibiotics, or broad resistance to multiple medications. These data demonstrate that wastewater from poultry slaughterhouses plays a crucial role as an ARG reservoir and in the spread of AMR into the environment. | 2024 | 39395082 |
| 5310 | 13 | 0.9998 | Antimicrobial-Resistant Bacterial Populations and Antimicrobial Resistance Genes Obtained from Environments Impacted by Livestock and Municipal Waste. This study compared the populations of antimicrobial-resistant bacteria and the repertoire of antimicrobial resistance genes in four environments: effluent of three municipal wastewater treatment facilities, three cattle feedlot runoff catchment ponds, three swine waste lagoons, and two "low impact" environments (an urban lake and a relict prairie). Multiple liquid and solid samples were collected from each environment. The prevalences and concentrations of antimicrobial-resistant (AMR) Gram-negative (Escherichia coli and Salmonella enterica) and Gram-positive (enterococci) bacteria were determined from individual samples (n = 174). The prevalences of 84 antimicrobial resistance genes in metagenomic DNA isolated from samples pooled (n = 44) by collection date, location, and sample type were determined. The prevalences and concentrations of AMR E. coli and Salmonella were similar among the livestock and municipal sample sources. The levels of erythromycin-resistant enterococci were significantly higher in liquid samples from cattle catchment ponds and swine waste lagoons than in liquid samples from municipal wastewater treatment facilities, but solid samples from these environments did not differ significantly. Similarly, trimethoprim/sulfamethoxazole-resistant E. coli concentrations were significantly higher in swine liquid than in municipal liquid samples, but there was no difference in solid samples. Multivariate analysis of the distribution of antimicrobial resistance genes using principal coordinate analysis showed distinct clustering of samples with livestock (cattle and swine), low impact environment and municipal samples forming three separate clusters. The numbers of class A beta-lactamase, class C beta-lactamase, and fluoroquinolone resistance genes detected were significantly higher (P < 0.05) in municipal samples than in cattle runoff or swine lagoon samples. In conclusion, we report that AMR is a very widespread phenomenon and that similar prevalences and concentrations of antimicrobial-resistant bacteria and antimicrobial resistance genes exist in cattle, human, and swine waste streams, but a higher diversity of antimicrobial resistance genes are present in treated human waste discharged from municipal wastewater treatment plants than in livestock environments. | 2015 | 26197056 |
| 3208 | 14 | 0.9998 | Effects 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. | 2025 | 40732167 |
| 5339 | 15 | 0.9998 | Metal 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. | 2019 | 31256402 |
| 5358 | 16 | 0.9997 | Abundance of antibiotics, antibiotic resistance genes and bacterial community composition in wastewater effluents from different Romanian hospitals. Antimicrobial resistance represents a growing and significant public health threat, which requires a global response to develop effective strategies and mitigate the emergence and spread of this phenomenon in clinical and environmental settings. We investigated, therefore, the occurrence and abundance of several antibiotics and antibiotic resistance genes (ARGs), as well as bacterial community composition in wastewater effluents from different hospitals located in the Cluj County, Romania. Antibiotic concentrations ranged between 3.67 and 53.05 μg L(-1), and the most abundant antibiotic classes were β-lactams, glycopeptides, and trimethoprim. Among the ARGs detected, 14 genes confer resistance to β-lactams, aminoglycosides, chloramphenicol, macrolide-lincosamide-streptogramin B (MLSB) antibiotics, sulfonamides, and tetracyclines. Genes encoding quaternary ammonium resistance and a transposon-related element were also detected. The sulI and qacEΔ1 genes, which confer resistance to sulfonamides and quaternary ammonium, had the highest relative abundance with values ranging from 5.33 × 10(-2) to 1.94 × 10(-1) and 1.94 × 10(-2) to 4.89 × 10(-2) copies/16 rRNA gene copies, respectively. The dominant phyla detected in the hospital wastewater samples were Proteobacteria, Bacteroidetes, Firmicutes, and Actinobacteria. Among selected hospitals, one of them applied an activated sludge and chlorine disinfection process before releasing the effluent to the municipal collector. This conventional wastewater treatment showed moderate removal efficiency of the studied pollutants, with a 55-81% decrease in antibiotic concentrations, 1-3 order of magnitude lower relative abundance of ARGs, but with a slight increase of some potentially pathogenic bacteria. Given this, hospital wastewaters (raw or treated) may contribute to the spread of these emerging pollutants in the receiving environments. To the best of our knowledge, this study quantified for the first time the abundance of antibiotics and ARGs in wastewater effluents from different Romanian hospitals. | 2017 | 28347610 |
| 5363 | 17 | 0.9997 | Irrigation 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. | 2022 | 36421294 |
| 5361 | 18 | 0.9997 | Microbiome and Resistome in Poultry Litter-Fertilized and Unfertilized Agricultural Soils. Background: Poultry litter is the main waste of poultry farming and is widely used as an agricultural fertilizer. However, owing to the use of antimicrobials in animal production, it can accumulate antimicrobial residues, antimicrobial-resistant bacteria (ARB), and antimicrobial resistance genes (ARGs). This study aimed to evaluate the impact of poultry litter use on the microbiome and resistome of agricultural soils. Methods: Soil samples from fertilized and unfertilized plots were collected from two horticultural farms that intensively use poultry litter. Microbiome composition was assessed using 16S rRNA sequencing. A culture-dependent method was used to isolate resistant strains on CHROMagar plates supplemented with sulfamethoxazole or ciprofloxacin. ARGs and integrase-encoding genes were identified by PCR. Results: Microbiome analysis revealed significant differences in structure and composition between poultry litter-fertilized and unfertilized soils. Fertilized soils exhibited greater alpha diversity and richness. Bacillota, commonly found in the avian gastrointestinal tract, were more abundant in fertilized soils. A total of 62 resistant strains were isolated, and 23 clinically relevant strains harbored ARGs, including fluoroquinolone (qnrA and qnrB) and β-lactam (bla(GES), bla(TEM), and bla(SHV)) resistance genes. Class 1 and 2 integron-associated genes (intI1 and intI2) were also detected. Notably, the rare bla(GES) gene was detected in Bacillus sp. from unfertilized soil. Similarly, qnrA co-occurred with bla(SHV) in a Bosea sp. strain from unfertilized soil. Conclusions: These findings highlight the potential for ARB dissemination in agricultural environments, where ARB and ARGs, once introduced into soils, may spread by weathering and other environmental factors, complicating negative control selection in in situ studies. | 2025 | 40298506 |
| 5357 | 19 | 0.9997 | Occurrence and diversity of antibiotic resistance in untreated hospital wastewater. Antibiotics, antibiotic-resistant bacteria (ARB), antibiotic-resistance genes (ARGs), and mobile genetic elements (MGEs) have been reported in many environments. However, the investigation of their occurrence and diversity in untreated hospital wastewater is still insufficient. High concentrations of antibiotic residues were found in hospital wastewater using solid-phase extraction and UPLC-MS/MS analysis. The concentrations of six of 14 antibiotics reached μg/L levels in the hospital wastewater, which is higher than reported in other aquatic environments. Results of high-throughput sequencing analysis indicated that sequences affiliated to genera Escherichia and Acinetobacter were the predominant in the cultivable multiple-antibiotic-resistant bacteria (CMARB) recovered from the wastewater of three hospitals in China, with compositions of 34%-74%. Notably, several genera containing clinically pathogenic or opportunistic CMARB (e.g., Escherichia, Acinetobacter, Aeromonas, Myroides, Enterococcus, Proteus, Pseudomonas, and Streptococcus) were detected at high relative abundances in the wastewaters of the three hospitals. High-capacity quantitative PCR showed that 131-139 unique ARGs of the 178 targeted genes were detected in the hospital wastewaters. The high prevalence of five MGEs and 12 ARGs was confirmed with qPCR, and some positive correlations between ARGs and MGEs were identified, such as between intI1 and qnrD, intI2 and sul3, intI3 and tetX, Tn916/Tn1545 and sul2, and ISCR1 and sul3. These results suggest that highly abundant antibiotic-resistant pathogens and highly mobile ARGs already exist in the human body, and that their release from hospitals without effective treatment poses high risks to environments and human health. | 2018 | 29054666 |