Urban wastewater overflows as hotspots for dissemination of bacteria producing extended-spectrum β-lactamases and carbapenemases in the Suquía River, Argentina. - Related Documents




#
Rank
Similarity
Title + Abs.
Year
PMID
012345
180801.0000Urban wastewater overflows as hotspots for dissemination of bacteria producing extended-spectrum β-lactamases and carbapenemases in the Suquía River, Argentina. Antimicrobial resistance (AMR) is a critical global challenge, yet the role of environmental dissemination of antibiotic-resistant bacteria remains underexplored, particularly in developing regions. This study investigated urban wastewater overflows from public streets as vectors for extended-spectrum-β-lactamase (ESBL)- and carbapenemase-producing Enterobacterales and Aeromonas in the Suquía River (Córdoba, Argentina). Sixty-two water samples were analyzed for coliform counts, antimicrobial susceptibility, and resistance genes. Horizontal gene transfer was assessed by conjugation. Sixty-five ESBL- and/or carbapenemase-producing isolates were recovered, including six carbapenemase producers subjected to whole-genome sequencing (WGS). Urban wastewater exhibited coliform levels >10(8) MPN/100 mL, while river counts increased 2-5 logs at urban and downstream sites compared to upstream, where no resistant strains were detected. ESBL- and/or carbapenemase-producers occurred in ~70% of wastewater and river samples, mainly Escherichia coli harboring bla(CTX-M) . Carbapenemase producers carried bla(KPC-2) or bla(NDM-1) in Enterobacter, Klebsiella, Citrobacter, and Aeromonas caviae. WGS revealed extensive resistomes, virulence genes, and plasmid replicons, including IncU and IncA/C2 linked to carbapenemases. Conjugation confirmed plasmid-mediated transfer of β-lactamase genes, and genetic context analysis identified clinically recognized transposons. Notably, Enterobacter kobei and Aeromonas caviae from the river carried bla(KPC-2) on plasmidic contigs combining clinical and environmental elements, consistent with genetic exchange within aquatic ecosystems and transfer of clinically significant resistance determinants to species adapted for riverine survival. These findings identify urban wastewater overflows as AMR hotspots that facilitate the dissemination of multidrug-resistant bacteria and mobile resistance elements into urban and peri-urban aquatic environments, underscoring the need for integrated environmental AMR surveillance.202541070122
276010.9998Extended-spectrum β-lactamase-producing bacteria and their resistance determinants in different wastewaters and rivers in Nepal. Wastewaters serve as significant reservoirs of antibiotic resistant bacteria. Despite the evidence of antimicrobial resistance in wastewaters and river water in Kathmandu, direct linkage between them is not discussed yet. This study investigated the prevalence of extended-spectrum β-lactamase (ESBL)-producing bacteria and associated resistance genes in wastewaters and river water. Out of 246 bacteria from wastewaters, 57.72% were ESBL producers and 77.64% of them were multidrug resistant (MDR). ESBL producing E. coli was dominant in municipal and hospital wastewaters (HWW) as well as in river water while K. pneumoniae was common in pharmaceutical wastewater. The bla(SHV) and bla(TEM) genes were prevalent and commonly co-occurred with aac(6')-Ib-cr in K. pneumoniae isolated pharmaceutical wastewater. bla(CTX-M) carrying E. coli from hospital co-harbored aac(6')-Ib-cr while that from municipal influent and river water co-harbored qnrS. Whole genome sequencing data revealed the presence of diverse ARGs in bacterial isolates against multiple antibiotics. In average, an E. coli and a K. pneumoniae isolate contained 55.75 ± 0.96 and 40.2 ± 5.36 ARGs, respectively. Multi-locus sequence typing showed the presence of globally high-risk clones with wider host range such as E. coli ST10, and K. pneumoniae ST15 and ST307 in HWW and river indicating frequent dissemination of antimicrobial resistance in wastewater of Kathmandu. Whole genome sequence data aligned with phenotypic antibiograms and resistance genes detected by PCR in selected isolates. The presence of significant plasmid replicons (IncF, IncY) and mobile genetic elements (IS903, IS26) indicate high frequency of spreading antibiotic resistance. These findings indicate burden and dissemination of antimicrobial resistance in the environment and highlight the need for effective strategies to mitigate the antibiotic resistance.202438795483
163820.9997First national study on genomic profiling of Escherichia coli in United Arab Emirates (UAE) aquatic environments shows diverse Quinolone and Cephalosporin resistance. Antimicrobial resistance (AMR) is a serious threat to human, animal and plant health, and over recent years the role of the aquatic environment as a hotspot and dissemination route for resistant bacteria has been increasingly recognised. The United Arab Emirates (UAE) has identified AMR as a critical area of concern; however, limited studies have been conducted regarding the presence of AMR in aquatic environments in the region. This study addresses this gap by conducting a national surveillance to better understand the prevalence of aquatic AMR. We investigated the phenotypic and genotypic resistances in Escherichia coli (E. coli) isolates (n= 256) from sewage impacted and unimpacted coastal waters and artificial lakes across the UAE. Multidrug resistance was observed in 34.2% of isolates, with 22.7% exhibiting resistance to 3(rd) and 4(th) generation cephalosporins, cefotaxime and ceftazidime, including 16.6% displaying an extended-spectrum β-lactamase (ESBL) phenotype. Resistance to fluoroquinolones, macrolides, and carbapenems was also detected. Whole-genome sequencing (n=92) revealed a high prevalence of the fimH virulence gene, as well as conjugative plasmids (IncF, IncA/C and IncY) carrying resistance determinants. Notably, qnrS1 and bla(CTX-M-15) resistance genes were identified in 39% of sequenced isolates, while the bla(NDM-5) gene was detected for the first time in a single isolate. These findings underscore the need for harmonised AMR surveillance and a regional monitoring framework to assess the environmental dissemination of AMR bacteria in a One Health context.202540969202
262530.9997Spread of extended-spectrum beta-lactamase-producing Escherichia coli from a swine farm to the receiving river. The dissemination of drug-resistant bacteria into different environments has posed a grave threat to public health, but data on the spread of extended-spectrum beta-lactamase (ESBL)-producing Escherichia coli (E. coli) from animal farms to the receiving river are limited. Here, 57 ESBL-producing E. coli isolated from a pig farm and the receiving river were analyzed in terms of drug resistance, ESBL genes, and enterobacterial repetitive intergenic consensus (ERIC). The results showed that ESBL-producing E. coli from swine feces and downstream water of the pig farm outfall overlapped substantially in drug resistance and ESBL genes. Additionally, six ESBL-producing E. coli from the downstream water exhibited 100 % genetic similarity with strains from the swine feces. In conclusion, effluents of animal farms are a likely contributor to the presence of ESBL-producing E. coli in aquatic environments.201525921760
275240.9997Antibiotic Resistance in Enterobacteriaceae from Surface Waters in Urban Brazil Highlights the Risks of Poor Sanitation. Surface waters are an unappreciated reservoir of antimicrobial resistance (AMR). Poor sanitation brings different species of environmental bacteria into contact, facilitating horizontal gene transfer. To investigate the role of surface waters as potential reservoirs of AMR, we studied the point prevalence of fecal contamination, AMR genes, and Enterobacteriaceae in an urban lake and rural river system in Northeast Brazil in comparison with a lake and sewer system in Northeast Ohio in the United States. Surface water samples were examined for evidence of human fecal contamination using microbial source tracking and screened for plasmid-mediated fluoroquinolone resistance and carbapenemase genes. Enterobacteriaceae were detected using selective agar followed by antimicrobial susceptibility testing and detection of AMR genes by microarray, and classified by repetitive sequence-based polymerase chain reaction and multilocus sequence typing. Concentrations of human fecal bacteria in the Brazilian urban lake and sewage in Northeast Ohio were similarly high. Filtered water samples from the Brazilian urban lake, however, showed the presence of bla (OXA-48), bla (KPC), bla (VIM-2), qnrS, and aac(6')-lb-cr, whereas only bla (VIM-2) was identified in raw sewage from Northeast Ohio. From the Brazilian urban lake, 85% of the Enterobacteriaceae (n = 40) cultured were resistant to at least one clinically important antibiotic, including ST131 Escherichia coli harboring the extended-spectrum beta-lactamase CTX-M. Although two isolates demonstrated polymyxin resistance, mcr-1/2 was not detected. Our findings indicate that surface waters in an urban Brazilian site can serve as an environmental reservoir of AMR and that improving wastewater treatment and sanitation generally may ameliorate AMR dissemination.201930994094
262850.9997Occurrence and persistence of multidrug-resistant Enterobacterales isolated from urban, industrial and surface water in Monastir, Tunisia. The One Health approach of antimicrobial resistance highlighted the role of the aquatic environment as a reservoir and dissemination source of resistance genes and resistant bacteria, especially due to anthropogenic activities. Resistance to extended-spectrum cephalosporins (ESC) conferred by extended-spectrum beta-lactamases (ESBLs) in E. coli has been proposed as the major marker of the AMR burden in cross-sectoral approaches. In this study, we investigated wastewater, surface water and seawater that are subjected to official water quality monitoring in Monastir, Tunisia. While all but one sample were declared compliant according to the official tests, ESC-resistant bacteria were detected in 31 (19.1 %) samples. Thirty-nine isolates, coming from urban, industrial and surface water in Monastir, were collected and characterized using antibiograms and whole-genome sequencing. These isolates were identified as 27 Escherichia coli (69.3 %) belonging to 13 STs, 10 Klebsiella pneumoniae (25.6 %) belonging to six STs, and two Citrobacter freundii (5.1 %). We observed the persistence and dissemination of clones over time and in different sampling sites, and no typically human-associated pathogens could be identified apart from one ST131. All isolates presented a bla(CTX-M) gene - bla(CTX-M-15) (n = 22) and bla(CTX-M-55) (n = 8) being the most frequent variants - which were identified on plasmids (n = 20) or on the chromosome (n = 19). In conclusion, we observed ESC resistance in rather ubiquitous bacteria that are capable of surviving in the water environment. This suggests that including the total coliform count and the ESBL count as determined by bacterial growth on selective plates in the official monitoring would greatly improve water quality control in Tunisia.202438460700
191360.9997Citrobacter spp. and Enterobacter spp. as reservoirs of carbapenemase bla(NDM) and bla(KPC) resistance genes in hospital wastewater. Antibiotic resistance has emerged as a global threat to public health, generating a growing interest in investigating the presence of antibiotic-resistant bacteria in environments influenced by anthropogenic activities. Wastewater treatment plants in hospital serve as significant reservoirs of antimicrobial-resistant bacteria, where a favorable environment is established, promoting the proliferation and transfer of resistance genes among different bacterial species. In our study, we isolated a total of 243 strains from 5 hospital wastewater sites in Mexico, belonging to 21 distinct Gram-negative bacterial species. The presence of β-lactamase was detected in 46.9% (114/243) of the isolates, which belonging to the Enterobacteriaceae family. We identified a total of 169 β-lactamase genes; bla(TEM) in 33.1%, bla(CTX-M) in 25.4%, bla(KPC) in 25.4%, bla(NDM) 8.8%, bla(SHV) in 5.3%, and bla(OXA-48) in 1.1% distributed in 12 different bacteria species. Among the 114 of the isolates, 50.8% were found to harbor at least one carbapenemase and were discharged into the environment. The carbapenemase bla(KPC) was found in six Citrobacter spp. and E. coli, while bla(NDM) was detected in two distinct Enterobacter spp. and E. coli. Notably, bla(NDM-1) was identified in a 110 Kb IncFII conjugative plasmid in E. cloacae, E. xiangfangensis, and E. coli within the same hospital wastewater. In conclusion, hospital wastewater showed the presence of Enterobacteriaceae carrying a high frequency of carbapenemase bla(KPC) and bla(NDM). We propose that hospital wastewater serves as reservoirs for resistance mechanism within bacterial communities and creates an optimal environment for the exchange of this resistance mechanism among different bacterial strains. IMPORTANCE: The significance of this study lies in its findings regarding the prevalence and diversity of antibiotic-resistant bacteria and genes identified in hospital wastewater in Mexico. The research underscores the urgent need for enhanced surveillance and prevention strategies to tackle the escalating challenge of antibiotic resistance, particularly evident through the elevated frequencies of carbapenemase genes such as bla(KPC) and bla(NDM) within the Enterobacteriaceae family. Moreover, the identification of these resistance genes on conjugative plasmids highlights the potential for widespread transmission via horizontal gene transfer. Understanding the mechanisms of antibiotic resistance in hospital wastewater is crucial for developing targeted interventions aimed at reducing transmission, thereby safeguarding public health and preserving the efficacy of antimicrobial therapies.202439012101
262770.9997High Prevalence of Drug Resistance and Class 1 Integrons in Escherichia coli Isolated From River Yamuna, India: A Serious Public Health Risk. Globally, urban water bodies have emerged as an environmental reservoir of antimicrobial resistance (AMR) genes because resistant bacteria residing here might easily disseminate these traits to other waterborne pathogens. In the present study, we have investigated the AMR phenotypes, prevalent plasmid-mediated AMR genes, and integrons in commensal strains of Escherichia coli, the predominant fecal indicator bacteria isolated from a major urban river of northern India Yamuna. The genetic environment of bla (CTX-M-15) was also investigated. Our results indicated that 57.5% of the E. coli strains were resistant to at least two antibiotic classes and 20% strains were multidrug resistant, i.e., resistant to three or more antibiotic classes. The multiple antibiotic resistance index of about one-third of the E. coli strains was quite high (>0.2), reflecting high contamination of river Yamuna with antibiotics. With regard to plasmid-mediated AMR genes, bla (TEM-1) was present in 95% of the strains, followed by qnrS1 and armA (17% each), bla (CTX-M-15) (15%), strA-strB (12%), and tetA (7%). Contrary to the earlier reports where bla (CTX-M-15) was mostly associated with pathogenic phylogroup B2, our study revealed that the CTX-M-15 type extended-spectrum β-lactamases (ESBLs) were present in the commensal phylogroups A and B1, also. The genetic organization of bla (CTX-M-15) was similar to that reported for E. coli, isolated from other parts of the world; and ISEcp1 was present upstream of bla (CTX-M-15). The integrons of classes 2 and 3 were absent, but class 1 integron gene intI1 was present in 75% of the isolates, denoting its high prevalence in E. coli of river Yamuna. These evidences indicate that due to high prevalence of plasmid-mediated AMR genes and intI1, commensal E. coli can become vehicles for widespread dissemination of AMR in the environment. Thus, regular surveillance and management of urban rivers is necessary to curtail the spread of AMR and associated health risks.202133633708
163680.9997Widespread high-risk clones of multidrug-resistant extended-spectrum β-lactamase-producing Escherichia coli B2-ST131 and F-ST648 in public aquatic environments. Aquatic environments are considered a reservoir for the dissemination of multidrug-resistant (MDR) bacteria, principally Escherichia coli, with the consequent spread of acquired antimicrobial resistance genes (ARGs). Widespread high-risk clones of MDR E. coli are responsible for human infections worldwide. This study aimed to characterise, through whole-genome sequencing (WGS), isolates of MDR E. coli harbouring ARGs obtained from public aquatic environments in Brazil. MDR E. coli isolates were obtained from rivers, streams and lakes that presented different Water Quality Index records and were submitted to WGS. The resistome, mobilome and virulome showed a great diversity of ARGs, plasmids and virulence genes, respectively. In addition, mutations in the quinolone resistance-determining regions of GyrA, ParC and ParE as well as several metal resistance genes (MRGs) and antibacterial biocide resistance genes (ABGs) were detected. Typing and subtyping of MDR E. coli revealed different lineages, with two belonging to widespread high-risk clones (i.e. B2-ST131-fimH30 and F-ST648-fimH27), which are grouped by core genome multilocus sequence typing (cgMLST) in clusters with E. coli lineages obtained from different sources distributed worldwide. MDR bacteria carrying MRGs and ABGs have emerged as a global human and environmental health problem. Detection of widespread high-risk clones calls for attention to the dissemination of fluoroquinolone-resistant QnrS1- and CTX-M-producing E. coli lineages associated with human infections in public aquatic environments.202032479889
276190.9997First reported detection of the mobile colistin resistance genes, mcr-8 and mcr-9, in the Irish environment. The emergence and dissemination of mobile colistin resistance (mcr) genes across the globe poses a significant threat to public health, as colistin remains one of the last line treatment options for multi-drug resistant infections. Environmental samples (157 water and 157 wastewater) were collected in Ireland between 2018 and 2020. Samples collected were assessed for the presence of antimicrobial resistant bacteria using Brilliance ESBL, Brilliance CRE, mSuperCARBA and McConkey agar containing a ciprofloxacin disc. All water and integrated constructed wetland influent and effluent samples were filtered and enriched in buffered peptone water prior to culture, while wastewater samples were cultured directly. Isolates collected were identified via MALDI-TOF, were tested for susceptibility to 16 antimicrobials, including colistin, and subsequently underwent whole genome sequencing. Overall, eight mcr positive Enterobacterales (one mcr-8 and seven mcr-9) were recovered from six samples (freshwater (n = 2), healthcare facility wastewater (n = 2), wastewater treatment plant influent (n = 1) and integrated constructed wetland influent (piggery farm waste) (n = 1)). While the mcr-8 positive K. pneumoniae displayed resistance to colistin, all seven mcr-9 harbouring Enterobacterales remained susceptible. All isolates demonstrated multi-drug resistance and through whole genome sequencing analysis, were found to harbour a wide variety of antimicrobial resistance genes i.e., 30 ± 4.1 (10-61), including the carbapenemases, bla(OXA-48) (n = 2) and bla(NDM-1) (n = 1), which were harboured by three of the isolates. The mcr genes were located on IncHI2, IncFIIK and IncI1-like plasmids. The findings of this study highlight potential sources and reservoirs of mcr genes in the environment and illustrate the need for further research to gain a better understanding of the role the environment plays in the persistence and dissemination of antimicrobial resistance.202336906027
1870100.9997Novel Insights into bla(GES) Mobilome Reveal Extensive Genetic Variation in Hospital Effluents. Mobile genetic elements contribute to the emergence and spread of multidrug-resistant bacteria by enabling the horizontal transfer of acquired antibiotic resistance among different bacterial species and genera. This study characterizes the genetic backbone of bla(GES) in Aeromonas spp. and Klebsiella spp. isolated from untreated hospital effluents. Plasmids ranging in size from 9 to 244 kb, sequenced using Illumina and Nanopore platforms, revealed representatives of plasmid incompatibility groups IncP6, IncQ1, IncL/M1, IncFII, and IncFII-FIA. Different GES enzymes (GES-1, GES-7, and GES-16) were located in novel class 1 integrons in Aeromonas spp. and GES-5 in previously reported class 1 integrons in Klebsiella spp. Furthermore, in Klebsiella quasipneumoniae, bla(GES-5) was found in tandem as a coding sequence that disrupted the 3' conserved segment (CS). In Klebsiella grimontii, bla(GES-5) was observed in two different plasmids, and one of them carried multiple IncF replicons. Three Aeromonas caviae isolates presented bla(GES-1), one Aeromonas veronii isolate presented bla(GES-7), and another A. veronii isolate presented bla(GES-16). Multilocus sequence typing (MLST) analysis revealed novel sequence types for Aeromonas and Klebsiella species. The current findings highlight the large genetic diversity of these species, emphasizing their great adaptability to the environment. The results also indicate a public health risk because these antimicrobial-resistant genes have the potential to reach wastewater treatment plants and larger water bodies. Considering that they are major interfaces between humans and the environment, they could spread throughout the community to clinical settings. IMPORTANCE In the "One Health" approach, which encompasses human, animal, and environmental health, emerging issues of antimicrobial resistance are associated with hospital effluents that contain clinically relevant antibiotic-resistant bacteria along with a wide range of antibiotic concentrations, and lack regulatory status for mandatory prior and effective treatment. bla(GES) genes have been reported in aquatic environments despite the low detection of these genes among clinical isolates within the studied hospitals. Carbapenemase enzymes, which are relatively unusual globally, such as GES type inserted into new integrons on plasmids, are worrisome. Notably, K. grimontii, a newly identified species, carried two plasmids with bla(GES-5), and K. quasipneumoniae carried two copies of bla(GES-5) at the same plasmid. These kinds of plasmids are primarily responsible for multidrug resistance among bacteria in both clinical and natural environments, and they harbor resistant genes against antibiotics of key importance in clinical therapy, possibly leading to a public health problem of large proportion.202235880869
878110.9996Environmental Spread of New Delhi Metallo-β-Lactamase-1-Producing Multidrug-Resistant Bacteria in Dhaka, Bangladesh. Resistance to carbapenem antibiotics through the production of New Delhi metallo-β-lactamase-1 (NDM-1) constitutes an emerging challenge in the treatment of bacterial infections. To monitor the possible source of the spread of these organisms in Dhaka, Bangladesh, we conducted a comparative analysis of wastewater samples from hospital-adjacent areas (HAR) and from community areas (COM), as well as public tap water samples, for the occurrence and characteristics of NDM-1-producing bacteria. Of 72 HAR samples tested, 51 (71%) samples were positive for NDM-1-producing bacteria, as evidenced by phenotypic tests and the presence of the bla(NDM-1) gene, compared to 5 of 41 (12.1%) samples from COM samples (P < 0.001). All tap water samples were negative for NDM-1-producing bacteria. Klebsiella pneumoniae (44%) was the predominant bacterial species among bla(NDM-1)-positive isolates, followed by Escherichia coli (29%), Acinetobacter spp. (15%), and Enterobacter spp. (9%). These bacteria were also positive for one or more other antibiotic resistance genes, including bla(CTX-M-1) (80%), bla(CTX-M-15) (63%), bla(TEM) (76%), bla(SHV) (33%), bla(CMY-2) (16%), bla(OXA-48-like) (2%), bla(OXA-1) (53%), and bla(OXA-47-like) (60%) genes. Around 40% of the isolates contained a qnr gene, while 50% had 16S rRNA methylase genes. The majority of isolates hosted multiple plasmids, and plasmids of 30 to 50 MDa carrying bla(NDM-1) were self-transmissible. Our results highlight a number of issues related to the characteristics and source of spread of multidrug-resistant bacteria as a potential public health threat. In view of the existing practice of discharging untreated liquid waste into the environment, hospitals in Dhaka city contribute to the potential dissemination of NDM-1-producing bacteria into the community.IMPORTANCE Infections caused by carbapenemase-producing Enterobacteriaceae are extremely difficult to manage due to their marked resistance to a wide range of antibiotics. NDM-1 is the most recently described carbapenemase, and the bla(NDM-1) gene, which encodes NDM-1, is located on self-transmissible plasmids that also carry a considerable number of other antibiotic resistance genes. The present study shows a high prevalence of NDM-1-producing organisms in the wastewater samples from hospital-adjacent areas as a potential source for the spread of these organisms to community areas in Dhaka, Bangladesh. The study also examines the characteristics of the isolates and their potential to horizontally transmit the resistance determinants. The significance of our research is in identifying the mode of spread of multiple-antibiotic-resistant organisms, which will allow the development of containment measures, leading to broader impacts in reducing their spread to the community.201728526792
1002120.9996Genetic diversity and prevalence of extended-spectrum beta-lactamase-producing Escherichia coli and Klebsiella pneumoniae in aquatic environments receiving untreated hospital effluents. The spread of extended-spectrum beta-lactamase (ESBL)-producing bacteria in the environment has been recognized as a challenge to public health. The aim of the present study was to assess the occurrence of ESBL-producing Escherichia coli and Klebsiella pneumoniae from selected water bodies receiving hospital effluents in Kerala, India. Nearly 69.8% of Enterobacteriaceae isolates were multi-drug resistant by the Kirby-Bauer disc diffusion method. The double disc synergy test was used to detect the ESBL production and the genes responsible for imparting resistance were detected by PCR. Conjugation experiments confirmed the mechanism of plasmid-mediated transfer of resistance. The prevalence of ESBL production in E. coli and K. pneumoniae was 49.2 and 46.8%, respectively. Among the ESBL-encoding genes, bla(CTX-M) was the most prevalent group followed by bla(TEM), bla(OXA), bla(CMY,) and bla(SHV). The results suggest that healthcare settings are one of the key contributors to the spread of ESBL-producing bacteria, not only through cross-transmission and ingestion of antibiotics but also through the discharge of waste without a proper treatment, leading to harmful effects on the aquatic environment. The high prevalence of ESBL-producing Enterobacteriaceae with resistance genes in public water bodies even post-treatment poses a serious threat.202336705498
1843130.9996Chromosome-Based blaOXA-48-Like Variants in Shewanella Species Isolates from Food-Producing Animals, Fish, and the Aquatic Environment. Carbapenems are considered last-resort antibiotics in health care. Increasing reports of carbapenemase-producing bacteria in food-producing animals and in the environment indicate the importance of this phenomenon in public health. Surveillance for carbapenemase genes and carbapenemase-producing bacteria in Dutch food-producing animals, environmental freshwater, and imported ornamental fish revealed several chromosome-based bla(OXA-48)-like variants in Shewanella spp., including two new alleles, bla(OXA-514) and bla(OXA-515) Carbapenemase genes were not associated with mobile genetic elements or Enterobacteriaceae.201727855066
1854140.9996Whole genome analysis reveals the distribution and diversity of plasmid reservoirs of NDM and MCR in commercial chicken farms in China. The increase in multidrug-resistant (MDR) Enterobacteriaceae presents a significant challenge to clinical treatment, particularly in infections where carbapenems and colistin serve as the last-resort antimicrobial agents. In this study, we isolated 119 non-repetitive gram-negative bacteria from MacConkey medium supplemented with imipenem and colistin. The isolates were dominated by Klebsiella pneumoniae (58.0%, n = 69) and Escherichia coli (31.1%, n = 37). The predominant sequence types (STs) of E. coli were ST226, ST1286, and ST11738, whereas K. pneumoniae displayed ST152, ST395, and ST709 as major types. Genomic analysis identified mcr-1/3/8/9 in 44 strains and bla(NDM) in 63 strains across various species. IncX3 (n = 57) and IncFII (n = 5) were the most common bla(NDM-5)-carrying plasmid types. Several plasmid replicons were associated with mcr genes, including IncI2, IncX4, and novel plasmids. Remarkably, we discovered four combinations of bla(NDM) and mcr co-occurrence in 28 isolates, including bla(NDM-5)/mcr-1, bla(NDM-5)/mcr-3, bla(NDM-5)/mcr-8, and bla(NDM-5)/mcr-9. Our findings reveal that chicken farms are significant reservoirs for both bla(NDM) and mcr genes, with frequent co-occurrence of these resistance determinants. The presence of these genes alongside other resistance factors, such as blaESBL, highlights a critical public health risk. This study underscores the need for enhanced surveillance and intervention strategies to mitigate the spread of MDR pathogens from agricultural environments to clinical settings.IMPORTANCEThis study reveals that commercial poultry farms in China serve as critical reservoirs for MDR gram-negative bacteria harboring carbapenemase (bla(NDM)) and mobilized colistin resistance (mcr) genes. By analyzing 119 isolates, we uncovered extensive genetic diversity and plasmid-mediated co-occurrence of these resistance determinants, enabling bacteria to evade nearly all available treatments. Alarmingly, the horizontal transfer of resistance genes via highly mobile plasmids facilitates their spread across microbial communities and potentially into clinical settings. These findings underscore the urgent need to address antibiotic overuse in agriculture and strengthen surveillance under the One Health framework. The persistence of MDR pathogens in poultry environments highlights a significant risk for zoonotic transmission, emphasizing the necessity of coordinated interventions to curb the global antimicrobial resistance crisis.202540488461
906150.9996Related carbapenemase-producing Klebsiella isolates detected in both a hospital and associated aquatic environment in Sweden. Carbapenem antibiotics are one of the last-resort agents against multidrug-resistant (MDR) bacteria. The occurrence of carbapenemase-producing Enterobacteriaceae (CPE) in wastewater and aquatic environments is an indication of MDR bacteria in the community. This study evaluated CPE in aquatic environments and compared them to the local hospital isolates in Sweden. Phenotypic and genotypic analyses of antibiotic resistance of environmental and clinical CPE were performed. The relatedness of the isolates and possible clonal dissemination was evaluated using phylogenetic and phyloproteomic analysis. Klebsiella oxytoca carrying carbapenemase genes (bla(VIM-1), bla(IMP-29)) were isolated from wastewater and the recipient river, while K. oxytoca (bla(VIM-1)) and Klebsiella pneumoniae (bla(VIM-1), bla(OXA-48), bla(NDM-1), bla(KPC-3)) were isolated from patients at the local clinics or hospital. The K. oxytoca classified as sequence type 172 (ST172) isolated from the river was genotypically related to two clinical isolates recovered from patients. The similarity between environmental and clinical isolates suggests the dispersion of bla(VIM-1) producing K. oxytoca ST172 from hospital to aquatic environment and the likelihood of its presence in the community. This is the first report of CPE in aquatic environments in Sweden; therefore, surveillance of aquatic and hospital environments for CPE in other urban areas is important to determine the major transfer routes in order to formulate strategies to prevent the spread of MDR bacteria.201830171482
2754160.9996Antimicrobial resistance in Aeromonas species isolated from aquatic environments in Brazil. AIM: The current study was conducted to determine the antimicrobial resistance profile and genetic relatedness of Aeromonas sp. isolated from healthcare and urban effluents, wastewater treatment plant (WWTP) and river water. METHODS AND RESULTS: We detected the presence of genes conferring resistance to β-lactam, quinolone and aminoglycoside. Multilocus sequence typing was carried out to differentiate the strains, and multilocus phylogenetic analysis was used to identify the species. A total of 28 cefotaxime-resistant Aeromonas sp. strains were identified, harbouring uncommon Guiana-extended-spectrum (GES)-type β-lactamases (GES-1, GES-5, GES-7 and GES-16). Multidrug-resistant Aeromonas sp. were found in hospital wastewater, WWTP and sanitary effluent, and A. caviae was identified as the most prevalent species (85·7%). CONCLUSION: The release of untreated healthcare effluents, presence of antimicrobials in the environment, in addition to multidrug-resistant Aeromonas sp., are all potential factors for the spread of resistance. SIGNIFICANCE AND IMPACT OF THE STUDY: We identified a vast repertoire of antimicrobial resistance genes (ARG) in Aeromonas sp. from diverse aquatic ecosystems, including those that encode enzymes degrading broad-spectrum antimicrobials widely used to treat healthcare-associated infections. Hospital and sanitary effluents serve as potential sources of bacteria harbouring ARG and are a threat to public health.202133306232
2750170.9996Extended-spectrum β-lactamases genes in Gram-negative isolates from an urban river in Nicaragua. Limited resources and inadequate surveillance systems in developing countries have hindered research on antibiotic resistance gene transfer in aquatic environments. In this context, our study aimed to identify extended-spectrum beta-lactamase gene variants in Gram-negative isolates from the Tipitapa River-a significant Central America ecosystem. Samples were collected and assessed for key water parameters: dissolved oxygen, electrical conductivity, pH, and temperature. We employed a mix of microbiological, biochemical and molecular techniques, including multiplex PCR and sequencing, to characterize bacteria and determine the bla gene variants. Water quality parameters indicated areas impacted by human activities with high mineralization and eutrophication conditions. Among the bacteria analyzed, 48% belonged to the Enterobacteriaceae family, and a significant 88% displayed extended-spectrum beta-lactamases. Sequencing revealed four distinct bla gene variants in 84% of the isolates: bla-SHV-24, bla-SHV-13, bla-TEM-1, and bla-TEM-116, with bla-SHV-24 being the most common (47.62%). This is the first report of bla gene variants in the Tipitapa River, revealing their presence in globally concerning bacteria. The robust methodology enhances surveillance, enables geographic profiling of bla gene variants, and improves our understanding of biochemical patterns and gene transmission dynamics, providing essential insights into the global distribution of antibiotic resistance genes in Central America's natural waters.202539907335
2621180.9996Extended Spectrum Beta-Lactamase (ESBL)-producing bacteria isolated from hospital wastewaters, rivers and aquaculture sources in Nigeria. Untreated wastewater is a risk factor for the spread of antibiotic resistance in the environment. However, little is known about the contribution of untreated wastewater to the burden of antibiotic resistance in the Nigerian environment. In this study, a total of 143 ceftazidime-/cefpodoxime-resistant bacteria isolated from untreated wastewater and untreated wastewater-contaminated surface and groundwater in Nigeria were screened for extended-spectrum β-lactamase (ESBL) genes, integrons and integron gene cassettes by PCR. The genetic environment of bla (CTX-M-15) was mapped by PCR and potentially conjugative plasmids were detected among the isolates by degenerate primer MOB typing (DPMT). ESBL production was confirmed in 114 (79.7%) isolates and ESBL genes (bla (SHV), bla (CTX-M-15) and bla (TEM)) were detected in 85 (74.6%) ESBL-producing isolates. bla (CTX-M-15) was associated with ISEcp1 and with orf477 in 12 isolates and with ISEcp1, IS26 and orf477 in six others. To the best of our knowledge, this is the first report of bla (CTX-M-15) in hand-dug wells and borehole serving as sources of drinking water and a first report of the genetic environment of bla (CTX-M-15) in environmental bacteria from Nigeria. The results of this study confirm untreated wastewater as an important medium for the spread of ESBL-producing bacteria within the Nigerian environment. Hence, the widespread practice of discharging untreated wastewater into the aquatic ecosystem in Nigeria is a serious risk to public health.201829139076
2634190.9996Characterization of Escherichia coli and Other Enterobacterales Resistant to Extended-Spectrum Cephalosporins Isolated from Dairy Manure in Ontario, Canada. Extended-spectrum cephalosporins (ESCs) resistance genes, such as bla(CTX-M), bla(CMY), and bla(SHV), have been found regularly in bacteria from livestock. However, information on their distribution in dairy cattle in Canada and on the associated genome sequences of ESC-resistant Enterobacterales is sparse. In this study, the diversity and distribution of ESC-resistant Escherichia coli throughout manure treatments in six farms in Southern Ontario were assessed over a one-year period, and their ESC-resistance plasmids were characterized. The manure samples were enriched using selective media. The resulting isolates were screened via polymerase chain reaction for bla(CTX-M), bla(CMY), and bla(SHV). No E. coli carrying bla(SHV) were detected. Escherichia coli (n = 248) carrying bla(CTX-M) or bla(CMY) underwent whole-genome sequencing using an Illumina MiSeq/NextSeq. These isolates were typed using multilocus sequence typing (MLST) and their resistance gene profiles. A subset of E. coli (n = 28) were sequenced using Oxford Nanopore Technologies. Plasmids were assembled using Unicycler and characterized via the resistance genes pattern, replicon type, plasmid MLST, phylogenetic analysis, and Mauve alignments. The recovery of ESC-resistant Enterobacterales (18 species, 8 genera) was drastically reduced in manure outputs. However, multiple treatment stages were needed to attain a significant reduction. 62 sequence types were identified, with ST10, ST46, ST58, ST155, ST190, ST398, ST685, and ST8761 being detected throughout the treatment pipeline. These STs overlapped with those found on multiple farms. The ESC-resistance determinants included CTX-M-1, -14, -15, -17, -24, -32, -55, and CMY-2. The plasmids carrying bla(CTX-M) were more diverse than were the plasmids carrying bla(CMY). Known "epidemic plasmids" were detected for both bla(CTX-M) and bla(CMY). IMPORTANCE The increase in antimicrobial resistance is of concern for human and animal health, especially when resistance is conferred to extended-spectrum cephalosporins, which are used to treat serious infections in both human and veterinary medicine. Bacteria carrying extended-spectrum cephalosporin resistance genes, including bla(CTX-M) and bla(CMY), are frequently found in dairy manure. Manure treatment influences the loads and diversity of bacteria, including those carrying antimicrobial resistance genes, such as Enterobacterales and Escherichia coli. Any bacteria that survive the treatment process are subsequently applied to the environment. Enterobacterales carrying bla(CTX-M) or bla(CMY) can contaminate soil and crops consumed by humans and animals, thereby increasing the potential for antimicrobial resistance genes to integrate into the human gut microflora through horizontal gene transfer. This furthers the dissemination of resistance. Therefore, it is imperative to understand the effects manure treatments have on ESC-resistance in environmentally applied manure.202336695602