Prevalence of Antibiotic-Resistant Escherichia coli in Drinking Water Sources in Hangzhou City.
ABSTRACT: This study investigated the distribution of antibiotic resistant Escherichia coli (E. coli) and examined the possible relationship between water quality parameters and antibiotic resistance from two different drinking water sources (the Qiantang River and the Dongtiao Stream) in Hangzhou city of China. E. coli isolates were tested for their susceptibility to 18 antibiotics. Most of the isolates were resistant to tetracycline (TE), followed by ampicillin (AM), piperacillin (PIP), trimethoprim/sulfamethoxazole (SXT), and chloramphenicol (C). The antibiotic resistance rate of E. coli isolates from two water sources was similar; For E. coli isolates from the Qiantang River, their antibiotic resistance rates decreased from up- to downstream. Seasonally, the dry and wet season had little impact on antibiotic resistance. Spearman's rank correlation revealed significant correlation between resistance to TE and phenicols or ciprofloxacin (CIP), as well as quinolones (ciprofloxacin and levofloxacin) and cephalosporins or gentamicin (GM). Pearson's chi-square tests found certain water parameters such as nutrient concentration were strongly associated with resistance to some of the antibiotics. In addition, tet genes were detected from all 82 TE-resistant E. coli isolates, and most of the isolates (81.87%) contained multiple tet genes, which displayed 14 different combinations. Collectively, this study provided baseline data on antibiotic resistance of drinking water sources in Hangzhou city, which indicates drinking water sources could be the reservoir of antibiotic resistance, potentially presenting a public health risk.
Project description:CTX-M-producing Escherichia coli is the predominant type of extended-spectrum ?-lactamase (ESBL)-producing E. coli worldwide. In this study, molecular typing was conducted for 139 CTX-M-producing E. coli isolates, phenotypically positive for ESBLs, isolated from environmental water, swine, healthy humans, and hospitalized patients in Hangzhou, China. The antibiotic resistance profiles of the isolates for the cephalosporins and fluoroquinolones were determined. The isolates showed 100% resistance to cefotaxime and ceftriaxone while maintaining relatively high susceptibility to cefoxitin, cefepime, and ceftazidime. A total of 61.9% (86/139) of the isolates, regardless of origin, showed high resistance to fluoroquinolones. PCRs and DNA sequencing indicated that blaCTX-M-14 was the most prevalent CTX-M-9 group gene and that blaCTX-M-15 and blaCTX-M-55 were the dominant CTX-M-1 group genes. Isolates from all sources with CTX-M types belonging to the CTX-M-1 or CTX-M-9 group were most frequently associated with epidemics. Molecular homology analysis of the isolates, conducted by phylogenetic grouping, pulsed-field gel electrophoresis (PFGE), and multilocus sequence typing (MLST), demonstrated that the dominant clones belonged to B2-ST131, D-ST648, D-ST38, or A-CC10. These four sequence types (STs) were discovered in E. coli isolates both from humans and from environmental water, suggesting frequent and continuous intercompartment transmission between humans and the aquatic environment. Seven novel sequence types were identified in the current study. In conclusion, this study is the first to report the molecular homology analysis of CTX-M-producing E. coli isolates collected from water, swine, and healthy and hospitalized humans, suggesting that pathogens in the environment might originate both from humans and from animals.
Project description:Escherichia coli, is intimately associated with both human health and water sanitation. E. coli isolates from water can either be (i) host associated commensals, indicating recent faecal contamination; (ii) diarrheal pathogens or (iii) extra-intestinal pathogens that pose a direct health risk; or (iv) free-living. In this study we genetically characterised 28 E. coli isolates obtained from treated drinking water in south eastern Australia to ascertain their likely source. We used full genome sequencing to assign the isolates to their phylogenetic group and multi-locus sequence type. The isolates were also screened in silico for several virulence genes and genes involved in acquired antibiotic resistance. The genetic characteristics of the isolates indicated that four isolates were likely human pathogens. However, these isolates were not detected in sufficient numbers to present a health risk to the public. An additional isolate was a human associated strain. Nine isolates were water associated free-living strains that were unlikely to pose a health risk. Only 14% of the isolates belonged to the host associated phylogenetic group (B2) and only a single isolate had any antibiotic resistance genes. This suggests that the primary source of the drinking water E. coli isolates may not have been recent human faecal contamination.
Project description:Access to safe drinking water is now recognized as a human right by the United Nations. In developed countries like Canada, access to clean water is generally not a matter of concern. However, one in every five First Nations reserves is under a drinking water advisory, often due to unacceptable microbiological quality. In this study, we analyzed source and potable water from a First Nations community for the presence of coliform bacteria as well as various antibiotic resistance genes. Samples, including those from drinking water sources, were found to be positive for various antibiotic resistance genes, namely, ampC, tet(A), mecA, β-lactamase genes (SHV-type, TEM-type, CTX-M-type, OXA-1, and CMY-2-type), and carbapenemase genes (KPC, IMP, VIM, NDM, GES, and OXA-48 genes). Not surprisingly, substantial numbers of total coliforms, including Escherichia coli, were recovered from these samples, and this result was also confirmed using Illumina sequencing of the 16S rRNA gene. These findings deserve further attention, as the presence of coliforms and antibiotic resistance genes potentially puts the health of the community members at risk.In this study, we highlight the poor microbiological quality of drinking water in a First Nations community in Canada. We examined the coliform load as well as the presence of antibiotic resistance genes in these samples. This study examined the presence of antibiotic-resistant genes in drinking water samples from a First Nations Community in Canada. We believe that our findings are of considerable significance, since the issue of poor water quality in First Nations communities in Canada is often ignored, and our findings will help shed some light on this important issue.
Project description:Escherichia coli are widely used as indicators of fecal contamination, and in some cases to identify host sources of fecal contamination in surface water. Prevalence, genetic diversity and antimicrobial susceptibility were determined for 600 generic E. coli isolates obtained from surface water and sediment from creeks and channels along the middle Santa Ana River (MSAR) watershed of southern California, USA, after a 12 month study. Evaluation of E. coli populations along the creeks and channels showed that E. coli were more prevalent in sediment compared to surface water. E. coli populations were not significantly different (P?=?0.05) between urban runoff sources and agricultural sources, however, E. coli genotypes determined by pulsed-field gel electrophoresis (PFGE) were less diverse in the agricultural sources than in urban runoff sources. PFGE also showed that E. coli populations in surface water were more diverse than in the sediment, suggesting isolates in sediment may be dominated by clonal populations.Twenty four percent (144 isolates) of the 600 isolates exhibited resistance to more than one antimicrobial agent. Most multiple resistances were associated with inputs from urban runoff and involved the antimicrobials rifampicin, tetracycline, and erythromycin. The occurrence of a greater number of E. coli with multiple antibiotic resistances from urban runoff sources than agricultural sources in this watershed provides useful evidence in planning strategies for water quality management and public health protection.
Project description:The aim of this study was to examine antibiotic resistance (AR) dissemination in coastal water, considering the contribution of different sources of fecal contamination. Samples were collected in Berlenga, an uninhabited island classified as Natural Reserve and visited by tourists for aquatic recreational activities. To achieve our aim, AR in Escherichia coli isolates from coastal water was compared to AR in isolates from two sources of fecal contamination: human-derived sewage and seagull feces. Isolation of E. coli was done on Chromocult agar. Based on genetic typing 414 strains were established. Distribution of E. coli phylogenetic groups was similar among isolates of all sources. Resistances to streptomycin, tetracycline, cephalothin, and amoxicillin were the most frequent. Higher rates of AR were found among seawater and feces isolates, except for last-line antibiotics used in human medicine. Multi-resistance rates in isolates from sewage and seagull feces (29 and 32%) were lower than in isolates from seawater (39%). Seawater AR profiles were similar to those from seagull feces and differed significantly from sewage AR profiles. Nucleotide sequences matching resistance genes bla TEM, sul1, sul2, tet(A), and tet(B), were present in isolates of all sources. Genes conferring resistance to 3rd generation cephalosporins were detected in seawater (bla CTX-M-1 and bla SHV-12) and seagull feces (bla CMY-2). Plasmid-mediated determinants of resistance to quinolones were found: qnrS1 in all sources and qnrB19 in seawater and seagull feces. Our results show that seawater is a relevant reservoir of AR and that seagulls are an efficient vehicle to spread human-associated bacteria and resistance genes. The E. coli resistome recaptured from Berlenga coastal water was mainly modulated by seagulls-derived fecal pollution. The repertoire of resistance genes covers antibiotics critically important for humans, a potential risk for human health.
Project description:Urban waterways represent a natural reservoir of antibiotic resistance which may provide a source of transferable genetic elements to human commensal bacteria and pathogens. The objective of this study was to evaluate antibiotic resistance of Escherichia coli isolated from the urban waterways of Milwaukee, WI compared to those from Milwaukee sewage and a clinical setting in Milwaukee. Antibiotics covering 10 different families were utilized to determine the phenotypic antibiotic resistance for all 259 E. coli isolates. All obtained isolates were determined to be multi-drug resistant. The E. coli isolates were also screened for the presence of the genetic determinants of resistance including ermB (macrolide resistance), tet(M) (tetracycline resistance), and ?-lactamases (bla OXA, bla SHV, and bla PSE). E. coli from urban waterways showed a greater incidence of antibiotic resistance to 8 of 17 antibiotics tested compared to human derived sources. These E. coli isolates also demonstrated a greater incidence of resistance to higher numbers of antibiotics compared to the human derived isolates. The urban waterways demonstrated a greater abundance of isolates with co-occurrence of antibiotic resistance than human derived sources. When screened for five different antibiotic resistance genes conferring macrolide, tetracycline, and ?-lactam resistance, clinical E. coli isolates were more likely to harbor ermB and bla OXA than isolates from urban waterway. These results indicate that Milwaukee's urban waterways may select or allow for a greater incidence of multiple antibiotic resistance organisms and likely harbor a different antibiotic resistance gene pool than clinical sources. The implications of this study are significant to understanding the presence of resistance in urban freshwater environments by supporting the idea that sediment from urban waterways serves as a reservoir of antibiotic resistance.
Project description:Sphingomonadaceae (n = 86) were isolated from a drinking water treatment plant (n = 6), tap water (n = 55), cup fillers for dental chairs (n = 21), and a water demineralization filter (n = 4). The bacterial isolates were identified based on analysis of the 16S rRNA gene sequence, and intraspecies variation was assessed on the basis of atpD gene sequence analysis. The isolates were identified as members of the genera Sphingomonas (n = 27), Sphingobium (n = 28), Novosphingobium (n = 12), Sphingopyxis (n = 7), and Blastomonas (n = 12). The patterns of susceptibility to five classes of antibiotics were analyzed and compared for the different sites of isolation and taxonomic groups. Colistin resistance was observed to be intrinsic (92%). The highest antibiotic resistance prevalence values were observed in members of the genera Sphingomonas and Sphingobium and for beta-lactams, ciprofloxacin, and cotrimoxazole. In tap water and in water from dental chairs, antibiotic resistance was more prevalent than in the other samples, mainly due to the predominance of isolates of the genera Sphingomonas and Sphingobium. These two genera presented distinct patterns of association with antibiotic resistance, suggesting different paths of resistance development. Antibiotic resistance patterns were often related to the species rather than to the site or strain, suggesting the importance of vertical resistance transmission in these bacteria. This is the first study demonstrating that members of the family Sphingomonadaceae are potential reservoirs of antibiotic resistance in drinking water.
Project description:Surface waters are important sources of water for drinking, industrial, agricultural, and recreational uses; hence, contamination of water by fecal, pathogenic, or antimicrobial resistant (AR) bacteria is a major environmental and public health concern. However, very little data is available on prevalence of these bacteria in surface water throughout a watershed. This study aimed to characterize Escherichia coli present in the Upper Oconee Watershed, a mixed-use watershed in Athens, GA, USA for potential pathogenicity and AR. E. coli were enumerated by colony counts, cultured by enrichment and direct plating, and characterized by phylo-groups, diarrheagenic pathotypes, and antimicrobial susceptibility. From the analysis, 99.3% (455/458) of the total samples were positive for E. coli resulting in 496 isolates. E. coli counts were as high as 1.2×104 CFU/100 ml, which is above the United States Environmental Protection Agency (U.S. EPA) threshold for recreational water (235 CFU/100 ml based on a one-time measurement). Phylo-groups B2 (31.7%; 157/496) and B1 (30.8%; 153/496) were the most prevalent among the isolates. Enteropathogenic E. coli (EPEC) (19/496) and Shiga toxin-producing E. coli (STEC) (1/496) were the only diarrheagenic pathotypes detected. AR was observed in 6.9% (34/496) of the isolates, 15 of which were multidrug resistant (MDR; resistance to two or more classes of antimicrobials). Tetracycline resistance was most often detected (76.5%; 26/34), followed by ampicillin (32.4%; 11/34), streptomycin (23.5%; 8/34), sulfisoxazole (23.5%; 8/34), and nalidixic acid (14.7%; 5/34). Results from this study showed that E. coli is prevalent in high levels in the Upper Oconee Watershed, suggesting possible widespread fecal contamination. The presence of pathogenic, AR E. coli in the watershed indicates that environmental water can serve as a reservoir of resistant bacteria that may be transferred to humans through drinking and recreational activities.
Project description:Introduction: Community-acquired infections due to extended-spectrum beta-lactamase (ESBL) producing Escherichia coli are rising worldwide, resulting in increased morbidity, mortality, and healthcare costs, especially where poor sanitation and inadequate hygienic practices are very common. Objective: This study was conducted to investigate the prevalence and characterization of multidrug-resistant (MDR) and ESBL-producing E. coli in drinking water samples collected from Rohingya camps, Bangladesh. Methods: A total of 384 E. coli isolates were analyzed in this study, of which 203 were from household or point-of-use (POU) water samples, and 181 were from source water samples. The isolates were tested for virulence genes, ESBL-producing genes, antimicrobial susceptibility by VITEK 2 assay, plasmid profiling, and conjugal transfer of AMR genes. Results: Of the 384 E. coli isolates tested, 17% (66/384) were found to be ESBL producers. The abundance of ESBL-producers in source water contaminated with E. coli was observed to be 14% (27/181), whereas, 19% (39/203) ESBL producers was found in household POU water samples contaminated with E. coli. We detected 71% (47/66) ESBL-E. coli to be MDR. Among these 47 MDR isolates, 20 were resistant to three classes, and 27 were resistant to four different classes of antibiotics. Sixty-four percent (42/66) of the ESBL producing E. coli carried 1 to 7 plasmids ranging from 1 to 103 MDa. Only large plasmids with antibiotic resistance properties were found transferrable via conjugation. Moreover, around 7% (29/384) of E. coli isolates harbored at least one of 10 virulence factors belonging to different E. coli pathotypes. Conclusions: The findings of this study suggest that the drinking water samples analyzed herein could serve as an important source for exposure and dissemination of MDR, ESBL-producing and pathogenic E. coli lineages, which therewith pose a health risk to the displaced Rohingya people residing in the densely populated camps of Bangladesh.
Project description:The study investigated the prevalence of potentially pathogenic and drug resistant Escherichia coli among drinking water sources in Jordan. A total of 109 confirmed E. coli isolates were analyzed. Antimicrobial susceptibility testing was done using the Kirby Bauer disk diffusion method. Phenotypic identification of extended spectrum beta-lactamase (ESBL) and carbapenemase production was done using the double disk synergy test and the modified Hodge test, respectively. Isolates' plasmid profiles were determined by gel electrophoresis. PCR was used for detection of virulence and resistance genes. Overall, 22.0% of the isolates were potentially intestinal pathogenic E. coli (IPEC); namely enteroaggregative E. coli (16.5%), enteropathogenic E. coli (2.8%), enteroinvasive E. coli (1.8%), and enterohemorrhagic E. coli (0.9%). A third of the isolates were multi-drug resistant. The highest rates of antimicrobials resistance were observed against ampicillin (93.6%) and sulfamethoxazole/trimethoprim (41.3%). All isolates were susceptible to imipenem, meropenem, doripenem and tigecycline. The prevalence of ESBL and carbapenemase producers was 54.1% and 2.8%, respectively. BlaVIM was the most prevalent resistance gene (68.8%), followed by blaCTX (50.5%), blaTEM (45.9%), blaNDM (11%), blaKPC (4.6%), and blaSHV (0.9%). Fifty-eight (53.2%) isolates contained one or more plasmid ranging from 1.0 to 8.0 kbp. Overall, high prevalence of potentially pathogenic and resistant isolates was observed.