Molecular characteristics of extended-spectrum β-lactamase-producing Escherichia coli isolated from the rivers and lakes in Northwest China

Abstract

BackgroundExtended-spectrum β-lactamases (ESBLs)-producing Escherichia coli (E. coli) isolates in environment water become progressively a potential threat to public health, while the detailed information about the ESBL-producing E. coli isolates in the rivers and lakes in Northwest China is scarce. In the present study, it was aimed to characterize the ESBL-producing E. coli isolated from the surface waters in Northwest China.ResultsA total of 2686 E. coli isolates were obtained from eleven rivers and lakes in Northwest China to screen for ESBL producers. Seventy-six (2.8%) isolates were classified as ESBL producers, and phylogenic groups D and A accounted for 59.2% of the ESBL producers. CTX-Ms were the predominant ESBLs genotype, and they were represented by seven blaCTX-M subtypes. blaCTX-M-14 was the most prevalent specific CTX-M gene, followed by blaCTX-M-9, blaCTX-M-123, blaCTX-M-15, blaCTX-M-27, blaCTX-M-1 and blaCTX-M-65. Moreover, 54 of the 76 ESBL producers carried at least one plasmid-mediated quinolone resistance (PMQR) gene, and aac(6′)-Ib-cr was predominant. The overall occurrence of virulence factors ranged from 1.3% (eae) to 48.7% (traT). Thirty-seven sequence types (STs) were confirmed among the 76 ESBL producers, and the predominant was ST10, which was represented by 10 isolates; importantly, clone B2-ST131, associated with severe infections in humans and animals, was detected three times.ConclusionThe prevalence of ESBL-producing E. coli from the rivers and lakes in Northwest China was low (2.8%), and the extraintestinal pathogenic E. coli (ExPEC) pathotype was the most commonly detected on the basis of the virulence factor profiles. 76.3% of ESBL producers harbored more than one β-lactamase gene, and blaCTX-M-14 was the predominant genotype. Notably, one ST131 isolate from Gaogan Canal simultaneously harbored blaCTX-M-9, blaCTX-M-15, blaCTX-M-123, blaKPC-2, blaNDM-1, blaOXA-2 as well as the PMQR genes qnrA, qnrS and aac(6′)-Ib-cr.

A survey of extended-spectrum beta-lactamase-producing Enterobacteriaceae in urban wetlands in southwestern Nigeria as a step towards generating prevalence maps of antimicrobial resistance

“…Thirty-five of the isolated 3GC-RB tested positive for ESBL production and were identified by partial 16S rRNA sequencing as belonging to the Enterobacteriaceae genera Escherichia (7 strains), Enterobacter (4 strains), and Citrobacter (1 strain), and to the "Pseudomonas putida group" [42,43] (10 strains; all with >99% identity to P. monteilii, P. taiwanensis, and P. plecoglossicida), Caulobacter (9 strains; about 95% identity with C. segnis), Achromobacter (2 strains; 98.61% identity with A. insuavis, and 99.12% identity with A. spanius, respectively), and Stenotrophomonas (2 strains; >99% similarity with S. pavanii). ESBL-producing bacteria have been isolated from aquatic ecosystems in different parts of the world [44][45][46][47][48][49] including Nigeria [9,50], in particular from sites were insufficiently treated wastewater is released into the aquatic environment.…”

“…E. coli ST617 is a member of the ST10 complex, which has emerged as important carrier mediating the spread of antimicrobial resistance genes including bla CTX-M-15 [55]. Members of the ST10 complex have a broad host range [56] and have been isolated from patients around the world including Nigeria [57,58], animals [59][60][61], food [62], and other environmental sources [48,49,63]. We are not aware of any published information on E. cloacae ST976 and C. freundii ST323 other than their mentioning in EnteroBase [64].…”

<p>Multi-Drug Resistant <em>Escherichia coli</em> Causing Early-Onset Neonatal Sepsis – a Single Center Experience from China</p>

“…In a recent study from China, a surprisingly high number (50.5%, 55/109) of fecal samples from healthy adults showed the presence of ESBL-producing E. coli 28. Even some (2.8%) of E. coli isolates obtained from rivers and lakes in Northwest China were found to be ESBL producers 29. This is because a significant increase in antibiotic consumption has been seen in China and other developing countries both as prescriptions for patients and feed additives in the agriculture industry 30.…”

Comparative distribution of extended-spectrum beta-lactamase–producing Escherichia coli from urine infections and environmental waters

“…coli in hospital environments has been extensively reported previously; however, hospitals are not the only reservoirs of antibiotic-resistant bacteria [34], as ESBL-producing E . coli have also been detected in community wastewaters [35], wild birds and animals [8, 36], and natural aquatic environments [37]. The transmission of ESBL-producing E .…”