Pathogenic Escherichia coli Strains Producing Extended-Spectrum β-Lactamases in the Yeongsan River Basin of South Korea

Abstract

A total of 3564 E. coli isolates obtained from Yeongsan River basin of South Korea were investigated for their production of extended-spectrum β-lactamases (ESBLs) and potential pathogenicity to better understand the linkage between antibiotic-resistant pathogens in the environment and their public health risks. Interestingly, 60% (53 of 89) of the screen-positive ESBL producers were determined to be potentially one or both of the diarrheagenic and extraintestinal pathogenic (ExPEC) pathotypes, suggesting that trade-off between resistance and virulence of E. coli may not apply to this study. In addition, 67% (60 of 89) of the screen-positive ESBL producers possessed more than one β-lactamase gene, and most (59 of 63) of the ESBL producers had the CTX-M-14 enzyme, which is the most dominant ESBL and seems to be related to urban anthropogenic activities. About 68% (36 of 53) of the potential pathogenic strains were resistant to more than 2 non-β-lactam antibiotics. Results from this study indicate that the Yeongsan River basin has been contaminated with antibiotic-resistant and potential pathogenic E. coli strains. While few studies have examined pathogenecity of ESBL-producing bacteria, this study reports the possible public health risk which could be caused by the fecal indicator bacterium itself containing both ESBL genes and virulence factors. This will likely impact the dissemination of potential pathogenic E. coli producing ESBLs in the environment and suggests the need for further investigations of antibiotic-resistant pathogens to prevent public health impacts in the Yeongsan River basin.

Identification and antibiotic resistance profiling of bacterial isolates from septicaemic soft-shelled turtles (Pelodiscus sinensis)

“…The literature data regarding the antimicrobial resistance patterns according to bacterial species and isolate sources are inconsistent (Foti et al 2009;Chen et al 2010;Al-Bahry et al 2011;Al-Bahry et al 2012;Aravena-Roman et al 2012;Jang et al 2013). In contrast to these previous reports, our major findings include higher resistance to cefotaxime and imipenem among enteric bacteria and aeromonads, respectively.…”

“…These results might be due to varying levels of enzyme produced in different bacterial species and/or isolates, and indeed previous findings demonstrated that the degree of resistance to β-lactams depends on the amount of TEM or SHV enzyme produced among isolates (Wu et al 1994;Livermore 1995). In addition, a high prevalence of the bla TEM-171 gene was reported in only one previous study with E. coli isolates collected from a river in Korea (Jang et al 2013). Although determining the prevalence of the bla TEM gene requires further study, this gene might be widely disseminated in natural Korean environments.…”

“…Many studies have indicated that the aquatic environment is a vehicle for the spread of antibioticresistant bacteria and resistance genes (Jang et al 2013;Marti et al 2014). The present data further support this idea, and show a high prevalence and diversity of genetic determinants among the present isolates recovered from freshwater turtle aquaculture.…”

Whole-Genome Analysis of Antimicrobial-Resistant and Extraintestinal Pathogenic Escherichia coli in River Water

“…Moreover, infections caused by MDR bacteria can lead to inadequate or delayed antimicrobial therapy (11). Importantly, many studies have reported the presence of MDR E. coli strains in surface waters and water-related environments, on the basis of phenotypic resistance testing and detection of several resistance determinants (12)(13)(14)(15)(16)(17)(18). Some studies also investigated the clonal composition of MDR E. coli strains based on MLST (13,14).…”

Use of Pyrosequencing for Characterizing Microbial Community at Phylum Level in Yeongsan River Watershed during Early Summer

“…또한 미생물의 군집 구조와 수온, pH, retention time과의 관계 (Lindstrom et al, 2005), Cyanobacterial bloom (Eiler and Bertilsson, 2004) 리고 토지사용과의 관계 (Foley et al, 2005 (Unno et al, 2009(Unno et al, , 2010a(Unno et al, , 2010bWill et al, 2010;Han et al, 2011;Jang et al, , 2013 Table S1). …”