Detection and genetic analysis of Escherichia coli from Tonle Sap Lake and its tributaries in Cambodia: Spatial distribution, seasonal variation, pathogenicity, and antimicrobial resistance. (15th December 2022)

• Record Type: Journal Article
• Authors: Yoneda, Ichiro; Rozanah, Ulya Nur; Nishiyama, Masateru; Mith, Hasika; Watanabe, Toru
• Is Part Of: Environmental pollution. Volume 315(2022)
• Publication Date: 2022-12-15
• Subjects: Tonle sap lake -- Fecal contamination -- Floating village -- Diarrheagenic Escherichia coli -- Multilocus sequence typing -- ESBL genotypes; Amoxicillin/clavulanate C/A -- Ampicillin ABPC -- antimicrobial-resistant bacteria ARB -- aztreonam AZT -- Brain Heart Infusion BHI -- cefotaxime CTX -- cefoxitin CFX -- chloramphenicol CP -- ciprofloxacin CPFX -- Clinical and Laboratory Standards Institute CLSI -- diarrheagenic E. coli DEC -- dissolved oxygen DO -- electrical conductivity EC -- enteroaggregative E. coli EAEC -- enterohemorrhagic E. coli EHEC -- enteroinvasive E. coli EIEC -- enteropathogenic E. coli EPEC -- enterotoxigenic E. coli ETEC -- extended-spectrum β-lactamase ESBL -- fosfomycin FOM -- gentamicin GM -- imipenem IPM -- multilocus sequence typing MLST -- sequence type ST -- sulfamethoxazol/trimethoprim ST. -- tazobactam/piperacillin T/P -- tetracycline TC -- Tonle Sap Lake TSL -- World Health Organization WHO; Pollution -- Periodicals; Pollution -- Environmental aspects -- Periodicals; Environmental Pollution -- Periodicals; Pollution -- Périodiques; Pollution -- Aspect de l'environnement -- Périodiques; Pollution -- Effets physiologiques -- Périodiques; Pollution; Pollution -- Environmental aspects; Periodicals; Electronic journals; 363.73
• DOI: 10.1016/j.envpol.2022.120406
• Languages: English
• ISSNs: 0269-7491

Abstract

Abstract: As an indicator of fecal contamination, Escherichia coli was monitored in Tonle Sap Lake, Cambodia, and its tributaries during low- and high-water seasons, focusing on the impacts on floating villagers inhabiting boathouses. E. coli concentrations in the floating villages (3.6 × 10 3 and 5.7 × 10 3 CFU/100 mL during the low- and high-water seasons, respectively) were significantly higher than those in other lake sites (4.0 × 10 1 and 7.0 × 10 0 CFU/100 mL during the low- and high-water seasons, respectively) and rivers (3.3 × 10 2 and 8.9 × 10 2 CFU/100 mL during the low- and high-water seasons, respectively), most likely because fecal materials from the boathouses were discharged without treatment. At most of the lake sampling sites remote from the boathouses, the E. coli concentration was lower during the high-water season than that during the low-water season, due to dilution by lake water. E. coli colonies detected during monitoring were isolated for pathotyping, antimicrobial susceptibility testing, beta-lactamase gene detection, and multilocus sequencing typing (MLST). Of the 659 E. coli isolates, 101 (15.3%) were diarrheagenic E. coli (DEC). The prevalence of DEC (52.2%) in the floating villages during the low-water season was higher than that during the high-water season (4.2%) and that in other sites during both seasons (10.6–21.3%). The DEC isolates from the floating villages during the low-water season showed high antimicrobial resistance, including ampicillin (83.4%) and ciprofloxacin (83.4%), and frequently possessed a beta-lactamase gene ( bla TEM ) (83.4%). MLST analysis indicated that the predominant sequence type (ST) of DEC isolates from the floating villages possibly originated from humans, whereas more diverse STs were detected in isolates from other sites. We revealed the wide presence of diarrheagenic and antimicrobial-resistant E. coli in Tonle Sap Lake and identified a considerable infection risk in floating villages, especially during the low-water season. Graphical abstract: Image 1 Highlights: A study of E.coli was conducted in Tonle Sap Lake, Cambodia and its tributaries. E. coli concentrations in floating villages were much higher than at other sites. E. coli colonies were isolated for analyses and to identify diarrheagenic strains. High prevalence of DEC is shown in E. coli isolates from floating villages. High antimicrobial resistance is shown in DEC isolates from floating villages.