标题：The prevalence of virulence genes specific for Escherichia coli in wastewater samples from wastewater treatment plants with the activated sludge process
摘要：Treated wastewater evacuated into the aquatic environment is
a potential reservoir of pathogenic and virulent bacteria. The aim of this study
was to analyze the presence of genes encoding virulence in E. coli bacteria in
samples of untreated (UWW) and treated (TWW) wastewater from
13 wastewater treatment plants deploying various sewage treatment methods.
Wastewater samples were passed through polycarbonate membrane filters, and
genomic DNA was extracted. Virulence genes specific for E. coli were detected
by standard PCR and were grouped according to their association with different
pathotypes. The stx2 gene was most prevalent in samples of UWW, and the eae
gene was most frequently detected in samples of TWW. An analysis of
virulence markers revealed a predominance of genes characteristic of STEC
and EIEC pathotypes. The highest variability of virulence genes was observed
in wastewater treatment plants where sewage is treated mechanically and
biologically, and the lowest variability was noted in plants deploying the A2/O
treatment process (3-stage Bardenpho). In several plants, the prevalence of
virulence genes increased after treatment. The results of this study suggest that
wastewater treatment plants are significant reservoirs of virulent bacteria. The
evacuation of TWW into water bodies can contribute to the dissemination of
virulence genes in the environment, which poses a serious health hazard for
humans and animals.
其他摘要：Treated wastewater evacuated into the aquatic environment is a potential reservoir of pathogenic and virulent bacteria. The aim of this study was to analyze the presence of genes encoding virulence in E. coli bacteria in samples of untreated (UWW) and treated (TWW) wastewater from 13 wastewater treatment plants deploying various sewage treatment methods. Wastewater samples were passed through polycarbonate membrane filters, and genomic DNA was extracted. Virulence genes specific for E. coli were detected by standard PCR and were grouped according to their association with different pathotypes. The stx 2 gene was most prevalent in samples of UWW, and the eae gene was most frequently detected in samples of TWW. An analysis of virulence markers revealed a predominance of genes characteristic of STEC and EIEC pathotypes. The highest variability of virulence genes was observed in wastewater treatment plants where sewage is treated mechanically and biologically, and the lowest variability was noted in plants deploying the A2/O treatment process (3-stage Bardenpho). In several plants, the prevalence of virulence genes increased after treatment. The results of this study suggest that wastewater treatment plants are significant reservoirs of virulent bacteria. The evacuation of TWW into water bodies can contribute to the dissemination of virulence genes in the environment, which poses a serious health hazard for humans and animals.
