Abstract

This study was aimed to determine the prevalence of antibiotic-resistant Escherichia coli in the Szreniawa river with detailed aims of: (i) assessment of differences in the number of microbiological indicators of water quality in a diurnal cycle in a vicinity of the sewage treatment plant (STP); (ii) determination of prevalence of antimicrobial resistant E. coli isolated from three sites located at varying locations toward the STP; (iii) evaluation of the presence of extended-spectrum beta lactamase (ESBL)-determining genes in waterborne E. coli isolated from three sites of Szreniawa and (iv) genetic similarity assessment among the E. coli populations. Bacteriological contamination (coliforms, E. coli, E. faecalis) was assessed using membrane filtration. Fifty E. coli strains, the species of which was confirmed by MALDI-TOF analysis, were subjected to antimicrobial resistance tests using standard disk-diffusion method. Double disk synergy test was used to assess the ESBL production and PCR tests were conducted to detect the ESBL-conferring genes and evaluate the genetic diversity. A significant variation in the number of bacteriological indicators was observed both within and between the sampling sites, suggesting the effect of effluent from the STP, point discharge of household sewage and agricultural runoff on the water contamination. The resistance to amoxicillin/clavulanate (90%) and ampicillin (36%) was most prevalent. Multidrug resistance was observed in 40% of strains but no ESBL-producing strains were observed phenotypically. However, the presence of three ESBL-determining genes (TEM, OXA and CTX-M) was detected in 24, 10 and 8% of strains, respectively. A number of factors caused considerable pollution of the river and numerous multidrug resistant E. coli strains were isolated.

摘要

本研究的目的是确定抗生素抗性的流行大肠杆菌在Szreniawa河流与详述的目的：在污水处理厂的附近的日循环中的水的质量的微生物指标数差异（I）的评估（STP）；（ii）确定从位于STP不同位置的三个位置分离出的抗药性大肠杆菌的流行率；（iii）评估从Szreniawa的三个位点分离出的水性大肠杆菌中是否存在超广谱β-内酰胺酶（ESBL）决定基因，以及（iv）大肠杆菌种群之间的遗传相似性评估。细菌污染（大肠菌，大肠杆菌，使用膜过滤法评估粪肠球菌。五十种大肠杆菌通过MALDI-TOF分析确认了其菌株的菌株，使用标准的圆盘扩散法进行了抗药性测试。使用双盘协同试验评估ESBL的产生，并进行PCR试验以检测有ESBL的基因并评估遗传多样性。在采样点内和采样点之间均观察到细菌学指标数量的显着变化，这表明污水处理厂出水，家庭污水的点排放和农业径流对水污染的影响。对阿莫西林/克拉维酸盐（90％）和氨苄青霉素（36％）的耐药性最为普遍。在40％的菌株中观察到多药耐药性，但在表型上未观察到产生ESBL的菌株。但是，存在三个ESBL决定基因（分别在24、10和8％的菌株中检测到TEM，OXA和CTX-M）。许多因素造成了河流的严重污染，并分离了许多具有多重耐药性的大肠杆菌。