Department of Marine Biology, Microbiology and Biochemistry, School of Marine Sciences, Cochin University of Science and Technology, Lakeside Campus, Cochin, 682 016, Kerala, India.
Department of Marine Biology, Microbiology and Biochemistry, School of Marine Sciences, Cochin University of Science and Technology, Lakeside Campus, Cochin, 682 016, Kerala, India.
Int J Hyg Environ Health. 2019 Mar;222(2):235-248. doi: 10.1016/j.ijheh.2018.11.002. Epub 2018 Nov 26.
The goal of this study was to investigate the involvement of a tropical Indian estuary in the emergence of antibiotic resistance genes (ARGs)-harboring hypervirulent E. coli of global significance. A total of 300 E. coli isolates was tested for antibiotic susceptibility to β-lactams, aminoglycosides, chloramphenicol, quinolones, sulphonamides, tetracyclines, and trimethoprim. The E. coli isolates were screened for the presence of antibiotic resistance genes (bla, bla, tetA, tetB, sul1, sul2, strA, aphA2, catI, dhfr1, and dhfr7), integrase (int1, int2, and int3), Shiga toxin genes (stx1 and stx2) and extraintestinal virulence genes (papAH, papC, sfa/focDE, kpsMT II, and iutA). The highest prevalence of antibiotic resistance was observed for ampicillin, followed by tetracycline, and nalidixic acid. Among E. coli isolates, 64% were resistant to at least one of the 15 antibiotics tested, and approximately 40% were multiple antibiotic-resistant (MAR). More than 40% (n = 122) of E. coli isolates had ARGs. Integrase 1 (int1) was found in 7.6% of E. coli isolates. Among E. coli isolates, 16.3% (n = 49) were extraintestinal pathogenic E. coli (ExPEC), and approximately 34.6% (n = 17) of ExPEC had ARGs. A hypervirulent ARGs-harboring STEC was isolated. The prevalence of Shiga toxin-producing E. coli (STEC) was low (n = 1). The prevalence of ARGs-harboring pathogenic E. coli isolates was higher in stations close to the City (urban area), than that of other stations. ERIC-PCR (enterobacterial repetitive intergenic consensus sequence polymerase chain reaction) analysis revealed a high degree of genetic diversity among the ARGs-harboring E. coli isolates. The results demonstrate a high prevalence of ARGs-harboring E. coli in estuarine water and confirm the need for a better wastewater treatment facility and proper control measures to reduce the discharge of sewage and wastewater into the aquatic environments.
本研究旨在探讨热带印度河口在具有全球重要意义的产超毒力耐抗生素基因（ARGs）大肠杆菌出现中的作用。共检测了 300 株大肠杆菌对β-内酰胺类、氨基糖苷类、氯霉素、喹诺酮类、磺胺类、四环素类和甲氧苄啶的抗生素敏感性。筛选了大肠杆菌是否存在抗生素耐药基因（bla、bla、tetA、tetB、sul1、sul2、strA、aphA2、catI、dhfr1 和 dhfr7）、整合酶（int1、int2 和 int3）、志贺毒素基因（stx1 和 stx2）和肠外毒力基因（papAH、papC、sfa/focDE、kpsMT II 和 iutA）。结果发现，对氨苄青霉素的耐药率最高，其次是四环素和萘啶酸。在大肠杆菌分离株中，64%至少对 15 种抗生素中的一种耐药，约 40%为多重耐药（MAR）。超过 40%（n=122）的大肠杆菌分离株携带 ARGs。发现整合酶 1（int1）在 7.6%的大肠杆菌分离株中。在大肠杆菌分离株中，16.3%（n=49）为肠外致病性大肠杆菌（ExPEC），约 34.6%（n=17）的 ExPEC 携带 ARGs。分离出一株携带超毒力基因和 ARGs 的产志贺毒素大肠杆菌（STEC）。产志贺毒素大肠杆菌（STEC）的流行率较低（n=1）。靠近城市（城区）的站点携带 ARGs 的致病性大肠杆菌分离株的流行率高于其他站点。ERIC-PCR（肠杆菌重复基因间保守序列聚合酶链反应）分析显示，携带 ARGs 的大肠杆菌分离株具有高度的遗传多样性。结果表明，河口水中携带 ARGs 的大肠杆菌的流行率较高，证实需要更好的污水处理设施和适当的控制措施，以减少污水和废水排入水生环境。
