Phenotyping and genotyping of antihiotic-resistant Escherichia coli isolated from a natural river basin
Phenotyping and genotyping of antihiotic-resistant Escherichia coli isolated from a natural river basin
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DOI：
10.1021/es7026746
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发表时间：
2008-05-01
影响因子：
11.4
通讯作者：
Kamagata, Yoichi
中科院分区：
文献类型：
--
作者：
Hu, Jianying;Shi, Jiachen;Kamagata, Yoichi
科学家们越来越关注环境中抗菌药物耐药性的发生。在这项研究中，大肠埃希菌筛选9种抗生素中的一种或多种抗生素耐药的中国北京温榆河流域，与平均频率48.7 +/-8.7%的388株在夏季和47 +/-6%的236株在冬季。夏季平均多药耐药指数（MAR）为0.11 ± 0.03，略低于冬季（0.14 ± 0.04）。最常见的耐药性出现磺胺类，四环素，氨苄西林。对20个四环素、3个磺胺类和3个β-内酰胺类耐药基因在耐药菌株中的分布进行了评估。97%的氨苄青霉素（AMP）耐药机制可由耐药基因TEM解释，90%的四环素（TC）和96%的磺胺（SXT）耐药机制可分别由tet（A）、tet（B）、tet（M）及其组合和sul（I）、sul（II）、sul（III）及其组合解释。team）及其与tet（A）或tet（B）的组合首次在大肠杆菌中被发现。结果表明，从天然河流流域分离的大肠杆菌中，除1株来自猪的大肠杆菌外，其他细菌的大肠杆菌中均未检测到该基因，表明该基因可能是通过水平基因转移从其他细菌物种中转移过来的。根据动物和人类磺胺类药物耐药基因型的比较，河流中磺胺类药物耐药大肠杆菌的来源应该主要来自人类。
Scientists have become increasingly concerned about the occurrence of antibacterial resistance in the environment. In this study, Escherichia coli resistant to one or more antibiotics among nine antibiotics was screened from Wenyu River Basin in Beijing, China, with mean frequency of 48.7 +/- 8.7% of 388 isolates in summer and 47 +/- 6% of 236 isolates in winter. The mean multiantibiotic resistance (MAR) index in summer was 0.11 +/- 0.03, slightly lower than that (0.14 +/- 0.04) in winter. Most frequent resistance appeared for sulfonamides, tetracycline, and ampicillin. The distribution of 20 tetracycline, three sulfonamicle, and three beta-lactam resistance genes was assessed in the resistant isolates. While 97% of the ampicillin (AMP) resistant mechanism could be explained by the resistance gene TEM, 90% of the tetracycline (TC) and 96% of the sulfonamide (SXT) resistances could be explained by tet(A), tet(B), tet(M), and their combinations and sul(I), sul(II), sul(III), and their combinations, respectively. team), a tetra cycline-resistant gene originally detected in Gram-positive bacteria, and its combinations with tet(A) or tet(B) were first detected in E. coli isolated from a natural river basin, suggesting that team) in E coli might have been transferred from other bacterial species through horizontal gene transfer which was supported by the fact that no team) was detected in the isolates of human and chicken sources, except for only one isolate from swine. The source of sulfonamide-resistant E coli in the river was supposed to be mainly from humans, based on a comparison of the sulfonamide resistance genotypes in animals and humans.