Department of Biology and CESAM, University of Aveiro, Campus Universitário de Santiago, Aveiro, Portugal.
Sci Total Environ. 2013 Sep 1;461-462:65-71. doi: 10.1016/j.scitotenv.2013.04.067. Epub 2013 May 25.
Fecal pollution of surface waters is a current world-wide public health concern and may contribute for the dissemination of antibiotic resistance. The Tagus estuary located in the south of Portugal is one of the largest wetlands in the west coast of Europe. In this study, water samples were collected from seven stations with different anthropic pressures along the estuary and evaluated for water quality indicator bacteria. Escherichia coli isolates (n=350) were typed by REP-PCR. Representatives of each REP profile (n=220) were evaluated phenotypically for resistance to 17 antibiotics and characterized in terms of phylogenetic group. Resistant isolates were screened for the presence of antibiotic resistance genes (tet(A), tet(B), sul1, sul2, qnrA, qnrB, qnrS, aacA4-cr, bla(TEM), bla(SHV), bla(CTX-M), bla(CMY-like), bla(IMP), bla(VIM)) and integrase genes (intI1 and intI2). The highest antibiotic resistance prevalence was observed for streptomycin and tetracycline followed by β-lactams and sulphonamides. Among E. coli isolates, 65.16% were resistant to at least one of the 17 antibiotics tested and approximately 19% were multiresistant. In our E. coli population phylo-groups A and D were predominant and characterized by higher prevalence of the antibiotic resistance. intI1 and intI2 genes were found in 12% of the isolates with prevalence of class 1 integrons. A strong correlation between the prevalence of integrons and multiresistance was observed. Differences in terms of antibiotic resistance between phylogenetic groups and between sampling sites were statistically significant. The results demonstrate a high prevalence of antibiotic resistance among E. coli circulating in the Tagus estuary with emphasis on the occurrence of resistance to last-resort antibiotics and on the high incidence of multiresistance.
地表水粪便污染是当前全球关注的公共卫生问题，可能导致抗生素耐药性的传播。塔霍河口位于葡萄牙南部，是欧洲西海岸最大的湿地之一。在这项研究中，从河口不同人为压力的七个站点采集水样，并评估水质指示菌。对 350 株大肠杆菌分离株进行重复扩展聚合酶链反应 (REP-PCR) 分型。对每个 REP 图谱的代表 (n=220) 进行表型耐药性评估，以评估对 17 种抗生素的耐药性，并根据系统发育群进行特征描述。筛选耐药分离株中是否存在抗生素耐药基因 (tet(A)、tet(B)、sul1、sul2、qnrA、qnrB、qnrS、aacA4-cr、bla(TEM)、bla(SHV)、bla(CTX-M)、bla(CMY-like)、bla(IMP)、bla(VIM)) 和整合酶基因 (intI1 和 intI2)。观察到的最高抗生素耐药率为链霉素和四环素，其次是β-内酰胺类和磺胺类。在大肠杆菌分离株中，65.16%至少对测试的 17 种抗生素中的一种具有耐药性，约 19%为多药耐药性。在我们的大肠杆菌种群中，A 群和 D 群占优势，并且表现出更高的抗生素耐药率。在 12%的分离株中发现了 intI1 和 intI2 基因，并且存在 1 类整合子的流行。整合子的流行与多药耐药性之间存在很强的相关性。在系统发育群和采样点之间，抗生素耐药性存在差异，具有统计学意义。研究结果表明，塔霍河口的大肠杆菌中存在高比例的抗生素耐药性，尤其突出的是对最后一线抗生素的耐药性以及多药耐药性的高发。
