摘要

       抗生素抗性细菌和抗生素抗性基因 (ARGs) 的传播已引起全球关注。本研究从湖泊地表水样中分离出 114 株大肠杆菌，以确定它们对抗生素的敏感性，包括四环素 (TC)、庆大霉素 (GN)、氨苄青霉素 (AMP)、链霉素 (ST)、土霉素 (OC)、左氧氟沙星 (LEV)、萘啶酸 (NA) 和磺胺甲恶唑/甲氧苄啶 (SFT)。对 TC、GN、AMP、ST、OC、LEV、NA 和 SFT 显示抗性的分离株分别占总分离株的 50%、76%、68%、71%、55%、32%、82% 和 85%。确定了 37 种不同的耐药模式，最丰富的耐药谱（104 个中的 28 个）是 TC/GN/AMP/ST/OC/LEV/NA/SFT。在其对应的抗性克隆中检测到29个ARG的出现，88%的TC抗性、94%的SFT抗性、90%的AMP抗性、78%的ST抗性和72%的喹诺酮抗性克隆可以用它们对应的 ARG 来描述。应该注意的是，这些抗生素抗性克隆中的大多数都包含至少两个相应的 ARG，表明这些分离株中出现了高频率的组合 ARG。此外，还获得了9个新的qnr(B)基因DNA序列，经系统进化树分析显示，它们被聚类到同一组中。这些结果表明抗生素抗性的发展可归因于通过水平基因转移的 ARG 重组的高频率。

       The spread of antibiotic-resistance bacteria and antibiotic-resistance genes (ARGs) has been of concern worldwide. In this study, 114 Escherichia coli isolates were isolated from surface water samples of a lake to identify their susceptibility to antibiotics, including tetracycline (TC), gentamicin (GN), ampicillin (AMP), streptomycin (ST), oxytetracycline (OC), levofloxacin (LEV), nalidixic acid (NA), and sulfamethoxazole/trimethoprim (SFT). Isolates showing resistance to TC, GN, AMP, ST, OC, LEV, NA, and SFT occurred in 50, 76, 68, 71, 55, 32, 82, and 85 % of the total isolates, respectively. Thirty-seven different resistance patterns were identified, and the most abundant resistance profile (28 of 104) was TC/GN/AMP/ST/OC/LEV/NA/SFT. The occurrence of 29 ARGs were detected in their corresponding resistance clones, and 88 % of TC-resistance, 94 % of SFT-resistance, 90 % of AMP-resistance, 78 % of ST-resistance, and 72 % of quinolone-resistance clones can be described by their corresponding ARGs. It should be noted that most of these antibiotic-resistance clones harbored at least two corresponding ARGs, indicating that high frequencies of combined ARGs occurred in these isolates. In addition, 9 new types of DNA sequence of qnr(B) gene were obtained and were clustered into the same group as showed by phylogenetic trees analysis. These results suggest that the development of antibiotic resistance can be ascribed to the high frequency in the recombination of ARGs through horizontal gene transfer.

https://link.springer.com/article/10.1007/s00244-013-9932-2