State Key Laboratory of Agricultural Microbiology, Laboratory of Animal Infectious Diseases, College of Animal Science & Veterinary Medicine, Huazhong Agricultural University, Wuhan, China.
Microb Pathog. 2011 May;50(5):207-12. doi: 10.1016/j.micpath.2011.01.004. Epub 2011 Jan 13.
Antibiograms and relevant genotypes of porcine extraintestinal pathogenic Escherichia coli (ExPEC) isolates (n = 315) recovered between 2004 and 2007 in China were assessed. Among the 14 antimicrobials tested, the most prevalent resistance was to ampicillin, trimethoprim, sulfadimidine, tetracycline, neomycin, streptomycin, kanamycin, ciprofloxacin and ofloxacin (ranging from 81.9 to 100%). Forty-six multiresistant patterns were found. For each antimicrobial agent, ampicillin resistance was primarily mediated by bla(TEM,) streptomycin resistance by strA and strB, kanamycin/neomycin resistance by aphA1, gentamicin resistance by aac(3)-IV, quinolones resistance by mutations in gyrA, tetracycline resistance by tet(A), tet(B) and tet(G), trimethoprim resistance by dfrA7, dfrA12 and dfrA13, and sulfadimidine resistance by sul1 and sul2. Both bla(TEM-1) and bla(CTX-M-14) were found in two ESBLs-producing isolates. Strains that harbored several genes that conferred resistance to the same antimicrobial agent were often significantly more multiresistant than others. Class 1 integrons were identified in 86 (27.3%) ExPEC isolates, which harbored dfrA14, aadA2, aadA22, dfrA17, aadA5, dfrA17-aadA2, dfrA1-aadA1, dfrA12-aadA2, dfrA17-aadA5 gene cassettes in five major different variable regions, conferring resistance to trimethoprim and aminoglycosides. These results provide novel insights into the epidemiological characteristics of porcine ExPEC strains in China, and suggest the need for the prudent use of antimicrobial agents in food animals.
2004 年至 2007 年间，中国从猪肠道外致病性大肠杆菌（ExPEC）分离株（n=315）中评估了抗生素谱和相关基因型。在所测试的 14 种抗生素中，最常见的耐药性是氨苄西林、甲氧苄啶、磺胺嘧啶、四环素、新霉素、链霉素、卡那霉素、环丙沙星和氧氟沙星（范围为 81.9%至 100%）。发现了 46 种多药耐药模式。对于每种抗生素，氨苄西林耐药主要由 bla(TEM,)介导，链霉素耐药由 strA 和 strB 介导，卡那霉素/新霉素耐药由 aphA1 介导，庆大霉素耐药由 aac(3)-IV 介导，喹诺酮类耐药由 gyrA 突变介导，四环素耐药由 tet(A)、tet(B)和 tet(G)介导，甲氧苄啶耐药由 dfrA7、dfrA12 和 dfrA13 介导，磺胺嘧啶耐药由 sul1 和 sul2 介导。两种 ESBLs 产生菌均发现 bla(TEM-1)和 bla(CTX-M-14)。携带多个赋予同一抗生素耐药性基因的菌株通常比其他菌株具有更高的多药耐药性。86 株（27.3%）ExPEC 分离株携带 1 类整合子，它们携带 dfrA14、aadA2、aadA22、dfrA17、aadA5、dfrA17-aadA2、dfrA1-aadA1、dfrA12-aadA2、dfrA17-aadA5 基因盒，存在于五个主要不同的可变区，对甲氧苄啶和氨基糖苷类抗生素具有耐药性。这些结果为中国猪源 ExPEC 菌株的流行病学特征提供了新的见解，并表明需要谨慎使用食品动物中的抗菌药物。
