Veterinary Medical Research Institute of Hungarian Academy of Sciences, H-1143 Budapest, Hungária Krt. 21, Hungary.
Vet Microbiol. 2012 Apr 23;156(1-2):110-8. doi: 10.1016/j.vetmic.2011.09.030. Epub 2011 Oct 2.
Recent data from the European and Hungarian Antimicrobial Resistance Monitoring Systems have indicated that the routine use of gentamicin in human and veterinary medicine frequently leads to the selection of gentamicin resistance in Escherichia coli. The aim of this study was to provide molecular characterization of gentamicin resistance in clinical and commensal E. coli strains representing humans and food producing animals by genotyping for antimicrobial resistance and virulence using a miniaturized microarray. All 50 strains tested proved to be multidrug resistant defined as resistance to three or more antimicrobial classes. Antimicrobial resistances genes such as aadA1-like, strB, bla(TEM), sul1 and tet(A) or tet(B), and corresponding phenotypes (streptomycin-, ampicillin-, sulfamethoxazole- and tetracycline resistance) were detected in >50% of isolates regardless of the host or clinical background. However, certain genes encoding gentamicin resistance such as aac(6')-Ib and ant(2″)-Ia as well as catB3-like genes for phenicol resistance were only detected in human isolates. Among virulence genes, the increased serum survival gene iss was predominant in all host groups. Although the majority of gentamicin resistant E. coli strains were characterized by diverse antimicrobial resistance, and virulence gene patterns, accentuated links between catB3-like, aac(6')-Ib, bla(CTX-M-1) and sat genes could be detected in human strains. Further resistance/virulence gene associations (tet(A) with iroN and iss) were detected in poultry strains. In conclusion, the simultaneous characterization of antimicrobial resistance and virulence genotypes of representative clinical and commensal strains of E. coli should be useful for the identification of emerging genotypes with human and or animal health implications.
最近来自欧洲和匈牙利抗菌药物耐药性监测系统的数据表明，庆大霉素在人类和兽医医学中的常规使用经常导致大肠杆菌中庆大霉素耐药性的选择。本研究的目的是通过使用微型化微阵列对代表人类和食用动物的临床和共生大肠杆菌菌株进行抗菌药物耐药性和毒力的基因分型，提供庆大霉素耐药性的分子特征。所有 50 株受试菌株均被证明是多药耐药，定义为对三种或更多抗菌药物类别的耐药性。耐药基因，如 aadA1-样、strB、bla(TEM)、sul1 和 tet(A)或 tet(B)，以及相应的表型（链霉素、氨苄西林、磺胺甲恶唑和四环素耐药），无论宿主或临床背景如何，在>50%的分离株中均被检测到。然而，某些编码庆大霉素耐药性的基因，如 aac(6')-Ib 和 ant(2″)-Ia 以及编码氯霉素耐药性的 catB3-样基因，仅在人分离株中检测到。在毒力基因中，所有宿主群体中均以增加的血清存活基因 iss 为主导。尽管大多数庆大霉素耐药的大肠杆菌菌株具有不同的抗菌药物耐药性和毒力基因模式，但在人分离株中可以检测到 catB3-样、aac(6')-Ib、bla(CTX-M-1)和 sat 基因之间的关联。在禽类分离株中还检测到 tet(A)与 iroN 和 iss 的进一步耐药/毒力基因关联。总之，对代表性临床和共生大肠杆菌菌株的抗菌药物耐药性和毒力基因型的同时表征，对于识别具有人类和/或动物健康意义的新兴基因型可能是有用的。
