Johnson A P, Malde M, Woodford N, Cunney R J, Smyth E G
Laboratory of Hospital Infection, Central Public Health Laboratory, London.
Epidemiol Infect. 1995 Feb;114(1):105-12. doi: 10.1017/s0950268800051955.
Twenty-two gentamicin-resistant urinary isolates of Escherichia coli and five gentamicin-resistant urinary isolates of Klebsiella pneumoniae from a Dublin hospital were examined for resistance to the veterinary aminoglycoside antibiotic apramycin. Five isolates of E. coli and one isolate of K. pneumoniae were found to be resistant. The apramycin-resistant isolates, which were also resistant to the veterinary anthelmintic agent hygromycin B, hybridized with a DNA probe for the gene encoding the enzyme 3-N-aminoglycoside acetyltransferase type IV (AAC(3)IV). Resistance to apramycin and hygromycin B was co-transferable in four of the five isolates of E. coli and the isolate of K. pneumoniae. In one isolate of E. coli apramycin resistance was not transferable. On the basis of their restriction enzyme digestion profiles and the antimicrobial resistance traits encoded, the transferable plasmids encoding resistance to apramycin and hygromycin B comprised three distinct types. Genetic linkage between the gene encoding AAC(3)IV and genes encoding resistance to ampicillin and either tetracycline or trimethoprim, means that the relatively widespread use of these antimicrobial agents provides a selective pressure for the persistence of resistance to apramycin and gentamicin even in the absence of bacterial exposure to aminoglycosides.
对都柏林一家医院的22株耐庆大霉素的大肠埃希菌尿液分离株和5株耐庆大霉素的肺炎克雷伯菌尿液分离株进行了对兽用氨基糖苷类抗生素阿普拉霉素的耐药性检测。发现5株大肠埃希菌分离株和1株肺炎克雷伯菌分离株具有耐药性。对阿普拉霉素耐药的分离株，同时也对兽用驱虫剂潮霉素B耐药，它们与编码IV型3-N-氨基糖苷乙酰转移酶（AAC(3)IV）的基因的DNA探针杂交。在5株大肠埃希菌分离株中的4株以及肺炎克雷伯菌分离株中，对阿普拉霉素和潮霉素B的耐药性是可共同转移的。在1株大肠埃希菌分离株中，阿普拉霉素耐药性不可转移。根据其限制性内切酶消化图谱和所编码的抗菌耐药特性，编码对阿普拉霉素和潮霉素B耐药性的可转移质粒包括三种不同类型。编码AAC(3)IV的基因与编码对氨苄西林和四环素或甲氧苄啶耐药性的基因之间的遗传连锁，意味着这些抗菌药物的相对广泛使用为即使在细菌未接触氨基糖苷类药物的情况下对阿普拉霉素和庆大霉素耐药性的持续存在提供了选择压力。
