Analysis of aminoglycoside-resistant genes in highly multidrug-resistant Pseudomonas aeruginosa

我们对2011年日本300株铜绿假单胞菌临床分离株进行了分子流行病学研究。其中，我们发现了一个新的氨基糖苷6 ′-N-乙酰转移酶基因aac（6 ′）-Iaj，其编码的蛋白质AAC（6 ′）-Iaj由184个氨基酸组成，与AAC（6 ′）-Ia的同源性为70%。用含有aac（6 '）-Iaj基因的质粒转化的大肠杆菌获得了对除庆大霉素之外的所有测试的氨基糖苷类的抗性。值得注意的是，aac（6 '）-Iaj有助于对阿贝卡星的耐药性。2012年，我们发现了两种新型IMP型金属β-内酰胺酶变体IMP-43和IMP-44，它们是在日本医疗环境中获得的多重耐药铜绿假单胞菌分离株中鉴定的。这两种变体对所有测试的碳青霉烯类，包括屈培南、亚胺培南、美罗培南和帕尼培南具有更有效的催化活性。

We performed a molecular epidemiolygical study of 300 clinical isolates of Pseudomonas aeruginosa in 2011 in Japan. Of them, we found a novel aminoglycoside 6'-N-acetyltransferase gene, aac(6')-Iaj.The encoded protein, AAC(6')-Iaj, was found to consist of 184 amino acids, with 70% identity to AAC(6')-Ia. Escherichia coli transformed with a plasmid containing the aac(6')-Iaj gene acquired resistance to all aminoglycosides tested except gentamicin. Of note, aac(6')-Iaj contributed to the resistance to arbekacin.In 2012, we found two novel IMP-type metallo-beta-lactamase variants, IMP-43 and IMP-44, which were identified in multidrug-resistant Pseudomonas aeruginosa isolates obtained in medical settings in Japan. These two variants had more efficient catalytic activities against all carbapenems tested, including dripenem, imipenem, meropenem and panipenem.