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

2011年，我们对日本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类6‘-N-乙酰基转移酶基因aac(6’)-iaj，其编码蛋白aac(6‘)-iaj由184个氨基酸组成，与aac(6’)-ia有70%的同源性。转化含有aac(6‘)-iaj基因的大肠杆菌对除庆大霉素外的所有氨基糖苷类药物均产生抗药性。值得注意的是，aac(6‘)-iaj参与了对阿贝卡星的耐药性。2012年，我们在日本医疗机构获得的多重耐药铜绿假单胞菌中发现了两个新的IMP型金属β-内酰胺酶变异体IMP-43和IMP-44。这两个变异体对所有测试的碳青霉烯类抗生素都有更有效的催化活性，包括卓培南、亚胺培南、美罗培南和帕尼培南。

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.