New aminoglycoside acetyltransferase gene, aac(3)-Id, in a class 1 integron from a multiresistant strain of Vibrio fluvialis isolated from an infant aged 6 months
New aminoglycoside acetyltransferase gene, aac(3)-Id, in a class 1 integron from a multiresistant strain of Vibrio fluvialis isolated from an infant aged 6 months
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DOI：
10.1093/jac/dkh221
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发表时间：
2004-06-01
影响因子：
5.2
通讯作者：
Shimamoto, T
中科院分区：
文献类型：
--
作者：
Ahmed, AM;Nakagawa, T;Shimamoto, T
目的：描述多重耐药河流弧菌H-08942临床分离株抗生素耐药性的分子基础。患者和方法：2002年，从印度一名患有霍乱样腹泻的6个月大的住院婴儿中分离出河流弧菌H-08942。肉汤微量稀释法用于测定一系列抗生素对该菌株的MIC。结果：河流弧菌H-08942对氯霉素、链霉素、大观霉素、复方新诺明、氨苄青霉素、呋喃唑酮、萘啶酸、庆大霉素等6种抗生素产生耐药性。1类整合子，含有一个新的氨基糖苷乙酰转移酶基因，aac（3）-Id，和氨基糖苷腺苷转移酶基因，aadA 7的特点。aac（3）-Id基因产物与AAC（3）-Ic、AAC（3）-Ia和AAC（3）-Ib的同源性分别为50%、45%和44%。克隆aac（3）-Id和aadA 7基因并在大肠杆菌中表达。系统发育分析表明aac（3）-Id代表氨基糖苷乙酰转移酶基因的第四个进化谱系。结论：本研究首次在河流弧菌中发现了一种新的氨基糖苷类乙酰转移酶基因aac（3）-Id，同时也是首次在河流弧菌中发现耐药基因和1类整合子。
Objectives: To characterize the molecular basis of antibiotic resistance in a multidrug-resistant clinical isolate of Vibrio fluvialis H-08942.Patient and methods: V. fluvialis H-08942 was isolated from a hospitalized infant aged 6 months suffering from cholera-like diarrhoea in India in 2002. The broth microdilution method was used to determine the MICs of a range of antibiotics for this strain. PCR, DNA sequencing, Southern hybridization, cloning and expression were used to characterize the molecular basis of antibiotic resistances.Results: V. fluvialis H-08942 showed resistance to chloramphenicol, streptomycin, spectinomycin, co-trimoxazole, ampicillin, furazolidone, nalidixic acid and gentamicin. A class 1 integron that contains a novel aminoglycoside acetyltransferase gene, aac(3)-Id, and aminoglycoside adenyltransferase gene, aadA7, was characterized. The aac(3)-Id gene product was found to share 50%, 45% and 44% identity to AAC(3)-Ic, AAC(3)-Ia, and AAC(3)-Ib, respectively. Both aac(3)-Id and aadA7 genes were cloned and expressed in Escherichia coli. Phylogenetic analysis suggested that the aac(3)-Id represents a fourth evolutionary lineage in the aminoglycoside acetyltransferase genes. Southern hybridization showed that this integron is located in the chromosome.Conclusions: In this study we identified a new type of aminoglycoside acetyltransferase gene, aac(3)-Id. In addition, this is the first report of identification of antibiotic resistance genes and a class 1 integron in V. fluvialis.