中文摘要：

为了解鸡沙门菌16SrRNA甲基化酶基因（armA，rmtA，rmtB，rmtC，rmtD，rmtE和72pmA）的扩散机制，在分离鉴定沙门菌的基础上，分别进行药敏试验、耐药基因检测、质粒接合及电转化、质粒分型、Southernblot以及耐药基因遗传环境分析等。结果显示，在分离的21株沙门菌中，只有1株对阿米卡星和庆大霉素高度耐药，且armA基因阳性。多次尝试进行质粒接合试验均未获成功，但质粒转化试验成功获得了转化子。质粒分型和Southern blot证实armA位于IncFⅡ质粒上。armA基因的遗传背景分析表明，该基因位于一个两端具有插入序列IS26的复合转座子上。本研究在动物源沙门菌检测到162rRNA甲基化酶基因armA，且证实armA基因位于IncFⅡ质粒的复合转座子上，提示转座子和质粒均可在afroA基因的水平扩散中发挥重要作用。

英文摘要：

In order to understand the molecular dissemine genes（armA, rmtA,rmtB,rmtC,rmtD, rmtE and npm tion mechanism of 16S rRNA methylase A ） in Salmonella strains isolated from chickens, antimicrobial susceptibility tests, PCR detection, conj ugation, transformation, plasmid incompatibility analysis,Southern blot and genetic environment analysis were performed. Of 21 Salmonella strains,only one strain was highly resistant to amikacin and gentamicin. PCR detection revealed that this strain was armA gene positive. The multiple attempts for conjugation experiment in this strain failed. However, the transformants were successfully obtained by electroporation. Plasmid incompatibility analysis and Southern blot confirmed the armA gene located on the IncF II plasmid. The genetic environment analysis showed that the armA gene located on the composite transposon. In conclusion, this study reported the first identification of the 16S rRNA methylase gene armA presented in an Salmonella strain of animal origin. Furthermore,the armA gene was associated with the composite transposon. These data suggested that both transposons and plasraids can have an important role in the horizontal dissemination of the armA gene.