中文摘要：

为检测质粒介导的喹诺酮类耐药性aac（6’）-Ib-cr基因在食品动物源沙门菌的分布状况。采用PCR结合BstCl酶切法，以及DNA测序法检测316株食品动物源沙门菌中aac（-6’）-Ib-cr基因；微量肉汤稀释法检测aac（6’）-Ib-cr阳性和阴性菌株对10种抗菌药物的耐药性；采用PFGE分析阳性菌株的亲缘关系。结果是aac（6’）-Ib—cr基因检出率15．82％（50／316）；aac（6’）-Ib-cr阳性株对氨基糖苷类耐药率高于阴性株，但对环丙沙星、恩诺沙星和氧氟沙星的耐药率低于阴性株；aac（6’）-Ib-cr阳性菌株具有不同的PFGE谱型。结论：aac（6’）-Ib-cr基因在本次检测的食品动物源沙门菌中普遍存在，以水平和垂直传播方式在菌群间传播。

英文摘要：

Objective To investigate the prevalence of plasmid-mediated quinolone resistance aac（6＇）-Ib-cr gene in the Salmonella isolates from food-animals. Methods PCR, the digestion with BstC1 and PCR-sequencing meth- ods were used to detect aac（6＇） -Ib-cr in 316 Salmonella isolates from food-animals; Antimicrobial susceptibility of Salmonella to 10 agents was examined by the broth microdilution method; PFGE was used to analyze the genomic homology in aac（6＇）-Ib-cr positive strains. Results The detection rate of aac（6＇）-Ib-cr was 15.82% （50/316） of i- solates; The resistant rate of aac （6＇）-Ib-cr positive strains to aminoglycosides was higher than that of negative strains, but to FQNS including ciprofloxacin, enrofloxacin and ofloxacin, the resistant rate of positive strains was low- er than that of negative strains, aac（6＇）-Ib-cr positive strains showed different PFGE patterns. Conclusion The plas- mid-mediated aac（6＇）-Ib-cr widely existed by horizontal and vertical transmission in Salmonella isolates tested.