肉鸡屠宰场多重耐药沙门氏菌Ⅰ类整合子与磺胺类耐药基因(sul1、sul2和sul3)的检测

Detection of Integton-1 and Sulphonamide Resistant Genes of Multi-Drug Resistant Salmonella Species Isolated from Broiler Slaughterhouse

目的:了解肉鸡屠宰场多重耐药沙门氏菌Ⅰ类整合子及磺胺类耐药基因携带情况。方法:采用纸片扩散法对肉鸡屠宰场84株沙门氏菌分离株进行10种抗生素敏感性实验;应用聚合酶链式反应(polymerase chain reaction,PCR)方法检测多重耐药沙门氏菌sul1、sul2、sul3和int1基因。结果:84株沙门氏菌对氨苄西林和萘啶酸耐药率高达100%,对环丙沙星、四环素、甲氧苄啶/磺胺甲噁唑、大观霉素、氟苯尼考、庆大霉素耐药率分别为39.29%、35.71%、35.71%、35.71%、22.62%、14.29%。38株沙门氏菌对3种及以上抗生素耐药,属于多重耐药菌株。38株多重耐药菌株中,有20株携带Ⅰ类整合子。30株对甲氧苄啶/磺胺甲噁唑耐药的菌株中,均能检测到sul1或sul2或sul3基因,与表型耐药100%符合,其检出率分别为40%、100%、63.3%。结论:肉鸡屠宰场中沙门氏菌耐药现象已不容乐观,沙门氏菌多重耐药性与Ⅰ类整合子的携带之间关系密切,且Ⅰ类整合子在磺胺类耐药菌株的产生中起到重要作用。

Objective: To characterize multi-drug resistant Salmonella isolates carrying integeon-1 and sulfonamides-resistant genes from broiler slaughterhouse. Methods: The susceptibility of 84 Salmonella isolates from broiler slaughterhouse to 10 varieties of antibiotics was evaluated by K-B disc method. In addition, PCR was used to detect the presence of the int1, sul1, sul2 and sul3 genes of multi-drug resistance in Salmonella isolates. Results: The resistant rates of these 84 Salmonellaisolates were 100% to ampicilin and nalidixic acid, and 39.29%, 35.71%, 35.71%, 35.71%, 22.62% and 14.29% to ciprofloxacin, tetracycline, benzyl methyl oxygen/sulfamethoxazole, spectinomycin, fluorine benzene nicol and gentamicin, respectively. It was found that 38 of these isolates exhibited resistance to at least three antibiotics as multi-drug resistant strains. Among the 38 multi-drug resistant Salmonella strains, 20 carried integron-1. Sulfonamide resistant genes such as sul1 or sul2 or sul3 genes were detected in 30 sulfonamides resistant Salmonella isolates, suggesting 100% consistency between the results of drug sensitivity tests and PCR. The detection rates of the sulfonamides resistant genes sul1, sul2 and sul3genes by PCR were 40%, 100% and 63.3%, respectively. Conclusion: These results implied that the antimicrobial resistance of Salmonella isolates from broiler slaughterhouse is not optimistic. A close correlation exists between the multi-drug resistance and the carrier condition of the integron-1, which may play a critical role in the sulphonamide resistance in Salmonella isolates.