动物源性沙门氏菌的耐药性分析及氟苯尼考类耐药基因的鉴定

Analysis of Antibiotic Resistance of SalmonellaIsolated from Animals and Identification of its Florfenicol Resistant Gene

为了解动物沙门氏菌的流行情况和药物敏感性及氟苯尼考耐药株的耐药基因分布,本试验对临床上疑似患沙门氏菌病的病料进行病原分离和细菌的多重PCR鉴定;采用K-B法测定分离株对23种抗菌药物的敏感性;选择氟苯尼考耐药菌株扩增floR、fexA、fexB、cfr和pexA基因。结果显示,共鉴定出61株沙门氏菌,其中肠炎沙门氏菌10株,鸡白痢沙门氏菌12株,鼠伤寒沙门氏菌39株。所有菌株对青霉素、红霉素、万古霉素耐药,90.16%对6种及6种以上抗菌药耐药。floR基因广泛存在于鼠伤寒沙门氏菌氟苯尼考耐药菌株中(8/12,66.67%),未发现其他耐药基因。研究结果表明鼠伤寒沙门氏菌是鹅源分离株中的优势血清型;floR基因主要介导沙门氏菌对氟苯尼考耐药性,但可能还存在其他机制。

The assay was aimed to investigate prevalent Salmonella strains from animal, their anti- biotic susceptibility, and distribution of florfenicol resistant genes in Salmonella isolates with resistance to florfenicol. Pathogens were isolated from clinical samples with suspected salmonello- sis,and identified by mPCR. Antibiotic resistance to 23 antibiotics was determined by antibiotic susceptibility test according to the K-B method. The isolates with resistance to florfenicol were chosen to PCR amplification for floR, fexA, fexB, cfr and pexA genes. The results showed 61 Salmonella strains were isolated, and the numbers of S. Enteritidis, S. Pullorum and S. Typhi- murium were 10,12 and 39 ,respectively. All strains were resistant to penicillin,erythromycin and vancomycin,and 90. 16% of the isolates were resistant to six or more than six actibiotics. The floR genes were detected in 8 out of 12 florfenicol-resisitant S. Typhimurium strains,and no other genes were detected. These data indicated that S. Typhimurium was the dominant serotype of Salmonella isolated from geese. The floR gene played a major role in its florfenicol resistance. However, it might exist other antibiotic resistance mechanism.