水貂沙门氏菌的分离鉴定及药物敏感性分析

为指导临床合理用药并为治疗患病水貂提供依据,本试验对山东省某水貂养殖场送检的7只疑似患有沙门氏菌病的病死水貂的肝脏和脾脏样品进行细菌分离鉴定及药物敏感性分析,通过分离纯化方法从样品中分离菌株,并采用革兰氏染色、生化鉴定和PCR方法对分离菌株进行鉴定。运用K-B药敏法检测菌株对临床常用药物的敏感性,并通过PCR方法检测菌株耐药基因及Ⅰ类整合子的携带情况。结果显示,本试验分离得到的7株菌均为革兰氏阴性、短小的杆菌;生化反应检测显示,分离菌株葡萄糖、麦芽糖、甘露醇、MR试验、枸橼酸盐、硫化氢试验均表现为阳性,初步鉴定分离菌株为沙门氏菌;PCR产物测序结果进一步表明7株分离菌均为沙门氏菌;药敏试验结果显示,7株沙门氏菌对头孢曲松、左氧氟沙星、氟苯尼考和多黏菌素较敏感,对氨基糖苷类药物、四环素和氨苄西林表现为耐药;耐药基因检测结果显示,7株沙门氏菌共检测出8种耐药基因blaTEM-1、blaCTX-M-1G、aadA1、aac(3′)-Ⅳ、aac(3′)-Ⅱc、aph(4′)-Ⅰa、aph(3′)-Ⅶ和oqxAB,以及基因盒为aadA1、arr-3-aacA4和blaPSE-1的Ⅰ类整合子。综上可知,本试验在送检的7只患病水貂的肝脏和脾脏样品中分离到7株沙门氏菌,分离菌株均为耐药菌株,且主要表现为多重耐药现象;耐药基因呈多样性,且存在位于质粒上的耐药基因扩大了耐药基因的传播范围,增加了细菌的耐药性,为临床用药治疗带来困难。

Isolation,Identification and Drug Sensitivity Analysis of Salmonella from Minks

In order to guide rational drug use and provide the basis for treatment of diseased mink,the bacteria of seven sick minks suffering from salmonellosis provided by mink farms in Shandong province were isolated and identified,and the drug sensitivity was tested.The strains were isolated from the samples by separation and purification methods,and the isolated strains were identified by Gram staining,biochemical identification and PCR.K-B susceptibility test was used to detect the sensitivity of strains to commonly used drugs,and the drug resistance gene and class Ⅰ integrants were detected by PCR.The results showed that 7 strains were isolated,all of which were Gram-negative and short bacilli.Biochemical reaction tests showed that the isolates were positive for glucose,maltose,mannitol,MR test,citrate and hydrogen sulfide test,and the isolates were preliminarily identified as Salmonella.The sequencing results of the PCR products further indicated that 7 isolated strains were Salmonella.The drug sensitivity test showed that 7 strains of Salmonella were sensitive to ceftriaxone,levofloxacin,florfenicol and polymyxin,and resistant to all of the aminoglycosides,tetracycline and ampicillin.The results of drug resistance gene test showed that 8 kinds of resistance genes were detected in 7 strains of Salmonella,bla_TEM-1,bla_CTX-M-1G,aadA1, aac(3')-Ⅳ,aac(3')-Ⅱc,aph(4')-Ⅰa,aph(3')-Ⅶ and oqxAB,and the class Ⅰ integrin of the gene cassettes aaA1,arr-3-aacA4 and bla_PSE-1 were detected.According to the above results,7 strains of Salmonella were isolated from the liver and spleen samples of 7 diseased minks,and the isolates were all resistant strains,and mainly showed multi-drug resistance;The drug resistance genes were diverse,and the presence of drug resistance genes on the plasmid expanded the spread of drug resistance genes and increased the drug resistance of bacteria,which brought difficulties for clinical drug treatment.