一株鹅源腐生葡萄球菌的分离鉴定、药敏试验、耐药基因及毒力基因检测

Isolation and identification of a goose derived Staphylococcus saprophyticus strain and its drug susceptibility,resistance and virulence genes detection

目的:查明某养殖户送检的以腿部肿胀为特征的16日龄病鹅病原菌,分析其抗生素耐性、毒力基因携带情况。方法:取病鹅腿部肿胀处的组织液,进行病原菌分离鉴定、药敏试验、耐药基因及毒力基因检测。结果:从病鹅腿部肿胀处的组织液中分离培养到1株球状、不规则排列的G_(+)菌。通过16S rRNA基因序列分析,确定为腐生葡萄球菌。药敏试验显示该菌对妥布霉素、庆大霉素、环丙沙星敏感,对链霉素、复方新诺明等药物耐药。耐药基因检测得出该菌含有卡那霉素类耐药基因aadA1、头孢菌素类耐药基因blaCMY-2、磺胺类耐药基因sul1。毒力基因检测得出该菌携带肠毒素基因seb、耐热核酸酶基因nuc、溶血素基因hla、毒素休克综合征毒素1基因TSST-1。结论:该鹅患病部分病原菌为腐生葡萄球菌,毒力强,治疗时应优先选用妥布霉素。

Objective:To identify the pathogenic bacteria of 16 day old diseased geese characterized by leg swelling and analyze their drug resistance and virulence gene.Methods:The tissue fluid was taken from the swollen area of the diseased goose's legs for pathogen isolation and identification,drug susceptibility testing,and detection of drug resistance gene and virulence gene.Results:A spherical,irregularly arranged Gram positive bacterium was isolated and cultured from the tissue fluid of the swollen leg of the sick goose.Through 16S rRNA gene sequence analysis,Staphylococcus saprophyticus was identified.The drug susceptibility testing showed that the bacteria were sensitive to tobramycin,gentamicin and ciprofloxacin,while resistant to drugs such as streptomycin and compound sulfamethoxazole.Drug resistance gene testing revealed that the bacterium contains the kanamycin drug resistance gene aadA 1,cephalosporin drug resistance gene blaCMY-2,and sulfonamide drug resistance gene sul 1.The virulence gene testing showed that the bacterium carries the enterotoxin gene seb,heat-resistant nuclease gene nuc,hemolysin gene hla,and toxin shock syndrome toxin 1 gene TSST-1.Conclusion:The pathogenic bacteria causing the disease in this goose are Staphylococcus saprophyticus,which has strong virulence.Tobramycin should be given priority during treatment.