金黄色葡萄球菌污染冰淇淋的调查

Tracing to the source of Staphylococccus aureus isolates from ice cream

目的通过冰淇淋及其各种原料和生产线样本分离、培养金黄色葡萄球菌，分析分离株的分子分型和表型特征，对金黄色葡萄球菌污染冰淇淋进行调查。方法采集冰淇淋及其各种原料和生产线投料口、切片机出口、成品托盘等样本，用国标方法分离、培养、鉴定金黄色葡萄球菌，VITEK32生化验证，Mini-Vidas检测分离株肠毒素（多克隆肠毒素SEA-SEE），PCR检测分离株肠毒素基因（肠毒素SEA．SEJ基因），VITEK32测定分离菌株抗生素的耐药性，脉冲凝胶电泳（PFGE）分析菌株间的基因指纹图谱特征。结果分别从冰淇淋和切片机出口分离到2株金黄色葡萄球菌。它们都含有肠毒素（多克隆肠毒素SEA-SEE），都有SEC、SED、SEG、SEH、SEI和SEJ肠毒素基因，耐药谱相同，脉冲凝胶电泳（PFGE）的指纹图谱相同。结论污染冰淇淋和切片机出口的金黄色葡萄球菌是同一克隆株，切片机出口的污染导致冰淇淋污染。

Objective To investigate the contamination of Staphylococccus aureus isolates in ice cream by phenotypic typing and molecular typing. Methods The Staphylococccus aureus isolates were separated from ice cream, filler, cutter, salvers and material. The separated isolates were characterized by drug-resistance, staphylococcal enterotoxin （ SEA-E ）, SE （ A-E, G-J ） genes and pulsed-field gel electrophoresis （PFGE） types. Result Two Staphylococccus aureus isolates were separated, one from ice cream, another from cutter. Their characteristics of drug-resistance, staphylococcal enterotoxin （SEA-E）, SE （A-E, G-J） genes and PFGE type were the same. Conclusion The two Staphylococccus aureus isolates were the same clone. The contaminated Staphylococccus aureus isolates could be traced to the contaminated cutters.