石家庄市市售婴幼儿食品中蜡样芽胞杆菌的监测及溶血素基因的分析

了解目前市售婴幼儿配方奶粉、谷基辅助食品样品中蜡样芽胞杆菌的污染及其毒素基因的携带情况。方法 采集石家庄市23个区县市售婴幼儿配方粉、谷基辅助食品共399份,依照国家标准 GB/T 4789.14—2003《食品卫生微生物学检验 蜡样芽胞杆菌检验》和《食源性致病菌监测工作手册》进行蜡样芽胞杆菌检测并计数,应用荧光PCR方法检测蜡样分离株的溶血素基因和非溶血素基因。结果 399份样品中蜡样芽胞杆菌检出85份,其中婴幼儿配方奶粉检出36份,检出率22.8%(36/158)；谷基辅助食品检出49份,检出率20.3%(49/241)。85份阳性样品中有48份呈溶血素基因阳性,检出率56.5%,非溶血素基因均为阴性。结论 婴幼儿食品中蜡样芽胞杆菌的污染较严重,存在潜在的食品风险。分析结果可为婴幼儿食品卫生学检验标准及监督管理等方面提供参考。

Survey and hemolysin gene analysis of Bacillus cereus in infant food fom Shijiazhuang market

To investigate the contamination of Bacillus cereus in infant formula milk powder and cereal-based complementary foods from Shijiazhuang market, and also to monitor the toxin genes of the isolated strains.MethodsInfant formula powder and cereal-based complementary foods from 23 counties of Shijiazhuang city were collected. Bacillus cereus strains were tested and counted according to the national standard GB/T 4789.14-2003 and foodborne pathogenic bacteria monitoring manual. The hemolytic toxin genes and non-hemolytic toxin genes of isolates were detected by real-time PCR. Results85 strains of Bacillus cereus were detected from 399 samples. The detection rate of infant formula powde was 20.3%(36/158) and cereal-based complemenary foods was 22.8%(49/241). The hemolysin gene was positive in 48 isolated strains and the detection rate was 56.5% with no isolates carrying non-hemolytic toxin gene.ConclusionThe contamination of Bacillus cereus in infant food was quite severe. These foods had a potential food poisoning risk. Our results could provide reference for the infant food hygiene inspection standard setting, supervision and management.