食品科学

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武汉市售茶中2 种食源性致病菌的检测与分析

窦玉淼,张 飞,张 翼,陈雅蘅,周帼萍*   

  1. 武汉轻工大学生物与制药工程学院,湖北 武汉 430023
  • 出版日期:2015-05-25 发布日期:2015-05-08
  • 通讯作者: 周帼萍
  • 基金资助:

    湖北省教育厅科学研究计划项目中青年项目(Q20111703);武汉轻工大学研究生创新基金项目(2013cx020);
    2014年武汉轻工大学大学生科研立项项目

Detection and Analysis of Two Food-Borne Pathogens in Tea Samples from Wuhan Market

DOU Yumiao, ZHANG Fei, ZHANG Yi, CHEN Yaheng, ZHOU Guoping*   

  1. School of Biological and Pharmaceutical Engineering, Wuhan Polytechnic University, Wuhan 430023, China
  • Online:2015-05-25 Published:2015-05-08
  • Contact: ZHOU Guoping

摘要:

为了解市售茶叶中菌落总数和2 种食源性致病菌(蜡样芽孢杆菌和克罗诺杆菌)的检出情况,根据国标对武汉地区市售的46 份茶叶样品进行菌落总数和2 种食源性致病菌的初步分离和鉴定,分别用16S rDNA内转录间隔区-聚合酶链式反应方法鉴别蜡样芽孢杆菌,用16S rDNA和fusA序列分析对疑似克罗诺杆菌的分离株进行鉴定,进而比较和分析不同产地和类别间微生物的检出情况。结果发现,蜡样芽孢杆菌在市售茶叶中检出率极高,达97.9%,而且其数量约占细菌总数的6.0%。鉴定出3 株阪崎克罗诺杆菌(Cronobacter),其检出率达6.5%,仅占细菌总数的0.1%~3.2%。花草茶中细菌总数最高,也是唯一检出克罗诺杆菌的茶类;发酵茶中蜡样芽孢杆菌数量最高,均超过1 100 MPN/g。不同产地茶叶在这3 个微生物指标上有显著差异。当茶及其深加工产品和其他食品原辅料混搭成新产品时,这2 种食源性致病菌可能带来风险隐患。

 

关键词: 茶, 细菌总数, 蜡样芽孢杆菌, 克罗诺杆菌, 检测, 鉴定

Abstract:

The objective of this study was to detect the aerobic plate count, and isolate and identify two food-borne
pathogens (Bacillus cereus and Cronobacter) in tea samples collected from local markets in Wuhan according to the Chinese
national standards. Bacillus cereus was identified by PCR analysis of 16S rDNA internal transcribed spacer (ITS) sequence
and Cronobacter by 16S rDNA and fusA sequence analysis. We further compared the detection rates of both bacterial
pathogens in tea samples from different producing areas and in different kinds of tea. Bacillus cereus was detected in 97.9%
of the investigated tea samples accounting for about 6.0% of the total bacterial population. Three strains of Conobacter spp.
were identified in 6.5% of these tea samples accounting for only 0.1%–3.2% of the total bacterial population. The highest
aerobic plate count and Conobacter spp. were found only in herbal tea. Fermented tea had the highest B. cereus counts,
exceeding 1 100 MPN/g in all samples. There were significant differences in the three microbial indicators among different
tea-producing regions. Thus, the food safety hazards of these food-borne pathogens cannot be ignored, especially when tea is
mixed with other materials.

Key words: tea, aerobic plate count, Cronobacter, Bacillus cereus, detection, identification

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