文章题目:Tracing Clostridium perfringens strains from beef processing of slaughter house by pulsed-field gel electrophoresis, and the distribution and toxinotype of isolates in Shaanxi province, China
应用脉冲场凝胶电泳追踪屠宰场牛肉加工过程中产气荚膜梭菌及其在陕西省的分布和毒力类型
文章出处:Food Microbiol, 2022, 101: 103887. 中国陕西西北农林科技大学兽医学院
工作站使用情况:BugBox
使用气体浓度:厌氧
摘要:本研究的目的是调查产气荚膜梭状芽孢杆菌(C. perfringens)在牛肉屠宰和屠宰过程中的分布、传播和交叉污染。共检出产气荚膜梭菌208 株(占21.2%),其中A 型80.8%,D 型19.2%,0.4% (3/708)的样本同时携带A 型和D型菌株,72.5%的D 型分离株同时携带cpe 和非典型cpb2 基因。在整个屠宰过程中鉴定出产气荚膜梭状芽孢杆菌,但未发现F 型(cpe 和cpa 分离株)。69 个菌株进一步分析,分为28 个PFGE 基因型,其中第一个分支包含94.2%的菌株和24 个PFGE 基因型,显示了遗传多样性和流行相关性。我们的研究追踪了C.产气荚膜杆菌污染沿着处理过程,并在整个过程中显示出逐渐上升的污染率,揭示了从屠宰牛的粪便和皮到屠宰车间的屠体,以及从切割车间的工具和人员到肉的广泛交叉污染。不同屠宰场(地区)的菌株同源性较高,以A 型毒力型为主。有必要监测和控制屠宰过程中交叉污染的几个关键点,以降低产气荚膜梭菌感染的风险。

Fig. 4. Isolation rate of C.perfringens from the whole slaughtering and butchering process of each slaughterhouse. Note: * indicates there is statistics significant difference between the column (p < 0.05); ** indicates highly significant difference (p < 0.01); *** indicates extremely significant difference (p < 0.001). The column without bar of halves carcass at chilling step in column of Total since samples only collected from S2(Jan.).

Fig. 5. Dendrogram of 69 C.perfringens isolates by PFGE analysis. Note: B (Bovine)+A/T/FS/H/M (air, tools, feces, hide, meat) +Year (18/19) +Sampling times (01, 02, 03, 04)+Number; Source: S1–S3 represents three slaughterhouses, respectively; All isolates were divided into four clades (I-IV) when the similarity>75.9%; PT1-PT28 represents different PFGE genotype with the similarity≥90%; PT61, …, PT19-3 represents different clusters with 100% similarity which were the same clone, respectivly.
产气荚膜梭菌在厌氧条件下(80% N2, 10% H2, 10% CO2)培养;
各屠宰场整个屠宰和屠宰过程中产气荚膜梭菌的分离率如图4 所示,屠宰车间空气与粪便、兽皮表面产气荚膜梭菌阳性率比较,差异无统计学意义,说明屠宰车间产气荚膜梭菌污染可能是由去皮过程中产生的皮和直肠内容物引起的。
PFGE 分析69 株产气荚膜囊孢杆菌的树状图(图5),69 个菌株进一步分析,分为28 个PFGE 基因型,其中第一个分支包含94.2%的菌株和24 个PFGE 基因型,显示了遗传多样性和流行相关性。