自贡冷吃兔生产环境中细菌的鉴定及溯源分析

Identification and Traceability Analysis of Bacteria in the Production Environment of Zigong Lengchitu

利用自然沉降法和涂抹采样法对自贡冷吃兔生产环境进行微生物监测,采用传统培养法结合16Sr DNA测序技术鉴定,确定生产环境中细菌的主要种属,建立潜在污染细菌库,最后通过构建系统发育树进行溯源分析。本次研究从生产环境中共分离出61株菌,分别属于21个属;生产车间空气、生产人员、设备与器具均检出不动杆菌属细菌,其次为气单胞菌属、假单胞菌属和葡萄球菌属;冷吃兔辅料处理间、辅料储存间、炒制间、冷却间、内包装间的菌落总数在生产过程中变化较小,原料处理间受人员操作影响变化较大。通过研究发现不动杆菌属在自贡冷吃兔生产环境中分布广泛;冷吃兔加工设备器具表面和人员手部是冷吃兔产品潜在的污染来源;真空包装冷吃兔腐败样品中芽孢杆菌属细菌主要来源于各生产车间空气微生物,葡萄球菌属细菌主要来源于炒制人员以及炒制间空气微生物。本研究深入了解了自贡冷吃兔生产环境的污染情况并能为其风险控制提供一定的科学依据。

The natural sedimentation and smear sampling methods were used to monitor microorganisms in the Zigong Lengchitu’s production environment.The traditional culture method combined with 16 S rDNA sequencing technology was used to identify the main species and genera of bacteria in this production environment,whereupon a database of potential bacterial pollutants was established.Finally,a phylogenetic tree was constructed for traceability analysis.In total,61 strains belonging to 21 genera were isolated from this environment.The predominant bacteria detected in the air and on production personnel,workshop equipment,and instruments were Acinetobacter strains,followed by Aeromonas,Pseudomonas,and Staphylococcus species.The total number of colonies in the food processing,storage,frying,cooling,and inner packing rooms changed only slightly during the Zigong Lengchitu’s production process,whereas that in the raw material processing room changed greatly under the influence of personnel operation.In particular,Acinetobacter was widely distributed in the production environment,with surfaces of processing equipment and workers’ hands being the potential contamination sources.Strains belonging to Bacillus and Staphylococcus were mainly from the air of each production workshop and from the air of the roasting room and the corresponding staff,respectively.This study provided an in-depth understanding of the sources of bacterial pollution in the production environment of Zigong Lengchitu and some scientific basis for their contamination risk control.