基于高通量测序的家用冰箱菌群分析

Analysis of microbial flora in domestic refrigerators based on high-throughput sequencing

目的了解家用冰箱不同环境中的微生物菌群情况,发现潜在致病菌,为人们日常使用冰箱提供一定参考意见。方法采集7个家庭的家用冰箱4℃、-20℃环境内部及冷凝水共19份样本,通过高通量测序方法检测16s rRNA,分析其菌群情况;并进一步和致病菌数据库进行比对分析,发现潜在致病菌。结果共检出30个不同的细菌门,其中变形菌门(74.59%)、厚壁菌门(15.73%)及拟杆菌门(7.80%)含量最高。三种环境中,冷凝水及4℃环境菌群特征比较接近,且G^-占比高于-20℃环境。4℃和冷凝水中,假单胞菌属和不动杆菌属分别含量最多,其次为大肠杆菌;而-20℃中,不动杆菌属和巨型球菌数丰度最高。共发现20种潜在致病菌,其中条件致病菌不动杆菌属、假单胞菌属及芽孢杆菌属丰度最高,同时还发现多种食源性致病菌,包括李斯特菌属、沙门菌属及大肠菌属等。结论冰箱环境中存在G^-为主的多种菌群及潜在致病菌,日常清理冰箱及其重要。

Objective To understand the status of microbial flora in domestic refrigerators with different environments, to reveal the possible potential pathogens in domestic refrigerators so as to provide some references and suggestions for daily usage of refrigerators. Methods We collected a total of 19 samples from 7 domestic refrigerators with internal environments reaching 4 ℃ and-20 ℃ and condensed water. High-throughput sequencing was used to detect 16 S ribosomal RNA, and the status of microbial flora was analyzed. The possible pathogens were further analyzed, and then compared with those from pathogen database. Results A total of 30 different bacterial phyla were identified, and most of them belonged to Proteobacteria(74.59%), Firmicutes(15.73%), and Bacteroidetes(7.80%). Among 3 types of internal environments, gram-negative bacteria detected in condensed water and internal environment reaching 4 ℃ had consistently higher relative abundance as compared with those detected in internal environment reaching-20℃. The most abundant genera detected in internal environment reaching 4℃ and condensed water were Pseudomonas and Acinetobactor, followed by Enterobacteriaceae. Acinetobactor and Macrococcus were the dominant genus detected in internal environment reaching-20℃. 20 possible pathogens were disclosed, of which opportunistic pathogens like Acinetobacter, Pseudomonas and Bacillus were the abundant pathogens. Various food-borne pathogens were simultaneously disclosed, including Listeria, Salmonella and Escherichia. Conclusions The domestic refrigerators were contaminated with gram-negative bacterial flora predominantly, and various possible pathogens were disclosed. Therefore, it is very important to clean refrigerators frequently.