Abstract：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 16S ribosomal RNA, and the status ofmicrobial 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 mostof 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.
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2020, Vol. 27 
