Isolation and Molecular Identification of Vibrio and Enteropathogenic Bacteria From Street Seafood Restaurants in Buriram Province

Abstract

Screening and identification of Vibrio and enteropathogenic bacteria in seafood were carried out. Seafood samples were randomly collected from five street food restaurants in Muang district, Buriram province. The bacterial selective medium thiosulfate-citrate-bile salts-sucrose (TCBS) agar was employed for the isolation of bacterial colonies. Amplification of 16S rRNA genes of each isolated bacterial colony was accomplished using polymerase chain reaction (PCR) and the purified amplicons obtained were subject to further analysis using bioinformatic strategies. Assignment of the amplicon sequences to genus and/or species level was based on BLASTN. The results were compared to the information in GenBank database using percent identity and total score in the priority parameters. The BLASTN results indicated that bacteria from six genera were found and categorized into two groups. The first group was pathogenic bacteria that were the causative agents of food poisoning in human, including Vibrio, Aeromonas, and Shewanella. The second group included Kluyvera, Providencia and Klebsiella, which were commonly found and caused food contamination during food processing, preservation process, transportation, and unhygienic cooking in street food restaurants. Based on the phylogenetic tree, it was found that Aeromonas was evolutionarily different from Vibrio, Shewanella, Kluyvera, Providencia, and Klebsiella. The phylogenetic tree manifesting the evolutionary relationships among the isolated bacterial strains implied a wide diversity of bacterial contamination that caused food poisoning, with their sources being from seafood and environmental contamination. The information obtained from this study should be of use for epidemiological surveillance of seafood poisoning caused by bacterial contamination in the future.