Analysis of microbiota on abalone (Haliotis discus hannai) in South Korea for improved product management.

Abalone is a popular seafood in South Korea; however, because it contains various microorganisms, its ingestion can cause food poisoning. Therefore, analysis of the microbiota on abalone can improve understanding of outbreaks and causes of food poisoning and help to better manage seafood products. In this study, we collected a total of 40 abalones from four different regions in March and July, which are known as the maximum abalone production areas in Korea. The microbiota were analyzed using high-throughput sequencing, and bacterial loads on abalone were quantified by real-time PCR. Over 2700 species were detected in the samples, and Alpha- and Gammaproteobacteria were the predominant classes. The differences in microbiota among regions and at each sampling time were also investigated. Although Psychrobacter was the dominant genus detected on abalone in both March and July, the species compositions were different between the two sampling times. Five potential pathogens (Lactococcus garvieae, Yersinia kristensenii, Staphylococcus saprophyticus, Staphylococcus warneri, and Staphylococcus epidermidis) were detected among the abalone microbiota. In addition, we analyzed the influence of Vibrio parahaemolyticus infection on shifts in abalone microbiota during storage at different temperatures. Although the proportion of Vibrio increased over time in infected and non-infected abalone, the shifts of microbiota were more dynamic in infected abalone. These results can be used to better understand the potential of food poisoning caused by abalone consumption and manage abalone products according to the microbiota composition.