Season-Specific Occurrence of Potentially Pathogenic Vibrio spp. on the Southern Coast of South Korea

Abstract

Vibrio species are widely distributed in warm estuarine and coastal environments, and they can infect humans through the consumption of raw and mishandled contaminated seafood. In this study, we aimed to isolate and observe the distribution of enteropathogenic Vibrio spp. from environments of the southern coast of South Korea over a season cycle. A total of 10,983 isolates of Vibrio spp. were obtained from tidal water and mud samples over a 1-year period from five sampling sites along the southwest coast of South Korea. We found that Vibrio alginolyticus (n ϭ 6,262) and Vibrio parahaemolyticus (n ϭ 1,757) were ubiquitous in both tidal water and mud year round, whereas Vibrio cholerae (n ϭ 24) and Vibrio vulnificus (n ϭ 130) were seasonally specific to summer. While all V. cholerae isolates were nontoxigenic (non-O1 and non-O139), more than 88% of V. vulnificus isolates possessed the virulence factor elastolytic protease (encoded by vvp). Interestingly, V. parahaemolyticus, which was omnipresent in all seasons, contained the virulence factors thermostable direct hemolysin (encoded by tdh) and thermostable direct hemolysin-related hemolysin (encoded by trh) in larger amounts in June (29 trh-positive strains) and September (14 tdh-, 36 trh-, and 12 tdh-and trh-positive strains) than in December (4 trh-positive strains) and February (3 tdh-positive strains), and virulence factors were absent from isolates detected in April. To understand why virulence factors were detected only in the warm season and were absent in the cold season although the locations are static, long-term monitoring and particularly seasonal study are necessary. IMPORTANCEThe presence of enteropathogenic Vibrio species (Vibrio cholerae, Vibrio parahaemolyticus, and Vibrio vulnificus), which cause acute diarrheal infection, septicemia, and wound infections upon ingestion through food and water, is usually associated with temperature. The World Health Organization (WHO) has estimated that there are 1.4 to 4.3 million cases and 28,000 to 142,000 deaths per year worldwide caused by cholera disease. In South Korea alone, consumption is as much as 52.4 kg of fish and shellfish per year per capita. Our findings suggested that seasonally specific acceleration of these possible pathogenic Vibrio spp. may threaten seafood safety and increase the risk of illness in South Korea, where local people consume raw fish during warmer months.

Studies on Bacterial Pathogens in Some Marine Fishes in EL-Mansoura, Egypt

“…2%). The obtained results of seasonal prevalence of V. alginolyticus were higher than what reported by Di et al (2017) who isolated V. alginolyticus at a prevalence of 8.57% in summer, 5.30% in autumn, 2.04% in spring and 0.81% in winter. This was in a disagreement with (Wang et al, 2017) who reported that V. alginolyticus were not associated with a particular season.…”

Prevalence, Genetic Diversity, Antimicrobial Resistance, and Toxigenic Profile of Vibrio vulnificus Isolated from Aquatic Environments in Taiwan

“…Therefore, the detection rate of V. vulnificus varies from 6% to 69% in different seasons, globally [ 40 , 41 , 42 ]. In this study, the detection rate of V. vulnificus in the river basins was higher in the winter season (20.8%) than in the summer season (12.5%), which is unique and different from what was shown in most of the previous studies [ 41 , 43 ]. The river site of our investigation is located in the subtropical area, where the weather temperature at the sampling time was over 33 °C in summer and approximately 22 °C in winter; thus, the winter season in Taiwan is more suitable for the survival of V. vulnificus , where, as previously highlighted, the optimal growth temperature ranges from 20–30 °C [ 9 , 43 , 44 , 45 , 46 ].…”

Microbial contamination including Vibrio cholerae in fishery auction markets in West Sea, South Korea

“…Therefore, fishery products from the West Sea may become cross-contaminated from these environments. In particular, Di et al (2017) detected V. cholerae (0.1%) in the tidal water collected from the southern coast in June and V. cholerae (0.5%) in the tidal water in September 2013. Therefore, the microbial contamination of products from the West Sea should be monitored.…”