Characterization of Vibrio parahaemolyticus isolated from oysters in Korea: Resistance to various antibiotics and prevalence of virulence genes

• Published in: Marine pollution bulletin Vol. 118; no. 1-2; pp. 261 - 266
• Main Authors: Kang, Chang-Ho, Shin, YuJin, Jang, SeokCheol, Yu, HongSik, Kim, SuKyung, An, Sera, Park, Kunbawui, So, Jae-Seong
• Format: Journal Article
• Language: English
• Published: England Elsevier Ltd 15-05-2017
• Subjects: Animals; Anti-Bacterial Agents - pharmacology; Aquaculture; Asia; Bacterial Toxins - genetics; Drug Resistance, Bacterial; Genes, Bacterial; Hemolysin Proteins - genetics; Occurrence; Ostreidae - microbiology; Oyster; Polymerase Chain Reaction; Republic of Korea; Shellfish; toxR; trh; Vibrio parahaemolyticus; Vibrio parahaemolyticus - drug effects; Vibrio parahaemolyticus - genetics; Vibrio parahaemolyticus - pathogenicity; Virulence; Virulence Factors - genetics; Vibrio parahaemolyticus; toxR; trh; Oyster; Occurrence
• ISSN: 0025-326X; 1879-3363
• DOI: 10.1016/j.marpolbul.2017.02.070

Vibrio parahaemolyticus, found frequently in oysters, is the most prevalent gastroenteritis-causing pathogen in Korea and in several other Asian countries. This study monitored changes in the environmental parameters and occurrence of V. parahaemolyticus in oyster aquaculture sites. Of the 44 presumed V. parahaemolyticus isolates obtained, when tested against 16 antibiotics, 90.9, 86.4, and 75.0% of the 44 isolates exhibited resistance to vancomycin, ampicillin, and streptomycin, respectively. PCR analysis for the presence of the toxR gene confirmed 31 of the 44 isolates as being positive V. parahaemolyticus strains. The toxR positive isolates were tested for the presence of thermostable direct hemolysin (tdh) and tdh-related hemolysin (trh) virulence genes. Only 9.1% toxR positive isolate exhibit the trh gene and none of the isolates were tested positive for tdh. The occurrence of multi drug resistance strains in the environment could be an indication of excessive usage of antibiotics in agriculture and aquaculture fields.
•V. parahaemolyticus was detected in 44 (37.6%) out of the 117 isolates examined.•The MAR value of almost half of the isolates was 0.31 or less.•The 31 (70.5%) of 44 samples were PCR-positive for V. parahaemolyticus.•Only 4 (9.1%) were positive for the trh virulence gene.•The monitoring of the prevalence of antimicrobial resistance in vibrios is necessary.