Isolation and Identification of Vibrio parahaemolyticus from Shrimp Culture Ponds and Analysis of its Drug Resistance and Virulence Genes

Abstract:

To understand the drug resistance and virulence genes of Vibrio parahaemolyticus in shrimp culture ponds, we collected and isolated V. parahaemolyticus from shrimp culture ponds in four different areas of Shandong Province in 2018. The Kirby-Bauer disk method was used to detect the resistance of V. parahaemolyticus to 12 antibiotics, and PCR was used to detect the heat-resistant direct hemolysin gene (tdh) and heat-resistant-related hemolysin gene (trh). A total of 50 V. parahaemolyticus strains were isolated from the shrimp culture ponds. Drug susceptibility test showed that the resistance of V. parahaemolyticus to gentamicin, neomycin sulfate, and ampicillin were high at 98%, 90%, and 86%, respectively. The susceptibility rates to florfenicol, chloramphenicol, and ceftazidime were higher, and the resistance rates were 10%, 10%, and 20%, respectively. Overall, 88% of the strains showed multidrug resistance. The virulence gene test showed that all the strains lacked the tdh gene and 4% of the strains were trh-positive. This study suggests that the antibiotic resistance of V. parahaemolyticus in a shrimp aquaculture environment is concerning. Etiological surveillance of V. parahaemolyticus should be strengthened, and antibiotics should be reasonably used in the aquaculture process to realize the healthy development of the aquaculture industry.