Virulence gene, antimicrobial resistance and phylogenetic characterization of Vibrio parahaemolyticus in migratory birds, Guangdong

Abstract Background Vibrio parahaemolyticus is an intestinal pathogen that is transmitted by contaminated aquatic products.Migratory birds ate foods infected with Vibrio parahaemolyticus, excreting feces on other foods. Other organisms ate contaminated food again, leading to the spread of strains. It were reported previously that Vibrio parahaemolyticus was sensitive to most antibiotics except penicillin such as ampicillin and amoxicillin. However, due to the frequent used of antibiotics in recent years, Vibrio parahaemolyticus developed resistance to antibiotics. The recommended antibiotics for Vibrio parahaemolyticus treatment were tetracycline, β-lactam, quinolone and sulfonamide. In the storage migratory bird, Vibrio parahaemolyticus could complete the accumulation of drug resistance, resulting in the generation of drug resistance genes, or the horizontal drug resistance genes transfer from other bacteria, resulting obtain drug resistance genes. Results In this study, 122 isolates of Vibrio parahaemolyticus were obtained for further pathogenicity identification, antibacterial susceptibility testing of 18 antimicrobial compounds and genetic characterization based on the whole genome sequencing. There is no pandemic serotype isolated between migratory birds, but 37 strains with cholera toxin. Five strains had col3M plasmid-moderately resistant drug-resistant strains of quinolone mediated by the qnrD1 gene. For the first time in China, Vibrio parahaemolyticus with col3M plasmid-mediated qnrD1 gene was isolated from migratory birds. Conclusion According to the mutltilocus sequence typing analysis, authors found the bacterial genetic diversity is higher, the clones are less and there is regional aggregation in Shenzhen. And mallards are more susceptible to Vibrio parahaemolyticus.