Antimicrobial resistance and virulence characteristics of Vibrio parahaemolyticus

Objective To explore drug resistance and virulence characteristics of clinically isolated Vibrio parahaemolyticus (VP). Methods The patient records were reviewed.The laboratory information system was employed to count the quantity of bacterial diarrhea pathogens at our intestinal clinic from 2009 to 2012.The drug resistant phenotype was tested by the method of disk diffusion.Polymerase chain reaction (PCR) was used to detect thermo-stable direct hemolysin (TDH) gene (tdh), TDH-related hemolysin gene (trh) and type Ⅲ secretion system 2 (T3SS2α, T3SS2β). Results The VP infection rate was 37.90% (274/723).Susceptibility test showed that the resistance rates of ampicillin, cefalotin, cefuroxime and amikacin were 100% (216/216), 44.91% (97/216), 24.07% (52/216),9.26% (20/216).The other 11 kinds of antibiotics were sensitive or intermediate.96.76% (209/216) VP harbored tdh gene, 1.39% (3/216) trh gene and 100% T3SS2 gene, with 213 strains T3SS2αpositive, 2 strains T3SS2βpositive and 1 strain both T3SS2αand T3SS2βpositive. Conclusion The resistant rate of VP to ampicillin is the highest and VP has different levels of resistance against other antibiotics.Most clinical isolates of VP harbor tdh gene and T3SS2 plays an important role in the pathogenicity of VP. Key words: Vibrio parahaemolyticus; Drug resistance,bacterial; Hemolysin; TypeⅢsecretion system