Abstract: Objective To master the drug resistance of Vibrio parahaemolyticus from aquatic animals in Liaoning Province,explore the correlation between drug resistance gene and phenotype,and further reveal the drug resistance mechanism,so as to provide a theoretical basis for scientific prevention and control of Vibrio parahaemolyticus food poisoning. Methods The drug resistance spectrum of 168 strains of Vibrio parahaemolyticus from aquatic animals was studied by broth dilution method.The minimum inhibitory concentration of the strains against 14 common antibiotics were determined.The minimum bactericidal concentrationof the strains against 4 common antibiotics were determined.7 common drug resistance genes and class I integron inT1 gene were detected by real-time PCR. Results The drug resistance rates of 168 strains of Vibrio parahaemolyticus from aquatic animals in Liaoning province to 14 common antibiotics were 98.21%of penicillin G,70.24% of sulfamethoxazole and 67.85% of ampicillin,respectively.The sensitivity rate of Vibrio parahaemolyticus from aquatic animals in Liaoning Province to enrofloxacin was the highest（97.62%）.168 strains of VP showed multiple drug resistance with different degrees of drug resistance,and AMP/PG/SMX and PG/SMX were the dominant drug-resistant strains.The dominant genotypes were blaCARB（29.55%）,blaCARB-blaTEM（15.26%） and blaCARB-Sul II（15.26%）.The coincidence rate between drug resistance genes and drug resistance phenotypes was not high. Conclusions Vibrio parahaemolyticus derived from aquatic animals had higher resistance rate to sulfamethoxazole and β-lactam antibiotics,and the highest sensitivity rate to Enrofloxacin.Enrofloxacin had significant bactericidal and bacteriostatic effects,suggesting that Enrofloxacin could be used as the first choice for prevention and treatment of vibrio parahaemolyticus disease.The resistance of Vibrio parahaemolyticus from aquatic animals is severe,and the number of multidrug-resistant strains is increasing.Many factors can affect the antibiotic resistance phenotype of Vibrio parahaemolyticus,and most of the resistance genes can be horizontally transmitted between Vibrio parahaemolyticus,which increases the difficulty of preventing and treating Vibrio parahaemolyticus disease from aquatic animals.It is necessary for relevant departments to strengthen the monitoring of drug resistant phenotypes and genotypes of Vibrio parahaemolyticus,further revealing its drug resistance mechanism,and providing theoretical basis for scientific prevention and control of Vibrio parahaemolyticus disease from aquatic animals.

Key words: Liaoning Province, Vibrio parahaemolyticus of aquatic animal origin, Drug resistance, Drug resistance gene, Drug resistance phenotype