对虾养殖池副溶血弧菌的分离鉴定及其耐药特征、毒力基因分析

为了解对虾养殖池中副溶血弧菌(Vibrio parahaemolyticus)的耐药性和毒力基因的携带情况，2018年从山东4个地区的对虾养殖池收集分离副溶血弧菌，采用Kirby-Bauer纸片法检测其对12种抗生素的耐药性，用PCR方法检测其携带耐热直接溶血素基因(tdh)和耐热相关溶血素基因(trh)的情况。从对虾养殖池共分离副溶血弧菌50株。药敏实验结果显示，副溶血弧菌对庆大霉素、硫酸新霉素和氨苄西林的耐药情况最为严重，耐药率分别高达98%、90%和86%，对氟苯尼考、氯霉素、头孢他啶等敏感性较高，耐药率分别为10%、10%和20%。88%的菌株具有多重耐药性。毒力基因检测结果显示，所有菌株均不携带tdh基因，4%的菌株表现为trh阳性。本研究表明，对虾养殖水环境中的副溶血弧菌对抗生素的耐药性较为严重，应加强副溶血弧菌的病原学监测，在养殖过程中合理使用抗生素，以实现水产养殖业健康发展。

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

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.