环渤海地区海水养殖鱼类耐药性及耐药基因分析

Analysis of Drug Resistance and Resistance Genes in Marine Aquaculture Fish in the Bohai Sea Region

摘要: 本研究以环渤海海水鱼类养殖中具有代表性的山东、辽宁2地为取样地，以海水鱼重点养殖品种大菱鲆、虹鳟和许氏平鮋为取样品种，对鲑气单胞菌进行耐药基因携带情况分析。于2020年~2023年分离出103株杀鲑气单胞菌，采用RT-PCR技术测定了氟苯尼考耐药基因floR、四环素类药物耐药基因tetR (含tetR家族5种基因型tetA、tetB、tetC、tetD、tetE)耐药性基因的携带情况，并采用微孔板稀释法测定其耐药性。结果表明：(1) 本研究中携带耐药性基因的病原菌占比87.38%，tetR耐药性基因携带率显著高于floR，耐四环素5种基因型中携带率最高的为tetA；本研究所监测的2个地区辽宁省携带耐药性基因病原菌数最高；来源于不同年份的病原菌耐药性基因携带率存在差异，从2021年到2023年，耐药性基因携带率呈先降低后上升的趋势。(2) 本研究分离的病原菌对四环素类表现耐药性的占比86.41%，对氟苯尼考耐药的占比37.86%。综上所述，水产养殖病原菌耐药性复杂多变，在疾病发生时应及时进行耐药性检测，选择药物敏感性高的抗菌药物种类，以加快治疗速度和降低病害损失；同时，可以根据渔用抗菌药物配伍搭配要求，采用多种药物联合使用的方式，实现快速、彻底地消灭病原菌，预防耐药性的产生。

Abstract: In this study, the resistance gene carrying of Salmonella was analyzed in the representative marine fish of Shandong and Liaoning, the key species of marine fish for intensive aquaculture, including the large flounder (Sciaenops bivalentus), rainbow trout (Salmo salmon), and Xu’s flatfish (Pseudosciaenops xu), were selected as sampling species, 103 Aeromonas salmonis were isolated to analysis the carriage of resistance genes. The carriage of floR, tetR, tetA, tetB, tetB, tetC, tetD, tetE resistance genes were determined by RT-PCR technology, and its resistance was determined by microplate dilution method. The results showed that: (1) In this study strains carrying drug resistance genes accounted for 87.38%, the tetR resistance gene carriage rate is much higher than that of floR, and tetA had the highest carrier rate of the five tetracycline genotypes; Shandong province had the highest number of strains carrying drug resistance genes; While with the extension of drug time, the carrier rate of resistance gene decreased first and then increased. (2) 86.41% bacterial strain showed resistance to doxycycline and 37.86% of the isolates were resistant to florfenicol. In conclusion, the drug resistance of aquatic pathogenic bacteria is complex and variable. When diseases occur, drug resistance testing should be conducted promptly to select antibiotics with high sensitivity, thereby accelerating treatment and reducing disease losses. Additionally, based on the compatibility requirements of fishery antibiotics, a combination of multiple drugs can be employed to achieve rapid and thorough eradication of pathogens, preventing the emergence of drug resistance.