摘要
为探明新疆白斑狗鱼(Esox lucius)发生细菌性败血症的原因,本研究调查了新疆呼图壁、乌鲁木齐米东区5个养殖鱼塘白斑狗鱼发病情况。通过对病鱼的临床症状与病理变化观察、高通量测序分析,以及病原的分离鉴定、毒力基因检测和回归感染试验,明确病原的种类及致病特点;采用Kirby-Bauer纸片扩散法分析病原菌对16种抗生素的敏感性,检测养殖场常用的氟苯尼考、恩诺沙星和多西环素最小抑菌浓度和最小杀菌浓度。结果:在患病白斑狗鱼的脏器中分离出4个优势菌株,分别是3株维氏气单胞菌(Aeromonas veronii)和1株温和气单胞菌(Aeromonas sobria),携带黏附素(ahal)、细胞毒性肠毒素(act)、丝氨酸蛋白酶(ahp)3种毒力基因。人工回归感染后,2种病原菌混合感染对鱼的致病性损伤更严重,半数致死量(LD_(50))为1.5×10^(5)CFU/mL。维氏气单胞菌对麦迪霉素、头孢噻吩以及喹诺酮类、氯霉素类、四环素类等12种抗生素敏感,对复方新诺明、万古霉素、青霉素和新霉素4种抗生素耐药;温和气单胞菌对万古霉素以及喹诺酮类、氯霉素类、四环素类等13种抗生素敏感,对头孢噻吩、青霉素和新霉素3种耐药。恩诺沙星、多西环素和氟苯尼考对维氏气单胞菌菌株抑菌效果最好,多西环素对温和气单胞菌菌株抑菌效果最好。综上,本研究首次报道了维氏气单胞菌和温和气单胞菌在新疆地区白斑狗鱼中的致病性及对不同抗生素的敏感性,为新疆地区白斑狗鱼细菌性败血症的诊断与防控提供了重要参考。
To investigate the causes of bacterial septicemia Esox lucius in Xinjiang,this study examined the incidence of the disease in five aquaculture ponds located in the Hutubi and Midong Districts of Urumqi.Through clinical symptom observation,pathological examination,high-throughput sequencing analysis,pathogen isolation and identification,virulence gene detection,and challenge tests,the pathogenic species and their characteristics were identified.The Kirby-Bauer disk diffusion method was employed to analyze the susceptibility of the pathogens to 16 antibiotics.Additionally,the minimum inhibitory concentration(MIC)and minimum bactericidal concentration(MBC)of commonly used antibiotics,including florfenicol,enrofloxacin,and doxycycline,were measured on the farms.And,four dominant bacterial strains were isolated from the organs ofthe diseased Esox lucius,comprising three strains of Aeromonas veronii and one strain of Aeromonas sobria,all of which carried three virulence genes:adhesin(ahal),cytotoxic enterotoxin(act),and serine protease(ahp).The artificial challenge tests showed that co-infection with the two pathogens resulted in more severe pathogenic damage,with a median lethal dose(LD_(50))of 1.5×10^(5) CFU/mL.A.veronii was susceptible to 12 antibiotics,including midecamycin,cephalothin,quinolones,chloramphenicol,and tetracyclines,and so on,but it exhibited resistance to sulfamethoxazole-trimethoprim,vancomycin,penicillin,and neomycin.A.sobria was susceptible to 13 antibiotics,including vancomycin,quinolones,chloramphenicol,and tetracyclines,and so on,but it was resistant to cephalothin,penicillin,and neomycin.Enrofloxacin,doxycycline,and florfenicol demonstrated the strongest inhibitory effects on A.veronii,while doxycycline was most effective against A.sobria.This study has been the first to report the pathogenicity of A.veronii and A.sobria in Esox lucius in Xinjiang,as well as their susceptibility to various antibiotics.This research provided important references for diagnosis and control of bacterial septicemia in Esox lucius in Xinjiang.
作者
赵怡阳
阎晓菲
王涛
刘冲
曹新玉
ZHAO Yiyang;YAN Xiaofei;WANG Tao;LIU Chong;CAO Xinyu(College of Veterinary Medicine,Xinjiang Agricultural University,Urumqi 830052,China;College of Life Sciences,Xinjiang Agricultural University,Urumqi 830052,China;Xinjiang Key Laboratory for Ecological Adaptation and Evolution of Extreme Environment Biology,Urumqi 830052,China)
出处
《畜牧与兽医》
北大核心
2025年第7期115-124,共10页
Animal Husbandry & Veterinary Medicine
基金
新疆维吾尔自治区高校基本科研业务费项目(XJEDU2022 Z003)。
关键词
白斑狗鱼
维氏气单胞菌
温和气单胞菌
分离鉴定
致病性
抗生素
Esox lucius
Aeromonas veronii
Aeromonas sobria
isolation and identification
pathogenicity
antibiotic
作者简介
第一作者:赵怡阳,女,硕士生;通信作者:阎晓菲,副教授,硕导,主要从事水产病害与防控方面的研究,E-mail:yanxf83@163.com。
