竹鼠源绿色气球菌的分离鉴定及耐药性分析  

Isolation,Identification and Drug Resistance Analysis of Aerococcus viridans from Rhizomys sinensis

作　　者：阎朝华 文明[1,2,3] 周碧君 张旭[1,2] 陈国权 赵大杰[1,2] 张天天 王娜 刘妍罕 YAN Chaohua;WEN Ming;ZHOU Bijun;ZHANG Xu;CHEN Guoquan;ZHAO Dajie;ZHANG Tiantian;WANG Na;LIU Yanhan(College of Animal Science,Guizhou University,Guiyang 550025,China;Institute of Animal Disease,Guizhou University,Guiyang 550025,China;Key Laboratory of Animal Diseases and Veterinary Public Health of Guizhou Province,Guiyang 550025,China)

机构地区：[1]贵州大学动物科学学院,贵阳550025 [2]贵州大学动物疫病研究所,贵阳550025 [3]贵州省动物疫病与兽医公共卫生重点实验室,贵阳550025

出　　处：《中国畜牧兽医》2020年第8期2643-2651,共9页China Animal Husbandry & Veterinary Medicine

基　　金：2019年度贵州省科技支撑计划“贵州竹馏规模养殖场育繁关键技术研究”(黔科合支撑[2019]2282号)。

摘　　要：为了查明造成贵州某竹鼠养殖场竹鼠死亡病因,本研究从送检竹鼠体内分离到1株细菌(GZ-S1),通过形态学观察、生化试验、16S rRNA基因序列分析、药敏试验及耐药基因检测、细菌致病性试验等方法对该分离菌进行鉴定。结果显示,该分离菌在鲜血琼脂平板上长出凸起、表面光滑、白色、呈α-溶血的革兰氏阳性球菌;生化试验显示该分离菌对蔗糖、果糖、葡萄糖、硝酸盐还原试验、靛基质试验、枸橼酸盐试验等均为阳性,半乳糖、甘露糖、硫化氢试验、VP试验、MR试验、赖氨酸脱羧酶接触试验等均为阴性;经16S rRNA基因测序及BLAST比对、系统进化树分析发现,分离菌株GZ-S1与气球菌菌株201707CJKOP-Y31(MG593595.1)、绿色气球菌菌株Mnlv2(GQ246745.1)等12株参考菌株在同一分支上。细菌药敏试验结果显示,分离菌株对苯唑西林、羧苄西林、头孢曲松3种药物敏感;对阿莫西林、氧氟沙星、复方新诺明、磺胺异噁唑、多黏菌素B、氟苯尼考、头孢拉定7种药物中敏;对恩诺沙星、卡那霉素、妥布霉素、新霉素、多西环素、四环素6种药物耐药。耐药基因检测结果显示,该分离菌株携带5种耐药基因:tetA(1031 bp)、tetB(513 bp)、tetD(326 bp)、aadd(146 bp)、aac(6′)Ⅰb(655 bp),与药敏表现型相符。人工感染试验结果显示,该分离菌有致病力。本研究对某竹鼠养殖场竹鼠发病的原因作出了准确诊断,为该养殖场细菌性竹鼠病的预防和合理用药提供参考。This experiment was aimed to find out the cause of death of Rhizomys sinensis in a Rhizomys sinensis farm in Guizhou.A strain of bacteria(GZ-S1)was isolated from the submitted Rhizomys sinensis in this study,which was identified through morphological observation,biochemical test,16S rRNA gene sequence analysis,antibiotic sensitivity tests,resistance genes detection and animal infection experiment.The results showed that the isolates was Gram-positive withα-hemolysis reaction and could grow smooth and white colonies on the blood plate.Biochemical identification showed that the isolates had positive reactions to sucrose,fructose,glucose,nitrate reduction,indigo matrix and citrate,but negative reactions to galactose,mannose,hydrogen sulfide test,VP test,MR test and lysine decarboxylase contact test.After 16S rRNA gene sequencing,BLAST alignment and phylogenetic tree analysis,it was found that the isolates GZ-S1 was on the same branch as 12 reference strains of the balloon strain 201707CJKOP-Y31(MG593595.1),Aerococcus viridans strain Mnlv2(GQ246745.1),and so on.The results of bacterial drug sensitivity test showed that the isolates were sensitive to oxacillin,carbenicillin and ceftriaxone,was moderate sensitivity to amoxicillin,ofloxacin,sulfamethoxazole,bacteresulf polymyxin B,florfenicol and cefradine,and was resistant to enrofloxacin,kanamycin,tobramycin,neomycin,doxycycline and tetracycline.The result of resistance genes detection showed that the isolates carried resistance genes including tetA(1031 bp),tetB(513 bp),tetD(326 bp),aadd(146 bp)and aac(6′)Ⅰb(655 bp),which was consistent with the antibiotic sensitivity phenotypes.The results of artificial infection test showed that the isolates had pathogenicity.This study made an accurate diagnosis of the causes of the disease in a Rhizomys sinensis farm,and provided a reference for the prevention and rational drug use of bacterial diseases for Rhizomys sinensis.

关 键 词：竹鼠 分离鉴定 绿色气球菌 16S rRNA基因 药敏特性 耐药基因 

分 类 号：S852.611[农业科学—基础兽医学]