天津地区猪链球菌3型菌株的致病性及耐药特性研究  

Study on Pathogenicity and Drug Resistance of Streptococcus suis Type 3 Strain in Tianjin

作　　者：池晶晶[1,2] 董志民 田向学[1,2,3] 谭世旭 李秀丽[1,2,3] 杨春蕾 任卫科 鄢明华[1,2,3] CHI Jingjing;DONG Zhimin;TIAN Xiangxue;TAN Shixu;LI Xiuli;YANG Chunlei;REN Weike;YAN Minghua(Tianjin Animal Science and Veterinary Research Institute,Tianjin 300381,China;Tianjin Scientific Observation Experiment Station of Veterinary Medicine and Diagnosis Technology,Ministry of Agriculture and Rural Affairs of the People’s Republic of China,Tianjin 300381,China;Tianjin Engineering Research Center for Livestock and Poultry Health Breeding,Tianjin 300381,China)

机构地区：[1]天津市畜牧兽医研究所,天津300381 [2]农业农村部兽用药物与诊断技术天津科学观测实验站,天津300381 [3]天津市畜禽健康养殖技术工程中心,天津300381

出　　处：《中国畜牧兽医》2019年第12期3740-3748,共9页China Animal Husbandry & Veterinary Medicine

基　　金：天津市生猪产业技术体系猪病防控岗位项目(ITTPRS2017003);天津市科技计划项目(18ZXBFNC00270)

摘　　要：试验旨在对分离自天津地区发病猪场的7株猪链球菌3型菌株(Streptococcus suis type 3,SS 3)进行致病性和耐药特性研究。应用剂量为1.0×10^7、1.0×10^8和1.0×10^9 CFU/只的细菌对小鼠进行致病力研究,用PCR方法检测7株SS 3型菌株的毒力基因mrp、ef、sly、gdh、gapdh、fbps和orf 2,并对这7株SS 3型菌株进行药物敏感试验。致病力试验结果显示,接种剂量为1.0×10^9和1.0×10^8 CFU/只时分别有6和3株SS 3型菌株可使小鼠100.0%(5/5)发病死亡,接种剂量1.0×10^7 CFU时仍有1株SS 3型菌株可使80.0%(4/5)小鼠发病死亡,这7株SS 3型菌株对小鼠的致病力依次为R15056>R15042=S15030>Y12024=Y09011>Y13125>Y13164。毒力基因检测结果表明,共有3种毒力基因型,R12024、Y13164、R15042和S15030株为gdh、gapdh、fbps和orf 2毒力基因阳性,Y13125和R15056株为sly、gdh、gapdh、fbps和orf 2毒力基因阳性,Y09011株为gdh、fbps和orf 2毒力基因阳性。药物敏感性试验结果显示,7株SS 3型对头孢喹肟相对最敏感,其次为阿莫西林、环丙沙星和磺胺间甲氧嘧啶钠,但对强力霉素100.0%耐药,且所有菌株均呈现3重以上的耐药性。本研究为进一步开展天津地区SS 3型流行特点及致病机理研究奠定了基础,可为天津地区SS 3型菌株的综合防控提供理论指导。The aim of this study was to investigate the pathogenicity and drug resistance of 7 Streptococcus suis type 3(SS 3)strains isolated from piggery in Tianjin.The pathogenicity of bacteria with doses of 1.0×10^7,1.0×10^8 and 1.0×10^9 CFU/mice was studied.The virulence genes mrp,ef,sly,gdh,gapdh,fbps and orf 2 of 7 strains of SS 3 strains were detected by PCR.Drug susceptibility tests of the 7 strains of SS 3 were also carried out.The results of pathogenicity test showed that 6 and 3 strains of SS 3 could cause 100.0%(5/5)morbidity and death in mice at inoculation dose of 1.0×10^9 and 1.0×10^8 CFU/mice,respectively.One strain of SS 3 could still cause 80.0%(4/5)morbidity and death in mice at inoculation dose of 1.0×10^7 CFU/mice.The order of pathogenicity of the 7 strains of SS3 strains in mice was R15056>R15042=S15030>Y12024=Y09011>Y13125>Y13164.The results of virulence gene test showed that there were three virulence genotypes:R12024,Y13164,R15042 and S15030 were positive for gdh,gapdh,fbps and orf 2 virulence genes;Y13125 and R15056 were positive for sly,gdh,gapdh,fbps and orf 2 virulence genes,and Y09011 was positive for gdh,fbps and orf 2 virulence genes.Drug susceptibility test showed that 7 SS 3 strains were relatively sensitive to cefquinoxime,followed by amoxicillin,ciprofloxacin and sulfamethoxacil sodium.However,they showed 100.0%resistance to doxycycline,and all strains showed more than 3-fold resistance.This study laid a foundation for the further development of epidemiological characteristics and pathogenic mechanism of SS 3 strains in Tianjin,and could provide theoretical guidance for the comprehensive prevention and control of SS 3 strains in Tianjin.

关 键 词：猪链球菌3型 鉴定 致病力 毒力基因 药物敏感试验 

分 类 号：S852.611[农业科学—基础兽医学]