Abstract: This test was researched for the pathogenic bacteria and drug resistance of dead pigs in a pig farm in Anning，Yunnan Province. Collecting liver，lung，spleen，and lymph nodes of dead pigs for smear staining， microscopic examination，separation culture，biochemical test，animal pathogenicity test，16S rRNA identification， serotype identification，virulence factor genotype and phenotype detection，and drug sensitivity test to study the isolated strains. The results showed that the Ynanning SS from the organs of dead pigs was Streptococcus suis type 2. The 16S rRNA gene sequence of Yinanning SS was 99.3% homologous to LC377187 and KM972351，and was higher than 92.5% homologous to other Streptococcus suis. Ynanning SS is resistance to gentamicin，clindamycin， lincomycin，cefazolin，cefuroxime，ceftazidime and sulfamethoxam，moderately sensitive to penicillin，ciprofloxacin， and sensitive to doxycycline，ceftriaxone，cefotaxime，tetracycline and sulfadiazine. Selecting sensitive drugs toclinical isolates can achieve good therapeutic effects. The research results provide a certain reference for the prevention and treatment of local Streptococcus suis disease.

Key words: Streptococcus suis； Isolation and identification； Serotype； Virulence factor gene； Drug sensitivity test

摘要： 为了解云南安宁某猪场病死猪的致病菌及耐药性。采集病死猪只的肝、肺、脾、淋巴 结进行涂片染色镜检、分离培养、生化试验、动物致病性试验、16S rRNA鉴定、血清型鉴定、毒力 因子基因表型检测、药敏试验等方法对分离菌株进行研究。结果表明从病死猪的脏器中分离 鉴定的菌株 Ynanning SS 为 2 型猪链球菌，Ynanning SS 的 16S rRNA 基因序列与 LC377187、 KM972351同源高达99.3%，与其它猪链球菌16S rRNA序列同源性都高于92.5%以上。且遗传 进化树与LC377187属于同一分枝，亲缘关系较近；Ynanning SS毒力因子基因表型为Epf+Mrp+ Sly+，属于强毒力菌株；Ynanning SS对庆大霉素、克林霉素、林可霉素、头孢唑林、头孢呋肟、头 孢他啶、磺胺对甲氧嘧啶耐药，对青霉素、环丙沙星中介，对多西环素、头孢曲松、头孢噻肟、四 环素、磺胺嘧啶敏感。选用对临床分离菌株敏感的药物进行防治可取得良好的治疗效果，相关 研究结果为当地猪链球菌病的防治提供一定参考依据。

关键词: 猪链球菌； 分离鉴定； 血清型； 毒力因子基因； 药敏试验