中国10省市健康母猪体内猪链球菌致病血清型分布及其耐药性研究

目的 为调查中国健康母猪体内猪链球菌的主要致病血清型分布和不同血清型猪链球菌的耐药性差异.方法 采集国内10个省市的健康母猪扁桃体并从中分离鉴定出猪链球菌421株,经与标准血清的凝集反应了解其主要致病血清型分布,并用微量肉汤法对不同血清型的猪链球菌进行耐药性检测,经统计分析了解小同血清型猪链球菌的耐药性差异.结果 健康母猪体内所分离猪链球菌的优势(致病)血清型依次为9、3和7型,所占比例分别为26.6%、23.5%和15.7%.在能分型的其他血清型中,猪链球菌2型所占的比例为7.4%;耐药性研究结果表明,不同血清型的猪链球菌对抗菌药物的耐药性不同,猪链球菌2型对所测12种药物的敏感性最强.结论 健康母猪体内猪链球菌的致病血清型分布结果再次证明猪链球菌是一种条件性致病菌,不同血清型的猪链球菌感染应根据抗生素敏感件测试结果选用不同的药物进行合理防治.

Distributions of pathogenic capsular types and in vitro antimicrobial susceptibility of different serotypes of Streptococcus suis isolated from clinically healthy sows from 10 provinces in China

Objective To determine the distributions of major pathogenic capsular types and in vitro antimicrobial susceptibility of different serotypes of Streptococcus suis isolated from clinically healthy sows in China. Methods Tonsil specimens of clinically healthy sows from 10 different provinces in China were collected, a total of 421 S.suis were isolated. Capsular types of S.suis were decided using the sera agglutination reaction. Antimicrobial susceptibility testing was performed using a broth microdilution method and the differences between serotypes were decided statistically. Results The prevalent capsular types of S.suis isolated from clinically healthy sows were 9(26.6% ), 3 (23.5%) and 7(15.7% ) types, respectively. 7.4% of isolates were confirmed to be S.suis type 2. Overall, differences in antimicrobial susceptibility among serotypes of S. suis were found. By comparison, lower resistance was observed for S.suis type 2 from clinically healthy sows. Conclusion The prevalence of pathogenic S.suis serotypes from clinically healthy sows again indicates S.suis is a conditional pathogenic bacterium. Differential prevention and treatment regimes should be considered according to antimicrobial susceptibility of different serotypes of S.suis.