猪链球菌病二价灭活疫苗候选株培养条件的优化及其安全性试验

Optimization of the culture condition and the safety tests of the bivalent vaccine against swine streptococcosis

筛选对猪致病力强、免疫原性良好的猪链球菌病兰氏C群LN0 1株和猪链球菌Ⅱ型LN0 5株 ,通过优化培养条件 ,LN0 1株和LN0 5株培养菌数最高分别为 1.2× 10 9和 2 .8× 10 9CFU/mL ;LN0 1株未见溶血素产生 ,LN0 5株溶血素效价为 1∶6 4;脱毒剂A (甲醛 )对其毒素的脱毒作用不明显 ,37℃脱毒 30d ,对仔猪的安全剂量为 5mL ;脱毒剂B的脱毒时间缩短为 3d ,安全剂量增加到 10mL ;试验还证实 ,37℃和 6

Streptococcus equi subsp. Zooepidemicus LN01 strain and Streptococcus suis type 2 LN05 strain were (selected) as the vaccine strains for their high virulence and good immunogenicity. After optimizing the (cultured) condition, LN01 and LN05 could both grow well at 37 ℃ for 12 hours. LN01 cannot produce hemolysin, whereas LN05 can produce hemolysin with the haemolytic titer of 1∶64. The (detoxification ) effect of formaldehyde was not obvious, the safety dosage to piglets of bacterial liquid was 5 mL after being detoxified 30 days at 37 ℃. With the homemade detoxificator, the detoxification time shortened to 3 days and the safety dosage to piglets was increase to 10 mL. The effect of the detoxification was not different obviously at 37 ℃ and 60 ℃.