猪源马链球菌兽疫亚种灭活疫苗对小鼠的免疫效力评价

 【目的】评价中国不同地区猪源马链球菌兽疫亚种分离株抗原性的差异，为猪链球菌病疫苗的研制提供指导。【方法】取从国内10省市分离的10株猪源马链球菌兽疫亚种分离株，分别制备灭活疫苗，免疫12周龄ICR小鼠，用同源菌株和ATCC35246株攻击。【结果】以同源菌株攻击免疫小鼠，除CG-74-63株外，其余菌株的保护率均在90％以上；而以异源菌株ATCC35246进行攻击，免疫小鼠的免疫保护率为80%～100%。【结论】中国不同地区的猪源马链球菌兽疫亚种分离株的抗原性差异不大，单一菌株制备的疫苗具有保护性。

Efficacy of Inactivated Vaccine Based on Streptococcus equi subsp.Zooepidemicus of Porcine Origin Against Virulent Challenge in Mouse Model

Abstract: Sreptococcus equi subsp zooepidemicus causes swine diseases in China and had made substantial economic losses in recent years. To evaluate the antigenic variability among the 10 local isolated Sreptococcus equi subsp zooepidemicus of pig origin , inbred 12-week-old ICR mice were immunized with formalin-inactivated whole bacterium cell in complete Freund’s adjuvant of the 10 local isolated strains respectively ，which were followed by a similar doses emulsifield in incomplete Freund’s adjuvant four weeks later .10 groups of vaccinated mice and control group mice were challenged two weeks later with 5 LD 50 homogenous strains given intraperitoneally in a dose volume of 0.1 mL, another 10 groups mice were challenged with 1.6×10 5CFU of an 18 h THB culture of Sreptococcus equi subsp zooepidemicus ATCC35246 strain. The results showed that the immunized mice were protected after homogenous strain challenges with 90 pecent protection and shared 80 percent protection against challenge by ATCC35246.