副猪嗜血杆菌小鼠毒力和仔猪毒力的相关性分析

旨在对我国最为流行的血清4、5、12和13型副猪嗜血杆菌(Haemophilus parasuis,HPS)(共36株)进行BALB/c小鼠和仔猪毒力试验的比较研究。小鼠毒力试验结果表明,4种血清型菌株的LD50分别介于9.80×10^7~4.60×10^9、2.10×10^8~8.85×10^9、4.81×10^7~7.01×10^9和1.75×10^8~8.45×10^8 CFU;整体毒力表现强弱依次是13、4、12、5型,但仅在5型与13型菌株之间毒力具有显著差异(P<0.05)。仔猪毒力试验结果表明,同一血清型中不同菌株的毒力具有明显差异,均存在强毒和弱毒菌株;整体毒力表现强弱依次是5、13、4、12型;但5型与4型(P=0.039)和12型(P=0.033)之间具有显著差异(P<0.05),与13型差异不显著(P=0.241)。综合对比分析HPS的小鼠和仔猪毒力试验结果,可以得出3个结论:1)4种国内流行性血清型菌株的整体毒力由强到弱依次是5、13、4和12型;2)但同一血清型中均存在强毒和弱毒菌株,HPS的血清型与其毒力之间不具有相关性;3)HPS虽能致死BALB/c小鼠,但其毒力结果与仔猪毒力试验结果并不一致,表明其作为替代模型具有一定的缺陷。

Correlation between Virulence of Haemophilus parasuis in Mice and Piglet

In this study, we compared the virulence of the most prevalent Haemophilus parasuis (36 strains) serovars 4, 5, 12, and 13 in China in BALB/c mice and piglets models. The results of mice virulence tests showed that the LD₅₀values of the four serotype strains were 9.80×10⁷-4.60×10⁹CFU (serovar 4),2.10×10⁸-8.85×10⁹ CFU (serovar 5),4.81×10⁷-7.01×10⁹ CFU (serovar 12) and 1.75×10⁸-8.45×10⁸ CFU (serovar 13), respectively. Serovar 13 was the most highly virulent serovar in mice, followed by serovars 4, 12, 5. However, there was a significant difference in virulence only between serovars 5 and 13 (P<0.05).The results of piglet virulence tests showed that the virulence of different strains in the same serovar were remarkably different, including virulent strains and weak strains. Serovar 5 was the most highly virulent in piglet, followed by serovars 13, 4, 12,but there were significant differences between serovars 5 and 4 (P=0.039), serovars 5 and 12 (P=0.033), and there was no significant difference between serovars 5 and 13 (P=0.241). Comparing the results of HPS virulence tests on mice and piglets, three conclusions can be drawn:first, the overall virulence of the four domestic epidemic serotypes from strong to weak were serovars 5, 13, 4 and 12 in turn; Second, there were both strong and weak strains in the same serotype, so there was no correlation between the serovar and virulence of HPS. Third, although HPS can kill BALB/c mice, its virulence result was not consistent with the piglet virulence test, indicating that it has some defects as an alternative model.