副猪嗜血杆菌国内流行血清型菌株的生物学特性比较研究

Comparative study on biological characterization of the epidemic serotypes Haemophilus suis in China

本研究对我国最流行的HPS血清4、5、12、13和14型共16株细菌的菌体形态、生长速度、生化特性、小鼠毒力等生物学特性进行了比较研究。革兰染色镜检结果表明,除4型菌株H4L3外,同一血清型HPS的菌体形态比较一致;不同血清型HPS的菌体形态具有明显差异,且具有型特异性。培养结果表明,在TSA固体培养基上生长24h后的菌落平均直径大小依次为13型2.02mm、4型1.91mm、5型1.80mm、14型1.71mm、12型1.66mm,同一血清型的不同菌株之间无显著差别。生化试验结果表明不同血清型HPS的生化反应存在明显差异,即使是同一血清型的不同菌株之间也有较大差别。小鼠毒力试验结果表明,除4型外,毒力强弱依次为血清12型、14型、5型、13型,其LD50分别介于（2.7~4.6）×10^8、（4.3~7.9）×10^8、（1.0~1.3）×10^9、（2.3~2.8）×10^9 CFU之间,同一血清型的不同菌株之间无显著差别。在血清4型菌株中,H4L3的毒力明显偏强（LD50为3.6×10^8 CFU）,其他菌株的LD50介于（1.4~1.6）×10^9 CFU之间。本研究为HPS不同血清型的快速鉴定、致病机理和疫苗研发等提供了理论依据。

Bacterial morpholog, growth rate, virulence, biological characteristics of 16 Haemophilus suis strains including the most epidemic HPS serotypes 4,5,12,13 and 14 were determined in this paper. Out of the H4L3 of strains serotype 4,all of the HPS strains with the same serotype have the similar morphology each other. There are significant differences in the bacterial morphology among the HPS strains with the different serotypes. The bacterial morphology is type-specific in these 5 serotypes of HPS. Culture on TSA solid medium for 24h results showed that the average diameter sizes of the colonies are 2.02 mm for serotype 13,1.91 mm for serotype 4,1.80 mm for serotype 5,1.71 mm for serotype 14,1.66 mm of serotype 12, respectively. There are no significant differences in the growth rates among the HPS strains with the same serotypes. There are different fermentation patterns of the various serotypes of strains on different carbohydrates, even are different in the HPS strains with the same serotype. With the exception of the serotype 4 strains,the serotype 12 HPS strains showed the most virulent to the BALB/c mice with the LD50 （2.7-4.6）×10^8 CFU, followed by serotype 14,5 and 13 strains with the LDs0 （4. 3-7.9）×10^8, （1.0-1.3）×10^9 ,and （2.3-2.8）×10^9 CFU respectively. And there were no significant difference among the different strains of the same serotype. Furthermore, the H4L3 strain of serotype 4 showed the most significantly virulent （LD50,3.6 × 10^8CFU）,other strains LDs0 were （1.4-1.6）×10^9 CFU. In conclusion, this study will provide a theoretical basis for the rapid identification, pathogenesis and vaccine development of the different serotypes of HPS.