Ward A C, Jaworski M D, Eddow J M, Corbeil L B
University of Idaho, College of Agriculture, Caine Veterinary Teaching and Research Center, Caldwell, Idaho 83605, USA.
Can J Vet Res. 1995 Jul;59(3):173-8.
Bacterial isolates (including 17 Haemophilus somnus isolates and an H. somnus-like isolate) from asymptomatic or diseased cattle and sheep, were evaluated for markers associated with virulence and host predilection. The isolates were separated into 6 distinct biovariants, 3 for sheep and 3 for cattle, based on reactions in a battery of 21 test media. Three bovine isolates associated with disease caused hemolysis of bovine blood. The rest of the isolates did not hemolyze either bovine or ovine erythrocytes. Protein profiles of all H. somnus isolates were similar with the exception of the major outer membrane proteins (MOMPs). The MOMPs of isolates associated with disease in cattle had a relative molecular weight of approximately 41 kDa compared with 33 kDa for the MOMPs of isolates from asymptomatic cattle. The MOMPs from sheep isolates were either slightly higher or lower than the 41 kDa MOMPs of bovine isolates. Major antigens detected by Western blotting were similar in all isolates except the H. somnus-like isolate. An immunodominant 40 kDa antigen was conserved in all H. somnus isolates. Antibodies to this antigen have previously been found to be protective in cattle and may also be protective for sheep. Marked differences between cattle and sheep isolates were revealed by use of restriction enzyme analysis, which separated the isolates into 12 ribotypes and 15 unique DNA profiles. Thus, cattle and sheep isolates in this collection had distinctive differences in biochemical reactions, MOMP profiles, and DNA analyses. Such differences have potential value for epidemiological studies and may also be used to evaluate host specificity of H. somnus isolates.
对从无症状或患病牛羊中分离出的细菌菌株（包括17株睡眠嗜血杆菌菌株和1株类睡眠嗜血杆菌菌株）进行评估，以寻找与毒力和宿主偏好相关的标志物。根据在一组21种测试培养基中的反应，这些菌株被分为6个不同的生物变种，其中3个针对绵羊，3个针对牛。3株与疾病相关的牛分离株可导致牛血溶血。其余分离株均不能使牛或羊的红细胞发生溶血。除主要外膜蛋白（MOMPs）外，所有睡眠嗜血杆菌分离株的蛋白质谱均相似。与患病牛相关的分离株的MOMPs相对分子量约为41 kDa，而无症状牛分离株的MOMPs相对分子量为33 kDa。绵羊分离株的MOMPs略高于或低于牛分离株的41 kDa MOMPs。除类睡眠嗜血杆菌分离株外，所有分离株经蛋白质印迹法检测的主要抗原均相似。一种免疫显性的40 kDa抗原在所有睡眠嗜血杆菌分离株中均保守。此前已发现针对该抗原的抗体对牛具有保护作用，对绵羊可能也有保护作用。通过限制性酶切分析发现牛和绵羊分离株之间存在显著差异，该分析将分离株分为12个核糖体分型和15种独特的DNA图谱。因此，该样本中的牛和绵羊分离株在生化反应、MOMP图谱和DNA分析方面存在明显差异。这些差异在流行病学研究中具有潜在价值，也可用于评估睡眠嗜血杆菌分离株的宿主特异性。
