Houghton S B, Gourlay R N
Res Vet Sci. 1984 Sep;37(2):194-8.
Samples of pneumonic lung tissue from 140 calves with subclinical pneumonia and 65 calves with fatal pneumonia were examined bacteriologically. Sixty-eight (48 per cent) of the lungs from the subclinical cases and 27 (41 per cent) of the lungs from the fatal cases contained bacteria at more than 10(4) colony forming units (cfu) per gram of tissue. Pasteurella haemolytica was associated more with fatal cases than subclinical cases (P less than 0.001). Of the seven species of bacteria inoculated endobronchially into gnotobiotic calves only P haemolytica produced severe respiratory disease, although some strains of P multocida produced a fatal septicaemia.
对140头患有亚临床肺炎的犊牛和65头患有致命性肺炎的犊牛的肺组织样本进行了细菌学检查。亚临床病例的68个（48%）肺组织和致命病例的27个（41%）肺组织中，每克组织含有的细菌超过10⁴菌落形成单位（cfu）。溶血巴斯德菌在致命病例中比在亚临床病例中更常见（P<0.001）。在内生支气管接种到无菌犊牛体内的7种细菌中，只有溶血巴斯德菌会引发严重的呼吸道疾病，尽管有些多杀巴斯德菌菌株会导致致命的败血症。
