Jánosi Katalin, Stipkovits László, Glávits Róbert, Molnár Tamás, Makrai László, Gyuranecz Miklós, Varga János, Fodor László
Department of Microbiology and Infectious Diseases, Faculty of Veterinary Science, Szent István University, Hungária krt. 23-25 H-1143 Budapest, Hungary.
Acta Vet Hung. 2009 Sep;57(3):347-56. doi: 10.1556/AVet.57.2009.3.1.
The purpose of this study was to develop and evaluate an aerosol infection method with Histophilus somni that closely resembles the natural way of infection of calves. Another aim was to compare the virulence of two H. somni strains by collecting clinical and postmortem data of experimentally infected and control animals. Seventeen conventionally reared 3-month-old calves were divided into three groups. Two groups of six animals each were exposed to suspensions containing H. somni on three consecutive days using a vaporiser mask. The third group of five animals was used as control. The data of individual clinical examination were recorded daily. All animals were exterminated, and gross pathology of all lungs was evaluated on the 15th day after the first infection. Both H. somni strains caused an increase of rectal temperature, respiratory signs, decrease of weight gain, and severe catarrhal bronchopneumonia in both infected groups. Although some chronic lesions were detected in the lungs of the control animals as well, the histopathological findings in the infected and control groups were different. H. somni was recultured from all lungs in the challenged groups but it could not be reisolated or detected by PCR examination in the control group. This is the first paper on aerosol challenge of calves with H. somni using repeated infection and verified by detailed pathological, bacteriological and histopathological examination. The infection method proved to be successful. There was no difference in the virulence of the two H. somni strains used in the trial.
本研究的目的是开发并评估一种用睡眠嗜血杆菌进行气溶胶感染的方法，该方法与犊牛的自然感染方式极为相似。另一个目的是通过收集实验感染动物和对照动物的临床及死后数据，比较两种睡眠嗜血杆菌菌株的毒力。将17头常规饲养的3月龄犊牛分为三组。两组各6头动物连续三天使用雾化面罩接触含有睡眠嗜血杆菌的悬液。第三组5头动物作为对照。每天记录个体临床检查数据。在首次感染后的第15天，对所有动物实施安乐死，并评估所有肺部的大体病理学情况。两种睡眠嗜血杆菌菌株均导致两个感染组的直肠温度升高、出现呼吸道症状、体重增加减少以及严重的卡他性支气管肺炎。尽管在对照动物的肺部也检测到了一些慢性病变，但感染组和对照组的组织病理学结果不同。在攻毒组的所有肺部均再次培养出睡眠嗜血杆菌，但在对照组中未通过PCR检测再次分离到或检测到该菌。这是第一篇关于使用重复感染对犊牛进行睡眠嗜血杆菌气溶胶攻毒，并通过详细的病理学、细菌学和组织病理学检查进行验证的论文。该感染方法被证明是成功的。试验中使用的两种睡眠嗜血杆菌菌株的毒力没有差异。
