University College of Veterinary and Animal Sciences, The Islamia University of Bahawalpur, 63100, Pakistan.
Department of Pathology, Faculty of Veterinary Science, University of Agriculture, Faisalabad 38040, Pakistan.
Microb Pathog. 2017 Nov;112:176-181. doi: 10.1016/j.micpath.2017.09.061. Epub 2017 Sep 29.
Mannheimia haemolytica is causative agent of pneumonic pasteurellosis (mannheimiosis) that causes huge economic losses to livestock farmers. We investigated the microbial and clinico-pathological patterns associated with ovine pneumonic pasturellosis during an outbreak. Prior to death, infected sheep revealed clinical signs including dyspnoea, salivation, pyrexia and mucopurulent nasal discharge. Mortality was significantly (p < 0.05) high in young sheep as compared to adults. Necropsy findings revealed presence of froth in trachea, congestion and consolidation of lungs, pulmonary edema, severe pleural adhesions, pericarditis, hemorrhages on mucosa of jejunum and kidneys. Histopathological examination revealed circumscribed and centrally calcified necrotic areas punctuated with chronic inflammatory cells and interstitial pneumonia. Moreover, bronchial epithelial hyperplasia, edema, congestion, mononuclear cell infiltration, thick interlobular septae and peri-vascular cuffing were the striking changes in lungs. Furthermore, lungs showed severe fibrin depositions along with abundant amount of fibrin meshwork on pleura infiltrated with chronic inflammatory cells. Histologically, liver, kidneys and lymph nodes showed degenerative changes. Mannheimia haemolytica and Pasteurella multocida were differentially identified on the basis of culture characteristics and biochemical tests. M. haemolytica was further confirmed by using polymerase chain reaction. From the findings of current study, it is concluded that M. haemolytica is a major respiratory threat in small ruminants that causes severe pneumonic changes in infected animals.
溶血曼海姆菌是引起肺炎巴氏杆菌病（曼海姆氏菌病）的病原体，给家畜养殖户造成了巨大的经济损失。我们在一次暴发期间调查了与绵羊肺炎巴氏杆菌病相关的微生物和临床病理模式。在死亡之前，受感染的绵羊表现出呼吸困难、流涎、发热和黏液脓性鼻分泌物等临床症状。与成年绵羊相比，幼羊的死亡率明显（p<0.05）更高。剖检发现气管中有泡沫、肺充血和实变、肺水肿、严重胸膜粘连、心包炎、空肠和肾脏黏膜出血。组织病理学检查显示有界限分明的中央钙化坏死区，伴有慢性炎症细胞和间质性肺炎。此外，支气管上皮增生、水肿、充血、单核细胞浸润、小叶间隔增厚和血管周围袖口是肺部的显著变化。此外，肺部还显示出严重的纤维蛋白沉积，以及大量纤维蛋白网在充满慢性炎症细胞的胸膜上的渗透。组织学上，肝脏、肾脏和淋巴结显示出退行性变化。根据培养特征和生化试验，可区分出溶血曼海姆菌和多杀巴斯德菌。通过聚合酶链反应进一步证实了溶血曼海姆菌的存在。从本研究的结果可以得出结论，溶血曼海姆菌是小反刍动物的主要呼吸道威胁，可引起感染动物严重的肺炎性变化。
