Pathological Changes Associated with Natural Outbreak of Swine Pasteurellosis

Abstract

Swine pasteurellosis is usually observed in descript as well as nondescript pigs imparting in huge economic losses to the pig producers. The disease is characterized by pyrexia, dullness, staggering gait, anorexia, serous nasal discharge and dyspnoea. Case fatality rate may as high as 95% in adult animals and 100% in piglets. Typical lesions of oedematous swellings may remarkably visible in the pharyngeal region, these swellings spread to the ventral cervical region and brisket of pigs. Gross lesions include severe pneumonia and haemorrhages in lungs, petechial haemorrhages on serous membranes and other visceral organs. Lymph nodes usually get enlarged, oedematous and haemorrhagic. The blood smears from heart blood and tissue impression smears reveal teaming numbers of bipolar organisms indicating the presence of Pasteurella spp., the etiological organism. The bacteriological isolation and characterization of causative agent should be ruled out to identify by Gram’ staining for purity and bipolar morphology and biochemical characterization of the organisms. Molecular characterization necessitates to confirm Pasteurella multocida along with capsular types of the organism. Histopathological examination of lungs usually reveals typical fibrinous bronchopneumonia, multifocal suppuration and pleural thickening. Heart of some pigs may show presence of thrombi, haemorrhages and necrosed myocardium.

Prevalence of virulence factor, antibiotic resistance, and serotype genes of Pasteurella multocida strains isolated from pigs in Vietnam

“…This study is the first report of the prevalence of virulence factor, antibiotic resistance, and capsular virulence genes of P. multocida strains isolated from pigs in Vietnam. Pasteurellosis is common disease of pigs worldwide with specific serotype and pathotype associated with the respiratory disease [17]. However, the distribution and prevalence of serotype and pathotype can vary considerably from region to region and over the time in a given region [8,18,19].…”