Phenotypic and Molecular Characterization of the Capsular Serotypes of Pasteurella multocida Isolated from Pneumonic Cases of Cattle in Ethiopia

Abstract

Background: Pasteurella multocida is a heterogeneous species and opportunistic pathogen associated with pneumonia in cattle. Losses due to pneumonia and associated expenses are estimated to be higher in Ethiopia with limited information about the distribution of capsular serotypes. Hence, this study was designed to determine the biotypes and capsular serotypes of P. multocida from pneumonic cases of cattle.Methods: A cross-sectional study with a purposive sampling method was employed in 400 cattle from April 2018 to January 2019. Nasopharyngeal swabs and lung tissue samples were collected from clinically suspected pneumonic cases of calves (n = 170) and adult cattle (n = 230). Samples were analyzed using the bacteriological and molecular assay.Result: Bacteriological analysis revealed isolation of 61 (15.25%) P. multocida subspecies multocida. Molecular assay targeting KMT1 gene (~460 bp) confirmed P. multocida species. Capsular typing revealed the presence of serogroup A (hyaD-hyaC) gene (~1044 bp) and serogroup D (dcbF) gene (~657 bp) in 56 (91.80%) and 5 (8.20%) isolates, respectively. Isolation of P. multocida A:3 highlights its prevalence in the study areas. Therefore, the current finding suggests further comprehensive studies on P. multocida capsular types and microbial diversity of respiratory infection in cattle to design an effective control strategy.