Prevalence and Molecular Detection of Pasteurella multocida, Mannheimia hemolytica , and Bibersteinia trehalosi in Sheep, Western Oromia, Ethiopia

Abstract Ethiopia has the biggest population of livestock in Africa, and small ruminants play a significant role in both meat consumption and revenue from the export of live animals and their skins. Infectious diseases, especially pneumonic pasteurellosis, are a key constraint in productivity, which is low despite their economic relevance for a variety of technological and non-technical reasons. Sheep are particularly susceptible to high rates of morbidity and mortality from the disease while under stress. These bacterial species were to be isolated, identified, and molecularly detected from sheep in certain regions of western Oromia, Ethiopia, that appeared to be healthy, as well as those that were clinically ill. Using multi-stage sampling, a cross-sectional study was carried out in three zones: Horro Guduru Wollega, East Wollega, and West Shawa, between January and December 2022. 384 sheep (220 healthy, 164 ill) had their nasal swabs taken, and they were analyzed bacteriologically, biochemically, and molecularly using PCR for the PHSSA, Rpt2, and CapA genes. To evaluate the relationships between risk factors and bacterial prevalence, data were examined using logistic regression and descriptive statistics. With P. multocida being the most commonly isolated species, followed by M. haemolytica and B. trehalosi, the overall prevalence of Pasteurellaceae was 21.1%. Pneumonic and young sheep had a greater prevalence, and there were significant correlations with age (OR = 2.41; 95% CI: 1.42–4.18) and illness status (OR = 3.47; 95% CI: 2.06–5.97), but not with sex or location. These results demonstrate the persistent risk of pneumonic pasteurellosis in Ethiopian sheep and the significance of species-level identification in directing focused interventions, such as management, treatment, and immunization plans. To molecularly describe isolates from other places and elucidate the pathogenic function of Pasteurella and Mannheimia species in illness development, more research is advised.