Isolation and Identification of Pasteurella multocida and Mannheim Hemolytica from Pneumonic Small Ruminants in Haramaya District, Eastern Ethiopia

Abstract Background Pasteurella species are frequently encountered as serious pathogens in small ruminants. Methods The cross-sectional study was conducted from December 2022 to April 2023 in Haramaya district, eastern Ethiopia, to isolate and identify Pasteurella multocida and Mannheimia haemolytica and estimate their prevalence, associated risk factors, and antimicrobial sensitivity of isolates in small ruminants using a purposive sampling method. A total of 384 samples (156 nasal swabs from clinic cases and 228 lung swabs from abattoir cases) were collected. STATA 14 statistical software was used to examine the data. In addition, multivariable logistic regression analysis was used to evaluate other factors. Results Out of the 384 samples analyzed, 164 were positive for Pasteurella, resulting in a 42.70% infection rate. 63 (38.4%) of the 164 positive results were from nasal swabs, while 101 (61.6%) came from lung samples. Mannheimia haemolytica accounted for 126 (76.82%) of the isolates, while Pasteurella multocida accounted for 38 (23.17%). Of the 63 nasal swab isolates, 33 (37%) were from goats and 30 (42.8%) were from sheep. And 17 (10.89%) and 46 (29.58%), respectively, were P. multocida and M. haemolytica. 46 (40%) of the 101 (44.3%) isolates of pneumonic lung samples were from goats, while 55 (48.47%) were from sheep. In this study, the factors of species, age, and BCS were found to be significant (p 0.05) predictors of Pasteurellosis. Pasteurella isolates evaluated for antibiotic susceptibility were resistant to Oxacillin (90.90%), Gentamycin (72.72%), and Penicillin (63.63%), but responsive to Chloramphenicol (90.90%), Tetracycline (63.63%), and Ampicillin (54.54%). Conclusion This study discovered that M. haemolytica and P. multocida are the most common causes of pasteurellosis in small ruminants, and isolates were resistant to commonly used antibiotics in the study area. As a result, an integrated immunization strategy, antimicrobial resistance monitoring, and avoidance of stress-inducing factor induction are recommended.