Abstract:
Respiratory infections, particularly pneumonic pasteurellosis due to Mannheimia haemolytica and
Pasteurella multocida are responsible for huge economic losses to the ovine population in Ethiopia. A
cross-sectional study was conducted from March 2023 to August 2023 with the aim to estimate the
prevalence, identify associated risk factors and determine the drug resistance profiles of Pasteurella
multocida and Mannheimia haemolytica isolated from sheep slaughtered at the Jigjiga municipality
abattoir. Bacteriological culture, biochemical tests, and in-vitro disc diffusion tests on selected
antimicrobial agents were employed. STATA version 16.0 statistical tool was used to analyze the data
using descriptive and analytical statistics. Out of the 384 lung samples, 103 [26.8%: 95%; (CI)
=22.46-31.55) were positive in which 19.79% and 7.03% for M. haemolytica and P. multocida,
respectively. A higher prevalence was recorded in young sheep (36.15%) than adults (22.04%).
Moreover, young sheep were 2.15 times (OR = 2.15; 95% CI 1.33-3.48; P= 0.002) more likely to be
infected then adults. The highest prevalence was found in sheep with poor body condition (35.18%)
and medium body condition (20.30%) was least. poor body condition was 2.44 times (OR =2.44; 95%
CI: 1.18–5.04; P=0.016) higher than those with medium body condition. The respective percentage of
susceptibility to gentamicin and kanamycin was 100% and 97.36% for M. haemolytica while 85.71%
and 92.85% for P. multocida isolates. High proportion of resistance was recorded with M.
haemolytica against oxytetracycline (92.10%), penicillin-G (86.84%), tetracycline (81.52%), and
ampicillin (73.52%), whereas P. multocida showed high resistance against oxytetracycline (100%),
tetracycline (92.85%), penicillin-G (85.71%), and ampicillin (78.57%). Moreover, 81.57% of the M.
haemolytica and 92.85% of P. multocida isolates showed multi-drug resistance. In conclusion, the
circulation of M. haemolytica was higher among lung samples and large proportion of both M.
haemolytica and P. multocida isolates were resistant to commonly used antibacterial agents.
Therefore, it is advisable to implementing preventive and control methods against these isolates and to
conduct molecular identification and serotyping of the circulating isolates in sheep population in their
source of origin.
