MALDI TOF Mass Spectrometry and Molecular detection of Mannheimia haemolytica from sheep and goats in Holeta and Sebeta Town, Oromia Special Zone, Ethiopia

Abstract

Background:Mannhemia haemolytica is one of the most important bacteria among causative agent of pneumonic pasteurellosis in small ruminants throughout worldwide and it is also economically devastating pathogen in Ethiopia. Methods: A cross sectional study was carried out from November 2021 to May 2022 with the aim to identify Mannheimia haemolytica from sheep and goat in Sebeta and Holeta town, Oromia special zone, Ethiopia. A total of 235 samples (213 nasal swabs and 22 whole blood) were collected. Sheep and goat with clinical signs suggestive of pneumonic pasteurollosis were purposively sampling. Bacterial identification was conducted using biochemical, Biolog, Matrix Assisted Laser Desorption Ionization-Time of Flight Mass Spectrometry (MALDI TOF MS) and Real time PCR detection. Moreover, antimicrobials susceptibility test was also conducted on the identified bacterial isolates using disc diffusion method. Results: The result showed that from a total of 235 samples, only two nasal swab samples were positive for M. haemolytica (0.85%). The two isolates were confirmed by all the tests and similar result was obtained by; biochemical, Biolog, MALDI TOF MS and real time PCR. Up on antimicrobial susceptibility testing, the two isolates were resistant to Streptomycin, Erythromycin and Clindamycin whereas they were susceptible to Tetracycline, Chloramphenicol, Trimethoprim/sulfonamides and Penicillin. Generally, this study revealed that M. haemolytica is among the causative agent of pneumonic pasteurellosis in sheep and goat in the study area. Although, the other remaining bacteria responsible for the disease. Conclusion: The research suggests that a combination of diagnostic methods such as MALDI TOF MS, Biolog, and real-time PCR should be used, as well as for a more in-depth investigation to identify the strain or serotype of M. haemolytica using advanced molecular sequencing and also analysis of the remaining causal agent from various species and locations in countries are significant to address the present vaccination and antibiotic resistance issues.