The role of Mycoplasma ovipneumoniae and Mycoplasma arginini in pneumonic lungs of slaughtered sheep

Mycoplasma ovipneumoniae is one of the most commonly mycoplasma species associated with respiratory diseases in sheep. This microorganism and Mycoplasma arginini have been routinely recovered from young lamb with "coughing syndrome". In this study, a polymerase chain reaction (PCR) based 16S RNA gene sequences was used for detection of M. ovipneumoniae and M. arginini in pneumonic lungs of slaughtered sheep. The lungs of 1000 sheep carcasses were grossly inspected at local abattoir. Pneumonia was detected in 40 (4%) of the carcasses. Al. ovipneumoniae and M. arginini were identified in 20% (n=8/40) and 2.5% (n=1/40) of ovine pneumonic lungs respectively. The pathologic findings associated with M. ovipneumoniae were including suppurative bronchopneumonia, fibrinous bronchopneumonia and interstitial pneumonia. The lung with M. arginini showed capillary congestion and serous exudate in alveoli. The observed pathologic findings were not diagnostic for mycoplasmal infection. Other bacteria such as Pasteurella multocida, Staphylococcus aureus, Corynebacterium pseudotuberculosis and Klebsiella pneumoniae were isolated from pneumonic samples. Our results suggest that Al. ovipneumoniae is an important agent in respiratory diseases of sheep, whereas the role of M. arginini in ovine pneumonia is not significant.