Identification of Mycoplasma ovipneumoniae and Mycoplasma arginini in sheep with pneumonia in North East of Iran

Background: Pneumonia due to Mycoplasma infections can cause serious health problems and economic losses in small ruminants industry. Aims: The aim of this study was isolation and identification of Mycoplasmas in sheep naturally infected with pneumonia in Northeastern Iran. Methods: This study used histopathology, culture and polymerase chain reaction (PCR) to examine samples from 50 lungs of sheep naturally infected with Mycoplasmas. Results: Grossly, irregular consolidation with lobular or lobar to diffuse pattern in the cranioventral to caudal lobes of affected lungs were observed. Histopathologically, bronchointerstitial pneumonia in 38 (76%), and purulent to fibrinopurulent bronchopneumonia in 12 (24%) affected sheep were diagnosed. DNA was extracted from lung tissue samples and replicated using genus and species specific primers for Mycoplasma. Mycoplasma growth was observed in 3 (6%) of a total of 50 lung samples. Genus-specific Mycoplasma DNA was identified by PCR in 12 (24%) of samples. Two (4%) and 7 (14%) samples of these 12 cases were positive for reaction with species-specific primers of Mycoplasma ovipneumoniae and Mycoplasma arginini, respectively. Conclusion: Our results showed that M. ovipneumoniae and M. arginini were the two agents that can be involved in inducing lung consolidation and pneumonia in sheep and PCR was more successful than the culture in detecting Mycoplasmas.