Introduction: Mycoplasma bovis is one of the main pathogens involved in cattle pneumonia. Other mycoplasmas have also been directly implicated in respiratory diseases in cattle. The prevalence of different Mycoplasma spp. in cattle affected by respiratory diseases and molecular characteristics of M. bovis field strains were evaluated. Material and Methods: In total, 713 nasal swabs from 73 cattle herds were tested. The uvrC gene fragment was amplified by PCR and PCR products were sequenced. PCR/DGGE and RAPD were performed. Results: It was found that 39 (5.5%) samples were positive for M. bovis in the PCR and six field strains had point nucleotide mutations. Additionally, the phylogenetic analysis of 20 M. bovis field strains tested with RAPD showed two distinct groups of M. bovis strains sharing only 3.8% similarity. PCR/DGGE analysis demonstrated the presence of bacteria belonging to the Mollicutes class in 79.1% of DNA isolates. The isolates were identified as: Mycoplasma bovirhinis, M. dispar, M. bovis, M. canis, M. arginini, M. canadense, M. bovoculi, M. alkalescens, and Ureaplasma diversum. Conclusion: Different Mycoplasma spp. strains play a crucial role in inducing respiratory diseases in cattle.

Introduction: The current study was designed to detect Mycoplasma agalactiae (Ma), Mycoplasma mycoides subsp. capri (Mmc), Mycoplasma capricolum subsp. capricolum (Mcc) and Mycoplasma putrefaciens (Mp) in sheep and goats with clinical signs consistent with contagious agalactia.Material and Methods: A total of 299 samples were collected from 55 mixed herds in Azarbaijan-e-Sharghi province, Iran. Samples were examined using PCR and culture methods.Results: The findings showed that in 40 herds at least one sample was positive by PCR or culture method. Moreover, out of 274 sheep samples, 101 were proved to be positive using the PCR technique and 76 were found positive using the culture method. Out of 25 goat samples, 10 were found positive using PCR and 9 were positive through the culture method. Less than 20% of isolated mycoplasmas were Ma. Ma was detected from almost all studied regions in the province while Mmc, Mcc, and Mp were detected only in a very limited area that was deemed by the research group the mixed infection zone.Conclusion: In vaccination or eradication projects, it would be more economical to focus on mixed infection zones. Further investigation on mixed infection zones could facilitate better understanding of contagious agalactia epidemiology.