A survey on the prevalence of mycoplasmal infections in infectious bovine keratoconjuntivitis

Infectious bovine keratoconjunctivitis (IBK) is the most common infectious ocular disease of cattle throughout the world. In addition to Moraxella bovis as the principal causative agent, Infectious Bovine Rhinotracheitis (IBR) virus and Mycoplasma species probably act as risk factors for IBK. The objective of this study is to investigate the prevalence of mycoplasma sp. in the conjunctival sac of dairy cattle and its relationship with different stages of IBK. A total number of 60 samples from IBK-affected and healthy eyes were collected from different dairy farms during outbreaks of IBK and polymerase chain reaction (PCR) was employed to investigate the presence of mycoplasma sp. in the conjunctival sac. In this study, affected and healthy eyes consisted 61.8% and 38.2% of those with positive PCR results. As well, cases of conjunctivitis, keratitis and corneal ulcers consisted 23.8%, 33.3% and 42.9%, respectively. In conclusion, although there was no significant difference, greater percentages of positive PCR results were IBK affected and in addition consisted more severe forms of the disease. Therefore, Mycoplasma sp. infection may have a role in the pathogenesis and severity of IBK lesions.