Clinico-serological studies of ovine infectious keratoconjunctivitis in adult ewes experimentally infected with Mycoplasma conjunctivae and/or Staphylococcus aureus

Abstract

The clinical and serological responses following single and mixed ocular inoculation with Mycoplasma conjunctivae and Staphylococcus aureus to ewes were investigated. Ewes in group II inoculated with M. conjunctivae and S. aureus showed more severe conjunctivitis than ewes in group I which were only inoculated with M. conjunctivae. The third group, inoculated with S. aureus alone, also showed mild conjunctivitis. In all three groups, no keratitis was induced. Although there were no significant differences ( P < 0.05) in the lacrimal and clinical responses to M. conjunctivae between the infected ewes of groups I and II, there were marked sero-conversions post-inoculation. Similarly, the quantification of the background bacterial flora before and during infection including the inoculated S. aureus did not appear to increase the clinical response. It appears that S. aureus may be significant in increasing the clinical response, perhaps in the presence of trauma and reduced ocular resistance.