Bacteria associated with infectious keratoconjunctivitis outbreak in confined lambs

Abstract

Introduction. Infectious keratoconjunctivitis is a significant ocular disease found in confined sheep. Little information about the aetiological agents and their antimicrobial susceptibility is available. Gap Statement. There is limited information on the aetiological agents involved in keratoconjunctivitis outbreaks in sheep. Aim. The present research aimed to determine the bacterial aetiological factors involved in an outbreak of infectious keratoconjunctivitis in confined lambs. Methodology. Ocular swabs were collected from 23 randomly selected lambs, which were classified into three groups according to the severity of the lesion: group I (N=6; no ocular involvement), group II (N=8; less severe injuries) and group III (N=9; more severe injuries). Isolation of aerobic bacteria and antimicrobial susceptibility tests were carried out. Molecular detection of Mollicutes was performed, and positive samples were tested to confirm the presence of the following species: Mycoplasma conjunctivae , Mycoplasma agalactiae and Mycoplasma mycoides subsp. capri . Results. Moraxella sp. and Mollicutes were detected in all groups, but we inferred that Moraxella sp. are only significant in the early stages of the disease. M. conjunctivae was detected in all tested groups, while M. agalactiae was detected in samples of group III only. One strain of Moraxella sp. was resistant to erythromycin and showed intermedite resistance to tetracycline. Conclusion. The presence of these species confirms their importance in the aetiology of this disease, and the low resistance profile observed in the studied farm suggested an increased cure success rate.