Isolation of Moraxella spp. strains in horses

Two species of Moraxella were isolated from swabs obtained from two symptomatic horses suffering from conjunctivitis and rhinitis. The isolates were identified via MALDI-TOF as Moraxella osloensis and Moraxella equi respectively, with a good genus identification and a probable species identification score. The first one was also confirmed by BLAST sequence analysis with a high homology (99%). Antimicrobial susceptibility testing obtained by minimum inhibitory concentration method showed that the two isolates were sensitive to all the tested molecules. The therapeutic protocols applied had an excellent clinical outcome in both cases with no relapses. Notwithstanding the difficulty in assessing the pathologic role of commensal microorganisms such as Moraxella, this genus should be taken into account in the differential etiologies of conjunctivitis and/or rhinitis in horses. Given also the scarce information and the difficulties in the identification of this species, it is important to report clinical cases in order to extend the knowledge in the veterinary field.