Association of different microbes and pathogenic factors in cases of infectious bovine keratoconjunctivitis in cattle from Eastern Kazakhstan.

BACKGROUND AND AIM

Infectious bovine keratoconjunctivitis (IBK) causes a significant economic loss to cattle industries in many countries, including Kazakhstan. Although is recognized as an etiologic agent of IBK, other bacterial and viral agents have been suspected to play a role in the pathogenesis of this disease. This study aimed to evaluate samples collected from the eyes of IBK-affected cattle in Eastern Kazakhstan at different stages of IBK for the presence of , , , , and Bovine Herpes Virus Type 1 (BHV-1) and to characterize gene sequence diversity from positive samples.

MATERIALS AND METHODS

Individual ocular swabs (n = 168) were collected from cattle that had clinical signs of IBK during the summer of 2022 on farms in the Abay region of Kazakhstan. Eye lesion scores (1, 2, and 3) were assigned depending on the degree of ocular damage. Infectious bovine keratoconjunctivitis-associated organisms were detected using a multiplex real-time polymerase chain reaction assay. The gene was sequenced from positive samples.

RESULTS

and BHV-1 were not detected in any of the collected samples. was identified in the majority of samples overall, usually in mixed infection with spp. was detected in 76.2% of animals and predominated in animals with eye lesion scores 2 and 3. was detected only in association with and/or in animals with eye lesion scores 2 and 3. was found in 57.7% of animals and was always identified in association with another organism. Sequencing of the gene in 96 samples from positive samples identified five PilA groups. The majority belonged to PilA group A. However, three new PilA groups were identified and designated PilA groups N, O, and P.

CONCLUSION

The results indicate a high prevalence of and in eyes of cattle with IBK on livestock farms in Eastern Kazakhstan. Additional novel PilA groups were identified.