Identifying the Infectious Cause of Pink Eye in Beef Cattle

Background

Infectious bovine keratoconjunctivitis (IBK), commonly known as pink eye, impacts cattle performance and is a major welfare concern world-wide with reported losses of $0.78 to $9 USD per head each year. For years, it was the common assumption that Moraxella bovis or Moraxella bovoculi were the main bacteria responsible for this disease. However, vaccines targeting these pathogens have not worked and Moraxella bovis is found in less than 5% of pink eye lesions. This could mean that Moraxella spp. may not be solely to blame for pink eye. It is clear that better pathogen identification is needed to more clearly identify the microorganisms associated with pink eye lesions in order to develop better preventative and treatment options for this prolific disease.

Objectives

•  Identify and compare the microorganisms (bacterial, viral, and fungal) that exist in healthy bovine eyes and those that are infected with pink eye, using the pathogen identification platform described in Costa et al. (2021)
• Identify the microorganisms that are specific to pink eye and understand how they work to create lesions on the eye.

What they will do

Fifty samples (25 IBK and 25 normal eye samples) from 3 herds in Western Canada will be collected and analyzed for the potential cause of pink eye. Ophthalmologists will diagnose cattle presumed to have pink eye, and a conjunctival sample will be taken once confirmed. These samples will then be processed in a lab using a “shotgun” metagenomics approach, and DNA and RNA sequencing will be used to profile the microbiome of the bovine eye.

All the microorganisms identified will then be used to compile a database to identify the causative agents linked to IBK lesions.

Implications

Having this information brings us one step closer to identifying the true causes of pink eye in North American cattle. The results from this study can inform future research as they move on to in vitro and animal models to verify the likely pathogens linked to IBK. Further, having a better understanding of what causes pink eye can help to identify solutions to prevent and treat the disease to reduce the reliance on antimicrobials and remedy a prolific welfare issue.