Austin Southard-Smith

Austin Southard-Smith

PI: Kelli Boyd, DVM, PhD, DACVP , Division of Animal Care

Characterizing cooperative bacterial species associated with Corynebacterium bovis infection induced hyperkeratosis in mice

A common pathogen among athymic nude mice, Corynebacterium bovis is also known to affect furred immunodeficient mice. In furred mice, an infection often leads to alopecia and hyperkeratosis dermatitis. Multiple NSG mice were presented to the TPSR with a history of alopecia and lethargy. They were found to be positive for C. bovis and one tested positive for Staphylococcus xylosus. Preliminary histological evaluation of the mice epidermis yielded distinct hyperkeratosis and colonization of the superficial skin surface and keratin layers by bacteria. We hypothesize that C. bovis induced hyperkeratosis in NSG mice results from a polymicrobial syndrome. To evaluate this, laser capture microdissection (LCM) was use to specifically extract the bacteria colonizing the skin of formalin-fixed paraffin-embedded (FFPE) tissue. The FFPE epidermis from nude mice known to be positive for C. bovis was used as a positive control, while the FFPE epidermis from a NSG mouse colony mate was used as a negative control. PCR will be run from the extracted bacterial DNA to identify the organisms present as well. Identifying the specific cause of the alopecia and hyperkeratosis observed in mice confirmed to be infected with C. bovis will allow for more specifically target prevention and treatment in animal facilities in the future.