Keeping the pathogen out of nude mice colonies is imperative to prevent skin disease, weight loss and poor growth, all of which can compromise research goals.
Transmission: The bacterium is carried on the skin and in the oral cavity of mammals, and is transmitted by direct contact and by fomite transmission (handling, flake contact, etc.). The primary means of entrance of C. bovis into vivaria is often unknown, although several reservoirs of the bacterium have been suggested. Fomites and keratin flakes often are implicated in the transmission of the bacterium, but demonstration and extent of cross-contamination in an experimental setting have not been documented.
In Mice: C. bovis is usually manifested as a hyperkeratosis with yellow-white flakes adherent to thickened skin.
Infection is characterized by a scaly appearance due to the presence of small yellow-white flakes adherent to the skin, most prominent along the dorsum and often extending laterally to the flanks. Affected mice may lose weight and are often removed from study because of reports of poor growth of transplanted tumors or hindrance of immunologic studies. Mortality is low and the hyperkeratosis is transient but may recur. Mice may be persistently colonized, even without displaying clinical signs. C. bovis has also been cultured from skin of asymptomatic hisute immunocompetent mice.