Naturally occurring dermatitis associated with Staphylococcus aureus in DS-Nh mice

A naturally occurring epizootic of dermatitis involved all the mice, provisionally designated as DS-Nh, housed under conventional conditions, regardless of age or sex. The disease primarily attacked the lateral aspect of the face, neck and shoulders. The histopathologic features of the dermatitis varied in severity, but all affected regions showed signs of chronic dermatitis, including infiltration of inflammatory cells, parakeratosis and amyloidosis, and contained Gram-positive cocci clusters. Bacteriologically, coagulase-positive Staphylococcus aureus (S. aureus) was recovered in pure culture from the skin lesions. The disease experimentally induced with the S. aureus isolates was indistinguishable from those observed in naturally occurring cases. The results suggested that S. aureus may be casually associated with the disease.