Klossiella muris infection in laboratory mice

Klossiella muris is ordinarily nonpathogenic، although in heavy infections the kidneys may have minute grayish necrotic foci over their entire surface and the epithelium of the infected kidney tubules may be destroyed. For histopathological diagnosis of Klossiella muris infection، kidneys of 24 mice were studied that Klossiella in various stages of development were observed in the renal tubules of 4 (16. 66%). The cytoplasm of infected tubular epithelial cell was markedly distended and the nucleus was displaced to one side of the cell. In some instances، however، tubular epithelium was not discernible and the parasite seemed to lie in a cystic space. Small focal infiltrations of lymphocytes، plasma cells in the interstitium of the cortex and renal tubular epithelial cell degeneration and necrosis were seen in association with the parasite in some sections. The parasite was identified as Klossiella muris based on host species، affected organ and morphological appearance. Due to the presence of Klossiella muris and its potential ability in creating histopathological lesions and reducing immune responses against different antigens، to prevent adverse effects and obtaining false results in different studies، sanitation during mice breeding is recommended and emphasized.