Isolation of Pasteurella ureae from reproductive tracts of congenic mice

Infertility noted in two congenic strains of mice was associated with abortion, metritis, and stillbirths. Pasteurella pneumotropica was recovered from affected uterine tracts of ATL mice. Tetracycline treatment for 6 weeks was instituted in an attempt to minimize Pasteurella-associated infertility. Nine ATL mice and 12 ATH mice were examined 4 and 12 months after cessation of tetracycline therapy, respectively. Histopathologically, all animals appeared normal. P. pneumotropica was recovered from six of nine prepuces of both ATH and ATL mice; similarly, two of three vaginal culture of the ATL mice yielded this bacterium. Pasteurella ureae was isolated from three of eight reproductive tracts of the female ATH mice, Negative indole and ornithine decarboxylase reactions and positive acid production for mannitol differentiated P. ureae from P. pneumotropica. This report represents the first confirmed isolation of P. urea from animals. Biochemical profiles of atypical strains of P. pneumotropica isolated from animals are discussed and compared with those of P. ureae. The need for careful biochemical characterization of all Pasteurella isolated from rodents is emphasized.