Abortion in mice associated with Pasteurella pneumotropica

Area of Science:

• Veterinary Microbiology
• Immunology
• Rodent Pathology

Background:

• Pasteurella pneumotropica is a common bacterium found in laboratory rodents.
• Understanding its role in reproductive failure and systemic disease is crucial for animal health and research integrity.

Observation:

• Pasteurella pneumotropica was isolated from aborting Swiss Carworth mice, including uteri, fetuses, lungs, and spleens.
• Infections were also identified in the pharyngeal, testicular, and seminal vesicle tissues of male mice.
• Normal pregnant and non-pregnant females carried the bacteria in their eyes and uteri, indicating widespread colonization.

Findings:

• Abortions and necrotizing, suppurative metritis were observed in infected female mice.
• Pregnant mice from a different colony did not abort following experimental Pasteurella pneumotropica inoculation.
• The study suggests a potential link between immunosuppression, possibly due to malignant lymphoma and mammary adenocarcinoma, and increased susceptibility to Pasteurella pneumotropica infections.

Implications:

• Pasteurella pneumotropica can be a significant pathogen contributing to reproductive losses in mouse colonies.
• Immunosuppression may play a critical role in the pathogenesis of Pasteurella pneumotropica infections, leading to severe clinical signs.
• These findings highlight the importance of monitoring and controlling Pasteurella pneumotropica in research animal populations to ensure animal welfare and experimental validity.