A naturally occurring intestinal mouse adenovirus infection associated with negative serologic findings

Area of Science:

• Veterinary Pathology
• Virology
• Mouse Models

Background:

• Intranuclear inclusions in the intestinal epithelium can indicate viral infections in mice.
• Accurate identification of causative agents is crucial for understanding disease pathogenesis and transmission.

Purpose of the Study:

• To characterize the cause of large basophilic intranuclear inclusions observed in the intestinal epithelium of clinically normal mice.
• To determine if the inclusions were associated with a known mouse adenovirus infection.

Main Methods:

• Histopathological examination of intestinal tissue.
• Electron microscopy to visualize the ultrastructure of the inclusions.
• Serological testing using complement fixation assay for mouse adenoviruses (FL strain).

Main Results:

• Large basophilic intranuclear inclusions were identified in the intestinal epithelium.
• Electron microscopy confirmed the inclusions were caused by an adenovirus.
• Serological testing for mouse adenovirus (FL strain) yielded negative results (no titers).
• The observed adenovirus infection was morphologically similar to that caused by the K87 strain.

Conclusions:

• A diagnosis of adenovirus infection was made in clinically normal mice, despite negative serological results for the FL strain.
• The findings suggest the presence of an adenovirus infection that may not be detected by standard serological assays for common mouse adenovirus strains.
• Further investigation into novel or atypical mouse adenovirus strains is warranted.