For the improvement of quality control of laboratory mouse, we investigated the environmental condition, histopathological findings and serological test using ELISA to mouse hepatitis virus(MHV), Mycoplasma pulmonis(MP), Clostridium piliforme(TZ) and Sendai virus (HVJ) of ICR, C57BL/6, CBA and C3H/He mice that were supplied from conventional laboratory animal facility.
1. The ammonia concentration of facility was below the recommended concentration, 15ppm, by the KNIH, and the room temperature(21∼23℃) and relative humidity(40∼60%) was optimum range recommend by the Ministry of Health and Welfare, respectively.
2. The incidence rate of inapparent disease was 86.6% and the major findings in the liver were vacuolar degeneration with nucleic pleomorphism. The lung was shown the thickening of alveolar wall and interstitial pneumonia with congestion. The kidney and spleen were observed the mild congestion and extramedullary hematopoiesis, respectively.
3. The positive reaction rates against MHV and MP in serological test was 97.9% and 37.5%, respectively but HVJ and TZ were negative.
These results suggest that laboratory mice could be infected with MHV and MP under conventional environments. Therefore we recommend to select thoroughly inapparent infected mice and to convert conventional system into SPF facility as soon as possible.
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