Immunodeficient animals are in demand in current biomedical research, and they contribute to medical progress. In Pneumocystis infections, a specific histological diagnostic tool may be immunochemistry (IC). However, it was recently reported that the antibody (3F6) was not suitable for detecting Pneumocystis in rats. We purchased another antibody [PNC007] from a commercial source for IC. We could detect positive signals at identical locations with IC and Toluidine blue O in lungs of infected rats. These results corresponded to the results obtained with PCR. We should study the relationship between unexpected positive signals seen in IC and trophic forms in lungs of infected rats. We could clinically diagnose pneumonia caused by Pneumocystis carinii with the diagnostic method we developed.

Studies to date have established that the physical environment inside cages can be controlled adequately by setting the intra-cage ventilation at 60 air changes per hour in a forced-air-ventilated micro-isolation system (FVMIS). In this study, the capability of FVMIS to prevent inter-cage transmission of microorganisms was evaluated using Pasteurella pneumotropica as a reference microorganism. One FVMIS rack and a conventional rack were used, and cages with mice positive for P. pneumotropica and those with P. pneumotropica-free mice were housed on both racks. The mice were examined for P. pneumotropica contamination every 4 weeks after initiating the experiment for 12 weeks using a polymerase chain reaction method. Some P. pneumotropica-free mice housed in open air cages in the conventional rack became positive for P. pneumotropica (four of 28 animals after 4 weeks; eight of 28 animals after 12 weeks), but all P. pneumotropica-free mice housed in the FVMIS cages remained negative for the bacterium throughout the experiment. The results demonstrate that FVMIS can prevent inter-cage transmission of P. pneumotropica when proper cage handling practice is under taken.