Colonization pattern of Pasteurella pneumotropica in mice with latent pasteurellosis.

Colonization pattern of Pasteurella pneumotropica (P. pneumotropica) in mice with latent pasteurellosis was examined with the original selective media, NKBT medium and TGN broth. In the mice of 0 to 15 weeks old, the organism was mainly isolated from the upper respiratory tract, lower intestinal tract, feces and vagina, with the highest isolation rate in the pharyngolarynx. In the pregnant and lactating mice, the organism was isolated from the same sites, but not from the uterus, fetus or mammary gland. In the neonates, the organism was isolated from the respiratory and intestinal tracts within 24hr after birth. The organism was constantly detected in the feces of the 0- to 20-week-old mice, with the highest viable count one week after birth. Through the monitoring of mouse colonies, the pharyngolarynx always showed higher isolation rate than the feces in several mouse strains. These results reveal that the pharyngolarynx is the primary colonization site of P. pneumotropica in mice, and the lower intestinal tract and vagina are also the main sites. Further, frequent isolation of the organism from the feces and vagina, and the results in neonates suggest the mode of the transmission to newborn mice in the colony, i.e., intravaginal infection at the partition, and oro-nasal infection through the maternal feces and saliva.

[Evaluation of enzyme-linked immunosorbent assay for serodiagnosis of Bordetella bronchiseptica infection in guinea pigs].

An enzyme-linked immunosorbent assay (ELISA) for serodiagnosis of Bordetella bronchiseptica (B. bronchiseptica) infection in guinea pigs was evaluated. An isolate of B. bronchiseptica from lung lesion of a guinea pig was used as antigen after ultrasonication. In the experimental infection, specific pathogen-free guinea pigs inoculated with the bacterium intranasally were examined every 5 or 10 days. The organism was recovered from all animals between 5 and 30 days post-inoculation (p.i.). Only one animal was sero-positive by agglutination test 30 and 50 days p.i.; whereas, by ELISA, one animal was positive 5 days p.i., and all the animals showed strong reaction 20 to 50 (end of experiment) days p.i. Field samples obtained from 1983 to 1989 were tested by ELISA. The results corresponded to those of macroscopic observations and bacterial isolation. The ELISA proved to be useful method for detection of B. bronchiseptica infection in guinea pigs.