Rats born to Brucella abortus infected mothers become latent carriers of Brucella.

Introduction: Rats are known to be infected with Brucella. Vertical transmission of brucellosis was recorded in rats. The study was performed to judge whether rats born from Brucella abortus infected mothers can act as latent carriers of Brucella infection.

Methodology: Female Sprague Dawley (SD) rats were experimentally infected with B. abortus biotype 1 and subsequently bred 10 days post infection (PI). Serum samples of rats (n = 48) born from infected dams were tested using the Rose Bengal plate test (RBPT), tube agglutination test (TAT), and enzyme-linked immunosorbent assay (ELISA) at one, two and three months of age. Tissue samples were plated onto Brucella agar and blood agar media and incubated at 37 °C with 5% CO2 for five to seven days for isolation of bacteria.

Results: B. abortus was isolated from 18 out of 48 rats born to infected dams, and the isolates were confirmed as B. abortus by AMOS (B. abortus, melitensis, ovis and suis) PCR assay with the production of a 498 bp PCR amplicon. Serum samples of rats (n = 48) born from infected dams were tested negative using the RBPT, TAT and ELISA at all time points.

Conclusion: We conclude from the study that rats born to infected dams may become latent carriers of Brucella infection potentially providing a reservoir for future transmission.