Brucella abortus S19 and RB51 vaccine immunogenicity test: Evaluation of three mice (BALB/c, Swiss and CD-1®) and two challenge strains (544 and 2308)

The aim of the present study was to evaluate the use of different mouse strains (BALB/c, Swiss and CD-1®) and different challenge strains (Brucella abortus 544 and 2308) in the study of B. abortus vaccine (S19 and RB51) immunogenicity test in the murine model. No significant difference in B. abortus vaccine potency assay was found with the use of B. abortus 544 or B. abortus 2308 as challenge strain. Results of variance analysis showed an interaction between treatment and mouse strain; therefore these parameters could not be compared separately. When CD-1® groups were compared, those vaccinated showed significantly lower counts than non-vaccinated ones (P < 0.05), independently of the vaccine received (S19 or RB51). Similar results were observed on BALB/c groups. However, in Swiss mouse groups, S19 was more protective than RB51 (P  <0.05), which showed protection when compared to the non-vaccinated group (P < 0.05). In summary, data from the present study showed that CD-1®, BALB/c and Swiss mice strains, as well as both challenge strains, B. abortus strains 544 and 2308, can be used in immunogenicity tests of S19 and RB51 vaccines.