ΔznuAΔpurE Brucella abortus 2308 mutant as a live vaccine candidate

To create a new, safe brucellosis live vaccine, a double mutant strain was constructed from Brucella abortus 2308. Using the ΔznuA B. abortus 2308 mutant, a second mutation was introduced by deleting purE gene. The ΔznuA ΔpurE B. abortus 2308 strain was less capable of surviving in macrophages. When evaluated in vivo, it was cleared within 8 weeks (wks) from mice, causing significantly less inflammation than spleens obtained from wild-type B. abortus 2308-infected mice. Furthermore, two doses of ΔznuA ΔpurE B. abortus 2308 conferred 0.79 log protection, similar to S19 as did a single dose of ΔznuA B. abortus 2308. Thus, this study shows the ΔznuA ΔpurE B. abortus 2308 strain to be a potential livestock vaccine candidate.