Microb Pathog.2017 May;106:30-39. doi: 10.1016/j.micpath.2017.01.043. Epub 2017 Jan 25.
Brucella abortus 2308ΔNodVΔNodW double-mutant is highly attenuated and confers protection against wild-type challenge in BALB/c mice.
Li Z1,Wang S1,Zhang J1,Yang G1,Yuan B1,Huang J1,Han J1,Xi L1,Xiao Y2,Chen C3,Zhang H4.
Abstract
Brucellosis is an important zoonotic disease of worldwide distribution, which causes animal and human disease. However, the current Brucella abortus (B. abortus) vaccines (S19 and RB51) have several drawbacks, including residual virulence for animals and humans. Moreover, S19 cannot allow serological differentiation between infected and vaccinated animals. We constructed double deletion (ΔNodVΔNodW) mutant from virulent B. abortus 2308 (S2308) by deleting the genes encoding two-component regulatory system (TCS) in chromosome II in S2308.2308ΔNodVΔNodW was significantly reduced survival in murine macrophages (RAW 264.7) and BALB/c mice. Moreover, the inoculated mice showed no splenomegaly. The mutant induced high protective immunity in BALB/c mice against challenge with S2308, and elicited an anti-Brucella-specific immunoglobulin G (IgG) response and induced the secretion of gamma interferon (IFN-γ) and interleukin-4 (IL-4). Moreover, NODV and NODW antigens would allow the serological differentiation between infected and vaccinated animals. These results suggest that 2308ΔNodVΔNodW mutant is a potential live attenuated vaccine candidate and can be used effectively against bovine brucellosis.