virB-Mediated survival of Brucella abortus in mice and macrophages is independent of a functional inducible nitric oxide synthase or NADPH oxidase in macrophages.
The Brucella abortus virB locus is required for establishing chronic infection in the mouse. Using in vitro and in vivo models, we investigated whether virB is involved in evasion of the bactericidal activity of NADPH oxidase and the inducible nitric oxide synthase (iNOS) in macrophages. Elimination of NADPH oxidase or iNOS activity in macrophages in vitro increased recovery of wild-type B. abortus but not recovery of a virB mutant. In mice lacking either NADPH oxidase or iNOS, however, B. abortus infected and persisted to the same extent as it did in congenic C57BL/6 mice up until 60 days postinfection, suggesting that these host defense mechanisms are not critical for limiting bacterial growth in the mouse. A virB mutant did not exhibit increased survival in either of the knockout mouse strains, indicating that this locus does not contribute to evasion of nitrosative or oxidative killing mechanisms in vivo.
Department of Medical Microbiology and Immunology, Texas A&M University System Health Science Center, College Station, USA.
Yao-Hui
YH
Sun
Andreas B
AB
den Hartigh
Renato Lima
RL
Santos
L Garry
LG
Adams
Renée M
RM
Tsolis
D000818:Animals; D001426:Bacterial Proteins / Q000235:genetics*; D002003:Brucella abortus / Q000235:genetics* / Q000254:growth & development / Q000472:pathogenicity*; D002006:Brucellosis / Q000201:enzymology / Q000235:genetics / Q000382:microbiology; D002460:Cell Line; D005798:Genes, Bacterial; D008262:Macrophage Activation; D017737:Macrophages, Peritoneal / Q000201:enzymology* / Q000382:microbiology*; D051379:Mice; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D009154:Mutation; D019255:NADPH Oxidases / Q000235:genetics / Q000378:metabolism; D019001:Nitric Oxide Synthase / Q000235:genetics / Q000378:metabolism; D052247:Nitric Oxide Synthase Type II; D013481:Superoxides / Q000378:metabolism; D014774:Virulence / Q000235:genetics; D037521:Virulence Factors
D001426:Bacterial Proteins; D037521:Virulence Factors; D013481:Superoxides; D019001:Nitric Oxide Synthase; D052247:Nitric Oxide Synthase Type II; C496317:Nos2 protein, mouse; D019255:NADPH Oxidases