Putative ATP-Binding Cassette Transporter Is Essential

Brucella ovis is a major cause of reproductive failure in sheep, which is associated with epididymitis and infertility in rams. Importantly, B. ovis is one of the few Brucella species that is not zoonotic. Due to the scarcity of studies on B. ovis infection, a murine model of infection was developed. The roles of B. ovis genes encoding a putative hemagglutinin and an ABC transporter were investigated in the mouse model. The kinetics of B. ovis infection were similar in BALB/c and C57BL/6 mice, and both strains of mice developed multifocal micro-granulomas in the liver and spleen, but only minimal colonization and histopathological changes were observed in the genital tract. Therefore, the mouse was considered a suitable infection model for B. ovis but not for B. ovis-induced genital disease. Two mutant strains were generated in this study (the abcAB and hmg strains). The B. ovis abcAB strain was attenuated in the spleens and livers of BALB/c mice compared to the wild-type (WT) strain (P < 0.001). Conversely, the hmg strain infected mice at the same level as WT B. ovis, suggesting that a putative hemagglutinin is not required for B. ovis pathogenesis. Additionally, the abcAB strain did no