Re-examination of the role of the Brucella melitensis HtrA stress responseprotease in virulence in pregnant goats

Based on previously reported studies describing the experimental infection of Pregnant goats with B. melitensis strain RWP5, we proposed that the HtrA protease plays an important role in the virulence of B. melitensis in its natural ruminant host. Subsequent studies, however, have shown that RWP5 is actually an htrA cycL double mutant. In order to definitively evaluate the role of the B. melitensis htrA in virulence, we constructed an authentic h trA mutant and examined this strain in pregnant goats. The findings of thes e studies indicate that the contribution of the htrA gene product to the vi rulence of B. melitensis in its natural host is not as great as was previou sly proposed. (C) 2001 Elsevier Science B.V. All rights reserved.