Evaluation of azithromycin, trovafloxacin and grepafloxacin as prophylaxis against experimental murine Brucella melitensis infection.

The prophylactic potential of the azalide azithromycin as well as the fluoroquinolones trovafloxacin and grepafloxacin was assessed for the control of infection with Brucella melitensis in an experimental mouse model, determined by reduction in splenic bacterial burden. Trovafloxacin showed limited protective efficacy when administered 2h following a low-dose B. melitensis challenge, whereas grepafloxacin was ineffective. In comparison, azithromycin provided significant control of infection both following low- and high-dose challenges. Overall, the data confirm the potential utility of azithromycin in the prophylaxis of brucellosis and suggest that neither trovafloxacin nor grepafloxacin would likely be valuable for post-exposure prophylaxis of Brucella infection.