THE IN-VITRO ANTI-RICKETTSIAL ACTIVITY OF MACROLIDES

The anti-rickettsial activity of azithromycin and clarithromycin was s tudied in Vero cells. The rate of rickettsial inhibition-growth caused by both macrolides was determined using rickettsial counts and ELISA. Both macrolides inhibited >50% the growth of Rickettsia conorii and R ickettsia typhi at concentrations of 1.0 and 0.1 mg/L, respectively. T he growth of Coxiella burnetii was inhibited to a rate of greater than or equal to 50% at the concentrations of 0.01 and 1.0 mg/L of azithro mycin and clarithromycin, respectively.