INVITRO ACTIVITY OF AZITHROMYCIN COMPARED WITH OTHER MACROLIDES AND ORAL ANTIBIOTICS AGAINST SALMONELLA-TYPHI

The in-vitro activity of azithromycin against 60 clinical isolates of Salmonella typhi was determined by broth microdilution and compared with eight macrolides, including erythromycin, and with other orally administered antimicrobial agents (ampicillin, amoxycillin, cefaclor, trimethoprim/sulphamethoxazole, chloramphenicol, tetracycline, and ciprofloxacin). Azithromycin was more potent (MIC range 416 mg/l; MIC908 mg/l) than erythromycin (MIC range 32- > 128 mg/l; MIC90, > 128 mg/l). Of the other macrolides, only rosaramkan showed increased activity against Salm. typhi (MIC range 1632 mg/l; MIC9032 mg/l) when compared with erythromycin. All 60 Salm. typhi were susceptible to ciprofloxacin (MIC < 0.5 mg/l). In 22 isolates, resistance to one or more of the following compounds occurred: Ampicillin, amoxycillin, cefaclor, tetracycline, chloramphenicol, trimethoprim/sulphamethoxazole. © 1990 The British Society for Antimicrobial Chemotherapy.