title: In vitro activity of azithromycin (CP-62,993), a novel macrolide, against enteric pathogens.
abstract: Azithromycin (CP-62,993 [9-deoxy-9A-methyl-9A-aza-9A-homoerythromycin]) is a novel macrolide antimicrobial. In this study the in vitro activity of CP-62,993 has been determined against selected enteropathogens, including Clostridium difficile, and compared with that of erythromycin. MICs were determined using an agar incorporation technique in Mueller-Hinton medium, containing saponin-lysed horse blood at a final concentration of 10% v/v, with an inoculum of 10(4) cfu. CP-62,993 was considerably more active than erythromycin against Salmonella typhi (MIC90 4 and greater than 32 mg/l, respectively), S. enteritidis (MIC90 4 and greater than 32 mg/l), Shigella flexneri (MIC90 2 and 32 mg/l), Sh. dysenteriae (MIC90 2 and 32 mg/l), Sh. sonnei (MIC90 4 and 32 mg/l), Campylobacter jejuni (MIC90 0.12 and 1 mg/l), Vibrio cholerae (MIC90 0.25 and 8 mg/l), V. parahaemolyticus (MIC90 0.5 and 8 mg/l), Yersinia enterocolitica (MIC90 4 and greater than 32 mg/l), Escherichia coli-ETEC (MIC90 4 and 32 mg/l), E. coli-EIEC (MIC90 4 and greater than 32 mg/l), Plesiomonas shigelloides (MIC90 1 and 8 mg/l) and Aeromonas hydrophila (MIC90 4 and 32 mg/l). CP-62,993 (MIC90 2 mg/l) was slightly less active than erythromycin (MIC90 1 mg/l) against isolates of C. difficile. The results suggest a potential clinical role for CP-62,993 in the treatment of enteric infections where antimicrobial therapy is indicated.
authors.affiliation: Department of Clinical Microbiology, University College Hospital, London, UK.
authors.forename: K
authors.initials: K
authors.lastname: Jones
authors.forename: D
authors.initials: D
authors.lastname: Felmingham
authors.forename: G
authors.initials: G
authors.lastname: Ridgway
mesh_terms: D017963:Azithromycin; D001419:Bacteria / Q000187:drug effects*; D003013:Clostridium / Q000187:drug effects; D004755:Enterobacteriaceae / Q000187:drug effects*; D004917:Erythromycin / Q000031:analogs & derivatives* / Q000494:pharmacology*; D012485:Salmonella typhi / Q000187:drug effects
chemical_list: D004917:Erythromycin; D017963:Azithromycin