Journal of Antimicrobial Chemotherapy (1988) 22, 637-641
© 1988 The British Society for Antimicrobial Chemotherapy
research-article |
Interpretative criteria for the agar diffusion susceptibility test with azithromycin
The Clinical Microbiology Institute Tualatin, Oregon 97062, USA
Received 3 March 1988; accepted 26 May 1988
Azithromycin (CP-62,993) is a macrolide with a tendency to concentrate in various body tissues. Difficulties that arise when establishing tentative minimum inhibitory concentration (MIC) breakpoints for such a drug include the question of whether MICs should be compared with the achievable concentrations in blood or in tissue. Pending clinical experience with this drug, we recommend the following tentative criteria for interpreting tests with 15 µg azithromycin discs: susceptible
18 mm (MIC
2mg/l) and resistant
13mm (MIC
mg/l).