List of strains.

All strains are derived from isolates taken before the onset of treatment, except for BPK164/1cl11 which is derived from an isolate taken at the end of treatment. The activity index to SSG is the ratio of the ED50 of a tested strain to the ED50 of the sensitive reference strain BPK206/0cl10. A strain with an activity index of 3 or higher is considered to be SSG-resistant as described elsewhere [4].