Fifteen adult patients will be included in this pilot study. This sample size was chosen not on the basis of formal statistical considerations. However, data from 15 patients will be sufficient to provide rough preliminary estimates of parameters that may be needed for developing power statements for a follow-up larger (randomized) trial. If macrolide resistance occurs in 5% or less of patients in this population, with ≥83% probability only one or zero of the 15 patients will develop resistance. If two or more of the 15 patients develop resistance then further investigations of resistance will be warranted before moving on to randomized trials.