Antibiotic resistance (proportion of carriers) in respiratory bacteria from Australian and Alaskan children at baseline and end of study.

*P<0.05, ** P<0.01 for difference in resistance between Australian and Alaskan carriers; CI, confidence interval. 1MacR, macrolide-resistant: azithromycin (Australia) and erythromycin (Alaska) minimum inhibitory concentration (MIC) >0.5 mg/L. 2AziIR, azithromycin intermediate resistant: MIC >0.12–4 mg/L; AziR, azithromycin resistant: MIC >4 mg/L for Australian children. 3All isolates from Alaskan children were susceptible on disk diffusion; MICs were not determined. 4Isolates from one swab did not grow on sensitivity plates. 5EryR, erythromycin resistant on disk diffusion. 6PenIR, penicillin intermediate resistant: MIC >0.06–2 mg/L; no resistant (MIC >2 mg/L) isolates were detected in either cohort. 7AmpR, ampicillin MIC >1 mg/L. 8BLpos, beta-lactamase positive. 9MethR, methicillin resistant on disk diffusion.