Rapid Changes in Nasopharyngeal Antibiotic Resistance Gene Profiles After Short Courses of Antibiotics in a Pilot Study of Ambulatory Young Children

We quantified antibiotic resistance genes before and after short antibiotic courses in nasopharyngeal specimens from ambulatory children. Carriage of certain bacteria and resistance genes was common before antibiotics. After antibiotics, we observed substantial reductions in pneumococcal and Staphylococcus aureus carriage and rapid expansion in the abundance of certain resistance genes.