In Vivo Penicillin MIC Drift to Extremely High Resistance in Serotype 14 Streptococcus pneumoniae Persistently Colonizing the Nasopharynx of an Infant with Chronic Suppurative Lung Disease: a Case Study

This is the first report of in vivo pneumococcal penicillin MIC drift from 4.0 to 16.0 mg/liter, possibly associated with alterations in the pbp1a gene. The case presented here is of an infant with early onset recurrent pneumonia and chronic bronchitis requiring repeated antibiotics.