A tale of two intensive care units (ICUs): Baseline Staphylococcus aureus colonization and mupirocin susceptibility in neonatal and pediatric patients requiring intensive care.

Abstract

To assess the incidence rate of S. aureus colonization at baseline along with the mupirocin susceptibility (or resistance) rate in patients in a neonatal intensive care unit (NICU) and a pediatric intensive care unit (PICU) in conjunction with the implementation of universal decolonization as the standard of care. Prospective cohort study. Children's Hospital of Michigan (CHM) inpatient intensive care units (ICUs). Newly admitted pediatric patients to the CHM NICU or PICU aged between 1 day and ≤21 years. Baseline and follow-up S. aureus screening cultures were obtained before patients underwent universal decolonization with mupirocin 2% antibiotic ointment (intranasal and umbilical) and chlorhexidine baths as standard of care to reduce CLABSI rates. Baseline S. aureus colonization rates of new admissions to the CHM NICU and PICU were high at 32% and 29%, respectively. Baseline mupirocin susceptibility to any S. aureus growth was 98.4%. All baseline culture isolates whether positive for MRSA or MSSA, with one exception, had minimum inhibitory concentrations (MICs) of ≤0.19 µg/mL. All follow-up study cultures after universal decolonization at 7 days or beyond with any S. aureus growth had mupirocin MICs of ≤0.125 µg/mL. Baseline S. aureus colonization rates of new admissions to the CHM ICUs were high as was baseline mupirocin susceptibility. Follow-up cultures, albeit limited in number, did not detect increasing mupirocin MICs over 1 year, despite broad mupirocin exposure due to the implementation of universal decolonization.