Aerobes isolated in fecal microflora of infants in the intensive care nursery: relationship to human milk use and systemic sepsis.

BACKGROUND

Staphylococcus epidermidis is a leading cause of nosocomial sepsis in the intensive care nursery. The relationship between rates of gastrointestinal colonization and the incidence of systemic sepsis with S. epidermidis in hospitalized neonates is under investigation.

METHODS

In this study, we enrolled 46 infants consecutively admitted to the intensive care nursery (mean +/- standard deviation, birth weight 1300 +/- 337 gm, gestational age 29.4 +/- 2.2 weeks). At the time of enrollment, infants had been fed enterally for at least 1 week (28 were fed formula and 18 received their own mothers' frozen milk). Stool samples were collected when infants were 2 to 3 weeks of age (16.3 +/- 7.4 days).

RESULTS

Aerobic stool flora were present in 65% of all patients. Human milk use was associated with a significant increase in the presence of aerobic stool flora (78% vs 46%, p = 0.035), as well as more frequent isolation of S. epidermidis. The incidence of S. epidermidis sepsis was 33% in those infants whose stool specimens grew S. epidermidis and 3.5% in those whose stool specimens did not (p < 0.01).

CONCLUSIONS

These findings suggest the gastrointestinal tract as a possible site of entry for S. epidermidis in the hospitalized preterm infant. In addition, frozen human milk may be a vehicle for gastrointestinal S. epidermidis colonization.