Objective: This study investigated the intestinal colonization with staphylococci in very low birth weight infants in relation to the type of enteral feeding and evaluated the intestine as potential source for staphylococcal bacteremia.
Patients and methods: Infants born in the Level III neonatal intensive care unit of a university hospital with a gestational age below 32 weeks and/or birth weight below 1,500 g were included in a prospective, observational study. The infants received either preterm formula or mother's own milk, with random allocation to raw or pasteurized milk. Precise viable staphylococcal counts of serial fecal specimens were examined in the first 8 weeks of life. In the case of bloodstream infection, fecal and blood isolates of staphylococci were compared by antibiotypes or pulsed-field gel electrophoresis.
Results: One hundred fifty neonates, with a mean of 29 weeks of gestation and 1,260 g at birth, had 1,045 fecal samples analyzed and were found to be heavy carriers of staphylococci in the intestine with 10(6)-10(7) colony-forming units/g of feces from the first week of life. Colonization rate and patterns were not different in relation to the type of enteral feeding. In nearly 80% of 42 patients exhibiting a staphylococcal bloodstream infection, intestinal colonization retrieved a predominant strain that was different from the one recovered from the blood.
Conclusions: In very low birth weight infants, predominance of staphylococci in the gut is not related to the type of enteral feeding. An endogenous origin of staphylococcal bloodstream infection seems to play a minor role.