J Pediatr Gastroenterol Nutr. 2016 Jan 2.
To evaluate the potential colonization of nosocomial bacteria in enteral feeding systems and its impact on early gut colonization of preterm neonates.
Mother's own milk, donor milk and preterm formula samples obtained after passing through the external part of the enteral feeding tubes were cultured. In addition, meconium and fecal samples from 26 preterm infants collected at different time points until discharge were cultured. Random amplification polymorphism DNA (RAPD) and Pulse field gel electrophoresis (PFGE) were performed to confirm the presence of specific bacterial strains in milk and infant fecal samples.
Approximately 4,000 bacterial isolates were identified at the species level. The dominant species in both feces from preterm infants and milk samples were Staphylococcus epidermidis, Staphylococcus aureus, Enterococcus faecalis, Enterococcus faecium, Serratia marcescens, Klebsiella pneumoniae and Escherichia coli. All of them were present at high concentrations independently of the feeding mode. RAPD and PFGE techniques showed that several bacteria strains were found in both type of samples. Furthermore, scanning electron microscopy (SEM) revealed the presence of a dense bacterial biofilm in several parts of the feeding tubes and the tube connectors.
There is a sharing of bacterial strains between the neonates' gastrointestinal microbiota and the feeding tubes used to feed them