RESUMO
BACKGROUND: Preterm infants are generally fed through nasogastric enteral feeding tubes (NEFTs). The aim of this work was to evaluate the role of NEFTs in the initial colonization of the preterm gut and its evolution within the first 2 weeks after birth. METHODS: For this purpose, fecal and NEFT-derived samples from 30 preterm infants hospitalized in a neonatal intensive care unit (NICU) were collected from birth to the second week of life. Samples were cultivated in ten culture media, including three for the isolation of antibiotic-resistant microorganisms. RESULTS: Isolates (561) were identified by 16S ribosomal RNA gene sequencing. Although the first NEFTs inserted into the neonates after birth were rarely colonized, analysis of NEFTs and fecal samples over time revealed a significant increase in bacterial abundance, diversity, and detection frequency. Results showed a parallel colonization between time-matched NEFTs and fecal samples, suggesting an ongoing bidirectional transfer of bacteria from the neonatal gut to the NEFTs and vice versa. CONCLUSIONS: In short-term hospitalization, length is by far the determinant factor for the early colonization of preterm infants. As NEFT populations reflect the bacterial populations that are colonizing the preterm in a precise moment, their knowledge could be useful to prevent the dissemination of antibiotic-resistant strains. IMPACT: The hospital environment modulates preterm colonization immediately after birth. The colonization of preterm feces and NEFTs occurs in parallel. There is an ongoing bidirectional transfer of microorganisms from the neonatal gut to the NEFTs and vice versa. Bacterial communities inside NEFTs could act as reservoirs of antibiotic resistance genes. NEFT populations reflect the bacteria that are colonizing the preterm at a precise moment.