Umbilical catheters as vectors for generalized bacterial infection in premature infants regardless of antibiotic use.

Introduction. Umbilical catheterization offers unique vascular access that is only possible in the neonatal setting due to unobstructed umbilical vessels from foetal circulation. With the cut of the umbilical cord, two arteries and a vein are dissected, allowing quick and painless catheterization of the neonate. Unfortunately, keeping the umbilical access sterile is challenging due to its mobility and necrosis of the umbilical stump, which makes it a perfect model for vessel catheter colonization analysis. Aim. The aim of this study was to evaluate bacterial colonization of the umbilical catheter, with a focus on the difference between various sections of the catheter, the duration of catheterization, patient status and gestational age. Methodology. We performed bacterial cultures for 44 umbilical catheters, analysing the superficial and deep parts of the catheter separately, and revealed colonization in one-third of cases. Results. One hundred per cent of the colonization occurred in preterm infants, with a shift towards extreme prematurity. The catheters were mainly colonized by coagulase-negative staphylococci. The majority of catheters presented with superficial colonization dominance, and there were no cases of deep colonization. The bacterial strains and their resistance were consistent between the catheter's proximal and distal parts, as well as positive blood cultures. The patients with the most intense bacterial catheter colonization presented with sepsis around removal time or a couple of days later, especially if they were extremely premature and exhibited very low birth weight. Catheterization time did not play a major role. Conclusion. Umbilical catheters are vectors for skin microflora transmission to the bloodstream via biofilm formation, regardless of antibiotic use and the duration of catheterization, especially in preterm neonates.