[Investigation of a neonatal case of Enterobacter sakazakii infection associated with the use of powdered infant formula]

Abstract

Introduction: The aim of this study was to describe the investigation of a case of meningitis in a neonatal intensive care unit in order to identify the source of infection and the associated risk factors.

Material and methods: An analysis was carried out on the possible risk factors associated with the infection. E. sakazakii was detected in the batch of the powdered infant formula used during the feeding of the neonate and the initial level of contamination of the microorganism was estimated. The strains of E. sakazakii previously isolated in blood and faeces of the infected neonate and those isolated in infant formula were characterised by biotype, pulsotype and antimicrobial susceptibility.

Results: E. sakazakii was detected in one opened and two unopened cases of a single batch of powdered infant formula. The E. sakazakii strains isolated in the samples of the product and those isolated in the infected neonate showed the same biochemical, antibiotic susceptibility and PFGE pattern.

Conclusions: The case of meningitis in the neonatal intensive care unit occurred as a result of the use of a powered infant formula contaminated with E. sakazakii at manufacturing level, and an inadequate preparation and storing of the reconstituted product were identified as risk factors.