Enterobacter sakazakii in Dried Infant Formulas and Milk Kitchens of Maternity Wards in São Paulo, Brazil

Abstract

This study was the first conducted in Brazil to evaluate the presence of Enterobacter sakazakii in milk-based powdered infant formula manufactured for infants 0 to 6 months of age and to examine the conditions of formula preparation and service in three hospitals in São Paulo State, Brazil. Samples of dried and rehydrated infant formula, environments of milk kitchens, water, bottles and nipples, utensils, and hands of personnel were analyzed, and E. sakazakii and Enterobacteriaceae populations were determined. All samples of powdered infant formula purchased at retail contained E. sakazakii at <0.3 [corrected] most probable number (MPN)/100 g. In hospital samples, E. sakazakii was found in one unopened formula can (0.3 MPN/100 g) and in the residue from one nursing bottle from hospital A. All other cans of formula from the same lot bought at a retail store contained E. sakazakii at <0.3 [corrected] MPN/100 g. The pathogen also was found in one cleaning sponge from hospital B. Enterobacteriaceae populations ranged from 10(1) to 10(5) CFU/g in cleaning aids and <5 CFU/g in all formula types (dry or rehydrated), except for the sample that contained E. sakazakii, which also was contaminated with Enterobacteriaceae at 5 CFU/g. E. sakazakii isolates were not genetically related. In an experiment in which rehydrated formula was used as the growth medium, the temperature was that of the neonatal intensive care unit (25 degrees C), and the incubation time was the average time that formula is left at room temperature while feeding the babies (up to 4 h), a 2-log increase in levels of E. sakazakii was found in the formula. Visual inspection of the facilities revealed that the hygienic conditions in the milk kitchens needed improvement. The length of time that formula is left at room temperature in the different hospitals while the babies in the neonatal intensive care unit are being fed (up to 4 h) may allow for the multiplication of E. sakazakii and thus may lead to an increased health risk for infants.

Screening for<b><i> Cronobacter</i></b> Species in Powdered and Reconstituted Infant Formulas and from Equipment Used in Formula Preparation in Maternity Hospitals

“…Nine (6%) of these, 4 domestic samples and 5 imported samples, were positive for Cronobacter spp. and the level was 0.36-0.91 MPN/100 g. Palcich et al [28] analyzed 186 PIF samples from Brazil with a target age of infants of 0-6 months. Cronobacter spp.…”

“…An informed assessment of neonatal exposure warrants further investigation for the prevalence of Cronobacter spp., especially CC4, in PIF and other sources. Previous studies of hospital practices following Cronobacter outbreaks have shown that equipment used for formula reconstitution and feeding practices can be significant risk factors [25,26,27,28]. …”

Riesgo de contaminación por Cronobacter Sakazakii en leches en polvo para la nutrición de lactantes

“…Cuantifi cación por número más probable (NMP): Se utilizó la técnica descrita por Palcich y cols (23). Los límites se establecieron de 0,009 a 316 NMP/g de LP con un 95% de confi anza.…”

Feeding and Fluids in the Premature and Sick Newborn in the Low-Middle Income Countries

“…When using powdered formula it is essential that it be prepared hygienically with good hand washing, clean water (ideally boiled) and clean utensils. There is a very small risk of bacterial contamination in powdered milk formula with Enterobacter sakasakii, a rare opportunistic pathogen associated with meningitis, necrotizing enterocolitis and sepsis (Gurtler et al, 2005;Palcich et al, 2009). As pointed out in a study in Tanzania, this is of particular concern in the preterm, but can occur at any age (Gurtler, et al, 2005;Mshana et al, 2011).…”