Short communication: Effect of refrigerated storage on the pH and bacterial content of pasteurized human donor milk.

Once pasteurized donor milk is thawed for its administration to a preterm or sick neonate, and until it is administered, it is kept refrigerated at 4 to 6°C for 24 h. After this time, unconsumed milk is discarded. This time has not been extended, primarily because of the concern of bacterial contamination. The aim of this study was to determine the changes in pH and bacterial count when pasteurized donor milk was kept under refrigeration for a prolonged period (14 d). In this prospective study, 30 samples of pasteurized donor milk from 18 donors were analyzed. Milk was handled following the regular operating protocols established in the neonatal unit and was kept refrigerated after thawing. pH measurements and bacteriology (on blood agar and MacConkey agar plates) were performed on each sample at time 0 (immediately after thawing) and then every day for 14 d. Changes in pH of samples over time were evaluated with linear mixed-effects regression models. A slow but gradual increase in milk pH was observed starting from the first day [mean (±SD) pH of 7.30 (±0.18) at time 0 and 7.69 (±0.2) on d 14]. No bacterial growth was observed in any of the samples throughout the complete trial except in one sample, in which Bacillus flexus was isolated. In conclusion, pasteurized human donor milk maintains its microbiological quality when properly handled and refrigerated (4-6°C). The slight and continuous increase in milk pH after the first day could be due to changes in the solubility of calcium and phosphate during refrigerated storage.

Listeriosis perinatal. ¿Una enfermedad prevenible? / Perinatal listeriosis. A presentable disease

La Listeria monocytogenes es un bacilo gran positivo ampliamente distribuido en el entorno cuyo reservorio principalmente distribuido en el entorno cuyo reservorio principal es el ganado porcino, ovino y bovino, pudiendo estar presente en alimentos, como la leche no pasteurizada, quesos blandos, carnes mal cocidas o verduras. Este germen es una causa poco frecuente de enfermedad en la población general. Sin embargo, en neonatos, gestantes, ancianos o inmunodeprimidos puede producir una infección grave con bacteriemia o meningoencefalitis. Aunque la mayoría del los casos son esporádicos se han descrito brotes epidémicos relacionados con el consumo de diversos alimentos. En este artículo describimos, un caos de sepsis por Listeria monocytogenes en un recién nacido pretérmino, y revisamos la epidemilogía, cuadro clínico y manejo de las infecciones por este germen en el período perinatal, haciendo especial hincapié en las medidas higiénicas destinadas a disminuir las tasas de infección por este patógeno en dicho período (AU)

Listeria monocytogenes is a Gram positive bacillus widelay distributed in the environment whose main host is the pig, ovine and bovine cattle, being able to be present in foods like non-pasteurized milk, soft cheeses, meats badly cooked or vegetables. This germ is a rare cause of disease in the general population. Nevertheless in newborn, pregnant women, old or inmunocompromissed patients it could produce a severe infection with bacteremia or meningoencephalitis. Although most of the cases are sporadic, several outbreaks have been related to contaminated food. In this article we report a case for sepsis by Listeria monocytogenes in a preterm, and we review the epidemiology, clinical picture and management of the infections by this germ in the perinatal period, making special emphasis in the hygienic measures destined to diminish the rates of infection by this pathogen in such period (AU)