[Maternal lactation. I. Resistance of maternal milk to bacterial contamination]. / Estudios en lactancia materna. I. Resistencia de la leche materna a la contaminación bacteriana.

Bacteriologic studies in hands, nipples and milk in 10 wet-nurses were done in order to establish regulation for the recollection of breast milk to be used in low -birth-weight infants. The same studies were done in the hands of 10 nurse-aids, that help in the recollection of breast milk. The results depicts that the breast milk has bacteriostatic and bactericidal properties enough to protect against contamination by germs of the mother's bacterial flora. It does not have the same property against germs that are not of their own flora: those of the nurse-aids's hands. The protection is such that is possible to maintain the breast milk at environmental temperature of 4 degrees C, for 72 hours, without having the developing of germs not isolated previously, and even with the disappearance of some strains present in the initial cultures.

PIP: To establish regulation for the recollection of breast milk to be fed to low birth weight infants, the authors conducted bacteriological studies on the hands, nipples, and breast milk of 10 wet nurses, and on the hands of 10 nurses who were helping in recollecting the breast milk. Results obtained indicated that breast milk has bacteriostatic and bactericidal properties strong enough to protect the mother against contamination by germs of her own microbic flora, but not against germs not her own, for example those found on the nurse's hands. Protection was found to be such that the milk could be kept at normal temperature or at 40F for 72 hours without development of germs. These results seem to indicate that sterilization of milk would not be necessary before use.

[Environment, nutrition and intellectual development]. / Medio ambiente, nutrición y desarrollo intelectual.

The differential effects of malnutrition and psychosocial cultural deprivation (PSAC) upon intellectual performance and psychomotor development were studied in 52 preschool children attending nursery schools in urban Santiago (Chile). Nutritional status was evaluated according to Gómez, intellectual performance according to Weschler's scale (WISP and WISC tests), psychomotor development according to the Denver Developmental Screening Test and PSAC according to a numerical scale constructed from maternal I.Q.; socioeconomic status (Graffar) and a psychological questionnaire the correlational analysis, undernutrition was assigned a single value calculated from the severity and duration of the disease. An inverse correlation of - 0.36 existed between malnutrition and intellectual performance, and of - 0.39 between malnutrition and psychomotor development. Also, there was an inverse and significant correlation of - 0.73 between PSAC and psychomotor development; there was no correlation between PSAC and intellectual performance. Verbal I.Q. was more affected (r = - 0.52) than manual I.Q. (r = - 0.18) and children malnourished during the first 6 months of life attained lower scores of I.Q. than normals. The duration of malnutrition (mild in all cases) had no influence upon subsequent I.Q. This study was the basis for a rehabilitation program (educational-nutritional) to be applied in preschool children from nonprivileged areas.

[Maternal lactation. II. Intestinal colonization in breast fed newborn infants]. / Estudio en la lactancia materna. II. Colonización intestinal en recién nacidos alimentados con leche humana.

Twenty-three low birth weight infants were studied to establish the role that breast milk plays in the intestinal colonization of the preterm infant, and in the control of epidemic diarrhea due to enteropathogenic E. coli, in nurseries. Twelve of these case were fed breast milk in bottles, and eleven with "humanized" powder cow's milk (NAN M.R.). Bacteriologic studies of feces were performed daily during the first 18 days of life. In 5 cases given breast milk, and in 8 receiving cow's milk, Staphylococcus aureus was isolated. Enteropathogenic E. coli was found in 3 cases with breast milk and in 6 with cow's milk. The finding of other non-pathogenic strains, was similar for both groups, except in the case of Proteus, that was found in 10 cases with breast milk, and in only 3 cases with cow's milk. Breast milk was unable to avoid the colonization by E. coli and in one case, was unable to eradicate this germ. None of the cases fed breast milk had diarrhea, including the three cases with E. coli. In another group, 4 cases developed severe acute diarrhea, due to enteropathogenic E. coli followed by 2 deaths. The results seem to point out that although colonization by enteropathogenic strains of E. coli is not completely avoided, these strains do not cause disease when these infants are fed breast milk.

PIP: To establish the role of maternal milk in intestinal colonization of premature newborns 23 cases were investigated; 12 were fed breast milk in bottles, and 11 were fed cow's milk. Bacteriological studies of feces were done every day for the first 18 days of life. Staphylococcus aureus was isolated in 5 babies given breast milk, and in 11 babies given cow's milk, and E. Coli was found in 3 and 6 babies, respectively. Other nonpathogenic strains were found in similar proportions in both groups, except Proteus, which was found in 10 babies fed breast milk, and in only 3 babies fed cow's milk. Breast milk did not avoid the colonization of E. Coli, but none of the babies fed breast milk had diarrhea, including the 3 cases with E. Coli, compared to 4 in the other group, 2 of whom died. From these results it is possible to assume that although breast milk cannot avoid colonization by E. Coli, this strain does not cause disease.