1ST STEPS IN THE BACTERIAL-COLONIZATION OF THE DIGESTIVE-TRACT OF NEONATES

  • 1 January 1979
    • journal article
    • research article
    • Vol. A130  (1) , 69-84
Abstract
Meconium samples obtained from 14 children aged 18-51 h were subjected to a quantitative differential analysis. The meconium of 1 child (47 h old) was sterile; in those of the 11 infants aged less than 47 h the dominant flora was composed of enterobacteria, mainly Escherichia coli sensitive to common antibiotics, or of Streptococcus. The genus Acinetobacter constituted the dominant flora in 1 case. Staphylococcus, Corynebacterium, Clostridium perfringens, Bacteroides and Peptococcus, when present in the meconium, represented a very small proportion of the total flora. In the 2 children aged 48 h and more, the flora was more complex and Bacteroides, Bifidobacterium, Veillonella, Peptostreptococcus, Clostridium and Staphylococcus were associated to streptococci and enterobacteria. A very small number of lactobacilli was found in 1 child only. No yeasts were detected. The sequence of establishment of the various bacteria was studied in a child (OG) by an analysis of 8 samples obtained 0-74 h after its birth. E. coli and Streptococcus became established 24 h after parturition, Bifidobacterium and Bacteroides the 2nd and 3rd day, respectively. Lactobacillus and Peptococcus were only present in very low numbers in the first 2 meconium samples and did not become established in the child, although they were present in a rather large number in the vaginal and fecal samples from the mother. Use of axenic mice inoculated with the 3rd meconium from OG revealed the existence of certain genera of bacteria probably of fecal origin which were not detected by the direct analysis of the meconium. These genera did not become established in the child. The meconium may choose among the fortuitous contaminations before true colonization of the digestive tract is established. The evolution of the ratio between the number of E. coli and Proteus morganii in the successive samples obtained from OG was very different from that observed in the mice inoculated with these samples.