ABSTRACT
Gastrointestinal degradation of urea might, according to a new hypothesis, have consequences for the regulation of acid-base balance as well as control of breathing during infancy. Thirteen infants were investigated from their first few days of life to the age of 6 months by collecting faecal samples at the age of 3 days, 2, 3, and 6 months, respectively. The faecal microflora was determined after aerobic and anaerobic cultivation and the faecal urease activity was assessed after 36 h aerobic and anaerobic preincubation. The infants were mostly breast fed and had a faecal microflora containing anaerobic bacteria such as Bifidobacteria, Bacterioides and Lactobacilli but also aerobics such as Escherichia coli, Enterococci and sometimes Klebsiella. The faecal pH increased from approximately 5.30 to 5.90, the pH after anaerobic preincubation being on an average 0.2 pH units lower than after aerobic preincubation. Simultaneously the nitric oxide production of the faecal specimens increased approximately 10-fold and the urease activity decreased by a factor of 3 to 5. We also found an inhibitory action of nitrate, nitrite (in mumolar concentration) and nitric oxide (in parts per million concentration) on the faecal urease activity. Hence, the present results warrant further research in order to determine more precisely the action of different concentrations of various nitrous oxides on individual bacterial species, and furthermore, to assay the faecal urease activity in victims of sudden infant death syndrome as well as in infants dead due to other causes.
Subject(s)
Bacteria, Aerobic/isolation & purification , Bacteria, Anaerobic/isolation & purification , Child Development , Feces/enzymology , Feces/microbiology , Urease/metabolism , Feces/chemistry , Female , Humans , Infant , Infant, Newborn , Ions , Male , Nitric Oxide/analysis , Quaternary Ammonium Compounds/analysis , Urea/analysisABSTRACT
Newborn infants are rapidly colonized by both aerobic and and anaerobic bacteria, initially with about 50% of each type. Several factors related both to the infant and its environment influence the composition of the intestinal microflora quantitatively as well as qualitatively. Major ecological disturbances are observed in newborn infants treated with antimicrobial agents. One way of minimizing the ecological disturbances, which may be seen in infants treated in neonatal intensive care units, is to provide them with fresh breast milk from their mothers and to use antimicrobial therapy only under strict clinical indications.
