[Current aspects of the fecal flora of the newborn without antibiotherapy during the first 7 days of life: Enterobacteriaceae, enterococci, staphylococci].

Last years, il became obvious that the colonization pattern described in 1976-1978 was no more valid: early colonization by Enterobacteriaceae at the 2-3 rd day of life in all newborns, with constant presence of antibioresistant strainseven in non treated newborns. To establish the new pattern of colonization, the same quantitative method of dilution and culture on selective media was used daily from day 1 to day 7 (5 days only for M). The number of Enterobacteriaceae, enterococci and staphylococci was determined in the stools of 10 newborns in the Maternity unit (= M) (term 40 weeks +/- 1, birth weight 3,356 g +/- 383), 10 in the Premature nursery (= P) (term 34.9 weeks +/- 1, birth weight 2,457 g +/- 676), and 14 in the Neonatal intensive care unit (= R) (term 35.2 weeks +/- 3.8, birth weight 2,457 g +/- 763). The results establish that colonization by Enterobacteriaceae is no more constant at D3. It could be demonstrated only in 8/10 M, 1/10 P, and 6/14 R (statistically different - p < 0.01 - between M and P). At D5, 9/10 M, 5/10 P, 10/14 R, and at D7, 6/10 P and 10/14 R were colonized. Resistant Enterobacteriaceae (Escherichia coli, Klebsiella pneumoniae, Enterobacter cloacae) could be found in only 3/10 M, 4/10 P and 6/14 R. Enterococci could be found in 1 newborn M, 2 P and 7 newborns R. Staphylococci appeared earlier: all newborns M, P and R were colonized at D2, 4 and 5 respectively. These bacteria were coagulase negative, associated with Staphylococcus aureus in 3 P. Our hypothesis is that late colonization with Enterobacteriaceae and enterococci is due to the improvement of hygiene procedures and due to the decontaminating effect of antibiotics in other treated newborns (Enterobacteriaceae by 3 rd generation cephalosporin and enterococci by pharyngeal vancomycin).