[Principles for choosing the antibiotic in neonatology].

After having decided to treat a neonate with antibiotics, two important topics are knowledge of its nature and surveillance of treatment. Infections of mother origin remain sensitive to the association ampicillin-aminoglycoside, except if the mother had received ampicillin. Nosocomial infections are due to more resistant agents; the nature of antibiotics to treat them depends upon local immunological status. It is necessary to associate an aminoglycoside to ampicillin against E. coli; this association permits a faster bactericidal effect than ampicillin alone, therefore seems better in the beginning of treatment. New antibiotics have improved our therapeutic possibilities; however it is obvious that new cephalosporins are inactive against Listeria. Antimicrobial therapy must be adapted both qualitatively and quantitatively, to obtain a treatment with low toxicity and good efficiency.