Antimicrobial therapy of bacterial sepsis in the newborn infant.

Septicemia continues to be an important cause of neonatal morbidity and mortality. The bacteria most commonly responsible are group B beta-hemolytic streptococci and Escherichia coli, but regional differences exist. Recently sepsis caused by Staphylococcus epidermidis has occurred with increasing frequency in several neonatal intensive care units. Other organisms are less commonly responsible. The choice of antibiotics for suspected sepsis is based on the possible organisms involved and their antibiotic susceptibility patterns, which vary from hospital to hospital and at different times in the same hospital. Currently recommended initial therapy consists of a penicillin and an aminoglycoside, usually ampicillin and gentamicin. The addition of vancomycin is indicated when staphylococcal septicemia is suspected. During outbreaks of neonatal sepsis caused by aminoglycoside-resistant gram-negative bacteria, the use of third-generation cephalosporins or acylaminopenicillins may be appropriate, depending on the results of susceptibility tests. Continuing efforts to develop antibiotics for the treatment of neonatal sepsis are warranted.