Enterobacteriaceae and neonatal necrotising enterocolitis.

A comparative study of bowel colonisation and incidence of necrotising enterocolitis in neonates admitted to an intensive care unit is reported. Neonates of less than 33 weeks gestational age requiring mechanical ventilation for respiratory distress syndrome were randomised during the first week of life to receive either vancomycin and aztreonam or vancomycin and gentamicin for episodes of suspected sepsis after the first week of life. A higher proportion of neonates who received vancomycin and gentamicin had faecal colonisation with enterobacteriaceae at the end of the second, third, and fourth weeks of life. Treatment with vancomycin and aztreonam was associated with a rapid quantitative reduction in faecal colonisation with enterobacteriaceae, whereas there was no quantitative reduction in colonisation with enterobacteriaceae associated with treatment with vancomycin and gentamicin. There were no differences between the two groups in faecal colonisation with anaerobes, Enterococcus sp, Staphylococcus sp, or yeasts. Six (14.6%) of 41 who received vancomycin and gentamicin compared with 0 of 40 who received vancomycin and aztreonam subsequently developed necrotising enterocolitis.