GENOTYPING MAY PROVIDE RAPID IDENTIFICATION OF ESCHERICHIA-COLI K1 ORGANISMS THAT CAUSE NEONATAL MENINGITIS

Escherichia coli K1 is the most common cause of gram-negative neonatal bacterial meningitis and septicemia. In an attempt to identify geneti c markers in E. coli K1 that are associated with the capacity of the o rganism to cause neonatal meningitis, we used rRNA gene restriction pa tterns, E. coli strains isolated from the CSF of neonates with meningi tis (n = 43) on two continents were compared to strains isolated from the blood of neonates with bacteremia who did not have meningitis (n = 29) and to isolates from the vaginas of asymptomatic pregnant women w hose neonates remained without infection (n = 39). E, coli strains fro m CSF are genetically less heterogeneous than isolates from blood and the vagina: 44.2% of the CSF isolates belonged to only two types, wher eas no more than two blood vaginal strains were of the same type, Afte r HindIII digestion, a 14.9-kb rDNA-containing fragment was found in 8 1.3% of the strains from CSF vs, 28.0% of the isolates from blood and only 12.8% of the vaginal isolates (P =.001). Thus, genotyping might p rovide markers to identify organisms in the maternal vaginal flora tha t are highly likely to cause neonatal meningitis, This observation may have very practical implications for the early identification of thes e organisms in pregnant women and thus for the selective establishment of preventive measures per partum or for the early treatment of colon ized neonates.