Outbreak of meningitis in a newborn intensive care unit caused by a single Escherichia coli K1 serotype.

Three cases of meningitis that occurred during a nine-day period in a newborn intensive care unit were caused by a single E. coli serotype 07:K1:H-. A single organism outbreak was suspected when the three spinal fluid isolates all possessed the same two unusual bacteriologic and biochemical characteristics: nonmotile and ornithine negative. Culture surveillance identified eight infants colonized with the same strain of E. coli; three of these infants are described. Clusters of cases of E. coli meningitis in newborn intensive care units should be evaluated and managed as potential outbreaks.