Use of Limulus lysate for detecting gram-negative neonatal meningitis.

The Limulus lysate test was evaluated as a method for rapid detection of neonatal gram-negative bacterial meningitis. A total of 208 CSF samples were collected from 145 newborn infants suspected of having meningitis. Initial samples from all six babies with culture-proven gram-negative bacterial meningitis had positive Limulus tests within 30 minutes of incubation. Samples from 14 infants with gram-negative organisms isolated only in blood and/or urine as well as from four neonates with gram-positive organisms in CSF cultures and from 13 with gram-positive organisms in blood cultures all yielded negative Limulus tests. Thus, of 37 newborn infants with bacteria demonstrated in systemic cultures, only those six with gram-negative organisms in CSF had positive CSF Limulus tests. The CSF Limulus test was shown to be a rapid, reliable, and specific test for the detection on neonatal gram-negative bacterial meningitis.