Use of limulus amebocyte lysate assay in the diagnosis of gram-negative bacterial meningitis

ABSTRACT

CSF specimens were obtained from 32 infants and children suspected of having bacterial meningitis, CSF specimens were cultured and gram- stained for bacteria according to routine bacteriology procedures. Specimens were also evaluated for leukocytic count, glucose and protein concentrations. The presence of endotoxin was tested by the Limulus amebocyte assay. Bacteria were isolated from 17 patients, the infecting organisms were H. influenzae type [b] [8 cases], Neisseria meningitidis [6 cases], group [B] streptococcus [2 cases], and streptococcus pneumoniae [1 case]. Limulus lysate assay was positive in all the 14 patients with meningitis due to gram-negative bacteria, while it was consistently negative on specimens taken from patients with meningitis due to gram-positive organisms or from patients diagnosed as having no or aseptic meningitis