Diagnosis of bacterial meningitis by gas-liquid chromatography. I. Chemotyping studies of Streptococcus pneumoniae, Haemophilus influenzae, Neisseria meningitidis, Staphylococcus aureus, and Escherichia coli.

With the use of gas-liquid chromatographic techniques, the chemical characteristics of Streptococcus pneumoniae type 3, Escherichia coli, group B Neisseria meningitidis, Haemophilus influenzae type b, and Staphylococcus aureus, organisms that commonly cause bacterial meningitis, were identified. The combination of lipid, carbohydrate, and lipopolysaccharide components provided discriminating markers for chemotyping these bacteria. E. coli had a high content of 17- and 19-carbon cyclopropane fatty acids, whereas none of the other organisms tested revealed any cyclic acids, apart from a possible trace amount in S. pneumoniae. The content of isomethyl branching fatty acids clearly distinguished S. pneumoniae and S. aureus. N. meningitidis and H. influenzae were somewhat similar in their overall fatty acid compositions, but the presence of galactose without rhamnose in extracts of N. meningitidis readily distinguished N. meningitidis from H. influenzae. Only extracts from E. coli contained mannose; erythrose was an exclusive marker in extracts of S. pneumoniae. These data suggest that these differences in chemotype might be useful in developing a gas-liquid chromatographic assay of spinal fluid for the rapid laboratory diagnosis of bacterial meningitis.