The use of protein A-containing staphylococci sensitized with anti-meningococcal antibodies for grouping Neisseria meningitidis and demonstration of meningococcal antigen in cerebrospinal fluid.

The co-agglutination technique, utilizing antibody coated protein A-containing staphylococci, was successfully adapted to grouping N. meningitidis strains. It was found to give more clear-cut results than the standard slide test, especially in the case of strains isolated from throat specimens. The co-agglutination technique has also other advantages over the standard slide test in the grouping of meningococci: minor influence by auto-agglutination, higher specificity, easy performance and low consumption of specific antisera. Preliminary results also showed that the co-agglutination technique could be applied for the rapid detection of meningococcal antigen in cerebrospinal fluid.