SUBTYPING OF NEISSERIA-MENINGITIDIS STRAINS ISOLATED IN QUEBEC, CANADA - CORRELATION BETWEEN DEDUCED AMINO-ACID-SEQUENCES AND SEROSUBTYPINGTECHNIQUES

Routine serosubtyping of Neisseria meningitidis relies upon reactivity of whole cells to monoclonal antibodies (mAbs). This procedure is lim ited in providing maximum serosubtype information because some epitope s in whole cells are masked and because mAbs are currently unavailable for some epitopes. To address masking of epitopes in whole cells, we isolated outer membrane vesicles (OMVs) from nine representative menin gococcal strains that were isolated (1991-1993) in the province of Que bec, Canada; the OMVs were used in enzyme-linked immunosorbent assay f or reactivity to mAbs, and improved serosubtyping information was obta ined. A recent proposal assigns subtypes based on deduced amino acid s equences in the variable regions of the class 1 outer membrane protein . This scheme maintains the subtyping nomenclature that is based on re activity to mAbs by defining the sequences in the epitopes recognized by the mAbs. We used this technique to assign subtypes to the meningoc occal strains isolated in Quebec. For the strains tested, serosubtypin g using mAbs and subtyping based on deduced amino acid sequences were in complete agreement. Subtyping using deduced amino acid sequences is superior because it does not depend on the availability of mAbs.