MOLECULAR SUBTYPING OF NEISSERIA-MENINGITIDIS SEROGROUP-B - COMPARISON OF 5 METHODS

In order to compare methods for subtyping Neisseria meningitidis serog roup B isolates, 96 isolates obtained from various locations in the Un ited States and northwestern Europe were subtyped by five methods: mon oclonal antibody (MAb)-based serotyping and serosubtyping, DNA macrore striction analysis by pulsed-field gel electrophoresis (PFGE), multilo cus enzyme electrophoresis (MEE), ribotyping, and PCR-restriction frag ment length polymorphism of the internally transcribed spacer region o f the rRNA operon (ITS PCR-RFLP). All N. meningitidis serogroup B isol ates were typeable by PFGE, MEE, ribotyping, and ITS PCR-RFLP. Only 44 .8% of the isolates were completely typeable (both serotype and serosu btype determination) by MAb-based serotyping and serosubtyping, 60.4% of the isolates could be serotyped but not serosubtyped, and 90.6% of the isolates could be either serotyped or serosubtyped. Simpson's disc rimination indices of diversity for the methods were as follows: PFGE, 99.7%; MEE, 99.4%; ribotyping, 98.8%; MAb serotyping, 75.8%; MAb sero typing and/or serosubtyping, 97.5%; and ITS PCR-RFLP, 84.2%. The high degree of diversity observed by PFGE, MEE, and ribotyping can be expla ined by the fact that isolates were collected from different geographi c locations at various times. PFGE, MEE, and ribotyping showed greater discriminatory abilities than MAb-based serotyping and serosubtyping or ITS PCR-RFLP.