Characterization of Neisseria meningitidis serogroup C by multilocus enzyme electrophoresis and ribosomal DNA restriction profiles (ribotyping).

We compared multilocus enzyme electrophoresis (MEE) and ribosomal DNA fingerprinting (ribotyping) for subtyping 44 strains of Neisseria meningitidis serogroup C that were isolated in Los Angeles County, California, between December 1985 and July 1986. The isolates were divided into six enzyme types (ETs) by MEE, but 36 of the isolates were clustered in one ET, 3. The same isolates were divided into 17 ribotypes by use of restriction endonucleases ClaI, EcoRI, and XhoI. Twenty of the 36 ET 3 isolates were divided into 17 ribotypes by use of restriction endonucleases ClaI, EcoRI, and XhoI. Twenty of the 36 ET 3 isolates were grouped in a single ribotype, J. The rate of infection with ribotype J strains was higher in the southern part of the study area than in the northern part. Isolates from each of eight pairs (each isolate pair was cultured from the same patient from the same or different sites) were found identical by MEE, but ribotyping revealed a difference in one pair. In this study, ribotyping showed a greater discriminating capacity than MEE for subtyping N. meningitidis serogroup C, but the epidemiologic relevance of this increased sensitivity needs further assessment.