| emergence of a virulent clone of neisseria meningitidis serotype 2a that is associated with meningococcal group c disease in canada. | multilocus enzyme electrophoresis was used to characterize 378 isolates of neisseria meningitidis serogroup c recovered during a period of an increase in group c meningococcal disease in canada. thirty-four enzyme electrophoretic types were found among the isolates, which were predominantly (96.0%) serotype 2a. one clone (et 15), characterized by a rarely occurring allele for the enzyme fumarase, was responsible for a focal outbreak in ontario followed by the spread of group c disease across the ... | 1991 | 1774254 |