Emergence of a virulent clone of Neisseria meningitidis serotype 2a that is associated with meningococcal group C disease in Canada

Abstract

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 province. This clone, which occurred infrequently among strains isolated in 1986, accounted for over 65% of group C strains associated with meningococcal disease in Canada in 1990.

Meningococcal disease in urban south western Sydney, 1990–1994

“…Factors influencing the outcome of meningococcal infection include clinical syndrome on presentation, age, timing of commencement of treatment, and strain causing infection. [21][22][23][24][25][26] Mortality increases in septicaemia with rapid bacterial multiplication. We used more detailed criteria to define clinical presentations than have been used in national surveillance data, thus more accurately separating cases of meningitis alone from those with a septicaemic component to their illness.…”

Neisseria meningitidis with decreased susceptibility to penicillin in Saskatchewan, Canada

“…Antigens were prepared as described by Abdillahi and Poolman (1). Monoclonal antibodies with serotype specificities 1, 2a, 2b, 2c, 4, 14, and 15 and subtype specificities P1.1, P1.2, P1.4, P1.5, P1.6, P1.7, P1.9, P1.10, P1.12, P1.14, P1.15, and P1.16 were used to type strains with rabbit anti-mouse immunoglobulin G conjugated to urease (Sigma Chemical Co.) as described previously (2). The monoclonal antibodies were kindly supplied by J. T. Poolman, National Institute of Public Health and Environment, Bilthoven, The Netherlands, and W. D. Zollinger, Walter Reed Army Institute of Research, Washington, D.C.…”

“…Distinctive combinations of alleles over the 13 enzyme loci were designated electrophoretic types (ETs). ET designations are the same as those described previously (2) and are independent of those described by Caugant et al (5).…”

Detection of the lst gene in different serogroups and LOS immunotypes of Neisseria meningitidis

“…Prototype strains representing the di¡erent serogroups and LOS immunotypes of N. meningitidis ( Table 1) and strains of other Neisseria species (Table 3) were from the culture collections of the authors' laboratories. Clinical isolates of N. meningitidis were supplied by the di¡erent Provincial Public Health Laboratories in Canada and had been studied using methods described before [9].…”

“…These strains tested included 15 serogroup B, 15 serogroup C, eight serogroup Y, eight serogroup W135 and four which were serologically non-groupable, and presented a wide variety of serotype (2a, 4, 14, 15) and serosubtype (P1. 1,2,5,6,7,9,13) antigens. Regardless of their source or antigenic formula, all 50 meningococcal strains tested were positive for the lst gene by PCR with each of the four sets of primers used.…”