INCREASE IN MODERATE PENICILLIN RESISTANCE AND SEROGROUP-C IN MENINGOCOCCAL STRAINS ISOLATED IN SPAIN - IS THERE ANY RELATIONSHIP

Serogroup B Neisseria meningitidis is the main cause of meningococcal disease in Spain, but in recent years we have detected an increase in the prevalence of infection due to serogroup C meningococci. At the sa me time, the frequency of moderately penicillin-resistant (Pen(R)) cli nical isolates, which include greater numbers of serogroup C meningoco cci than do penicillin-susceptible (Pen(s)) strains, has also been inc reasing. When we analyzed the prevalence of serogroups B and C in Pen( R) and Pen(s) meningococcal strains, we found a simultaneous increase in serogroup C strains and a decrease in serogroup B meningococci affe cting both Pen(R) and Pen(s) isolates. To analyze this epidemiological change in Spain, we have applied serotyping, subtyping, and multilocu s enzyme electrophoresis to serogroup C (Pen(R) and Pen(s)) strains. T he two major serotypes were 2b and 2a in both groups (Pen(R) and Pen(s )), but our results suggested an association between serotype 2b and P en(R) strains. However, multilocus enzyme electrophoresis showed that 75% of the major serotypes belonged to the same electrophoretic type. It does not appear that a new clone distinct from those already establ ished is contributing to the increase in serogroup C meningococci in S pain.