[A clone of Neisseria meningitidis serogroup C was responsible in 1994 of an unusual high rate of strains with a moderate resistance to penicillin in Caracas (Venezuela)]

The aim of the study was to analyse meningococcal strains isolated from patients in Caracas (Venezuela) with epidemiological markers and to determine their susceptibility to antimicrobial agents.We analyzed 29 meningococcal clinical strains isolated during 1994 in Caracas by serogrouping, serotyping and subserotyping, multilocus enzyme analysis (MEE), ribotyping and pulse field electrophoresis (PFGE) profile. We also determined the Minimal Inhibitory Concentration (MIC) to 5 antimicrobial agents.Twenty four (82.7%) were group C meningococcal strains. All group C meningococci were characterized as C: 2b: P1.5, belonging to the same electrophoretic type (ET) by MEE and showing the same profile by PFGE by using Bg/II endonuclease restriction enzyme. These group C meningococci showed two different patterns by ribotyping, with only one band difference. All Group C and one group B N. meningitidis isolates were moderately resistant to penicillin (MICor = 0.12 mg/l).During 1994 an unusual high incidence of meningococcal strains moderately resistant to penicillin (PenMR) was detected in Caracas (Venezuela). A clone of C: 2b: P1.5 meningococci seem to be responsable for this high incidence of PenMR isolates.