EN
Neisseria meningitidis carriers strains were isolated from 17-19 teenagers (n=14) and recruits (n=267). The longitudinal study comprises three meningococcal carriage trials performed on healthy young men during two - six months of their service in Polish military units. Altogether 54, 124 and 89 meningococcal strains were obtained during spring 1998 and autumn 1998,1999 trials. Sixty two percent of meningococcal carrier strains were non-groupable,however among the remaining strains, serogroup B was predominant (29,5%). During spring 1998 and autumn 1999 trials the predominant phenotypes were N. meningitidis NG:21:P1.7, but during the autumn 1998 NG:21:P1.7 or NG:NT:P1.5. Ribotyping of type 21 and/or subtype P1.7 strains (n=27) showed presence of 2 main ribotypes. Pulsed Field Gel Electrophoresis of consecutive isolates recovered from the same carrier showed great similarity of the patterns.