Antibiotic susceptibility patterns of Neisseria meningitidis isolates frompatients and asymptomatic carriers

The activities of seven antimicrobial agents used for treatment and prophyl axis of meningococcal disease was investigated against 901 Neisseria mening itidis isolates, 112 of which were recovered from patients and 789 of which were recovered from asymptomatic carriers. The proportions of isolates wit h decreased susceptibility to penicillin were 55.3 and 39.0%, respectively. Penicillin- and ampicillin-intermediate strains were more common among ser ogroup C meningococci than among non-serogroup C meningococci from both pat ients and carriers.