Sulphadiazine-resistant group A meningococci isolated during the 1968 meningitis epidemic in Greece

During the 1968 epidemic of meningococcal meningitis in Greece, 90% of the meningococci recovered from the spinal fluid of patients belonged to serological group A. In one army barracks and in one Naval Training Centre, where cases occurred, a rate of 52% and 38·9% respectively of healthy nasopharyngeal carriers of group A meningococci was found, despite repeated courses of sulpha-prophylaxis given to all the population of these military establishments shortly before the swabs were taken.

The susceptibility to sulphadiazine of 64 group A meningococci isolated from patients in different regions of the country and from healthy carriers was tested in vitro. It was found that only one strain was sensitive to a concentration of 0·1 mg./100 ml. of sulphadiazine and another to 1 mg./100 ml. For the remaining strains, the minimal inhibitory concentrations of sulphadiazine ranged from 5 mg./100 ml. to more than 20 mg./100 ml.

Thirty-six strains of group B meningococci were isolated from 34 healthy carriers and from two patients. Some of these strains were resistant to sulphadiazine. Only three strains of group C meningococci were isolated from healthy nasopharyngeal carriers in one army barracks.

We wish to express our thanks to Dr R. Faucon, Director of the International Reference Centre for meningococci, for the valuable help he gave to us during our investigation, as well as for the supply of the group-specific agglutinating antimeningococcal sera.