PNEUMOCOCCAL RESISTANCE TO ANTIMICROBIAL AGENTS IN THE PROVINCE OF QUEBEC, CANADA

The serogroup/serotypes (SGTs) and antimicrobial susceptibilities to 1 0 antimicrobial agents of 110 clinical strains of Streptococcus pneumo niae were determined. Strains intermediately resistant or highly resis tant to penicillin G (80 of 110) belonged predominantly to SGTs 23 (45 .0%), 19 (13.7%), 6 (10.0%), 9 (6.2%), and 14 (3.7%). The MICs of all cephalosporins, tetracycline, trimethoprim-sulfamethoxazole, and chlor amphenicol increased along with the MICs of penicillin G. However, ery thromycin resistance and clindamycin resistance were observed more fre quently among the intermediately penicillin-resistant strains. Multipl e resistance was observed for 32 strains, of which 25 were highly resi stant to penicillin G and belong to SGT 23F. All strains were suscepti ble to vancomycin.