Antibiotic sensitivity pattern of recent clinical isolates of Streptococcus pneumoniae.

Antimicrobial susceptibility of 180 recent isolates of Streptococcus pneumoniae was determined by microdilution technic. There was a high degree of susceptibility to both penicillin G and cefuroxime, except for one strain which required 0.25 microgram/ml. All strains were inhibited by 0.06 microgram/ml of ampicillin, clindamycin and erythromycin. When tested against doxycycline 97.2% of the strains were inhibited by 1.0 microgram/ml. 8 microgram/ml inhibited all strains. Three of the strains were chloramphenicol-resistant with MIC more than 8 microgram/ml. These strains could be shown to inactivate chloramphenicol. All strains but three were susceptible to 20/l microgram/ml of sulfamethoxazole/trimethoprim.