Study of in vitro antibacterial activities on 69 strains of Streptococcus pneumoniae

Object To investigate the in vitro activities of penicillin etc. against Streptococcus pneumoniae isolates and provide the basis for infection and resistance of Streptococcus pneumoniae. Methods Activities of eleven antibiotics against 69 strains of Streptococcus pneumoniae isolated from clinical samples were detected during Nov. 2002 to Feb. 2004 by using ATBSTREP5 strips. Results Antibiotics susceptibility test were showed that 58% of Streptococcus pneumoniae were sensitive to penicillin(MIC≤0.063mg/L)(PSSP), 36% were intermediaten(MIC≤0.125mg/L)(PISP), and only 6% were resistant (MIC≥2mg/L)(PRSP). The resistance rates of Streptococcus pneumoniae to erythromycin, trimeth-sulfa and tetracycline were over 60% and the resistance rates to vancomycin, amoxicillin were 0.0%. Conclusions The resistances of Streptococcus pneumoniae to erythromycin, tetracycline trimeth-sulfa are high, and the resistance to penicillin is PISP strains produced in low degree .