[In vitro susceptibility to antibiotics and the most common Streptococcus pneumoniae serotypes: a multicenter study]. / Sensibilidad in vitro a los antibióticos y serotipos más frecuentes de Streptococcus pneumoniae. Estudio multicéntrico.

ABSTRACT

The susceptibility and serotypes of 211 strains of Streptococcus pneumoniae collected from 12 Spanish hospitals in December 2003 were studied. Susceptibility tests for eight antibiotics were carried out by E-test, and the serotype classification was carried out using pneumococcus antiserum from the Copenhagen Statens Serum Institute. Overall, the most frequent serotypes were 19 (12.2%); 6 (10.7%); 23 (10.2%); 3 (8.1%); 9 (6.6%); 14 (6.1%); and 29 (5.1%). In blood, the most frequent were 19 (16.6%) and 14 (11.9%), and 8.6% were nontypable. Under NCCLS (M7-A5) criteria, 55.6% of the strains were susceptible to penicillin (MIC < or =0.06 mg/l) and 7.9% showed high resistance (MIC > or =2 mg/l). Susceptibility to other antibiotics was 98% to moxifloxacin; 97.1% to levofloxacin; 94.6% to amoxicillin-clavulanic acid; 71.2% to cefuroxime; 84.4% to ceftriaxone; and 63.1% to clarithromycin and azithromycin. Only 13.3% of the strains showed susceptibility to the antibiotics tested. The greatest percentage of strains resistant to other antibiotics was found among the strains resistant to penicillin. Nine resistant phenotypes were detected.