[In vitro susceptibility of streptococcus pneumoniae strains isolated from lower respiratory infections in Instituto Nacional del Tórax (INT)].

BACKGROUND

The rising antimicrobial resistance of streptococcus pneumoniae, requires permanent surveillance. Antimicrobial treatments of invasive infections must be modified accordingly.

AIM: To assess the in vitro antimicrobial susceptibility of streptococcus pneumoniae strains isolated from lower respiratory infections.

MATERIAL AND

METHODS

Seventy five strains isolated during three periods in consecutive years were studied. In vitro susceptibility towards penicillin, erythromycin and ceftriaxone was studied using E-test technique minimal inhibitory concentrations.

RESULTS

Five percent of strains were penicillin resistant and 11% had an intermediate sensitivity. Erythromycin resistance was observed in 1.3% of strains. Eight percent of strains had an intermediate sensitivity towards ceftriaxone and no resistance was observed. Comparing susceptibility in the three studied periods, it remained low and stable.

CONCLUSIONS

High and intermediate resistance of Streptococcus pneumoniae towards penicillin is less prevalent than in other countries. A close surveillance must be maintained (Rev Méd Chile 2002; 130: 304-8).