Antimicrobial Susceptibility Among Respiratory Tract Pathogens From the Northern States of the USA

Abstract

As part of the PROTEKT US surveillance program, 6236 Streptococcus pneumoniae, 2463 Streptococcus pyogenes, and 1664 Haemophilus influenzae isolates were collected from patients with community-acquired respiratory tract infections in the northern United States in 2000-2001. Penicillin resistance was found in 22.9% of S. pneumoniae isolates, erythromycin resistance in 28.0%, and fluoroquinolone resistance in 1.0%. Combined resistance to penicillin and erythromycin occurred in 17.8% of S. pneumoniae isolates. Overall, 6.0% of S. pyogenes isolates were resistant to erythromycin and 29.6% of H. influenzae isolates were β-lactamase producers. Antimicrobial resistance among all 3 pathogens showed considerable between-state variability. Telithromycin was highly active against all strains of S. pneumoniae (99.6% susceptible) and H. influenzae (96.4% susceptible), and had an MIC90 of 0.03 μg/mL against S. pyogenes. The results highlight the wide variability in resistance rates among northern US states and the high activity of telithromycin against respiratory tract pathogens.