Trends of penicillin and erythromycin resistance among invasive Streptococcus pneumoniae in Europe

Objectives: To forecast trends in resistance to penicillin and erythromycin among Streptococcus pneumoniae in Europe. Methods: Since 1999, the European Antimicrobial Resistance Surveillance System (EARSS) has collected routine antimicrobial susceptibility test results of S. pneumoniae. To observe and predict changes of reduced susceptibility over time, we used a multinomial logistic regression model. Results: Large variations in penicillin and erythromycin non-susceptibility were observed between countries, and reduced susceptibility to erythromycin (17%) has become more frequent than reduced susceptibility to penicillin (10%) in Europe overall. An overall decrease in single penicillin non-susceptibility, but an increase in dual non-susceptibility was observed, indicating a shift of single penicillin to combined non-susceptibility with erythromycin. By 2006, the proportion of single erythromycin and dual non-susceptibility could increase to as much as 20.4% and 8.9%, respectively. Conclusions: Our results indicate that appropriately dosed beta-lactams for empirical therapy are still the treatment of choice, and that macrolides should be used with prudence.