Antimicrobial susceptibility patterns of respiratory pathogens--a global perspective.

Antimicrobial resistance among respiratory tract pathogens poses a major challenge for the ongoing use of antimicrobial agents for treating infected patients. Global antimicrobial susceptibility data has documented the existence of widespread resistance issues. Streptococcus pneumoniae, Haemophilus influenzae, and Moraxella catarrhalis constitute the principal community-acquired respiratory tract bacterial pathogens. For H. influenzae, resistance to ampicillin varies from less than 5% in some European countries to greater than 30% in North America and Southeast Asia. For H. influenzae, resistance to trimethoprim/sulfamethoxazole has been shown to range from less than 5% in North America and Europe to greater than 25% in Europe, the Middle East, and India. For M. catarrhalis, 85% to 100% of isolates worldwide are beta-lactamase positive and, therefore, ampicillin and amoxicillin resistant. Penicillin-resistant S. pneumoniae shows considerable variability worldwide ranging from 6% to 80% whereas macrolide resistance among the pneumococci range from 0% to 90%. Clearly, documenting and understanding the emergence, dissemination, and infection with pathogens resistant to antimicrobial agents is essential for developing strategies to deal with this global problem. This article highlights the frequency of antimicrobial resistance among the respiratory pathogens from a global perspective. Also, mechanisms of resistance and factors associated with the emergence, dissemination, and colonization of resistant organisms are discussed.