title: Activity of oral beta-lactam antimicrobial agents versus respiratory tract isolates of Streptococcus pneumoniae, Haemophilus influenzae, and Moraxella catarrhalis in the era of antibiotic resistance.
abstract: The management of outpatient respiratory tract infections with oral beta-lactam antimicrobial agents has been complicated by the emergence of beta-lactamase-producing strains of Haemophilus influenzae and Moraxella catarrhalis and isolates of Streptococcus pneumoniae that express varying levels of beta-lactam resistance because of altered penicillin-binding proteins. There is no question that all 3 of these important respiratory tract pathogens have changed conspicuously in the context of decreased activity of beta-lactam antimicrobial agents. The question arises, what does this change mean from a clinical perspective? In this review, the in vitro activity of various oral beta-lactam antimicrobial agents versus contemporary isolates of H influenzae, M catarrhalis, and S pneumoniae will be compared. The approach that is used in defining organisms as being susceptible or resistant to beta-lactam antimicrobial agents will be elucidated. Finally, an effort will be made to assess the ramifications of beta-lactam resistance for therapeutic efficacy in patients with respiratory tract infections caused by these 3 bacteria. We conclude that, notwithstanding diminished beta-lactam activity for many clinical isolates of H influenzae, M catarrhalis, and S pneumoniae, certain agents remain effective in treating outpatient respiratory tract infections.
authors.affiliation: Department of Pathology, University of Iowa Hospitals and Clinics, Clinical Microbiology Laboratories, University of Iowa College of Medicine, USA. gary-doern@uiowa.edu
authors.forename: Gary V
authors.initials: GV
authors.lastname: Doern
mesh_terms: D000284:Administration, Oral; D000900:Anti-Bacterial Agents / Q000008:administration & dosage / Q000494:pharmacology*; D006193:Haemophilus influenzae / Q000187:drug effects*; D006801:Humans; D066298:In Vitro Techniques; D008826:Microbial Sensitivity Tests; D001936:Moraxella catarrhalis / Q000187:drug effects*; D013296:Streptococcus pneumoniae / Q000187:drug effects*; D018440:beta-Lactam Resistance; D047090:beta-Lactams
chemical_list: D000900:Anti-Bacterial Agents; D047090:beta-Lactams