title: Macrolide Resistance inStreptococcus pneumoniae.
abstract: Streptococcus pneumoniaeis a common commensal and an opportunistic pathogen. Suspected pneumococcal upper respiratory infections and pneumonia are often treated with macrolide antibiotics. Macrolides are bacteriostatic antibiotics and inhibit protein synthesis by binding to the 50S ribosomal subunit. The widespread use of macrolides is associated with increased macrolide resistance inS. pneumoniae, and the treatment of pneumococcal infections with macrolides may be associated with clinical failures. InS. pneumoniae, macrolide resistance is due to ribosomal dimethylation by an enzyme encoded byerm(B), efflux by a two-component efflux pump encoded bymef(E)/mel(msr(D)) and, less commonly, mutations of the ribosomal target site of macrolides. A wide array of genetic elements have emerged that facilitate macrolide resistance inS. pneumoniae; for exampleerm(B) is found on Tn917, while themef(E)/meloperon is carried on the 5.4- or 5.5-kb Mega element. The macrolide resistance determinants,erm(B) andmef(E)/mel, are also found on large composite Tn916-like elements most notably Tn6002, Tn2009, and Tn2010. Introductions of 7-valent and 13-valent pneumococcal conjugate vaccines (PCV-7 and PCV-13) have decreased the incidence of macrolide-resistant invasive pneumococcal disease, but serotype replacement and emergence of macrolide resistance remain an important concern.
authors.affiliation: Departments of Medicine, Emory University Atlanta, GA, USA.
authors.forename: Max R
authors.initials: MR
authors.lastname: Schroeder
authors.affiliation: Departments of Medicine, Emory UniversityAtlanta, GA, USA; Departments of Microbiology and Immunology, Emory UniversityAtlanta, GA, USA; Departments of Epidemiology, Emory UniversityAtlanta, GA, USA.
authors.forename: David S
authors.initials: DS
authors.lastname: Stephens
mesh_terms: D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D001426:Bacterial Proteins / Q000235:genetics; D004338:Drug Combinations; D024881:Drug Resistance, Bacterial / Q000187:drug effects / Q000235:genetics*; D005798:Genes, Bacterial / Q000235:genetics; D005838:Genotype; D006801:Humans; D018942:Macrolides / Q000494:pharmacology* / Q000627:therapeutic use*; D008565:Membrane Proteins / Q000235:genetics; D008826:Microbial Sensitivity Tests; D009154:Mutation; D011008:Pneumococcal Infections / Q000188:drug therapy / Q000517:prevention & control; D022242:Pneumococcal Vaccines; D012335:RNA, Ribosomal / Q000235:genetics; D012703:Serotyping; D013296:Streptococcus pneumoniae / Q000187:drug effects* / Q000201:enzymology / Q000235:genetics*; D018074:Vaccines, Conjugate
chemical_list: C538862:13-valent pneumococcal vaccine; D000900:Anti-Bacterial Agents; D001426:Bacterial Proteins; D004338:Drug Combinations; D018942:Macrolides; C117866:MefA protein, Streptococcus; D008565:Membrane Proteins; D022242:Pneumococcal Vaccines; D012335:RNA, Ribosomal; D018074:Vaccines, Conjugate
keywords: Mega; Streptococcus pneumoniae; antibiotic resistance; erm(B); macrolide resistance; mef(A/E)/mel(msr(D)); pneumococci