title: Activities of cethromycin and telithromycin against recent North American isolates of Streptococcus pneumoniae.
abstract: The in vitro activities of two investigational ketolides, cethromycin (formerly ABT-773) and telithromycin, were determined for a selected group of 312 Streptococcus pneumoniae isolates from a national surveillance program. The MIC of cethromycin at which 50% of the isolates were inhibited was 0.008 micro g/ml, and the MIC at which 90% of the isolates were inhibited was 0.06 micro g/ml; the corresponding values for telithromycin were </=0.015 and 0.25 micro g/ml, respectively. For six quinupristin-dalfopristin-resistant strains, the cethromycin MICs were 0.25 to 16 micro g/ml and the telithromycin MICs were 1 to 4 micro g/ml. However, there was only 0.3% resistance to telithromycin.
authors.affiliation: Department of Pathology, University of Texas Health Science Center, San Antonio, Texas, USA. jorgensen@uthscsa.edu
authors.forename: James H
authors.initials: JH
authors.lastname: Jorgensen
authors.forename: Sharon A
authors.initials: SA
authors.lastname: Crawford
authors.forename: M Leticia
authors.initials: ML
authors.lastname: McElmeel
authors.forename: Cynthia G
authors.initials: CG
authors.lastname: Whitney
mesh_terms: D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D024881:Drug Resistance, Bacterial; D004917:Erythromycin / Q000031:analogs & derivatives / Q000494:pharmacology*; D005798:Genes, Bacterial / Q000235:genetics; D006801:Humans; D048628:Ketolides; D018942:Macrolides / Q000494:pharmacology*; D008826:Microbial Sensitivity Tests; D009656:North America; D011008:Pneumococcal Infections / Q000382:microbiology; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013296:Streptococcus pneumoniae / Q000187:drug effects* / Q000235:genetics
chemical_list: D000900:Anti-Bacterial Agents; D048628:Ketolides; D018942:Macrolides; D004917:Erythromycin; C405499:cethromycin; C106791:telithromycin