title: Susceptibilities of Mycoplasma hominis, M. pneumoniae, and Ureaplasma urealyticum to GAR-936, dalfopristin, dirithromycin, evernimicin, gatifloxacin, linezolid, moxifloxacin, quinupristin-dalfopristin, and telithromycin compared to their susceptibilities to reference macrolides, tetracyclines, and quinolones.
abstract: The susceptibilities of Mycoplasma hominis, Mycoplasma pneumoniae, and Ureaplasma urealyticum to eight new antimicrobial agents were determined by agar dilution. M. pneumoniae was susceptible to the new glycylcycline GAR-936 at 0.12 microg/ml and evernimicin at 4 microg/ml, but it was resistant to linezolid. It was most susceptible to dirithromycin, quinupristin-dalfopristin, telithromycin, reference macrolides, and josamycin. M. hominis was susceptible to linezolid, evernimicin, and GAR-936. It was resistant to macrolides and the ketolide telithromycin but susceptible to quinupristin-dalfopristin and josamycin. U. urealyticum was susceptible to evernimicin (8 to 16 microg/ml) and resistant to linezolid. It was less susceptible to GAR-936 (4.0 microg/ml) than to tetracycline (0.5 microg/ml). Telithromycin and quinupristin-dalfopristin were the most active agents against ureaplasmas (0.06 microg/ml). The new quinolone gatifloxacin was active against M. pneumoniae and M. hominis at 0.12 to 0.25 microg/ml and active against ureaplasmas at 1.0 microg/ml. The MICs of macrolides were markedly affected by pH, with an 8- to 32-fold increase in the susceptibility of M. pneumoniae as the pH increased from 6.9 to 7.8. A similar increase in susceptibility with increasing pH was also observed with ureaplasmas. Tetracyclines showed a fourfold increase of activity as the pH decreased 1 U, whereas GAR-936 showed a fourfold decrease in activity with a decrease in pH.
authors.affiliation: Department of Pathobiology, School of Public Health and Community Medicine, University of Washington, Seattle, Washington 98195, USA. kennyg@u.washington.edu
authors.forename: G E
authors.initials: GE
authors.lastname: Kenny
authors.forename: F D
authors.initials: FD
authors.lastname: Cartwright
mesh_terms: D042462:4-Quinolones; D000081:Acetamides / Q000494:pharmacology; D000617:Aminoglycosides; D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D001372:Aza Compounds; D004917:Erythromycin / Q000031:analogs & derivatives / Q000494:pharmacology; D024841:Fluoroquinolones; D000077734:Gatifloxacin; D006801:Humans; D006863:Hydrogen-Ion Concentration; D048628:Ketolides; D000069349:Linezolid; D018942:Macrolides; D008826:Microbial Sensitivity Tests; D008911:Minocycline / Q000031:analogs & derivatives / Q000494:pharmacology; D000077266:Moxifloxacin; D019535:Mycoplasma hominis / Q000187:drug effects*; D009177:Mycoplasma pneumoniae / Q000187:drug effects*; D023303:Oxazolidinones / Q000494:pharmacology; D011804:Quinolines; D013754:Tetracyclines / Q000494:pharmacology; D000078304:Tigecycline; D016990:Ureaplasma urealyticum / Q000187:drug effects*; D014769:Virginiamycin / Q000031:analogs & derivatives* / Q000494:pharmacology
chemical_list: D042462:4-Quinolones; D000081:Acetamides; D000617:Aminoglycosides; D000900:Anti-Bacterial Agents; D001372:Aza Compounds; D024841:Fluoroquinolones; D048628:Ketolides; D018942:Macrolides; D023303:Oxazolidinones; D011804:Quinolines; D013754:Tetracyclines; D014769:Virginiamycin; C062940:quinupristin-dalfopristin; C053853:dirithromycin; C001202:evernimicin; D004917:Erythromycin; D000078304:Tigecycline; D008911:Minocycline; D000069349:Linezolid; C106791:telithromycin; D000077734:Gatifloxacin; C113826:dalfopristin; D000077266:Moxifloxacin