title: In vitro activity of ramoplanin against Clostridium difficile, including strains with reduced susceptibility to vancomycin or with resistance to metronidazole.
abstract: We evaluated the in vitro activity of ramoplanin, an antimicrobial compound that inhibits cell wall synthesis by acting at the level of lipid intermediate formation, against Clostridium difficile. We included strains with reduced susceptibilities to vancomycin (vancomycin-intermediate [Van(i)] strains) or with resistance to metronidazole (Mtz(r)), in order to assess the potential utility of ramoplanin for the treatment of C. difficile-associated diarrhea. We tested the activity of ramoplanin against a total of 105 nonduplicate clinical isolates of toxigenic C. difficile, including 8 Van(i) isolates and 6 Mtz(r) isolates, obtained from our laboratory. Ramoplanin was active against all strains tested at concentrations ranging from 0.03 to 0.5 microg/ml (MICs at which 50 and 90% of isolates were inhibited, 0.25 microg/ml; geometric mean MIC, 0.22 microg/ml). All isolates, independently of their levels of susceptibility to vancomycin or metronidazole, were considered susceptible to ramoplanin (MICs, < or =0.5 microg/ml).
authors.affiliation: Deparment of Clinical Microbiology and Infectious Diseases, Hospital General Universitario Gregorio Marañón, C/ Dr. Esquerdo 46, 28007, Madrid, Spain. terepelaez@teleline.es
authors.forename: T
authors.initials: T
authors.lastname: Peláez
authors.forename: L
authors.initials: L
authors.lastname: Alcalá
authors.forename: R
authors.initials: R
authors.lastname: Alonso
authors.forename: A
authors.initials: A
authors.lastname: Martín-López
authors.forename: V
authors.initials: V
authors.lastname: García-Arias
authors.forename: M
authors.initials: M
authors.lastname: Marín
authors.forename: E
authors.initials: E
authors.lastname: Bouza
mesh_terms: D016360:Clostridioides difficile / Q000187:drug effects*; D047630:Depsipeptides / Q000494:pharmacology*; D024881:Drug Resistance, Bacterial; D008795:Metronidazole / Q000494:pharmacology*; D008826:Microbial Sensitivity Tests; D014640:Vancomycin / Q000494:pharmacology*
chemical_list: D047630:Depsipeptides; C041438:ramoplanin; D008795:Metronidazole; D014640:Vancomycin
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