title: In vivo efficacy of the ketolide ABT-773 (cethromycin) against enterococci in a mouse peritonitis model.
abstract: Using six Enterococcus faecalis and five Enterococcus faecium strains, the ketolide ABT-773 (ABT), now known as cethromycin, was found to have in vivo efficacy against both erythromycin (ERY)-susceptible (Ery(s)) and -intermediate (Ery(i)) enterococci (ABT 50% protective doses [PD(50)s], 0.5 to 4.1 and 10.3 to 16.2 mg/kg of body weight, respectively). Against four highly Ery-resistant (Ery(r)) strains for which ABT MICs were low, ABT showed much greater activity (PD(50), 6.3 to 32.5 mg/kg) than ERY (PD(50), >200 mg/kg) but was not protective for strains for which ABT MICs were high. In conclusion, ABT-773 showed in vivo efficacy and considerably greater activity than ERY in a mouse peritonitis model.
authors.affiliation: Center for the Study of Emerging and Re-Emerging Pathogens, The University of Texas Medical School, Houston, Texas 77030, USA.
authors.forename: Suresh R
authors.initials: SR
authors.lastname: Pai
authors.forename: Kavindra V
authors.initials: KV
authors.lastname: Singh
authors.forename: Barbara E
authors.initials: BE
authors.lastname: Murray
mesh_terms: D000818:Animals; D015169:Colony Count, Microbial; D016984:Enterococcus faecium / Q000187:drug effects; D004917:Erythromycin / Q000031:analogs & derivatives / Q000494:pharmacology / Q000627:therapeutic use*; D016908:Gram-Positive Bacterial Infections / Q000188:drug therapy* / Q000382:microbiology; D048628:Ketolides; D007928:Lethal Dose 50; D051379:Mice; D008813:Mice, Inbred ICR; D008826:Microbial Sensitivity Tests; D010538:Peritonitis / Q000188:drug therapy* / Q000382:microbiology
chemical_list: D048628:Ketolides; D004917:Erythromycin; C405499:cethromycin