title: In vitro activity of the new ketolide ABT-773 against community acquired respiratory tract isolates and Viridans Streptococci.
abstract: A total of 230 isolates were collected from clinical specimens of patients attending five health centers of the Buenos Aires, Argentina. ABT-773 was compared to erythromycin, azithromycin and clindamycin against bacterial isolates responsible for community-acquired respiratory tract infections and viridans streptococci showing different resistance patterns. Time-kill curves were also performed against selected resistant isolates. All but one of the 105 pneumococcal isolates were susceptible to ABT-773. Among the erythromycin resistant S. pyogenes isolates, all the M type and inducible isolates were susceptible to ABT-773. ABT-773 showed excellent activity against macrolide, azalide, lincosamide (MAL) inducible S. aureus producers but was inactive against constitutive producers. ABT-773 activity against viridans streptococci was also excellent.ABT-773 exerted bactericidal activity against selected isolates of S. pneumoniae, M. catarrhalis and H. influenzae, however, it was only bacteriostatic against methicillin-susceptible S. aureus.
authors.affiliation: Centro de Estudios en Antimicrobianos, Buenos Aires, Argentina. casellasjm@cpsarg.com
authors.forename: José María
authors.initials: JM
authors.lastname: Casellas
authors.forename: Gabriella
authors.initials: G
authors.lastname: Tomé
authors.forename: Matías
authors.initials: M
authors.lastname: Visser
authors.forename: Laura
authors.initials: L
authors.lastname: Gliosca
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000900:Anti-Bacterial Agents / Q000494:pharmacology; D001419:Bacteria / Q000187:drug effects* / Q000302:isolation & purification; D002648:Child; D002675:Child, Preschool; D017714:Community-Acquired Infections / Q000382:microbiology*; D024881:Drug Resistance, Bacterial; D004917:Erythromycin / Q000031:analogs & derivatives* / Q000494:pharmacology*; D006193:Haemophilus influenzae / Q000187:drug effects; D006801:Humans; D048628:Ketolides; D008826:Microbial Sensitivity Tests / Q000379:methods / Q000592:standards; D008875:Middle Aged; D001936:Moraxella catarrhalis / Q000187:drug effects; D012141:Respiratory Tract Infections / Q000382:microbiology*; D013211:Staphylococcus aureus / Q000187:drug effects; D013291:Streptococcus / Q000187:drug effects; D013296:Streptococcus pneumoniae / Q000187:drug effects
chemical_list: D000900:Anti-Bacterial Agents; D048628:Ketolides; D004917:Erythromycin; C405499:cethromycin