title: In vitro susceptibilities of Rhodococcus equi and other common equine pathogens to azithromycin, clarithromycin, and 20 other antimicrobials.
abstract: The objective of this study was to determine in vitro activities of azithromycin (AZM), clarithromycin (CLR), and 20 other antimicrobial agents against Rhodococcus equi and other common equine bacterial pathogens. A total of 201 bacterial isolates from various equine clinical samples were examined. CLR was more active than AZM against R. equi, with MICs at which 90% of the isolates were inhibited of 0.12 and 1.0 micro g/ml, respectively. Other antimicrobial agents highly active against at least 90% of R. equi isolates in vitro included rifampin, gentamicin, and imipenem. Both AZM and CLR showed good activity against beta-hemolytic streptococci and Staphylococcus spp. AZM was more active than other macrolides against Pasteurella spp. and Salmonella enterica.
authors.affiliation: Department of Large Animal Clinical Sciences, College of Veterinary Medicine, University of Florida, Gainesville, Florida 32610-0136, USA.
authors.forename: Stephanie S
authors.initials: SS
authors.lastname: Jacks
authors.forename: Steeve
authors.initials: S
authors.lastname: Giguère
authors.forename: An
authors.initials: A
authors.lastname: Nguyen
mesh_terms: D000818:Animals; D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D017963:Azithromycin / Q000494:pharmacology*; D017291:Clarithromycin / Q000494:pharmacology*; D006736:Horses; D008826:Microbial Sensitivity Tests; D016929:Rhodococcus equi / Q000187:drug effects*
chemical_list: D000900:Anti-Bacterial Agents; D017963:Azithromycin; D017291:Clarithromycin