title: Antimicrobial testing of selected fluoroquinolones against Pseudomonas aeruginosa isolated from canine otitis.
abstract: A total of 100 Pseudomonas aeruginosa (P. aeruginosa) isolates were collected over a 1.5-year period from cases of canine otitis. Sensitivities to enrofloxacin, marbofloxacin, and orbifloxacin were determined using minimum inhibitory concentration testing (MICT). Isolates were also tested for sensitivities to enrofloxacin and marbofloxacin using disk-diffusion susceptibility testing (DDST). Isolates were significantly more sensitive to marbofloxacin than to enrofloxacin (z = -4.57; P<0.05) or orbifloxacin (z = -5.02; P<0.05). Agreement was 87% between MICT and DDST for marbofloxacin, with approximately equal numbers of overestimation and underestimation errors. Agreement was 74% between MICT and DDST for enrofloxacin, but DDST tended to overestimate the number of enrofloxacin-susceptible strains. These results suggest that marbofloxacin is more effective against P. aeruginosa than either enrofloxacin or orbifloxacin and that relying on DDST may lead to ineffective enrofloxacin treatment.
authors.affiliation: Department of Dermatology, VCA-Aurora Animal Hospital, 2600 West Galena Boulevard, Aurora, Illinois 60506, USA.
authors.forename: Lindsay
authors.initials: L
authors.lastname: McKay
authors.forename: Crystal D Schuman
authors.initials: CD
authors.lastname: Rose
authors.forename: Jennifer L
authors.initials: JL
authors.lastname: Matousek
authors.forename: Lynn S
authors.initials: LS
authors.lastname: Schmeitzel
authors.forename: Nicole M
authors.initials: NM
authors.lastname: Gibson
authors.forename: Jack M
authors.initials: JM
authors.lastname: Gaskin
mesh_terms: D000818:Animals; D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D002939:Ciprofloxacin / Q000031:analogs & derivatives / Q000494:pharmacology; D015169:Colony Count, Microbial; D004283:Dog Diseases / Q000188:drug therapy*; D004285:Dogs; D004305:Dose-Response Relationship, Drug; D024881:Drug Resistance, Bacterial; D024901:Drug Resistance, Multiple, Bacterial; D000077422:Enrofloxacin; D024841:Fluoroquinolones / Q000494:pharmacology*; D008826:Microbial Sensitivity Tests / Q000662:veterinary; D010031:Otitis / Q000188:drug therapy / Q000382:microbiology / Q000662:veterinary*; D011552:Pseudomonas Infections / Q000188:drug therapy / Q000382:microbiology / Q000662:veterinary*; D011550:Pseudomonas aeruginosa / Q000187:drug effects* / Q000302:isolation & purification; D015363:Quinolones / Q000494:pharmacology; D012680:Sensitivity and Specificity; D016896:Treatment Outcome
chemical_list: D000900:Anti-Bacterial Agents; D024841:Fluoroquinolones; D015363:Quinolones; D000077422:Enrofloxacin; D002939:Ciprofloxacin; C095163:orbifloxacin; C080260:marbofloxacin