title: Antimicrobial resistance, integron carriage, and gyrA and gyrB mutations in Pseudomonas aeruginosa isolated from dogs with otitis externa and pyoderma in Brazil.
abstract: BACKGROUND
  Pseudomonas aeruginosa is associated with otitis and pyoderma in dogs and is frequently resistant to several antimicrobial drugs. Resistance genes can be carried by integrons with quinolone resistance mainly due to mutations in DNA topoisomerases II and IV.
  
  
  OBJECTIVE
  To evaluate the antimicrobial susceptibility, integron carriage, and gyrA and gyrB mutations in P. aeruginosa isolates from canine otitis and pyoderma.
  
  
  METHODS
  One hundred and four P. aeruginosa strains isolated from dogs with otitis externa (n = 93) and pyoderma (n = 11).
  
  
  METHODS
  Antimicrobial susceptibility against 16 antibacterial agents was evaluated through agar diffusion tests. Integron carriage, class and gyrA and gyrB mutations were analysed by PCR, restriction fragment length polymorphism (RFLP)-PCR and genetic sequencing assays.
  
  
  RESULTS
  Isolates were mostly resistant to enrofloxacin (72.2%) and ticarcillin (59.7%). Lower resistance to ciprofloxacin (7.7%), tobramycin (3.8%) and polymixin B (0.0%) was detected. Ten (9.6%) multidrug-resistant (MDR) strains were detected. Eight (7.7%) strains carried class 1 integrons and this was associated with MDR (three isolates, P ≤ 0.05). Five of the integron-carrying strains exhibited aminoglycoside resistance genes. Mutations of gyrA and gyrB were observed in 10 isolates, seven of them resistant to all fluoroquinolones tested.
  
  
  CONCLUSIONS
  Enrofloxacin and ticarcilin resistance was widespread in P. aeruginosa isolated from dogs in Brazil. Pseudomonas aeruginosa carrying integrons may present a significant challenge for treatment.
authors.affiliation: Department of Microbiology and Parasitology, Federal Fluminense University (UFF), Rua Hernani Mello, 101, Niterói, 24210130, RJ, Brazil.
authors.forename: Lavicie R
authors.identifier: http://orcid.org/0000-0003-4638-0793
authors.initials: LR
authors.lastname: Arais
authors.affiliation: Department of Microbiology and Parasitology, Federal Fluminense University (UFF), Rua Hernani Mello, 101, Niterói, 24210130, RJ, Brazil.
authors.forename: André V
authors.initials: AV
authors.lastname: Barbosa
authors.affiliation: Department of Microbiology and Parasitology, Federal Fluminense University (UFF), Rua Hernani Mello, 101, Niterói, 24210130, RJ, Brazil.
authors.forename: Cristiane A
authors.initials: CA
authors.lastname: Carvalho
authors.affiliation: Department of Microbiology and Parasitology, Federal Fluminense University (UFF), Rua Hernani Mello, 101, Niterói, 24210130, RJ, Brazil.
authors.forename: Aloysio M F
authors.initials: AM
authors.lastname: Cerqueira
mesh_terms: D000818:Animals; D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D001938:Brazil / Q000453:epidemiology; D027081:DNA Gyrase / Q000235:genetics / Q000378:metabolism*; D004283:Dog Diseases / Q000382:microbiology*; D004285:Dogs; D024881:Drug Resistance, Bacterial; D015964:Gene Expression Regulation, Bacterial; D015971:Gene Expression Regulation, Enzymologic; D032023:Integrons; D009154:Mutation; D010032:Otitis Externa / Q000453:epidemiology / Q000382:microbiology / Q000662:veterinary; D011552:Pseudomonas Infections / Q000453:epidemiology / Q000382:microbiology / Q000662:veterinary; D011550:Pseudomonas aeruginosa / Q000187:drug effects* / Q000235:genetics* / Q000378:metabolism; D011711:Pyoderma / Q000453:epidemiology / Q000382:microbiology / Q000662:veterinary; D017192:Skin Diseases, Bacterial / Q000453:epidemiology / Q000382:microbiology / Q000662:veterinary
chemical_list: D000900:Anti-Bacterial Agents; D027081:DNA Gyrase