title: Comparison of two in vitro antifungal sensitivity tests and monitoring during therapy of Sporothrix schenckii sensu stricto in Malaysian cats.
abstract: BACKGROUND
  Feline sporotrichosis is common in Malaysia. Thermosensitivity and effects of azole treatment on fungal susceptibility are unknown.
  
  
  OBJECTIVE
  To evaluate thermotolerance and antifungal susceptibility of feline Malaysian Sporothrix isolates, compare microdilution (MD) and E-test results, and investigate changes in susceptibility during azole therapy.
  
  
  METHODS
  Sporothrix schenckii sensu stricto was isolated from 44 cats. Thermotolerance was determined via culture at 37°C for 7 days. Susceptibility to itraconazole (ITZ), ketoconazole (KTZ) and terbinafine (TRB) was assessed in 40 isolates by MD; to amphotericin B (AMB), KTZ, ITZ, fluconazole (FLC) and posaconazole (POS) by E-test. Results were statistically compared by Pearson's Product Moment. In eight ketoconazole treated cats, susceptibility testing to itraconazole and ketoconazole was repeated every two months for six months.
  
  
  RESULTS
  Thermotolerance was observed in 36 of 44 (82%) isolates. Assuming that isolates growing at antifungal concentrations ≥4 mg/mL were resistant, all were resistant on E-test to FLC and AMB, 11 (28%) to POS, 6 (15%) to ITZ and 1 (3%) to KTZ. On MD, 27 of 40 (68%) were resistant to TRB, 2 (5%) to ITZ and 3 (8%) to KTZ. There was no correlation between E-test and MD results (KTZ r = 0.10, P = 0.54, and ITZ r = 0.11, P = 0.48). MD values for ITZ and KTZ did not exceed 4 mg/L during KTZ therapy.
  
  
  CONCLUSIONS
  The majority of feline isolates in Malaysia are thermosensitive. Lack of correlation between E-test and MD suggests that the E-test is unreliable to test antifungal susceptibility for Sporothrix spp. compared to MD. KTZ was the antifungal drug with the lowest MIC. Prolonged KTZ administration may not induce changes in antifungal susceptibility.
authors.affiliation: Han Veterinary Surgery, 50 JLN Molek 2/2, TMN Molek, 81100, Johor Bahru, Johor, Malaysia.
authors.forename: Hock Siew
authors.initials: HS
authors.lastname: Han
authors.affiliation: Department of Pathobiology, Nihon University College of Bioresource Sciences, 1866, Kameino, Fujisawa, Kanagawa, 252-0880, Japan.
authors.forename: Rui
authors.initials: R
authors.lastname: Kano
authors.affiliation: Asian Veterinary Specialist Referral Center, 109 Section 4, XinYi Road, Taipei, Taiwan.
authors.forename: Charles
authors.initials: C
authors.lastname: Chen
authors.affiliation: Servizi Dermatologici Veterinari, Strada Bedale della Ressia 2, 12016, Peveragno (CN), Italy.
authors.forename: Chiara
authors.initials: C
authors.lastname: Noli
mesh_terms: D000666:Amphotericin B / Q000627:therapeutic use; D000818:Animals; D000935:Antifungal Agents / Q000627:therapeutic use*; D002371:Cat Diseases / Q000188:drug therapy*; D002415:Cats / Q000382:microbiology; D066298:In Vitro Techniques; D017964:Itraconazole / Q000627:therapeutic use; D007654:Ketoconazole / Q000627:therapeutic use; D008296:Malaysia; D008826:Microbial Sensitivity Tests / Q000379:methods / Q000662:veterinary*; D009281:Naphthalenes / Q000627:therapeutic use; D013175:Sporothrix / Q000187:drug effects*; D013174:Sporotrichosis / Q000188:drug therapy / Q000382:microbiology / Q000662:veterinary*; D000077291:Terbinafine; D014230:Triazoles / Q000627:therapeutic use
chemical_list: D000935:Antifungal Agents; D009281:Naphthalenes; D014230:Triazoles; D017964:Itraconazole; C101425:posaconazole; D000666:Amphotericin B; D000077291:Terbinafine; D007654:Ketoconazole