Antifungal agent susceptibilities and interpretation ofMalassezia pachydermatisandCandida parapsilosisisolated from dogs with and without seborrheic dermatitis skin

Abstract

Malassezia pachydermatis and Candida parapsilosis are recognized as commensal yeasts on the skin of healthy dogs but also causative agents of eborrheic dermatitis, especially in atopic dogs. We determined and compared the susceptibility levels of yeasts isolated from dogs with and without seborrheic dermatitis (SD) using the disk diffusion method (DD) for itraconazole (ITZ), ketoconazole (KTZ), nystatin (NYS), terbinafine (TERB) and 5-fluorocytosine (5-FC) and the broth microdilution method (BMD) for ITZ and KTZ. The reliability between the methods was assessed using an agreement analysis and linear regression. Forty-five M. pachydermatis and 28 C. parapsilosis isolates were identified based on physiological characteristics and an approved molecular analysis. By DD, all tested M. pachydermatis isolates were susceptible to ITZ, KTZ, NYS and TERB but resistant to 5-FC. Only 46 - 60% of the tested C. parapsilosis isolates were susceptible to KTZ, TERB and 5-FC, but ITZ and NYS were effective against all. By BMD, over 95% of M. pachydermatis isolates were susceptible to KTZ and ITZ with an MIC90 < 0.03 and 0.12 μg/ml, respectively. The frequency of KTZ- and ITZ-resistant C. parapsilosis was 29% and 7%, and the MIC90 values were 1 μg/ml and 0.5-1 μg/ml, respectively. Regarding the agreement analysis, 2.2% of minor errors were observed in M. pachydermatis and 0.2-1% of very major errors occurred among C. parapsilosis. There were no significant differences in the yeast resistance rates between dogs with and without SD. KTZ and ITZ were still efficacious for M. pachydermatis but a high rate of KTZ resistant was reported in C. parapsilosis.

Antifungal susceptibility testing of Malassezia yeast: comparison of two different methodologies

“…We assessed for the first time, the suitability of the Neo‐Sensitabs ® tablets assay for testing FLC, VCZ, ITZ, MCZ, TRB and AMB against lipid‐dependent Malassezia species, compared with a broth microdilution method using supplemented medium. A similar study was realised by Yurayart et al ., but only for M. pachydermatis and with no modification of the methodologies used.…”

In vitro antifungal susceptibility of Malassezia furfur from bloodstream infections

“…The susceptibility of Malassezia spp. isolated from the skin of symptomatic and asymptomatic animals and humans has been assessed employing the modified Clinical and Laboratory Standards Institute (CLSI) broth microdilution (BMD) technique, using different media (Jesus et al , 2011; Cafarchia et al , 2012a; Carrillo-Muñoz et al , 2013; Yurayart et al , 2013). Significant variations in MIC ranges have been recorded, depending on the medium used, eventually resulting in erroneous susceptibility classification (Cafarchia et al , 2012a).…”

Effects in dogs with behavioural disorders of a commercial nutraceutical diet on stress and neuroendocrine parameters

“…interferon-γ) release in vitro ( Di Cerbo and others 2015 , Odore and others 2015 , Guidetti and others 2016 ). Thus, the chronic intake of contaminated food is suggested to affect overall homeostasis and possibly induce a chronic inflammatory status in healthy animals, triggering potentially behavioural changes, such as anxiety and depression ( Maier and Watkins 1998 ), dermatological changes, such as itching and erythema ( Noli and others 2015 ), paving the way with depressed immunity for secondary infections, that is, by Malassezia pachydermatis and Candida parapsilosis ( Yurayart and others 2013 ).…”