Brito Erika H S, Fontenelle Raquel O S, Brilhante Raimunda S N, Cordeiro Rossana A, Soares Júnior Franciso A, Monteiro André J, Sidrim José J C, Rocha Marcos F G
Veterinary Faculty, Post-Graduation Program in Veterinary Science, State University of Ceará, Fortaleza-CE, Brazil.
Vet J. 2007 Jul;174(1):147-53. doi: 10.1016/j.tvjl.2006.05.021. Epub 2006 Dec 22.
Yeasts of the genera Candida and Malassezia can be found as commensal microorganisms in animals. The main species of importance in veterinary medicine are Malassezia pachydermatis and Candida albicans. The objectives of this study were to conduct a phenotypic characterization and to evaluate the in vitro antifungal sensitivity of strains of C. albicans (n=5), C. tropicalis (n=3) and M. pachydermatis (n=32) isolated from dogs. The phenotyping was based on macro and micromorphological features as well as biochemical analysis. The techniques of microdilution in broth and dilution in agar were used to evaluate the in vitro sensitivity of Candida spp. and M. pachydermatis, respectively. The tested drugs were ketoconazole (KTC), itraconazole (ITC), fluconazole (FLC) and amphotericin B (AMB). The morphological analysis of the strains of Candida spp. and M. pachydermatis did not show any noteworthy alterations when compared to standard strains. On the other hand, in the biochemical tests, 34.4% of the strains of M. pachydermatis were negative for the urease test. Four strains of C. albicans were resistant to FLC with a minimum inhibitory concentration (MIC) >64microg/mL and all were resistant to KTC and ITC (MIC>16microg/mL). The MIC for two strains of C. tropicalis were >16microg/mL for KTC and ITC, and >64microg/mL for FLC. It is worth highlighting that all of the strains tested were sensitive to AMB with the MIC varying from 0.25-1.0microg/mL. All strains of M. pachydermatis were sensitive to ITC with a minimum fungistatic concentration (MFC) 0.0075microg/mL. The MIC for 29 strains was the same (MFC0.0075microg/mL) for KTC. The MFCs for FLC varied from 1 to 16microg/mL, and for AMB, the MFC interval was 0.125-8microg/mL. There were no alterations in the classic phenotypic features of the strains of Candida spp. and M. pachydermatis isolated from dogs but, unlike M. pachydermatis, Candida spp. were much more resistant to azole antifungal agents.
念珠菌属和马拉色菌属的酵母可作为动物体内的共生微生物被发现。兽医学中重要的主要菌种是厚皮马拉色菌和白色念珠菌。本研究的目的是对从犬类分离出的白色念珠菌（n = 5）、热带念珠菌（n = 3）和厚皮马拉色菌（n = 32）菌株进行表型特征分析，并评估其体外抗真菌敏感性。表型分析基于宏观和微观形态特征以及生化分析。分别采用肉汤微量稀释法和琼脂稀释法评估念珠菌属和厚皮马拉色菌的体外敏感性。所测试的药物为酮康唑（KTC）、伊曲康唑（ITC）、氟康唑（FLC）和两性霉素B（AMB）。与标准菌株相比，念珠菌属和厚皮马拉色菌菌株的形态分析未显示任何值得注意的变化。另一方面，在生化试验中，34.4%的厚皮马拉色菌菌株脲酶试验呈阴性。四株白色念珠菌对氟康唑耐药，最低抑菌浓度（MIC）>64μg/mL，且均对酮康唑和伊曲康唑耐药（MIC>16μg/mL）。两株热带念珠菌对酮康唑和伊曲康唑的MIC>16μg/mL，对氟康唑的MIC>64μg/mL。值得强调的是，所有测试菌株对两性霉素B敏感，MIC在0.25 - 1.0μg/mL之间。所有厚皮马拉色菌菌株对伊曲康唑敏感，最低抑菌浓度（MFC）为0.0075μg/mL。29株菌株对酮康唑的MIC相同（MFC 0.0075μg/mL）。氟康唑的MFC在1至16μg/mL之间，两性霉素B的MFC区间为0.125 - 8μg/mL。从犬类分离出的念珠菌属和厚皮马拉色菌菌株的经典表型特征没有变化，但与厚皮马拉色菌不同，念珠菌属对唑类抗真菌药物的耐药性更强。
