Background: Oral candidiasis (OC) has a profound effect on the life quality of immunocompromised patients, such as those undergoing chemotherapy. Objective: Systematic investigation of clinical outcome and microbiological features of yeast isolates recovered from the oral cavity of 150 Iranian patients with hematological malignancies. Design: MALDI-TOF MS, 21-plex PCR, and rDNA sequencing were used for identification. Antifungal susceptibility testing (broth microdilution, CLSI M27-A3/S4) and genotypic diversity of yeast isolates (amplified fragment length polymorphism) were assessed. Results: Nystatin treatment resulted in 70% therapeutic failure and administration of 150 mg fluconazole (FLZ) + nystatin for patients with OC relapse showed 70% clinical failure. Previous history of OC was significantly correlated with FLZ treatment requirement and nystatin failure (P = 0.005, α < 0.05). Candida albicans (80.3%) and Kluyveromyces marxianus (C. kefyr) (12.7%) were the two most prevalent yeast species isolated. FLZ and AMB exhibited the highest geometric mean values. 21-PCR showed 98.9% agreement with MALDI-TOF MS. K. marxianus isolates had the same genotype, while C. albicans isolates grouped in 15 genotypes. Conclusions: Marked rate of therapeutic failure of nystatin necessitated OC treatment with systemic antifungals. K. marxianus was the second most prevalent yeast and 21-plex PCR could be considered as an inexpensive identification tool.

背景： 口腔念珠菌病（OC）对免疫功能低下的患者（例如正在接受化疗的患者）的生活质量产生深远影响。目的： 对150例伊朗血液系统恶性肿瘤患者口腔中分离的酵母分离物的临床结果和微生物学特征进行系统研究。设计：  MALDI-TOF MS，21重PCR和rDNA测序用于鉴定。评估了抗真菌药敏试验（肉汤微稀释，CLSI M27-A3 / S4）和酵母分离株的基因型多样性（扩增的片段长度多态性）。结果： 制霉菌素治疗导致70％的治疗失败，而OC复发患者给予150 mg氟康唑（FLZ）+制霉菌素则显示70％的临床失败。先前的OC史与FLZ治疗需求和制霉菌素失败显着相关（P  = 0.005，α<0.05）。 白色念珠菌 （80.3％）和 马克斯克鲁维酵母 （C. kefyr）（12.7％）是分离的两个最普遍的酵母菌种。FLZ和AMB的几何平均值最高。21-PCR显示与MALDI-TOF MS的98.9％一致性。 马克斯克鲁维酵母 分离株具有相同的基因型，而 白色念珠菌 分离株分为15个基因型。结论： 制霉菌素的治疗失败率显着升高，因此必须使用全身性抗真菌剂进行OC治疗。 马克斯克鲁维 酵母是第二流行的酵母菌，21-plex PCR可以被认为是一种廉价的鉴定工具。