Antifungal susceptibility and distribution of Candida spp. isolates from the University Hospital in the municipality of Dourados, State of Mato Grosso do Sul, Brazil

Introduction Hospital infections caused by Candida spp. are a leading cause of morbidity and mortality in hospitalized patients, particularly those that are critically ill or immunocompromised. In this study, the distribution of Candida species in isolates from the University Hospital of the Federal University at Grande Dourados and their in vitro susceptibility to antifungal drugs were analyzed. Methods Yeasts were phenotypically identified using classical methodologies. Antifungal susceptibility tests to amphotericin B and fluconazole were performed using the broth microdilution technique. Results A total of 50 Candida isolates were obtained from hospitalized patients during the study period. We analyzed yeast isolates from urine (n=31; 62%), blood (n=12; 24%), and tracheal secretions (n=7; 14%). The following Candida species were identified: C. tropicalis (n=21; 42%), C. albicans (n=18; 36%), C. glabrata (n=10; 20%), and C. krusei (n=1; 2%). Antifungal susceptibility tests demonstrated that C. albicans was susceptible to both antifungal agents. However, 31.2% of the non-C. albicans Candida isolates displayed dose-dependent susceptibility to fluconazole, and 3.1% were resistant to amphotericin B. Conclusions In contrast to previous reports, our results indicated that C. tropicalis was the most commonly isolated yeast species among the hospital patients. The predominance of non-C. albicans Candida infections confirms the importance of species-level identification for implementing appropriate antifungal therapies.引言 念珠菌属（Candida spp.）引发的医院感染是住院患者，尤其是重症或免疫功能低下人群发病与死亡的首要诱因之一。本研究针对大杜拉多斯联邦大学附属医院分离株中的念珠菌属菌种分布情况，及其对抗真菌药物的体外药敏活性展开分析。 方法 研究采用经典表型鉴定方法对酵母菌进行菌种识别；以肉汤微量稀释法开展两性霉素B（amphotericin B）与氟康唑（fluconazole）的体外药敏试验。 结果 本研究周期内共从住院患者体内分离得到50株念珠菌。本次分析的酵母菌分离株来源分别为尿液（n=31，占比62%）、血液（n=12，占比24%）与气道分泌物（n=7，占比14%）。经鉴定确认的念珠菌属菌种包括：热带念珠菌（C. tropicalis，n=21，占比42%）、白念珠菌（C. albicans，n=18，占比36%）、光滑念珠菌（C. glabrata，n=10，占比20%）以及克柔念珠菌（C. krusei，n=1，占比2%）。药敏试验结果显示，白念珠菌对两种抗真菌药物均敏感；但有31.2%的非白念珠菌分离株对氟康唑呈现剂量依赖性敏感，另有3.1%的分离株对两性霉素B耐药。 结论 与既往研究报道不同，本研究结果显示热带念珠菌是本院住院患者中分离率最高的酵母菌属菌种。非白念珠菌感染的占比优势，证实了开展菌种水平鉴定对制定合理抗真菌治疗方案的重要性。