Antifungal susceptibility profile of diferent yeasts isolates from wild animals, cow’s milk with subclinical mastitis and hospital environment

Abstract Yeast infections have acquired great importance due to increasing frequency in immunocompromised patients or patients undergoing invasive diagnostic and therapeutic techniques, and also because of its high morbidity and mortality. At the same time, it has been seen an increase in the emergence of new pathogenic species difficult to diagnose and treat. The aim of this study was to determine the in vitro susceptibility of 89 yeasts from different sources against the antifungals amphotericin B, voriconazole, fluconazole and flucytosine, using the VITEK® 2 Compact system. The antifungal susceptibility was performed automatically by the Vitek® 2 Compact system. The origin of the yeasts was: Group 1 - microbiota of wild animals (W) (26/89), 2 - cow’s milk with subclinical mastitis (M) (27/89) and 3 - hospital enviorment (H) (36/89). Of the 89 yeasts submitted to the Vitek® 2 test, 25 (20.9%) were resistant to fluconazole, 11 (12.36%) to amphotericin B, 3 (3.37%) to voriconazole, and no sample was resistant to flucytosine. Regarding the minimum inhibitory concentration (MIC), fluconazole showed an MIC between 1 and 64 mg/mL for the three groups, voriconazole had an MIC between 0.12 and 8 mg/mL, amphotericin B had an MIC between 0.25 and 4 mg/mL for group H and group W respectively, between 0.25 and 16 mg/mL for group M and flucytosine had an MIC equal to 1μg/mL for all groups. The yeasts isolated from the H group showed the highest resistance to fluconazole 12/89 (13.49%), followed by group W (7.87%) and group M (5.62%). The more resistant group to voriconazole was followed by the M and H groups, the W group showed no resistance to this antifungal. Group H was the least resistant (2.25%) to amphotericin.

摘要 酵母菌感染因免疫功能低下患者、接受侵入性诊断与治疗操作的患者群体中发病率持续升高，且该类感染具有较高的发病率与死亡率，其临床重要性日益凸显。与此同时，难以诊断与治疗的新型致病酵母菌菌株的检出率亦呈上升趋势。本研究旨在借助VITEK® 2 Compact全自动微生物药敏系统，测定89株不同来源酵母菌对两性霉素B (amphotericin B)、伏立康唑 (voriconazole)、氟康唑 (fluconazole) 及氟胞嘧啶 (flucytosine) 的体外药敏活性。本次药敏试验由VITEK® 2 Compact系统全自动完成。本次研究纳入的89株酵母菌来源如下：第1组为野生动物菌群（W组，26/89），第2组为患有亚临床乳腺炎的牛乳样本（M组，27/89），第3组为医院环境样本（H组，36/89）。经VITEK® 2系统检测的89株酵母菌中，25株（20.9%）对氟康唑耐药，11株（12.36%）对两性霉素B耐药，3株（3.37%）对伏立康唑耐药，未检出对氟胞嘧啶耐药的菌株。关于最低抑菌浓度 (MIC)：氟康唑在三组样本中的MIC值范围为1~64 mg/mL；伏立康唑的MIC值范围为0.12~8 mg/mL；两性霉素B的MIC值在H组与W组中为0.25~4 mg/mL，在M组中为0.25~16 mg/mL；氟胞嘧啶在所有组别中的MIC值均为1μg/mL。从H组分离得到的酵母菌对氟康唑的耐药率最高，为12/89（13.49%），其次为W组（7.87%）与M组（5.62%）。对伏立康唑耐药性最高的组别为M组，其次为H组，W组未检出对该抗真菌药物的耐药菌株。H组对两性霉素B的耐药率最低，为2.25%。