Comparative study of Candida spp. isolates: Identification and echinocandin susceptibility in isolates obtained from blood cultures in 15 hospitals in Medellin, Colombia
Comparative study of Candida spp. isolates: Identification and echinocandin susceptibility in isolates obtained from blood cultures in 15 hospitals in Medellin, Colombia
复制标题
DOI：
10.1016/j.jgar.2017.11.010
复制
发表时间：
2018-06-01
影响因子：
4.6
通讯作者：
Robledo, Jaime
中科院分区：
文献类型：
--
作者：
Berrio, Indira;Maldonado, Natalia;Robledo, Jaime
目的：侵袭性念珠菌病对住院患者的发病率和死亡率有很高的影响。准确和及时的念珠菌属鉴定方法。方法：采用基质辅助激光解吸电离飞行时间质谱法（MALDI-TOF/MS）对147株念珠菌进行鉴定，并与rRNA基因复合体28亚基D1/D2区序列测定进行比较。从念珠菌血症患者获得的分离物。采用微量肉汤稀释法（BMD）和Etest进行药敏试验。结果：分离出的念珠菌以白色念珠菌最多（40.8%），其次为近平滑念珠菌（23.1%）和热带念珠菌（17.0%）。MALDI-TOF/MS鉴定结果与分子鉴定结果的总体符合率为99.3%。BMD法测定阿尼芬净和卡泊芬净的敏感性分别为98.0%和88.4%。Etest对阿尼芬净和卡泊芬净的敏感率分别为93.9%和98.6%。Etest和BMD之间的分类一致性，阿尼芬净为91.8%，卡泊芬净为89.8%，C.阿尼芬净（76.5%）和C.光滑型卡泊芬净（40.0%）。未发现与耐药相关的突变，在FKS基因，虽然54株呈现同义多态性的热点sequenced.Conclusions：MALDI-TOF/MS是一个很好的替代念珠菌属的常规鉴定。分离株FKS基因的DNA测序表明，分析的菌株对棘白菌素敏感;或者，未知的耐药机制或与抗真菌药敏试验相关的限制可能解释了在少数菌株中发现的耐药性。(C)2017年国际感染和癌症化疗学会。由爱思唯尔有限公司出版。保留所有权利。
Objectives: Invasive candidiasis has a high impact on morbidity and mortality in hospitalised patients. Accurate and timely methods for identification of Candida spp. and determination of echinocandin susceptibility have become a priority for clinical microbiology laboratories.Methods: This study was performed to compare matrix-assisted laser desorption/ionisation time-offlight mass spectrometry (MALDI-TOF/MS) identification with sequencing of the D1/D2 region of the rRNA gene complex 28 subunit in 147 Candida spp. isolates obtained from patients with candidaemia. Antimicrobial susceptibility testing was performed by broth microdilution (BMD) and Etest. Sequencing of the FKSI and FKS2 genes was performed.Results: The most common species isolated were Candida albicans (40.8%), followed by Candida parapsilosis (23.1%) and Candida tropicalis (17.0%). Overall agreement between the results of identification by MALDI-TOF/MS and molecular identification was 99.3%. Anidulafungin and caspofungin susceptibility by the BMD method was 98.0% and 88.4%, respectively. Susceptibility to anidulafungin and caspofungin by Etest was 93.9% and 98.6%, respectively. Categorical agreement between Etest and BMD was 91.8% for anidulafungin and 89.8% for caspofungin, with lower agreements in C. parapsilosis for anidulafungin (76.5%) and C. glabrata for caspofungin (40.0%). No mutations related to resistance were found in the FKS genes, although 54 isolates presented synonymous polymorphisms in the hotspots sequenced.Conclusions: MALDI-TOF/MS is a good alternative for routine identification of Candida spp. isolates. DNA sequencing of the FKS genes suggested that the isolates analysed were susceptible to echinocandins; alternatively, unknown resistance mechanisms or limitations related to antifungal susceptibility tests may explain the resistance found in a few isolates. (C) 2017 International Society for Chemotherapy of Infection and Cancer. Published by Elsevier Ltd. All rights reserved.