阅读方式:

Screening for drug-resistant Candida yeasts with chromogenic agar.
以产色琼脂筛选耐药念珠菌属酵母菌

出处: Med Mycol   2010   Jan  

作者:Kirkpatrick WR;Zimmerman JD;Haikal FP;Broker MJ;Brockway E;Fothergill AW;McCarthy DI;Patterson TF;Redding SW

PMID:20109095

We examined the utility of agar dilution to screen yeasts for reduced susceptibility to several newer antifungal drugs including echinocandins and azoles. We compared agar dilution susceptibility screening with the Clinical and Laboratory Standards Institute (CLSI) method for Candida isolates. We added echinocandins and azoles to CHROMagar Candida medium prior to its solidification. Assessment of resistance was based on growth characteristics, wherein decreased colony size in the presence of antifungal drugs was used as an indicator of susceptibility. Clinical Candida isolates of C. albicans, C. glabrata, C. parapsilosis, C. tropicalis, C. guilliermondii, C. lusitaniae, C. rugosa and C. dubliniensis were screened for drug susceptibility. Overall, antifungal susceptibility of the yeasts to anidulafungin, caspofungin, micafungin, posaconazole and voriconazole, determined using CHROMagar agar dilution, were shown to be 96, 80, 94, 90 and 97% as accurate, respectively, as those determined by the CLSI method, i.e., within one tube dilution of CLSI MICs. Categorical errors by percentage had a broader range. Major errors noted with anidulafungin, caspofungin and micafungin were 3, 6 and 0%, respectively, while very major errors were 15, 55 and 38%, respectively. Major errors with posaconazole and voriconazole were 12 and 0%, respectively, while very major errors were 0 and 22%, respectively, compared to CLSI standards. Most of the assessment errors were found with C. glabrata and C. parapsilosis. Agar dilution screening for drug susceptibility with the current panel of antifungal drugs is rapid, accurate and effective. However, the determination of resistance or non-susceptibility in yeasts may be more problematic, and may be species dependent.

我们研究了琼脂稀释法筛选对多种新型抗真菌药物包括棘白菌素和唑类敏感性降低酵母菌的实用性。我们比较了念珠菌株的琼脂稀释法药物敏感性筛查和临床实验室标准化研究所(CLSI)法。在显色琼脂固化之前,向显色琼脂念珠菌培基中加入棘白菌素和唑类。耐药性的评估基于生长特性,抗真菌药物存在时菌落大小缩小被视为敏感性的指标。筛查了临床分离的白色念珠菌、平滑念珠菌、近平滑念珠菌、热带念珠菌、季也蒙念珠菌、葡萄牙念珠菌、皱褶念珠菌和杜氏假丝酵母菌株的药物敏感性。总体而言,使用显色琼脂稀释法,酵母菌对阿尼芬净、卡泊芬净、米卡芬净、泊沙康唑和伏立康唑的抗真菌敏感性分别为96,80,94,90和97%,其准确性与CLSI法测定即CLSI MIC试管稀释法一致。分类错误的百分比范围较广。阿尼芬净、卡泊芬净和米卡芬净的主要错误分别为3,6和0%,非常重大错误率分别为15,55和38%。与CLSI标准相比,泊沙康唑和伏立康唑的主要错误分别为12和0%,而非常重大错误分别为0和22%。大多数评估错误见于光滑念珠菌和近平滑念珠菌。琼脂稀释法对于筛查当前抗真菌药物敏感性是快速、准确、有效的。然而,测定耐药或不敏感的酵母菌可能更有问题,这可能与真菌菌种有关。