Sequence-based identification, genotyping and EUCAST antifungal susceptibilities of Trichosporon clinical isolates from Greece
Sequence-based identification, genotyping and EUCAST antifungal susceptibilities of Trichosporon clinical isolates from Greece
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DOI：
10.1111/1469-0691.12501
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发表时间：
2014-08-01
影响因子：
14.2
通讯作者：
Velegraki, A.
中科院分区：
文献类型：
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作者：
Arabatzis, M.;Abel, P.;Velegraki, A.
毛孢酵母构成新兴病原体，涉及器官特异性和全身性感染。本研究首次对希腊Trichosporon临床分离株进行了综合研究，通过对大亚单位（LSU） rDNA基因高变D1/D2结构域的测序鉴定了42株分离株，通过对Intergenic Spacer 1区域的测序进行了基因分型，并采用EDef 7.2 （EUCAST）方法与CLSI标准进行了抗真菌敏感性测定。主要菌种为粗纹毛磷虫（37株），其次为核状毛磷虫、皮炎毛磷虫、鲁比氏毛磷虫和毒霉毛磷虫。一种菌株仍未被确认。记录了7个朝日弓形虫基因型。主要基因型为基因4型（29%）和基因3型（26%），其次为1型、5型和7型（各占9.5%）。鉴定出两个新的基因型，分别为10和11。58%（两性霉素B）、41%（伊曲康唑）、41%（泊沙康唑）和38%（伏立康唑）的EUCAST MIC >= 2 mg/L。23.8%的分离株中氟康唑的mic值为>= 32 mg/L。对绝对值进行方差分析，两性霉素B、伊曲康唑、泊沙康唑和伏立康唑的mic值相等。氟康唑的MIC值通常较高。7个不同基因型的抗真菌敏感性是均匀的。EUCAST与CLSI的协议范围为88.1 - 97.62%。总体而言，在所有试验药物中记录的高mic值证明了对临床分离株进行常规药敏试验的合理性。
Trichosporon yeasts constitute emerging pathogens, implicated in organ-specific and systemic infections. In this first, comprehensive study of Trichosporon clinical isolates in Greece, 42 isolates were identified by sequencing the hypervariable D1/D2 domain of the Large Subunit (LSU) rDNA gene, while Trichosporon asahii were genotyped by sequencing the Intergenic Spacer 1 region, and antifungal susceptibilities were determined by the EDef 7.2 (EUCAST) method, in parallel with the CLSI standard. Trichosporon asahii was the primary species (37 isolates) followed by Trichosporon coremiiforme, Trichosporon dermatis, Trichosporon loubieri and Trichosporon mycotoxinivorans. One strain remained unidentified. Seven T. asahii genotypes were recorded. The major genotypes were: genotypes 4 (29%) and 3 (26%) followed by 1, 5 and 7 (9.5% each). Two novel genotypes were identified designated as 10 and 11. EUCAST MIC >= 2 mg/L was recorded in 58% of the isolates (amphotericin B), 41% (itraconazole), 41% (posaconazole) and 38% (voriconazole). Fluconazole MICs of >= 32 mg/L were recorded in 23.8% of the isolates. Analysis of variance performed on absolute values showed that the amphotericin B, itraconazole, posaconazole and voriconazole MICs of T. asahii were equivalent. Typically higher MIC values were displayed by fluconazole. Antifungal susceptibilities of the seven different genotypes were homogeneous. Agreements between EUCAST and CLSI ranged from 88.1 to 97.62%. Overall, the high MICs recorded among the Trichosporon isolates for all tested drugs justify routine susceptibility testing of clinical isolates.