Department of Mycology Unit, Microbiology and Infection Control, Statens Serum Institut, Copenhagen, Denmark.
Department of Medical Microbiology and Infectious Diseases, Canisius-Wilhelmina Hospital, The Netherlands.
Clin Microbiol Infect. 2016 Jun;22(6):570.e1-9. doi: 10.1016/j.cmi.2016.04.001. Epub 2016 Apr 16.
Azole-resistant Aspergillus fumigatus originating from the environment as well as induced during therapy are continuously emerging in Danish clinical settings. We performed a laboratory-based retrospective study (2010-2014) of azole resistance and genetic relationship of A. fumigatus at the national mycology reference laboratory of Denmark. A total of 1162 clinical and 133 environmental A. fumigatus isolates were identified by morphology, thermotolerance and/or β-tubulin sequencing. Screening for azole resistance was carried out using azole agar, and resistant isolates were susceptibility tested by the EUCAST (European Committee on Antimicrobial Susceptibility Testing) E.Def 9.2 reference method and CYP51A sequenced. Genotyping was performed for outbreak investigation and, when appropriate, short tandem repeat Aspergillus fumigatus microsatellite assay. All 133 environmental A. fumigatus isolates were azole susceptible. However, from 2010 to 2014, there was an increasing prevalence of azole resistance (from 1.4 to 6% isolates (p <0.001) and 1.8 to 4% patients (p <0.05)) among the clinical isolates, with the well-known environmental CYP51A variant TR34/L98H responsible for >50% of the azole resistance mechanisms. Among 184 Danish A. fumigatus isolates, 120 unique genotypes were identified and compared to a collection of 1822 international genotypes. Seven (5.8%) Danish genotypes were shared between isolates within Denmark but with different origin, 19 (15.8%) were shared with foreign genotypes, and two (11.8%) of 17 genotypes of isolates carrying the TR34/L98H resistance mechanisms were identical to two Dutch TR34/L98H isolates. Our findings underlines the demand for correct identification and susceptibility testing of clinical mould isolates. Furthermore, although complex, genotyping supported the hypotheses regarding clonal expansion and the potential of a single origin for the TR34/L98H clone.
在丹麦的临床环境中，不断出现源于环境的以及治疗中诱导产生的唑类耐药烟曲霉。我们在丹麦国家真菌学参考实验室进行了一项基于实验室的回顾性研究（2010-2014 年），研究了烟曲霉的唑类耐药性和遗传关系。通过形态学、热敏性和/或β-微管蛋白测序，共鉴定了 1162 例临床和 133 例环境烟曲霉分离株。采用唑类琼脂进行唑类耐药性筛查，对耐药分离株采用 EUCAST（欧洲抗菌药物敏感性试验委员会）E.Def 9.2 参考方法进行药敏试验，并对 CYP51A 进行测序。进行基因分型以进行暴发调查，并在适当情况下进行短串联重复烟曲霉微卫星分析。所有 133 例环境烟曲霉分离株均对唑类敏感。然而，从 2010 年到 2014 年，临床分离株中唑类耐药的流行率不断上升（从 1.4%至 6%的分离株（p<0.001）和 1.8%至 4%的患者（p<0.05）），其中众所周知的环境 CYP51A 变体 TR34/L98H 负责超过 50%的唑类耐药机制。在 184 株丹麦烟曲霉分离株中，鉴定出 120 种独特的基因型，并与收集的 1822 株国际基因型进行了比较。在丹麦分离株中，7 株（5.8%）相同基因型来自不同来源，19 株（15.8%）与国外基因型相同，携带 TR34/L98H 耐药机制的 17 株分离株中的 2 株（11.8%）与 2 株荷兰 TR34/L98H 分离株相同。我们的研究结果强调了正确鉴定和药敏试验临床霉菌分离株的必要性。此外，尽管复杂，基因分型支持了关于克隆扩张和 TR34/L98H 克隆单一起源的假设。
