基于 Cyp51A PCR 扩增子熔解曲线分析检测唑类敏感和唑类耐药烟曲霉混合感染。
Detection of azole-susceptible and azole-resistant Aspergillus coinfection by cyp51A PCR amplicon melting curve analysis.
机构信息
Department of Internal Medicine, Section of Infectious Diseases, Erasmus University Medical Center, Rotterdam, The Netherlands.
Department of Medical Microbiology, Erasmus University Medical Center, Rotterdam, The Netherlands.
出版信息
J Antimicrob Chemother. 2017 Nov 1;72(11):3047-3050. doi: 10.1093/jac/dkx262.
BACKGROUND
The AsperGenius® assay is a multiplex real-time PCR test that allows the simultaneous detection of Aspergillus species and identification of the most common mutations in the Aspergillus fumigatus cyp51A gene conferring resistance (TR34/L98H and TR46/T289A/Y121F) by using melting curve analysis. Mixed infections with azole-resistant and susceptible A. fumigatus have rarely been described.
METHODS
The AsperGenius® multiplex real-time PCR assay (PathoNostics, Maastricht, the Netherlands) was used on bronchoalveolar lavage (BAL) samples of 91 consecutive patients with a suspected invasive Aspergillus infection at the Erasmus MC University Medical Center, Rotterdam.
RESULTS
In three cases the AsperGenius® assay indicated the simultaneous presence of WT and mutant genes (two patients with TR34/L98H mutation and one patient with TR46/T289A/Y121F mutation) and therefore mixed infections with azole-susceptible and -resistant isolates. In one of the three cases, the mixed infection was confirmed by phenotypic antifungal testing of multiple A. fumigatus colonies.
CONCLUSIONS
The use of a dedicated A. fumigatus cyp51A resistance PCR allowed the detection of mixed infections with azole-resistant and -susceptible Aspergillus strains. These mixed infections may remain undiagnosed with conventional phenotypic susceptibility testing.
背景
AsperGenius® 检测是一种多重实时 PCR 检测方法，通过熔解曲线分析，可同时检测曲霉菌属物种，并鉴定最常见的烟曲霉 Cyp51A 基因突变（TR34/L98H 和 TR46/T289A/Y121F），从而确定对唑类药物的耐药性。唑类药物耐药和敏感的烟曲霉混合感染很少有报道。
方法
在鹿特丹伊拉斯谟医学中心，对 91 例疑似侵袭性曲霉菌感染的患者的支气管肺泡灌洗液（BAL）样本，使用了 AsperGenius® 多重实时 PCR 检测法（PathoNostics，马斯特里赫特，荷兰）。
结果
在三种情况下，AsperGenius® 检测法同时显示 WT 和突变基因的存在（两例患者携带 TR34/L98H 突变，一例患者携带 TR46/T289A/Y121F 突变），因此存在唑类药物敏感和耐药分离株的混合感染。在这三种情况中的一种，通过对多个烟曲霉菌落进行表型抗真菌药敏试验，证实了混合感染。
结论
使用专门的烟曲霉 Cyp51A 耐药 PCR 可检测到唑类药物耐药和敏感的烟曲霉菌株的混合感染。这些混合感染可能无法通过传统的表型药敏试验检测出来。
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