普通裂褶菌致肺部感染的实验室诊断研究

Laboratory diagnosis of pulmonary infection caused by common schizophyllum

目的探讨普通裂褶菌(schizophyllumcommune)致肺部感染的实验室诊断方法,为临床诊断提供实验室支持依据。方法 2018年6月,两次收集1名胸闷、气短男性患者肺泡灌洗液进行真菌培养,通过真菌菌落和镜下形态及ITS测序鉴定菌株;用YEAST ONE和FUNG 3进行药敏试验。结果普通裂褶菌用沙保弱培养基和马铃薯培养基在28℃和35℃均生长良好,3~5 d生长白色绒毛样菌落;经乳酸棉酚蓝和真菌荧光染色,镜下均可见菌丝有钉状突起和闭锁联合结构;15~20 d可在培养基见到子实体;ITS测序为普通裂褶菌;体外药敏试验MIC分布为0.25~256 mg/L,伊曲康唑和泊沙康唑MIC值最低(0.25 mg/L),氟康唑MIC值最大(256 mg/L)。结论普通裂褶菌为条件致病菌;临床病例少,易误诊漏诊;需熟悉形态,准确鉴定,正确选药,才能有效诊疗。

Objective To explore a laboratory diagnostic method of pulmonary infection caused by Schizophyllum commune,and to provide a laboratory support for clinical diagnosis and treatment.Methods The alveolar lavage fluid samples were collected twice from a male patient with chest distress and shortness of breath for fungal culture in June 2018.Fungal strains were identified by fungal colony,microscopic morphology and internal transcribed spacer sequencing.The drug sensitivity test was performed with YEAST ONE and FUNG 3.Results The Schizophyllum commune grew well both on Sabouraud dextrose agar and Potato dextrose Agar at 28℃and 35℃,and presented white fluff-like colonies within 3~5 days.Microscopic detection of the fungus(staining with lactophenol-cotton blue solution and Fungi fluorescence solution)showed hyphae with spicules and clamp connections,fruiting bodies were present on PDA after 15-20 days and ITS sequencing showed the fungus was Schizophyllum commune.The minimal inhibitory concentration(MIC)of in vitro susceptibility test was between 0.25 and 256μg/ml,with the lowest MIC of itraconazole and posaconazole of 0.25μg/ml and the highest MIC of Fluconazole of 256μg/ml.Conclusions Schizophyllum commune is a conditional pathogen which is hard to be diagnosed or usually misdiagnosed.It is crucial to be familiar with it′s morphology,accurate identification,and proper drug selection for effective diagnosis and treatment.