Colombo Alberto, Maccari Giuseppe, Congiu Terenzio, Basso Petra, Baj Andreina, Toniolo Antonio
Laboratory of Medical Microbiology, Department of Clinical and Experimental Medicine, University of Insubria and Ospedale di Circolo e Fondazione Macchi, 21100 Varese, Italy.
Case Rep Med. 2013;2013:618358. doi: 10.1155/2013/618358. Epub 2013 Jul 2.
The incidence of opportunistic infections by filamentous fungi is increasing partly due to the widespread use of central venous catheters (CVC), indwelling medical devices, and antineoplastic/immunosuppressive drugs. The case of a 13-year-old boy under treatment for acute lymphoblastic leukemia is presented. The boy was readmitted to the Pediatric Ward for intermittent fever of unknown origin. Results of blood cultures drawn from peripheral venous sites or through the CVC were compared. CVC-derived bottles (but not those from peripheral veins) yielded hyaline fungi that, based on morphology, were identified as belonging to the Fusarium solani species complex. Gene amplification and direct sequencing of the fungal ITS1 rRNA region and the EF-1alpha gene confirmed the isolate as belonging to the Fusarium solani species complex. Portions of the CVC were analyzed by scanning electron microscopy. Fungi mycelia with long protruding hyphae were seen into the lumen. The firm adhesion of the fungal formation to the inner surface of the catheter was evident. In the absence of systemic infection, catheter removal and prophylactic voriconazole therapy were followed by disappearance of febrile events and recovery. Thus, indwelling catheters are prone to contamination by environmental fungi.
丝状真菌引起的机会性感染发病率正在上升，部分原因是中心静脉导管（CVC）、植入式医疗设备以及抗肿瘤/免疫抑制药物的广泛使用。本文介绍了一名正在接受急性淋巴细胞白血病治疗的13岁男孩的病例。该男孩因不明原因的间歇性发热再次入住儿科病房。比较了从外周静脉部位或通过CVC采集的血培养结果。来自CVC的培养瓶（而非外周静脉的培养瓶）培养出了透明真菌，根据形态学鉴定为茄病镰刀菌复合种。对真菌ITS1 rRNA区域和EF-1α基因进行基因扩增和直接测序，证实分离株属于茄病镰刀菌复合种。通过扫描电子显微镜对CVC的部分进行了分析。在管腔内可见带有长突出菌丝的真菌菌丝体。真菌结构与导管内表面紧密粘连明显。在没有全身感染的情况下，拔除导管并进行预防性伏立康唑治疗后，发热事件消失且患儿康复。因此，植入式导管容易受到环境真菌的污染。
