Watanabe Naoki, Ohkusu Kiyofumi, Okuda Masaya, Imataki Osamu, Ishii Tomoya, Negayama Kiyoshi, Tadokoro Akira, Kita Nobuyuki, Takagi Takehiro, Kanaji Nobuhiro, Kadowaki Norimitsu, Bandoh Shuji
Department of Internal Medicine, Hematology, Rheumatology and Respiratory Medicine, Faculty of Medicine, Kagawa University, 1750-1 Ikenobe, Miki-cho, Kita-gun, Kagawa, 761-0793, Japan.
Department of Microbiology, Tokyo Medical University, 6-1-1 Shinjuku, Shinjuku-ku, Tokyo, 160-8402, Japan.
BMC Infect Dis. 2017 Feb 10;17(1):135. doi: 10.1186/s12879-017-2244-9.
Phanerochaete sordida is a species of wood rotting fungus, which can degrade lignin, cellulose and hemicellulose contained in wood and other hard-to-biodegrade organic substances. However, to date, there have been no other reports demonstrating that P. sordida can infect humans.
A 66-year-old Japanese man presented for a mass increasing in size on his left thigh. He had been suffering from rheumatoid arthritis for 18 years and chronic obstructive pulmonary disease for 20 years, for which he was being treated with 5 mg/day prednisolone and 8 mg/week methotrexate. The mass resection was performed two months later, and was diagnosed as malignant fibrous histiocytosis. However, a computed tomography examination for tumor recurrence after surgery showed a newly emergent pulmonary nodule. We therefore decided to resect the nodule by thoracoscopic procedure. Histopathological examination of the excised specimen showed that the lesion was a granuloma, with necrotic tissue and clumping of Aspergillus-like hyphae. Therefore, the nodule was diagnosed as a fungal infection and tissue specimens were cultured microbiologically. However, fungal growth was not observed. We consequently performed genetic analysis using a broad-range polymerase chain reaction. The 28S rRNA sequence demonstrated 100% homology with P. sordida using the NCBI BLAST program against the GenBank DNA databases.
Using broad-range polymerase chain reaction, we identified P. sordida as the causative agent of a pulmonary nodule. These findings indicate that P. sordida may be an additional opportunistic causative organism of pulmonary infection in immunocompromised patients.
污色原毛平革菌是一种木材腐朽真菌，能够降解木材中所含的木质素、纤维素和半纤维素以及其他难以生物降解的有机物质。然而，迄今为止，尚无其他报告表明污色原毛平革菌可感染人类。
一名66岁的日本男性因左大腿肿物增大前来就诊。他患类风湿关节炎18年，慢性阻塞性肺疾病20年，正在接受每日5毫克泼尼松龙和每周8毫克甲氨蝶呤的治疗。两个月后进行了肿物切除术，诊断为恶性纤维组织细胞瘤。然而，术后计算机断层扫描检查肿瘤复发情况时发现了一个新出现的肺结节。因此，我们决定通过胸腔镜手术切除该结节。对切除标本进行组织病理学检查显示，病变为肉芽肿，伴有坏死组织和类似曲霉菌丝的聚集。因此，该结节被诊断为真菌感染，并对组织标本进行了微生物培养。然而，未观察到真菌生长。于是，我们使用广谱聚合酶链反应进行了基因分析。使用NCBI BLAST程序在GenBank DNA数据库中进行比对，28S rRNA序列显示与污色原毛平革菌有100%的同源性。
通过广谱聚合酶链反应，我们鉴定出污色原毛平革菌是肺结节的病原体。这些发现表明，污色原毛平革菌可能是免疫功能低下患者肺部感染的另一种机会致病菌。
