Departamento de Análises Clínicas e Toxicológicas, Faculdade de Farmácia, Universidade Federal de Minas Gerais, Brazil.
Microbiology, Genetics, and Immunology, Biomedical Laboratory Diagnostics, Michigan State University, East Lansing, Michigan, United States of America.
PLoS Negl Trop Dis. 2024 Nov 4;18(11):e0012602. doi: 10.1371/journal.pntd.0012602. eCollection 2024 Nov.
The genus Prototheca (alga) comprises a unique group of achlorophyllic saprotrophic and mammalian pathogen species. Despite its rare occurrence in humans and animals, protothecosis is considered an emerging clinical entity with relevance in immunocompromised patients. In this study, the characterization of spherical structures with endospores recovered from a blood culture in an HIV patient was investigated using phenotypic and molecular methodologies. On 2% Sabouraud dextrose agar, the isolate displayed morphological and biochemical characteristics found on isolates identified as Prototheca wickerhamii. To validate these analyses, molecular phylogeny of the internal transcript space (ITS) partial gene confirmed the identity of the isolate as P. wickerhamii. This is the first case of systemic human protothecosis in Brazil. The present case of human Prototheca and those reported in the medical literature highlight the need for novel methodologies to identify pathogenic algae in the clinical laboratory, improving in this way the diagnosis and treatment of this group of neglected pathogens.
原核生物属（藻类）包括一组独特的非叶绿素腐生和哺乳动物病原体物种。尽管原核生物在人类和动物中很少发生，但它被认为是一种具有免疫功能低下患者相关性的新兴临床实体。在这项研究中，使用表型和分子方法研究了从 HIV 患者血液培养物中回收的具有内生孢子的球形结构的特征。在 2%的沙氏葡萄糖琼脂上，该分离株显示出与鉴定为粘质沙雷氏菌的分离株相同的形态学和生化特征。为了验证这些分析，内部转录间隔区（ITS）部分基因的分子系统发育证实了该分离株为粘质沙雷氏菌。这是巴西首例系统性人类原核生物病。本病例的人类原核生物和文献中的报道突出表明需要在临床实验室中使用新的方法来鉴定致病性藻类，从而改善对这群被忽视的病原体的诊断和治疗。
