Special Mycology Laboratory, Division of Infectious Diseases, Department of Medicine, Universidade Federal de São Paulo (UNIFESP), São Paulo, SP, Brazil.
Hospital do Rim, Fundação Oswaldo Ramos, São Paulo, SP, Brazil.
Mycoses. 2018 Nov;61(11):845-852. doi: 10.1111/myc.12823. Epub 2018 Jul 27.
Pneumocystis jirovecii can cause severe potentially life-threatening pneumonia (PCP) in kidney transplant patients. Prophylaxis of patients against PCP in this setting is usually performed during 6 months after transplantation. The aim of this study is to describe the molecular epidemiology of a cluster of PCP in renal transplant recipients in Brazil. Renal transplant patients who developed PCP between May and December 2011 had their formalin-fixed paraffin-embedded (FFPE) lung biopsy samples analysed. Pneumocystis jirovecii 23S mitochondrial large subunit of ribosomal RNA (23S mtLSU-rRNA), 26S rRNA, and dihydropteroate synthase (DHPS) genes were amplified by polymerase chain reaction (PCR), sequenced, and analysed for genetic variation. During the study period, 17 patients developed PCP (only four infections were documented within the first year after transplantation) and six (35.3%) died. Thirty FFPE samples from 11 patients, including one external control HIV-infected patient, had fungal DNA successfully extracted for further amplification and sequencing for all three genes. A total of five genotypes were identified among the 10 infected patients. Of note, four patients were infected by more than one genotype and seven patients were infected by the same genotype. DNA extracted from FFPE samples can be used for genotyping; this approach allowed us to demonstrate that multiple P. jirovecii strains were responsible for this cluster, and one genotype was found infecting seven patients. The knowledge of the causative agents of PCP may help to develop new initiatives for control and prevention of PCP among patients undergoing renal transplant and improve routine PCP prophylaxis.
肺孢子菌可引起接受肾移植患者的严重、潜在致命性肺炎（PCP）。在此情况下，患者在移植后 6 个月内通常会接受预防肺孢子菌感染的治疗。本研究旨在描述巴西肾移植受者中肺孢子菌感染聚集的分子流行病学情况。对 2011 年 5 月至 12 月期间发生 PCP 的肾移植患者进行了福尔马林固定石蜡包埋（FFPE）肺活检样本分析。通过聚合酶链反应（PCR）扩增了肺孢子菌 23S 线粒体核糖体 RNA 大亚基（23S mtLSU-rRNA）、26S rRNA 和二氢叶酸合成酶（DHPS）基因，对其进行测序，并分析遗传变异。研究期间，17 名患者发生了 PCP（仅有 4 例感染发生在移植后 1 年内），其中 6 人（35.3%）死亡。11 名患者的 30 份 FFPE 样本（包括 1 名外部对照 HIV 感染者）成功提取了真菌 DNA，可进一步用于所有 3 个基因的扩增和测序。在 10 名感染患者中，共鉴定出 5 种基因型。值得注意的是，有 4 名患者被一种以上的基因型感染，7 名患者被同一种基因型感染。从 FFPE 样本中提取的 DNA 可用于基因分型；这种方法使我们能够证明有多种肺孢子菌菌株导致了此次聚集性感染，并且有一种基因型感染了 7 名患者。了解 PCP 的病原体有助于为肾移植患者制定新的 PCP 控制和预防措施，并改善常规 PCP 预防。
