Clinical Pathology Laboratory, HCI, National Cancer Institute, Rio de Janeiro, Brazil.
Mycology Laboratory, Evandro Chagas National Institute of Infectious Diseases, Oswaldo Cruz Foundation, Rio de Janeiro, Brazil.
Med Mycol. 2021 Mar 4;59(3):235-243. doi: 10.1093/mmy/myaa044.
Bloodstream infections (BSI) caused by Candida species are the fourth cause of healthcare associated infections worldwide. Non-albicans Candida species emerged in the last decades as agents of serious diseases. In this study, clinical and microbiological aspects of six patients with BSI due to the Meyerozyma (Candida) guilliermondii species complex from an oncology reference center in Brazil, were evaluated. To describe demographic and clinical characteristics, medical records of the patients were reviewed. Molecular identification of the isolates was performed by ITS1-5.8S-ITS2 region sequencing. Antifungal susceptibility was evaluated by the EUCAST method and the minimal inhibitory concentrations (MIC) assessed according to the epidemiological cutoff values. Virulence associated phenotypes of the isolates were also studied. Ten isolates from the six patients were evaluated. Five of them were identified as Meyerozyma guilliermondii and the others as Meyerozyma caribbica. One patient was infected with two M. caribbica isolates with different genetic backgrounds. High MICs were observed for fluconazole and echinocandins. Non-wild type isolates to voriconazole appeared in one patient previously treated with this azole. Additionally, two patients survived, despite infected with non-wild type strains for fluconazole and treated with this drug. All isolates produced hemolysin, which was not associated with a poor prognosis, and none produced phospholipases. Aspartic proteases, phytase, and esterase were detected in a few isolates. This study shows the reduced antifungal susceptibility and a variable production of virulence-related enzymes by Meyerozyma spp. In addition, it highlights the poor prognosis of neutropenic patients with BSI caused by this emerging species complex.
Our manuscript describes demographic, clinical and microbiological characteristics of patients with bloodstream infection by the Meyerozyma guilliermondii species complex at a reference center in oncology in Brazil.
血液感染（BSI）由念珠菌引起，是全球第四大与医疗保健相关的感染原因。非白念珠菌属念珠菌在过去几十年中成为严重疾病的病原体。在这项研究中，我们评估了巴西一家肿瘤学参考中心的六例由梅耶罗酵母（念珠菌）属复合体引起的 BSI 患者的临床和微生物学方面。为了描述人口统计学和临床特征，我们回顾了患者的病历。通过 ITS1-5.8S-ITS2 区域测序对分离株进行分子鉴定。采用 EUCAST 方法评估抗真菌药敏性，并根据流行病学截断值评估最小抑菌浓度（MIC）。还研究了分离株的毒力相关表型。从六名患者的十个分离株进行了评估。其中五个被鉴定为梅耶罗酵母属，其他五个被鉴定为梅耶罗酵母属。一名患者感染了两个遗传背景不同的梅耶罗酵母属。氟康唑和棘白菌素的 MIC 值较高。一名先前用唑类药物治疗的患者出现了对伏立康唑的非野生型分离株。此外，尽管两名患者感染了氟康唑的非野生型菌株并接受了该药物治疗，但仍存活下来。所有分离株均产生溶血素，但与不良预后无关，且均不产生磷脂酶。在少数分离株中检测到天冬氨酸蛋白酶、植酸酶和酯酶。本研究表明，梅耶罗酵母属的抗真菌药物敏感性降低，且与毒力相关的酶的产生存在差异。此外，它强调了中性粒细胞减少症患者由这种新兴的种复合体引起的 BSI 的预后较差。
