Mulet-Bayona Juan Vicente, Cancino-Muñoz Irving, Salvador-García Carme, Tormo-Palop Nuria, Guna-Serrano María Del Remedio, Ferrer-Gómez Carolina, Melero-García Mercedes, González-Candelas Fernando, Gimeno-Cardona Concepción
Servicio de Microbiología y Parasitología, Consorcio Hospital General Universitario de Valencia, Valencia, Spain.
Unidad Mixta Infección y Salud Pública FISABIO-Universidad de Valencia, Valencia, Spain.
Mycoses. 2024 Aug;67(8):e13776. doi: 10.1111/myc.13776.
The investigation of Candida auris outbreaks is needed to provide insights into its population structure and transmission dynamics. We genotypically and phenotypically characterised a C. auris nosocomial outbreak occurred in Consorcio Hospital General Universitario de Valencia (CHGUV), Spain.
Data and isolates were collected from CHGUV from September 2017 (first case) until September 2021. Thirty-five isolates, including one from an environmental source, were randomly selected for whole genome sequencing (WGS), and the genomes were analysed along with a database with 335 publicly available genomes, assigning them to one of the five major clades. In order to identify polymorphisms associated with drug resistance, we used the fully susceptible GCA_003014415.1 strain as reference sequence. Known mutations in genes ERG11 and FKS1 conferring resistance to fluconazole and echinocandins, respectively, were investigated. Isolates were classified into aggregating or non-aggregating.
All isolates belonged to clade III and were from an outbreak with a single origin. They clustered close to three publicly available genomes from a hospital from where the first patient was transferred, being the probable origin. The mutation VF125AL in the ERG11 gene, conferring resistance to fluconazole, was present in all the isolates and one isolate also carried the mutation S639Y in the FKS1 gene. All the isolates had a non-aggregating phenotype (potentially more virulent).
Isolates are genotypically related and phenotypically identical but one with resistance to echinocandins, which seems to indicate that they all belong to an outbreak originated from a single isolate, remaining largely invariable over the years. This result stresses the importance of implementing infection control practices as soon as the first case is detected or when a patient is transferred from a setting with known cases.
对耳念珠菌暴发进行调查，以深入了解其种群结构和传播动态。我们对西班牙巴伦西亚大学综合医院（CHGUV）发生的一起耳念珠菌医院感染暴发进行了基因分型和表型特征分析。
收集了CHGUV从2017年9月（首例病例）至2021年9月的数据和分离株。随机选择35株分离株，包括1株来自环境源的分离株，进行全基因组测序（WGS），并将这些基因组与一个包含335个公开可用基因组的数据库一起进行分析，将它们归入五个主要分支之一。为了鉴定与耐药性相关的多态性，我们使用完全敏感的GCA_003014415.1菌株作为参考序列。研究了ERG11和FKS1基因中分别赋予对氟康唑和棘白菌素耐药性的已知突变。分离株被分类为聚集型或非聚集型。
所有分离株均属于分支III，且来自单一来源的暴发。它们聚集在与首例患者转出医院的三个公开可用基因组附近，该医院可能是源头。ERG11基因中的VF125AL突变赋予对氟康唑的耐药性，存在于所有分离株中，且有1株分离株还携带FKS1基因中的S639Y突变。所有分离株均具有非聚集表型（可能更具毒性）。
分离株在基因上相关且表型相同，但有1株对棘白菌素耐药，这似乎表明它们都属于源自单一分离株的暴发，多年来基本保持不变。这一结果强调了在检测到首例病例或患者从有已知病例的环境中转出时立即实施感染控制措施的重要性。
