Genotypic and phenotypic characterisation of a nosocomial outbreak of Candida auris in Spain during 5 years.

OBJECTIVES: 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. METHODS: 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. RESULTS: 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). CONCLUSIONS: 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.

Candida auris: descripción de un brote / Candida auris: report of an outbreak

Candida auris es una levadura multirresistente emergente que causa infecciones invasivas graves y brotes con una alta mortalidad. El control de C. auris es un reto. Laboratorios, clínicos e instituciones sanitarias deben trabajar conjuntamente para mejorar la identificación y el tratamiento de la infección, así como el control de la transmisión. Esta revisión describe los aspectos generales de la biología, diagnóstico y tratamiento de C. auris, al igual que las recomendaciones publicadas recientemente por un grupo de expertos. También se presenta la experiencia de un brote de C. auris en el Consorcio Hospital General Universitario de Valencia desde septiembre de 2017 hasta agosto de 2019. Se detectaron un total de 203 pacientes infectados y/o colonizados por C. auris. Se diagnosticaron 30 infecciones invasivas (29 candidemias y 1 meningitis). El 32% de las candidemias del año 2018 fueron por C. auris. Todas las cepas fueron resistentes a fluconazol

Candida auris is an emerging multidrug-resistant yeast that causes serious invasive infections and outbreaks with high mortality. Controlling C. auris is a challenge in which laboratories, clinicians and public health agencies are needed to identify and treat infections and prevent transmission. This review describes the general aspects of the biology, diagnosis and treatment of C. auris infection, as well as the main recommendations recently published by expert groups. We also present our experience of the C. auris outbreak at the Consorcio Hospital General Universitario de Valencia from September 2017 to August 2019. A total of 203 patients were colonised and/or infected by C. auris. Thirty invasive infections (29 blood cultures and one case of meningitis) were diagnosed. In all, 32% cases of candidemia were caused by C. auris in 2018. All strains were resistant to fluconazole