A Chowdhary1, J B Stielow2, G Upadhyaya3, P K Singh3, A Singh3, J F Meis4. 1. Department of Medical Mycology, Vallabhbhai Patel Chest Institute, University of Delhi, Delhi, India. Electronic address: dranuradha@hotmail.com. 2. Thermo Fisher Diagnostics, Specialty Diagnostics Group, Landsmeer, the Netherlands; Centre of Expertise in Mycology Radboudumc/CWZ, Nijmegen, the Netherlands. 3. Department of Medical Mycology, Vallabhbhai Patel Chest Institute, University of Delhi, Delhi, India. 4. Centre of Expertise in Mycology Radboudumc/CWZ, Nijmegen, the Netherlands; Department of Medical Microbiology and Infectious Diseases, Canisius-Wilhelmina Hospital (CWZ), Nijmegen, the Netherlands.
Abstract
OBJECTIVE: Outbreaks of fungal sepsis due to emerging and rare multidrug-resistant Candida species are increasingly reported in health-care settings. We report an outbreak of fungaemia due to the rare multidrug-resistant yeast Candida blankii in an Indian neonatal unit. MATERIALS AND METHODS: Blood cultures grew C. blankii in nine neonates in the Neonatal Intensive Care Unit of a multispecialty hospital in Delhi during a period of 7 months. Isolates were identified by internal transcribed spacer and D1/D2 region sequencing. Antifungal susceptibility testing was performed by M27-A3 CLSI broth microdilution. To determine genetic relatedness among C. blankii isolates we undertook amplified fragment length polymorphism analysis and DNA sequencing using the Illumina NextSeq500 platform. RESULTS: Candida blankii fungaemia occurred at 2-3 postnatal days in nine low birthweight/very low birthweight neonates. All neonates were treated with fluconazole and four of the nine neonates died, resulting in a case fatality rate of 45%. Candida blankii was misidentified or not identified by automated identification systems. Fluconazole had higher geometric mean (GM) MICs (8 mg/L) than the other azoles. Also, anidulafungin (GM-MIC 2 mg/L) had high MICs. Genome sequencing confirmed transmission of genetically mostly indistinguishable strains. The C. blankii genome showed an altered 1,3-β-d-glucan synthase protein and several larger deletions in the echinocandin target FKS1 gene, suggesting potential for development of antifungal resistance. CONCLUSIONS: The study emphasizes the emergence of a rare and uncommon yeast, C. blankii, with reduced susceptibility to one or more antifungal agents, in nosocomial fungaemia. Genomic insights of this rare yeast are reported using whole-genome sequence typing.
OBJECTIVE: Outbreaks of fungal sepsis due to emerging and rare multidrug-resistant Candida species are increasingly reported in health-care settings. We report an outbreak of fungaemia due to the rare multidrug-resistant yeastCandida blankii in an Indian neonatal unit. MATERIALS AND METHODS: Blood cultures grew C. blankii in nine neonates in the Neonatal Intensive Care Unit of a multispecialty hospital in Delhi during a period of 7 months. Isolates were identified by internal transcribed spacer and D1/D2 region sequencing. Antifungal susceptibility testing was performed by M27-A3 CLSI broth microdilution. To determine genetic relatedness among C. blankii isolates we undertook amplified fragment length polymorphism analysis and DNA sequencing using the Illumina NextSeq500 platform. RESULTS:Candida blankii fungaemia occurred at 2-3 postnatal days in nine low birthweight/very low birthweight neonates. All neonates were treated with fluconazole and four of the nine neonates died, resulting in a case fatality rate of 45%. Candida blankii was misidentified or not identified by automated identification systems. Fluconazole had higher geometric mean (GM) MICs (8 mg/L) than the other azoles. Also, anidulafungin (GM-MIC 2 mg/L) had high MICs. Genome sequencing confirmed transmission of genetically mostly indistinguishable strains. The C. blankii genome showed an altered 1,3-β-d-glucan synthase protein and several larger deletions in the echinocandin target FKS1 gene, suggesting potential for development of antifungal resistance. CONCLUSIONS: The study emphasizes the emergence of a rare and uncommon yeast, C. blankii, with reduced susceptibility to one or more antifungal agents, in nosocomial fungaemia. Genomic insights of this rare yeast are reported using whole-genome sequence typing.
Authors: Ryan Mirchin; Jonathan M Czeresnia; Erika P Orner; Sudha Chaturvedi; Kerry Murphy; Joshua D Nosanchuk Journal: J Fungi (Basel) Date: 2022-02-09