Candida blankii: an emerging yeast in an outbreak of fungaemia in neonates in Delhi, India

Abstract

ObjectiveOutbreaks 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 methodsBlood 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. ResultsCandida 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. ConclusionsThe 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.