Project description:Diutina catenulata is an ascomycetous yeast, that is regularly fluconazole-resistant and increasingly reported as the cause of invasive infection in humans. Here, we describe the de novo genome assembly of the clinical D. catenulata type-strain CBS565 and provide insights into the genome and compared it to an Illumina-sequenced environmental strain.
Project description:Diutina catenulata (Candida catenulata) is an ascomycetous yeast that has been isolated from humans, animals and environmental sources. The species is a contaminant of dairy products, and has been linked to superficial and invasive infections in both humans and animals. Previous phylogenetic analyses have assigned the species to the Saccharomycetales, but failed to identify its specific clade. Here, we report the genome sequence of an environmental isolate of D. catenulata. Examination of the tRNA repertoire and coding potential of this species shows that it translates the CUG codon as serine and not leucine. In addition, two phylogenetic analyses using 204 ubiquitous gene family alignments and 3,826 single-copy genes both confirm the placement of the species in the Debaryomycetaceae/Metschnikowiaceae, or CTG-Ser clade. The sequenced isolate contains an MTL? idiomorph. However, unlike most MTL loci in related species, poly (A) polymerase (PAP) is not adjacent to MTL?1.
Project description:Diutina catenulata (Candida catenulata) is an ascomycete yeast species widely used in environmental and industrial research and capable of causing infections in humans and animals. At present, there are only a few studies on D. catenulata, and further research is required for its more in-depth characterization and analysis. Eleven strains of D. catenulata collected from China Hospital Invasive Fungal Surveillance Net (CHIF-NET) and the CHIF-NET North China Program were identified using matrix-assisted laser desorption ionization-time of flight mass spectrometry and internal transcribed spacer sequencing. The antifungal susceptibility of the Diutina catenulata strains was tested using the Clinical and Laboratory Standards Institute broth microdilution method and Sensititre YeastOne™. Furthermore, ERG11 and FKS1 were sequenced to determine any mutations related to azole and echinocandin resistance in D. catenulata. All isolates exhibited low minimum inhibitory concentration (MIC) values for itraconazole (0.06-0.12 μg/ml), posaconazole (0.06-0.12 μg/ml), amphotericin B (0.25-1 μg/ml), and 5-flucytosine (range, <0.06-0.12 μg/ml), whereas four isolates showed high MICs (≥4 μg/ml) for echinocandins. Strains with high MIC values for azoles showed common ERG11 mutations, namely, F126L/K143R. In addition, L139R mutations may be linked to high MICs of fluconazole. Two amino acid alterations reported to correspond to high MIC values of echinocandin, namely, F621I (F641) and S625L (S645), were found in the hot spot 1 region of FKS1. In addition, one new amino acid alteration, I1348S (I1368), was found outside of the FKS1 hot spot 2 region, and its contribution to echinocandin resistance requires future investigation. Diutina catenulata mainly infects patients with a weak immune system, and the high MIC values for various antifungals exhibited by these isolates may represent a challenge to clinical treatment.
