Whole genome sequence of first Candida auris strain, isolated in Russia.

Candida auris is an emergent yeast pathogen, easily transmissible between patients and with high percent of multidrug resistant strains. Here we present a draft genome sequence of the first known Russian strain of C. auris, isolated from a case of candidemia. The strain clustered within South Asian C. auris clade and seemingly represented an independent event of dissemination from the original species range. Observed fluconazole resistance was probably due to F105L and K143R mutations in ERG11.

Genotyping of Russian isolates of fungal pathogen Trichophyton rubrum, based on simple sequence repeat and single nucleotide polymorphism.

BACKGROUND: The Trichophyton rubrum species group consists of prevalent causative agents of human skin, nail and hair infections, including T rubrum sensu stricto and T violaceum, as well as other less well-established or debatable taxa like T soudanense, T kuryangei and T megninii. Our previous study provided limited evidence in favour of the existence of two genetic lineages in the Russian T rubrum sensu stricto population. OBJECTIVES: We aimed to study the genetic structure of the Russian population of T rubrum and to identify factors shaping this structure. METHODS: We analysed the polymorphism of 12 simple sequence repeat (SSR or microsatellite) markers and single nucleotide polymorphism in the TERG_02941 protein-coding gene in 70 T rubrum isolates and performed a phylogenomic reconstruction. RESULTS: All three types of data provided conclusive evidence that the population consists of two genetic lineages. Clustering, performed by means of microsatellite length polymorphism analysis, was strongly dependent on the number of nucleotide repeats in the 5'-area of the fructose-1,6-bisphosphate aldolase gene. Analysis of molecular variance (AMOVA) on the basis of SSR typing data indicated that 22%-48% of the variability was among groups within T rubrum. There was no clear connection of population structure with types of infection, places of geographic origin, aldolase gene expression or urease activity. CONCLUSION: Our results suggest that the Russian population of T rubrum consists of two cosmopolitan genetic lineages.

Species boundaries in the Trichophyton mentagrophytes / T. interdigitale species complex.

The fungi Trichophyton mentagrophytes and T. interdigitale are closely related species, causing superficial infections in humans and other mammals. The status of these taxa is a field of long-lasting debates. To clarify their phylogenetic relationships within the genus Trichophyton and sharpen the species boundaries, we performed sequencing of four T. mentagrophytes genomes and also evaluated three previously published multilocus data sets. We performed computational species delimitation analysis on all available in GenBank internal transcribed spacer region (ITS) sequences of Trichophyton spp. Phylogenomic data, phylogenetic network, and species delimitation analyses implied that T. mentagrophytes and T. interdigitale belong to the same phylogenetic species. However, we argue that taxonomic status quo should be retained, from the perspective of epidemiological data and the principle of taxonomic stability. Since there is a correlation between ITS genotype and epidemiological source of an isolate, restriction of T. interdigitale to purely anthropophilic ITS genotypes seems to be reasonable.

Single-nucleotide polymorphism in a local population of Trichophyton rubrum.

Trichophyton rubrum is an important causative agent of superficial mycoses worldwide. To uncover a genetic composition of a local population of this fungus, we sequenced A7C99_6411 and A7C99_6714 loci, coding for hypothetical proteins and revealed two complex genotypes, differing by a single missense mutation in each locus. One of the two A7C99_6411/6714 genotypes was not found in tinea pedis cases and demonstrated mostly longer TRS-1 elements when compared to another genotype. Thus, we present a description of nucleotide polymorphism in protein-coding loci in T. rubrum and provide evidence for ecological preferences of T. rubrum genotypes at a local scale.

A Genome of Temperate Enterococcus Bacteriophage Placed in a Space of Pooled Viral Dark Matter Sequences.

In the human gut, temperate bacteriophages interact with bacteria through predation and horizontal gene transfer. Relying on taxonomic data, metagenomic studies have associated shifts in phage abundance with a number of human diseases. The temperate bacteriophage VEsP-1 with siphovirus morphology was isolated from a sample of river water using Enterococcus faecalis as a host. Starting from the whole genome sequence of VEsP-1, we retrieved related phage genomes in blastp searches of the tail protein and large terminase sequences, and blastn searches of the whole genome sequences, with matches compiled from several different databases, and visualized a part of viral dark matter sequence space. The genome network and phylogenomic analyses resulted in the proposal of a novel genus "Vespunovirus", consisting of temperate, mainly metagenomic phages infecting Enterococcus spp.

Two Novel Lytic Bacteriophages Infecting Enterococcus spp. Are Promising Candidates for Targeted Antibacterial Therapy.

The rapid emergence of antibiotic resistance is of major concern globally. Among the most worrying pathogenic bacteria are vancomycin-resistant enterococci. Phage therapy is a highly promising method for controlling enterococcal infections. In this study, we described two virulent tailed bacteriophages possessing lytic activity against Enterococcus faecalis and E. faecium isolates. The SSsP-1 bacteriophage belonged to the Saphexavirus genus of the Siphoviridae family, and the GVEsP-1 bacteriophage belonged to the Schiekvirus genus of Herelleviridae. The genomes of both viruses carried putative components of anti-CRISPR systems and did not contain known genes coding for antibiotic-resistance determinants and virulence factors. The conservative arrangement of protein-coding sequences in Saphexavirus and Schiekvirus genomes taken together with positive results of treating enterococcal peritonitis in an animal infection model imply the potential suitability of GVEsP-1 and SSsP-1 bacteriophages for clinical applications.