SARS-CoV-2 Impact on Red Blood Cell Morphology.

Severe COVID-19 alters the biochemical and morphological characteristics of blood cells in a wide variety of ways. To date, however, the vast majority of research has been devoted to the study of leukocytes, while erythrocyte morphological changes have received significantly less attention. The aim of this research was to identify erythrocyte morphology abnormalities that occur in COVID-19, compare the number of different poikilocyte types, and measure erythrocyte sizes to provide data on size dispersion. Red blood cells obtained from 6 control donors (800-2200 cells per donor) and 5 COVID-19 patients (800-1900 cells per patient) were examined using low-voltage scanning electron microscopy. We did not discover any forms of erythrocyte morphology abnormalities that would be specific to COVID-19. Among COVID-19 patients, we observed an increase in the number of acanthocytes (p = 0.01) and a decrease in the number of spherocytes (p = 0.03). In addition, our research demonstrates that COVID-19 causes an increase in the median (p = 0.004) and interquartile range (p = 0.009) when assessing erythrocyte size. The limitation of our study is a small number of participants.

Basic Predictive Risk Factors for Cytokine Storms in COVID-19 Patients.

Objective: A critical role in coronavirus disease 2019 (COVID-19) pathogenesis is played by immune dysregulation that leads to a generalized uncontrolled multisystem inflammatory response, caused by overproduction of proinflammatory cytokines, known as "a cytokine storm" (CS), strongly associated with a severe course of disease. The aim of this study is to identify prognostic biomarkers for CS development in COVID-19 patients and integrate them into a prognostic score for CS-associated risk applicable to routine clinical practice. Materials and Methods: The authors performed a review of 458 medical records from COVID-19 patients (241 men and 217 women aged 60.0 ± 10.0) who received treatment in the St. Petersburg State Budgetary Institution of Healthcare City Hospital 40 (City Hospital 40, St. Petersburg), from Apr. 18, 2020 to Nov. 21, 2020. The patients were split in two groups: one group included 100 patients with moderate disease symptoms; the other group included 358 patients with progressive moderately severe, severe, and extremely severe disease. The National Early Warning Score (NEWS) score was used alongside with clinical assessment, chest computed tomographic (CT) scans, electrocardiography (ECG), and lab tests, like ferritin, C-reactive protein (CRP), interleukin (IL)-6, lactate dehydrogenase (LDH), and D-dimer. Results: The basic risk factors for cytokine storms in COVID-19 patients are male gender, age over 40 years, positive test result for replicative severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) RNA, absolute lymphocyte count, dynamics in the NEWS score, as well as LDH, D-dimer, ferritin, and IL-6 levels. These clinical and instrumental findings can be also used as laboratory biomarkers for diagnosis and dynamic monitoring of cytokine storms. The suggested prognostic scale (including the NEWS score dynamics; serum IL-6 greater than 23 pg/ml; serum CRP 50 mg/L or greater; absolute lymphocyte count less than 0.72 × 109/L; positive test result for replicative coronavirus (SARS-CoV-2) RNA; age 40 years and over) is a useful tool to identify patients at a high risk for cytokine storm, requiring an early onset of anti-inflammatory therapy.

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.

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.

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.