Biology subjects

Babenko, V. V.

Publications and source records attributed to Babenko, V. V..

8 recordsLinked to original sources

bioRxiv2025

Snappy: de novo identification of DNA methylation sites based on Oxford Nanopore reads

SummaryNowadays, search for methylation sites in bacteria is usually performed by direct detection of nucleotide motifs over-represented in modified contexts, using classical motif enrichment approaches oriented only on context sequences themselves. Herein, we present a new algorithm Snappy, which is actually rethinking of the original Snapper algorithm but does not use any enrichment heuristics and does not require control sample sequencing. Opposite to previous methods, Snappy uses raw basecalling data simultaneously with the motif enrichment process, thus significantly enhancing the enrichment sensitivity and accuracy compared with other enrichment algorithms. The versatility of the method was shown on both our and external data, representing different bacterial taxa with complex and simple methylome. Availability and implementationSource code and documentation is hosted on GitHub (https://github.com/DNKonanov/ont-snappy) and Zenodo (zenodo.org/records/16731817). For accessibility, Snappy is installable from PyPi using pip install ont-snappy command.

bioinformatics↗

bioRxiv2023

Newly obtained genome of fungi-related amoeba is enriched with genes shared with animals-related protists

Nuclearariids are a group of Opisthokonta, forming the deepest branch in Holomycota - one of the two major Opisthokonta clades, containing Fungi as a crawn group. They are the only members of Holomycota retaining the filose amoeboid state ancestral for Opisthokonta. The newly assembled genome of Nuclearia thermophila (Holomycota, Rotosphaerida) had a total length of 49 Mb, 15 321 protein-coding genes and a GC percentage of 44%. This is the first sequenced genome for this genus and the the third for Rotosphaerida as a whole. It was shown that N. thermophila shares more protein domains with Holozoa, than with the rest of Holomycota. Protein domains that were presumably acquired or lost by the common ancestors of the Holomycota and Holozoa groups were identified. The Holomycota ancestor had probably more gains and losses of protein domains compared to the Holozoa ancestor, which is particularly true for metabolism-related domains. However, this trend should be confirmed by studying the genomes of free-living organisms of the Teretosporea group.

genomics↗

bioRxiv2021

Analysis of the upper respiratory tract microbiota in mild and severe COVID-19 patients

The microbiota of the respiratory tract remains a relatively poorly studied subject. At the same time, like the intestinal microbiota, it is involved in modulating the immune response to infectious agents in the host organism. A causal relationship between the composition of the respiratory microbiota and the likelihood of development and the severity of COVID-19 may be hypothesized. We analyze biomaterial from nasopharyngeal smears from 336 patients with a confirmed diagnosis of COVID-19, selected during the first and second waves of the epidemic in Russia. Sequences from a similar study conducted in Spain were also included in the analysis. We investigated associations between disease severity and microbiota at the level of microbial community (community types) and individual microbes (differentially represented species). To search for associations, we performed multivariate analysis, taking into account comorbidities, type of community and lineage of the virus. We found that two out of six community types are associated with a more severe course of the disease, and one of the community types is characterized by high stability (very similar microbiota profiles in different patients) and low level of lung damage. Differential abundance analysis with respect to comorbidities and community type suggested association of Rothia and Streptococcus genera representatives with more severe lung damage, and Leptotrichia, unclassified Lachnospiraceae and Prevotella with milder forms of the disease.

molecular biology↗

bioRxiv2021

BioCAT: PSSM-based algorithm to search biosynthetic gene clusters producing nonribosomal peptides with known structure

MotivationNonribosomal peptides are a class of secondary metabolites synthesized by multimodular enzymes named nonribosomal peptide synthetases and mainly produced by bacteria and fungi. It has been shown that non-ribosomal peptides have a huge structural and functional diversity including antimicrobial activity, therefore, they are of increasing interest for modern biotechnology. Methods such as NMR and LC-MS/MS allow to determine a peptide structure precisely, but it is often not a trivial task to find natural producers of them. Today, the search is usually performed manually, mostly with tools such as antiSMASH or Prism. However, there are cases when potential producers should be found among hundreds of strains, for instance, when analyzing metagenomes data. Thus, the development of automated approaches is a high-priority task for further nonribosomal peptides research. ResultsWe developed BioCAT, a two-side approach to find biosynthetic gene clusters which may produce a given nonribosomal peptide when the structure of interesting nonribosomal peptide has already been found. Formally, BioCAT unites the antiSMASH software and the rBAN retrosynthesis tool but some improvements were added to both gene cluster and peptide chemical structure analyses. The main feature of the method is an implementation of position specific score matrix to store specificities of nonribosomal peptide synthetase modules, which has increased the alignment quality in comparison with more strict approaches developed earlier. An ensemble model was implemented to calculate the final alignment score. We tested the method on a manually curated nonribosomal peptides producers database and compared it with a competing tool called GARLIC. Finally, we showed the method applicability on several external examples. AvailabilityBioCAT is available on the GitHub repository or via pip Contactkonanovdmitriy@gmail.com

bioinformatics↗

bioRxiv2020

The ecogenomics of dsDNA bacteriophages in feces of stabled and feral horses

The viromes of the mammalian lower gut were shown to be heavily dominated by bacteriophages; however, only for humans were the composition and intervariability of the bacteriophage communities studied in depth. Here we present an ecogenomics survey of dsDNA bacteriophage diversity in the feces of horses (Equus caballus), comparing two groups of stabled horses, and a further group of feral horses that were isolated on an island. Our results indicate that the dsDNA viromes of the horse feces feature higher richness than in human viromes, with more even distribution of genotypes. No over-represented phage genotypes, such as CrAssphage-related viruses found in humans, were identified. Additionally, many bacteriophage genus-level clusters were found to be present in all three geographically isolated populations. The diversity of the horse intestinal bacteriophages is severely undersampled, and so consequently only a minor fraction of the phage contigs could be linked with the bacteriophage genomes. Our study indicates that bacteriophage ecological parameters in the intestinal ecosystems in horses and humans differ significantly, leading them to shape their corresponding viromes in different ways. Therefore, the diversity and structure of the intestinal virome in different animal species needs to be experimentally studied. Short abstract (needed in some journals as eLife)The viromes of the mammalian gut were shown to be heavily dominated by bacteriophages; however, only for humans were the composition and intervariability of the bacteriophage communities studied in depth. Here we present an ecogenomics survey of dsDNA bacteriophage diversity in the feces of horses (Equus caballus), comparing stabled horses, and feral horses that were isolated on an island. The viromes equine fecal viromes feature higher richness than in human viromes, with more even distribution of genotypes. No over-represented phage genotypes were identified. Additionally, many bacteriophage genus-level clusters were found to be present in geographically isolated populations. Only a minor fraction of the phage contigs could be linked with the bacteriophage genomes. Our study indicates that bacteriophage ecological parameters in the intestinal ecosystems in horses and humans differ significantly, leading them to shape their corresponding viromes in different ways. Importance. (needed for mBio)The study presents the first in depth analysis of the composition and variability of the gut dsDNA bacteriophage community in the mammalian species, other than humans. The study demonstrates that the bacteriophage ecology in the gut is substantially different in different animal species. The results also indicate that the genetic diversity of the equine intestinal bacteriophages is immense and almost totally unexplored by the moment.

genomics↗

bioRxiv2019

Phages associated with horses provide new insights into the dominance of lateral gene transfer in virulent bacteriophages evolution in natural systems

Tailed bacteriophages (Caudovirales order) are omnipresent on our planet. Their impressive ecological and evolutionary success largely relies on the bacteriophage potential to adapt to great variety of the environmental conditions found in the Biosphere. It is believed that the adaptation of bacteriophages, including short time scale adaptation, is achieved almost exclusively via the (micro)evolution processes. In order to analyze the major mechanisms driving adaptation of phage genomes in a natural habitat we used comparative genomics of G7C-like coliphage isolates obtained during 7 years period from the feces of the horses belonging to a local population. The data suggest that even at this relatively short time scale the impact of various recombination events overwhelms the impact of the accumulation of point mutations. The access to the large pool of the genes of a complex microbial and viral community of the animal gut had major effect on the evolutionary trajectories of these phages. Thus the "real world" bacteriophage evolution mechanisms may differ significantly from those observed in the simplified laboratory model systems.

evolutionary biology↗

bioRxiv2018

Far beyond common leeching: insights into an ancient medical device through integrated omics data

Salivary cell secretion (SCS) plays a critical role in blood feeding by medicinal leeches, making them of use for certain medical purposes even today. We annotated the Hirudo medicinalis genome and performed RNA-seq on salivary cells isolated from three closely related leech species, H. medicinalis, Hirudo orientalis, and Hirudo verbana. Differential expression analysis verified by proteomics identified salivary cell-specific genes, many of which encode previously unknown salivary components. However, the genes encoding known anticoagulants were not differentially expressed in the salivary cells. The function-related analysis of the unique salivary cell genes enabled an update of the concept of interactions between salivary proteins and components of haemostasis. Thus, our study provides one of the most comprehensive knowledge of the genetic fundamentals of the blood-sucking lifestyle in leeches.

systems biology↗

bioRxiv2018

Shifts in the gut microbiota structure caused by Helicobacter pylori eradication therapy

The human gut microbiome plays an important role both in health and disease. The use of antibiotics can alter gut microbiota composition, which can cause complications of various kinds. Here we report a whole genome sequencing metagenomic study of the intestinal microbiota changes caused by Helicobacter pylori eradication therapy. We have found the decrease in taxonomic alpha-diversity due to the therapy. The changes observed were more extensive for patients with duodenal ulcer and female ones. As well across the patients under the therapy we have detected the shifts in the metabolic potential and resistome. Seven KEGG pathways associated with quorum sensing, genetic Information processing and environmental Information processing were increased, while metabolic pathways related with metabolism of cofactors and vitamins and glycan biosynthesis and metabolism decreased. Changes in the resistome profile have also been identified. We observed perturbations in intraspecies structures, which were higher in group of patients under the therapy than in control group of people without treatment. The Eubacterium rectale pangenome extracted from metagenomic data were changed. We also isolated and sequenced Enterococcus faecium strains from two patients before and after eradication therapy. After the therapy this bacterium increased as the antibiotic resistance in vitro, as well the number of ARGs to macrolides and tetracyclines and metagenomic relative abundance in comparison with strains before therapy. In summary, microbial community demonstrated shift to reduce metabolic potential and to increased mechanisms, which mediate more survival condition through intraspecies perturbations.\n\nImportanceThe human gut microbiome plays an important role both in health and disease. The use of antibiotics can alter gut microbiota composition, which can cause complications of various kinds. H. pylori eradication therapy causes multiple shifts and alterations (including intraspecies changes) of the intestinal microbiota structure and leads to the accumulation of genes which determine resistance to macrolides. Since these changes are not the same for patients with various diseases, patients with duodenal ulcer may be further paid special attention for reducing side effects, such as antibiotic-induced dysbiosis. Also, study of antibiotic treatment in terms of its impact upon the human gut microbiota allows shedding light on of the complex processes that cause accumulation and spread of antibiotic resistance. An identification and understanding of these complicated processes may help to constrain antibiotic resistance spread, which is of great importance for human health care.

microbiology↗