Publications by authors named "Marina S Dyachkova"
Article Synopsis
- The study focuses on how gut microbiota, particularly commensal bacteria like lactobacilli, interact with the host immune system's cytokines, which are critical in managing inflammation and gut health.
- Using next-generation RNA sequencing, researchers examined the transcriptional responses of lactobacillus strains K32 and R19-3 to various cytokines, revealing significant changes in gene expression linked to metabolism and stress response, especially upon exposure to IL-8 and IL-10.
- The findings highlight a complex adaptation mechanism where these bacteria adjust their gene expression in response to inflammatory signals, paving the way for potential probiotic therapies for conditions like inflammatory bowel disease (IBD).
Background: Klebsiella pneumoniae, which is frequently associated with hospital- and community-acquired infections, contains multidrug-resistant (MDR), hypervirulent (hv), non-MDR/non-hv as well as convergent representatives. It is known that mostly international high-risk clonal lineages including sequence types (ST) 11, 147, 258, and 307 drive their global spread. ST395, which was first reported in the context of a carbapenemase-associated outbreak in France in 2010, is a less well-characterized, yet emerging clonal lineage.
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- Transcriptomics, specifically through RNA-Seq, was used to analyze gene expression in bifidobacteria during different growth phases, highlighting their importance in human gut health.
- The study found that during the lag phase, there is increased expression of ABC transporters as bifidobacteria prepare for division, while the exponential phase is characterized by the activation of genes related to amino acid synthesis and energy metabolism to support rapid growth.
- In the stationary phase, gene expression shifts to promote defense mechanisms, indicating a strategy for survival under nutrient scarcity as the rate of cell division decreases.
The origin of genetic code and translation system is probably the central and most difficult problem in the investigations on the origin of life and one of the most complex problems in the evolutionary biology in general. There are multiple hypotheses on the emergence and development of existing genetic systems that propose the mechanisms for the origin and early evolution of genetic code, as well as for the emergence of replication and translation. Here, we discuss the most well-known of these hypotheses, although none of them provides a description of the early evolution of genetic systems without gaps and assumptions.
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- Bifidobacteria, important members of the gut microbiota, adapt to the host's immune response, but their survival mechanisms during inflammation are not well understood.
- The study proposes a new method using high-throughput sequencing and transcriptome analysis to identify genes affected by pro-inflammatory cytokines IL-6 and TNFα in bifidobacteria.
- Findings revealed that these cytokines influence gene expression without significantly affecting growth, leading to the identification of potential regulatory pathways that help bifidobacteria resist inflammatory responses, highlighting their anti-inflammatory role in the gut.
Most species of the genus Bifidobacterium contain the gene cluster PFNA, which is presumably involved in the species-specific communication between bacteria and their hosts. The gene cluster PFNA consists of five genes including fn3, which codes for a protein containing two fibronectin type III domains. Each fibronectin domain contains sites similar to cytokine-binding sites of human receptors.
View Article and Find Full Text PDFBifidobacteria are commensal microorganisms that inhabit a wide range of hosts, including insects, birds and mammals. The mechanisms responsible for the adaptation of bifidobacteria to various hosts during the evolutionary process remain poorly understood. Previously, we reported that the species-specific PFNA gene cluster is present in the genomes of various species of the genus.
View Article and Find Full Text PDFThe draft genome sequences of Bifidobacterium angulatum GT102 and Bifidobacterium adolescentis 150 strains isolated from the human intestinal microbiota are reported. Both strains are able to produce gamma-aminobutyric acid (GABA). Detailed genomes analysis will help to understand the role of GABA in the functioning of gut-brain axis.
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