Mycoplasma hominis
is an opportunistic human pathogen that causes acute and chronic infections of the urogenital tract. A new form of
M. hominis
colonies (microcolonies) was isolated, that differed ...from typical colonies by morphology, size, growth rate, and resistance to unfavorable factors, in particular, to antibiotics. The formation of microcolonies is associated with a switch in energy metabolism towards nucleoside utilization, which leads to a decrease in energy production and a transition to a persistor-like state. Typical and microcolony cultures of
M. hominis
H-34 were obtained and a comparative analysis of their adhesive-invasive potential, morphology, and size was carried out. It was shown that both typical and microcolonies can effectively attach and penetrate into HeLa cells. Unlike microcolonies, the morphology and size of cells in typical colonies change significantly after HeLa infection. This indicates functional changes in cells of typical colonies during infection.
A new
Mycoplasma hominis
phenotype forming mini-colonies (MC) on agar and distinct from the phenotype forming typical colonies (TC) not only in size, but also in morphology, growth rate, and ...resistance to adverse factors, has been previously identified. In this study, the phenotype of colonies was determined and a comparative analysis of the amino acid sequence of the main variable antigen Vaa of the laboratory strain N-34 and seven clinical isolates of
M. hominis
was performed. It is demonstrated that the amino acid sequence of Vaa in clinical isolates forming TC (similar to the laboratory strain N-34) is entirely analogous to that of laboratory strain. Clinical isolates forming MC carry amino acid substitutions in the variable C-terminal region of Vaa, which can contribute to adhesion to eukaryotic cells and immune evasion. The connection between colony phenotype and amino acid sequence of Vaa is established.
Interaction of microbiota with hybrid vaterite-pectin microparticles as an attractive multifunctional vehicle for mucosal delivery should not provoke inflammation. Our purpose was to study the ...reaction of bacteria
E. coli
strain Mg1655 and isolate SharL from a patient with Crohn disease on the cultivation with hybrid microparticles and vaterite, and the subsequent activation of neutrophils. Vaterite-pectin microparticles enhanced leakage of ATP from bacteria. For
E. coli
Mg1655, the concentration of DNA decreased, while intracellular ATP increased. For
E. coli
SharL, the intracellular ATP decreased with simultaneous growth of DNA. Bacteria and microparticles together did not enhance activation of neutrophils in comparison with the particles
per se
in the medium without serum and in comparison with bacteria in the medium supplemented with serum; microparticles did not reduce functional activity of neutrophils.
Culturing of
Mycoplasma hominis
in the presence of arginine and thymidine and subsequent comparative proteomic analysis of cells showed that, in addition to the already known arginine dihydrolase ...pathway of energy metabolism,
M. hominis
can utilize deoxyribose phosphates formed as a result of catabolism of pyrimidine nucleosides. In this case, a sharp deceleration of cell growth was observed. This allows
M. hominis
to occupy new niches in the host organism and survive under competitive conditions when the main sources of energy are unavailable.
Mycoplasma gallisepticum
belongs to the class
Mollicutes
and induces severe chronic respiratory disease in chickens. It lacks the cell wall and contains a very small genome and, accordingly, a ...reduced set of regulatory proteins. It is assumed that one of the regulatory mechanisms in mycoplasmas may be the dynamics of the spatial organization of the chromosome.
M. gallisepticum
has only two known nucleoid-associated (NAP) histone-like proteins (Hup_1 and Hup_2). To search for new potential NAP that may play a role in the infection process, we isolated nucleoid fractions from
M. gallisepticum
cells before and after infection of HD3 chicken erythroblast cell line and performed a comparative proteomic analysis of these fractions. We identified several potential NAP that included the components of the terminal organelle and adhesion, VlhA antigen, NADH oxidase, and PykF pyruvate kinase.
Mycoplasma gallisepticum (M. gallisepticum) belongs to the class of Mollicutes. It causes chronic respiratory disease in avian species. It is characterized by lack of cell wall and reduced genome ...size. As a result of genome reduction, M. gallisepticum has a limited variety of DNA-binding proteins (DBP) and transcription factors. Consequently, the diversity of DNA-binding proteins and transcription factors (TF) in M. gallisepticum is limited in comparison with related bacteria such as Bacillus subtilis. Studies have shown, however, that mycoplasmas demonstrate a wide range of differential expression of genes in response to various stress factors, which promotes effective adaptation to unfavorable conditions. We assume that in the case of mycoplasmas, which are characterized by a combination of the reduction of known gene expression regulation systems and a high adaptive potential, the coordination of gene expression can be provided due to local changes in the structure and spatial organization of the chromosome. The study of the dynamic changes of the proteomic profile of M. gallisepticum nucleoid may assist in revealing its mechanisms of functioning, regulation of chromosome organization and stress adaptation including its changes upon invasion of the host cells.
It is assumed that unknown mechanisms can be involved in adaptation
Mycoplasma gallisepticum
to unfavorable factors, one of these can be local rearrangements of the structure and spatial organization ...of the chromosome. To study these mechanisms, we obtained a culture of
M. gallisepticum
with synchronized division and isolated the nucleoid fraction from this culture by the method of mild cell lysis and centrifugation in a sucrose gradient. Liquid chromatography-mass spectrometry analysis of the proteome showed that in comparison with the cell lysate, the nucleoid fraction was enriched with DNA-binding proteins. This analysis will help to find new nucleoid-associated proteins and to study their dynamics, distribution, and their role during infection and under stress conditions.
We present the complete genome sequence and proteogenomic map for Acholeplasma laidlawii PG-8A (class Mollicutes, order Acholeplasmatales, family Acholeplasmataceae). The genome of A. laidlawii is ...represented by a single 1,496,992-bp circular chromosome with an average G+C content of 31 mol%. This is the longest genome among the Mollicutes with a known nucleotide sequence. It contains genes of polymerase type I, SOS response, and signal transduction systems, as well as RNA regulatory elements, riboswitches, and T boxes. This demonstrates a significant capability for the regulation of gene expression and mutagenic response to stress. Acholeplasma laidlawii and phytoplasmas are the only Mollicutes known to use the universal genetic code, in which UGA is a stop codon. Within the Mollicutes group, only the sterol-nonrequiring Acholeplasma has the capacity to synthesize saturated fatty acids de novo. Proteomic data were used in the primary annotation of the genome, validating expression of many predicted proteins. We also detected posttranslational modifications of A. laidlawii proteins: phosphorylation and acylation. Seventy-four candidate phosphorylated proteins were found: 16 candidates are proteins unique to A. laidlawii, and 11 of them are surface-anchored or integral membrane proteins, which implies the presence of active signaling pathways. Among 20 acylated proteins, 14 contained palmitic chains, and six contained stearic chains. No residue of linoleic or oleic acid was observed. Acylated proteins were components of mainly sugar and inorganic ion transport systems and were surface-anchored proteins with unknown functions.
The hippocampus is known as the brain region implicated in visuospatial processes and processes associated with learning and short- and long-term memory. An important functional characteristic of the ...hippocampus is lifelong neurogenesis. A decrease or increase in adult hippocampal neurogenesis is associated with a wide range of neurological diseases. We have previously shown that in adult male mice with a chronic positive fighting experience in daily agonistic interactions, there is an increase in the proliferation of progenitor neurons and the production of young neurons in the dentate gyrus (in hippocampus), and these neurogenesis parameters remain modified during 2 weeks of deprivation of further fights. The aim of the present work was to identify hippocampal genes associated with neurogenesis and involved in the formation of behavioral features in mice with the chronic experience of wins in aggressive confrontations, as well as during the subsequent 2-week deprivation of agonistic interactions. Hippocampal gene expression profiles were compared among three groups of adult male mice: chronically winning for 20 days in the agonistic interactions, chronically victorious for 20 days followed by the 2-week deprivation of fights, and intact (control) mice. Neurogenesis-associated genes were identified whose transcription levels changed during the social confrontations and in the subsequent period of deprivation of fights. In the experimental males, some of these genes are associated with behavioral traits, including abnormal aggression-related behavior, an abnormal anxiety-related response, and others. Two genes encoding transcription factors (
and
) were likely to contribute the most to the between-group differences. It can be concluded that the chronic experience of wins in agonistic interactions alters hippocampal levels of transcription of multiple genes in adult male mice. The transcriptome changes get reversed only partially after the 2-week period of deprivation of fights. The identified differentially expressed genes associated with neurogenesis and involved in the control of a behavior/neurological phenotype can be used in further studies to identify targets for therapeutic correction of the neurological disturbances that develop in winners under the conditions of chronic social confrontations.
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