Gut microbiota of patients with Parkinson’s disease and healthy volunteers was analyzed by the method of high throughput 16S rRNA sequencing of bacterial genomes. In patients with Parkinson’s ...diseases, changes in the content of 9 genera and 15 species of microorganisms were revealed: reduced content of
Dorea
,
Bacteroides
,
Prevotella
,
Faecalibacterium
,
Bacteroides massiliensis
,
Stoquefichus massiliensis
,
Bacteroides coprocola
,
Blautia glucerasea
,
Dorea longicatena
,
Bacteroides dorei
,
Bacteroides plebeus
,
Prevotella copri
,
Coprococcus eutactus
, and
Ruminococcus callidus
, and increased content of
Christensenella
,
Catabacter
,
Lactobacillus
,
Oscillospira
,
Bifidobacterium
,
Christensenella minuta
,
Catabacter hongkongensis
,
Lactobacillus mucosae
,
Ruminococcus bromii
, and
Papillibacter cinnamivorans
. This microbiological pattern of gut microflora can trigger local inflammation followed by aggregation of α-synuclein and generation of Lewy bodies.
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.
Accurate species-level identification of alpha-hemolytic (viridans) streptococci (VGS) is very important for understanding their pathogenicity and virulence. However, an extremely high level of ...similarity between VGS within the mitis group (S. pneumoniae, S. mitis, S. oralis and S. pseudopneumoniae) often results in misidentification of these organisms. Earlier, matrix-assisted laser desorption ionization–time of flight mass spectrometry (MALDI-TOF MS) has been suggested as a tool for the rapid identification of S. pneumoniae. However, by using Biotyper 3.0 (Bruker) or Vitek MS (bioMérieux) databases, Streptococcus mitis/oralis species can be erroneously identified as S. pneumoniae. ClinProTools 2.1 software was used for the discrimination of MALDI-TOF mass spectra of 25 S. pneumoniae isolates, 34 S. mitis and three S. oralis. Phenotypical tests and multilocus gene typing schemes for the S. pneumoniae (http://spneumoniae.mlst.net/) and viridans streptococci (http://viridans.emlsa.net/) were used for the identification of isolates included in the study. The classifying model was generated based on different algorithms (Genetic Algorithm, Supervised Neural Network and QuickClassifier). In all cases, values of sensitivity and specificity were found to be equal or close to 100%, allowing discrimination of mass spectra of different species. Three peaks (6949, 9876 and 9975 m/z) were determined conferring the maximal statistical weight onto each model built. We find this approach to be promising for viridans streptococci discrimination.
Accurate species-level identification of viridans group streptococci (VGS) is very important for understanding of their pathogenicity and virulence. However, an extremely high level of the similarity ...between VGS, especially Streptococcus pneumoniae, Streptococcus mitis, Streptococcus oralis and Streptococcus pseudopneumoniae, often results in misidentification of these organisms, so there is an urgent need of novel approaches to species identification.
A set of 50 randomly selected clinical isolates of alpha-hemolytic streptococci from upper respiratory tract were characterized by the routine phenotypic methods (alpha-hemolysis, colony morphology, Gram stain and optochin susceptibility). Modern proteomic and genetic approaches – the direct bacterial profiling (DBP) by means of matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) technique and multilocus sequence analysis (MLSA) scheme (http://viridans.emlsa.net/) – were applied for the accurate species identification. After that all isolates were stored at −70°C. Later they were re-inoculated, and a number of additional tests (bile solubility, latex agglutination by commercial “Slidex® pneumo-kit” and repeated optochin test) were performed.
A considerable discrepancy was discovered in the results of the different approaches. Looking in the future, one could say that MLSA-like schemes based on the analysis of the nucleotide sequences of seven or more loci of the bacterial genome, appeared to be the most useful instrument in the VGS discrimination, in contrast to the numerous one-target identification schemes, which have been introduced into practice by now.
Protein‐protein interactions play a central role in numerous processes in the cell and are one of the main fields of functional proteomics. This review highlights the methods of bioinformatics and ...functional proteomics of protein‐protein interaction investigation. The structures and properties of contact surfaces, forces involved in protein‐protein interactions, kinetic and thermodynamic parameters of these reactions were considered. The properties of protein contact surfaces depend on their functions. The contact surfaces of permanent complexes resemble domain contacts or the protein core and it is reasonable to consider such complex formation as a continuation of protein folding. Characteristics of contact surfaces of temporary protein complexes share some similarities with active sites of enzymes. The contact surfaces of the temporary protein complexes have unique structure and properties and they are more conservative in comparison with active site of enzymes. So they represent prospective targets for a new generation of drugs. During the last decade, numerous investigations were undertaken to find or design small molecules that block protein dimerization or protein(peptide)‐receptor interaction, or, on the contrary, to induce protein dimerization.
Mollicutes (mycoplasmas) feature a significant loss of known regulators of gene expression. Here, we identified the recognition site of the MraZ-family regulator of Mycoplasma gallisepticum, which is ...conserved in many species of different clades within class Mollicutes. The MraZ binding site is AAAGTGT/G, in the promoter of mraZ gene it forms a series of direct repeats with a structure (AAAGTGT/GN3)k, where k = 3 most frequently. MraZ binds to a single repeat as an octamer complex. MraZ can also bind a single binding site or a series of repeats with different spacer lengths (2–4 nt); thus, it may play a role in the regulation of multiple operons in Mollicutes. In M. gallisepticum, MraZ acts as a transcriptional activator. The overexpression of MraZ leads to moderate filamentation of cells and the formation of aggregates, likely as a result of incomplete cytokinesis.
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•MraZ-family transcription factor of Mycoplasma gallisepticum binds sequence (AAAGTGT/GN3)k, where k = 3.•MraZ binding site is conserved in Mollicutes, but repeat number may vary.•MraZ binds to a single repeat as an octamer.•Overexpression of MraZ in M. gallisepticum leads to the upregulation of transcription of division and cell wall gene cluster.•MraZ-overexpressing cells demonstrate elongated cell shape.
Autoantibody-mediated tissue destruction is among the main features of organ-specific autoimmunity. This report describes "an antibody enzyme" (abzyme) contribution to the site-specific degradation ...of a neural antigen. We detected proteolytic activity toward myelin basic protein (MBP) in the fraction of antibodies purified from the sera of humans with multiple sclerosis (MS) and mice with induced experimental allergic encephalomyelitis. Chromatography and zymography data demonstrated that the proteolytic activity of this preparation was exclusively associated with the antibodies. No activity was found in the IgG fraction of healthy donors. The human and murine abzymes efficiently cleaved MBP but not other protein substrates tested. The sites of MBP cleavage determined by mass spectrometry were localized within immunodominant regions of MBP. The abzymes could also cleave recombinant substrates containing encephalytogenic $MBP_{85-101}$ peptide. An established MS therapeutic Copaxone appeared to be a specific abzyme inhibitor. Thus, the discovered epitope-specific antibody-mediated degradation of MBP suggests a mechanistic explanation of the slow development of neurodegeneration associated with MS.
Differential diagnosis of bacterial and viral meningitis is an urgent problem of the modern clinical medicine. Early and accurate detection of meningitis etiology largely determines the strategy of ...its treatment and significantly increases the likelihood of a favorable outcome for the patient. In the present work, we analyzed the peptidome and cytokine profiles of cerebrospinal fluid (CSF) of 17 patients with meningitis of bacterial and viral etiology and of 20 neurologically healthy controls. In addition to the identified peptides (potential biomarkers), we found significant differences in the cytokine status of the CSF of the patients. We found that cut-off of 100 pg/ml of IL-1β, TNF, and GM-CSF levels discriminates bacterial and viral meningitis with 100% specificity and selectivity. We demonstrated for the first time the reduction in the level of two cytokines, IL-13 and GM-CSF, in the CSF of patients with viral meningitis in comparison with the controls. The decrease in GM-CSF level in the CSF of patients with viral meningitis can be explained by a disproportionate increase in the levels of cytokines IL-10, IFN-γ, and IL-4, which inhibit the GM-CSF expression, whereas IL-1, IL-6, and TNF activate it. These observations suggest an additional approach for differential diagnosis of bacterial and viral meningitis based on the normalized ratio IL-10/IL-1β and IL-10/TNF > 1, as well as on the ratio IFN-γ/IL-1β and IFN-γ/ TNF < 0.1. Our findings extend the panel of promising clinical and diagnostic biomarkers of viral and bacterial meningitis and reveal opposite changes in the cytokine expression in meningitis due to compensatory action of proand antiinflammatory factors.
Determine the primary antibiotic resistance of Helicobacter pylori (H. pylori) strains isolated from patients living in the European part of the Russian Federation.
As part of a clinical laboratory ...study, from 2015 to 2018, 27 gastrobiopsy samples obtained from H. pylori-infected patients were analyzed. H. pylori infection was verified using a rapid urease test or a 13C-urea breath test. The values of the minimum inhibitory concentration (MIC) of antibiotics were determined by the diffusion method using E-test strips (BioMerieux, France) according to the recommendations of the manufacturer. The sensitivity of the isolates was determined for 6 antibacterial drugs (amoxicillin, clarithromycin, metronidazole, levofloxacin, tetracycline, rifampicin).
According to the data obtained, resistance to amoxicillin was 0%, clarithromycin 11.1%, metronidazole 59.3%, levofloxacin 3.7%, tetracycline 0%, and rifampicin 14.8%. Dual resistance to clarithromycin and metronidazole was recorded in two isolates (7.4%).
Thus, the first results of the evaluation of H. pylori antibiotic resistance in the European part of the Russian Federation indicate a low resistance of the microorganism to clarithromycin and quite high to metronidazole.
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