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Vol 34, No 3 (2019)
- Year: 2019
- Articles: 6
- URL: https://journal-vniispk.ru/0891-4168/issue/view/11080
Reviews
A Look at Phage Therapy One Hundred Years After the Bacteriophages Discovery
Abstract
This overview discusses the literature data on the use of bacteriophages in the treatment of both acute and chronic infectious diseases caused by antibiotic-resistant pathogens. Traditionally, phage therapy is based on the use of naturally occurring phages for infection and lysis of bacteria at the site of infection. It has fundamental advantages over antibiotic therapy. At the same time, it has some disadvantages. Currently, the application of biotechnological methods, such as the development of the recombinant bacteriophages, makes it possible to eliminate the shortcomings of antimicrobial phage therapy and to expand its opportunities due to the use of lytic proteins of phages and their modified derivatives.
149-158
SOX9 as One of the Central Units of Regulation Axis of Pancreas Embryogenesis and Cancer Progression
Abstract
The embryonic development of all body systems is controlled by coordinated interactions of a group of genes encoding master regulators of development, which determine the fate of cells in the process of differentiation. These genes are often involved in the processes of malignant degeneration of cells. Hence, they are considered as targets of targeted gene therapy in the development of modern approaches to cancer treatment. One of the most aggressive forms of cancer is pancreatic ductal adenocarcinoma (PDAC). Thus, the study of pancreas master regulators genes is a challenging task. This review is devoted to SOX9, which is one of the key master regulators of pancreatic development and is a crucial factor in the induction and progression of PDAC.
159-169
Experimental Works
In vitro Biofilm Formation by the Respiratory Mycoplasmosis Pathogen Mycoplasma pneumonia
Abstract
This paper reports a study of biofilm formation by the Mycoplasma pneumoniae (Mp) strain Fh on an abiotic surface using light and electron microscopy. Quantitative assessment of the effectiveness of biofilm formation was carried out in polystyrene plates with crystal-Violet cell staining. To study the ultrastructural organization of the Mp cells, scanning electron microscopy was used, which allowed a well-formed multicellular clearly defined structure of considerable size to be revealed by the third day of culturing in which Mp cells were submerged into the extracellular matrix with a clearly detectable system of pores. The morphology of the detected aggregations was absolutely identical to that of the biofilms described for other microorganisms, which confirmed that Mp had the ability to to form biofilms. The described phenomenon of the ability of Mp to grow in the form of the biofilm is of great importance both for understanding the causes of the long-term persistence of Mp in the human organism and for the development of new approaches for the treatment of protracted and chronic forms of infectious diseases caused by Mp.
170-175
Bioinformatic Analysis of the Genome of the Lactobacillus fermentum 90 TC-4 Production Strain
Abstract
At present, the Lactobacillus fermentum 90 TC-4 strain is widely used for production of probiotics, dietary supplements, and food. It is for this reason that it is topical to study this strain using modern molecular genetic methods. The biochemical properties of the strain were examined using the API 50 CHL test system (BioMerieux, France), genome sequencing was carried out using the MiSeq (Illumina) platform, and de novo genome assembly was performed using the Spades, MIRA 4.0, and Newbler 2.6 software. Genome annotation was carried out with the help of the Prokka v. 1.11 utility and RAST and BASys genomic servers. The main characteristics of the L. fermentum 90 TC-4 genome were established. It was proven that the genome does not have any determinants of pathogenicity, virulence or antibiotic resistance. It was shown that the low saccharolytic ability of the strain is associated with the absence of appropriate transport systems—the sucrose-specific phosphonolpyruvate system PTS_ScrA and ribose-specific RbsD permease—as well as several enzymes. The CRISPR-Cas locus of the strain was analyzed, unique spacers (which in future can be used for strain indication) were revealed, and molecular mechanisms of antibiotic resistance of the strain were studied. Using the MLST scheme presented in the scientific literature, allelic profiles of housekeeping genes were established. It was also found that the allelic profile obtained for the L. fermentum 90 TC-4 strain does not correspond to any of the previously described sequence types. Since L. fermentum 90 TC-4 does not have determinants of antibiotic resistance, pathogenicity, virulence, or integrated plasmids, the strain does not pose any hazard in terms of spread of these determinants and can be used as a probiotic producer strain. The observed features of the CRISPR locus and allelic profile can further be used to indicate the strain.
176-181
Comparative Genomics of the Escherichia coli Strains АВ1157, АВ2463, АВ2494, and АВ1885
Abstract
Whole genome sequencing of the Escherichia coli strain АВ1157 and its mutants AB1885 uvrB5, AB2463 recA13, and AB2494 lexA1, which have deficient DNA repair, recombination, and mutagenesis systems, was performed. It was found that the genomes of the AB2463 recA13 and AB2494 lexA1 strains differ from the genome of ancestral strain in several hundred mutations which arose most probably in the course of a single treatment of AB1157 with N-methyl-N-nitro-N-nitrosoguanidine. At the same time, the genome of the strain AB1885 obtained after treatment with nitrous acid contained ten times fewer differences from its parent strain. Mutations in the AB2463 recA13 and AB2494 lexA1 genomes were predominantly represented by GC to AT transitions distributed randomly along the genomes, and their locations did not coincide in these strains. The effect of spontaneous mutations on the differences between the strains studied that appeared during the period from their isolation to the sequence experiments seems to be insignificant. Earlier known genetic and phenotypic traits are annotated on the molecular level.
182-187
Identification of Markers for Dengue Infection in Patients after Visiting Dengue-Endemic Countries
Abstract
In studied blood serum samples from Russian patients hospitalized with suspected dengue fever, one or more markers of dengue fever have been detected, namely, viral RNA, NS1 antigen, and IgM or IgG antibodies. Moreover, only the combined use of various immunological and genetic methods provided a more effective diagnosis of dengue fever. The detection of IgG to dengue virus in patients with high titers of IgG to tick-borne encephalitis virus (TBEV) and, conversely, the detection of IgG to TBEV virus in patients with high titers of IgG to dengue has been documented. The results confirm the literature data on pronounced antigenic cross-sections between different representatives of flaviviruses, which may complicate the ELISA diagnosis of TBEV and dengue in patients. Genotyping of obtained dengue virus isolates showed that imported cases of dengue fever are caused by subtypes 1–4 of the dengue virus, with the prevalence of infection cases caused by dengue virus 1. Sequencing of these dengue virus isolates, including genome-wide, showed that viral isolates obtained on the territory of Russia are phylogenetically close to modern variants of the dengue virus circulating in the countries of Southeast Asia.
188-194