O. Y. Slovareva
Pages 1-12 (Rus)
Grain export is an important branch of the food business in Russia. The countries of Europe, Asia, Africa and South America are importers of Russian grain. Each importing country has its own requirements for the phytosanitary condition of imported products. One important requirement of importers is the absence of pathogens that can cause bacterial diseases of grain crops, such as Pectobacterium rhapontici, Rathayibacter tritici, Pseudomonas fuscovaginae, Pseudomonas syringae pvs., Acidovorax avenae subsp. avenae, Xanthomonas translucens pvs., Rathayibacter rathayi and Pseudomonas cichorii. Reliable information on the distribution of these bacterial strains in the territory of Russian Federation is limited. Methods for isolation and identification of these bacterial pathogens have not been developed to date, which increases the risk of the spread of phytopathogens and eventually can cause significant economic harm to agriculture.
The purpose of this study was to isolate and identify the causative agents of bacterial diseases of wheat and barley. In order to do this, we collected samples of plant material of wheat and barley in Rodionovo-Nesvetaysky, Myasnikovsky, Zernograd, Azov and Martynovsky districts of the Rostov Oblast. Various bacterial strains were isolated from the obtained samples using appropriate culture media. The strains were tested by polymerase chain reaction (PCR) using primers designed for the 16S ribosomal RNA region (PSF/PSR and 8UA/519B) and SyD1/SyD2 primers selected for the Pseudomonas syringae genome region (GenBank CP047267.1) with subsequent sequencing according to Sanger.
As a result, the following bacterial strains were isolated and identified from wheat and barley samples: Curtobacterium sp., Paenibacillus sp., Enterobacteriaceae, Pseudomonas azotoformans, P. poae, P. azotoformans, P. hibiscicola, P. fluorescens, Stenotrophomonas sp., P. syringae pv. syringae, P. syringae pv. atrofaciens, Bacillus sp., Erwinia sp., Pantoea sp. and Pantoea agglomerans.
Kirill A. Vasilyev, Anna-Polina S. Shurygina, Marina A. Stukova, Andrej Y. Egorov
Influenza viruses with truncated NS1 protein stimulate more intensive innate immune response compared to their wild type counterparts. Here we investigate whether the shortening of the NS1 protein enhances the immunogenicity of conserved T-cellular epitopes of influenza virus. Using flow cytometry, we showed that intraperitoneal (i.p.) immunization of mice with influenza virus encoding 124 N-terminal amino acid residues of the NS1 protein (A/PR8/NS124) induced increased quantities of CD8+ T-cells recognizing immunodominant (NP366-374) and sub-immunodominant (NP161-175, NP196-210, HA323-337, HA474-483, NA427-433) epitopes compared to the virus expressing full-length NS1 (A/PR8/NSfull). It is important to note that the response to the immunodominant influenza epitope NP366-374 was achieved with the lower immunization dose of A/PR8/NS124 virus comparing to the reference wild type strain. Despite the polyfunctional CD8+ effector memory T-lymphocytes simultaneously producing two (IFNγ and TNFα) or three (IFNγ, IL2 and TNFα) cytokines prevailed in the immune response to both viruses, the relative number of such T-cells was higher in A/PR8/NS124-immunized mice. Furthermore, we found that polyfunctional populations of lymphocytes generated upon immunization with the mutant virus demonstrated increased capacity to produce IFNγ compared to corresponding populations derived from the A/PR8/NSfull-immunized mice. Thus, attenuated influenza viruses encoding truncated NS1 protein ensures generating more potent CD8+ T-cell immune response.