Volume 5, Number 1, 2018

Every person over the course of their lifetime is repeatedly infected by a variety of respiratory viruses that represent risk factors for the development of bacterial complications. The most dangerous among the etiological factors of acute respiratory viral diseases is the influenza A virus. This virus is capable of causing catastrophic pandemics with high mortality mainly due to secondary bacterial pneumonia. As has been shown in numerous recent studies, the main mechanism of provoking bacterial infections irrespective of the type of respiratory virus is the imbalanced response of the antiviral innate immunity – excessive interferon response and uncontrolled inflammation. The probability of severe bacterial complications in the course of acute respiratory viral infections is determined by both the virulence of the virus itself and by the composition of the respiratory microbiota at the time of the viral infection as well as by the genetic characteristics of the organism. The occurrence of severe bacterial complications is also affected by the chronic diseases that have an impact on the regulation of the innate immune response. This review summarizes the current concept of the mechanisms of the development of post viral bacterial complications as well as the potential prevention strategies for these complications. 

The widespread circulation of highly pathogenic avian influenza viruses (HPAIVs) and their occasional transmission to humans creates a constant pandemic threat and leads to significant economic losses in the poultry industry. The development of an effective and safe vaccine for the broad protection of poultry from H5N1 HPAIVs remains an important goal. Prevention of the virus transmission between ducks and chickens is important for the efficient control of the spread of avian influenza. The oral administration of live vaccines corresponds to the natural route of infection that leads to virus replication in the intestinal epithelial cells that cause a well-balanced and broad immune response providing protection against the viruses of distant clades. The broad protection is the important advantage of live-attenuated influenza vaccines when compared to inactivated ones. Here, we give an overview of the latest approaches and results in the development of live poultry vaccine candidates against HPAIVs.

The development of a new medicine is a process that requires enormous time and tremendous financing. It takes 10-15 years from the discovery of an active compound to the launch of its production and the start of drug marketing with the total costs of the project reaching 1.8 billion US dollars. These large time and financial costs stem from repeated testing and elimination of a large percentage of compounds over the course of screening at each stage of preclinical and clinical trials. Many investors have lost interest in financing new drug discovery projects (or pharmaceutical start-up companies) due to the high risk and extensive time required to produce a return on investments. Since all the research data are considered confidential by pharmaceutical companies and thus never shared with scientific community, different scientific groups waste significant resources repeating the same costly experiments in drug discovery. In this article, we discuss new approaches to drug discovery involving open access to the research data and alternative financing that could significantly streamline the search for new cures for human diseases.

The truncation of the nonstructural NS1 protein is a novel approach for the generation of immunogenic attenuated influenza viruses. However, the innate immune mechanisms that cause the increased immunogenicity of influenza viruses with altered NS1 proteins are poorly understood. The goal of this study was to compare the immune responses in mice immunized with two variants of the influenza A/Puerto Rico/8/1934 (A/PR8) virus: the wild type virus (А/PR8/full NS) and the variant with the NS1 protein shortened to 124 amino acid residues (А/PR8/NS124). The investigated parameters of immunity included cytokine production, the dynamic variation of the innate immune cell populations, and the rate of the influenza-specific T-cell responses. An intraperitoneal route of immunization was chosen due to the variability in the replication capacity of the investigated viruses in the respiratory tract. The levels of interferon β (IFNβ), tumor necrosis factor α (TNFα), monocyte chemo-attractant protein 1 (MCP1), interleukin 6 (IL6), and IL27 in peritoneal washings of mice immunized with А/PR8/NS124 were significantly higher compared to the mice immunized with the wild-type virus. The А/PR8/NS124 treated group showed a delayed attraction of monocytes and neutrophils as well as a more pronounced reduction in the percentage of dendritic cells in the peritoneal cavity. The expression level of the CD86 activation marker on the cells expressing the molecules of the major histocompatibility complex II (MHCII⁺) was significantly higher in mice immunized with А/PR8/NS124 than in the group immunized with А/PR8/full NS. Finally, immunization with А/PR8/NS124 led to an increased formation of influenza-specific CD8⁺ effector T-cells characterized by the simultaneous production of IFNγ, IL2, and TNFα. We hypothesize that elevated cytokine production, enhanced dendritic cell migration, and increased CD86 expression on antigen-presenting cells upon immunization with А/PR8/NS124 lead to a more effective presentation of viral antigens and, therefore, promote an increased antigen-specific CD8⁺ immune response.

Fungi of the ascomycete genus Diaporthe have been identified worldwide. Typically, Diaporthe species are saprobes, endophytes, or plant pathogens. The distinction between the species of this genus has historically been based on the combination of the morphological information, cultural characteristics, and host affiliation. The correct identification of the Diaporthe species should be carried out based on a combination of molecular genetic traits. A comprehensive analysis of Diaporthe species in the Russian Federation using molecular phylogeny methods has never been accomplished. 

The goal of this study was the identification of the isolate Diaporthe sp. MF 16-010, extracted from stems of Helianthus annuus L. that was collected in the Krasnodar region of the Russian Federation. According to the morphology data and DNA sequence analyses of the nuclear ribosomal internal transcribed spacer (ITS) region as well as of the translation elongation factor-1α (EF‑1α) and ß-tubulin genes, the isolate MF 16-010 was identified as Diaporthe phaseolorum (Cooke & Ellis) Sacc. To the best of our knowledge, this isolate represents the first report of Diaporthe phaseolorum associated with sunflower in the Russian Federation. The development of the stem lesions as a result of the artificial inoculation of MF 16-010 to sunflower proved that this isolate is pathogenic for sunflower. 

The content of fungal DNA and mycotoxins in cereal crops (31 varieties of wheat, oats, and barley) was quantitatively determined and used for the comparative characterization of grains. The quantitative PCR has been adapted for the analysis of the target DNA of Alternaria spp., Bipolaris sorokiniana (B. sorokiniana), Fusarium graminearum (F. graminearum), F. culmorum, and F. sporotrichioides fungi, which are often present in the mycobiota of small grain cereals. The content of the DNA of the aggressive pathogen B. sorokiniana was determined using quantitative PCR for the first time.

The DNA of Alternaria fungi was found abundantly in all grain samples, but its content in the oat was significantly higher compared to barley and wheat (5 and 9 times higher, respectively). In barley grain, the content of B. sorokiniana DNA was on average significantly higher than in the grains of oats and wheat. All of the analyzed grain samples contained the DNA of F. graminearum while F. culmorum DNA was found in 70% of the oat samples and in all of the samples of barley and wheat. Mycotoxin deoxynivalenol (DON) produced by these fungi was detected in all the analyzed cereal grains in a range from 77 to 4,133 μg/kg. The DNA of F. sporotrichioides was detected in 70% of oats and 50% of barley samples but was not found in wheat. The T-2 toxin produced by this fungus was detected in 45% of all samples within a range from 2 to 89 μg/kg.

The statistically significant positive correlation with the Pearson correlation coefficient (r) equal to 0.49 (p<0.05) was observed between the content of F. graminearum DNA and the amount of DON in the grain samples. Another significant positive correlation (r=0.72, p<0.01) was found between the DNA contents of Alternaria fungi and F. sporotrichioides in the grain samples. This leads to the suggestion that conditions for the growth of these fungi in grain substrates are similar.