Infectious bronchitis (IB) of chickens is a highly contagious disease characterized by damage of the respiratory system and reproductive organs in young animals caused by a virus of the genus Gamma coronavirus. The condition of the respiratory system caused by the IB virus in chickens has many similarities with the pathology of the respiratory system caused by SARS-CoV-2 in humans. The effectiveness of virucidal drugs (Argovit, Triviron, Ecocid, and lauric acid monoglyceride) was tested on chickens inoculated with a tenfold dose of a vaccine strain based on the attenuated virus H120 against IB of chickens. On the 6th day after inoculation, inflammatory changes in the intestines, lungs, and thymus were observed in the control group. The experimental groups were characterized by less pronounced inflammatory reactions and a lower proportion of thymus and lung probes containing genomic IB virus RNA. Since the virucidal activity of four orally administrated formulations was possible only in the intestine, the experimental data indirectly confirmed the hypothesis of the possibility of the predominant accumulation of coronaviruses in the intestine and subsequent lung damage due to the hematogenous redistribution of viral particles and IBV antigens. It was suggested that other coronaviruses including SARS-CoV-2 can implement a similar mechanism.

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Marek’s disease virus is ubiquitous and can harm not only poultry, but also be oncogenic for humans. VBM and malignant tumors induced by them are a convenient and accessible natural model for studying herpesvirus-associated carcinogenesis. To date, according to our observations, there are additional risks of human infection with the Marek’s disease virus - the disease began to appear in broiler chickens 30 days and older, i.e. contact with poultry meat carries a risk of infection. In addition, COVID-19 disease may be accompanied by folic acid deficiency, i.e. a violation of the folate cycle in humans, which increases the risk of manifestation of diseases associated with DNA viruses, since a violation of the folate cycle can reduce the activity of DNA methylation, incl. viral DNA. Methylation is carried out enzymatically in the first minutes after DNA replication, i.e. postreplicatively. Since the DNA nucleotide sequence does not change, methylation is essentially an epigenetic event. We have studied the relationship between the methylation of promoters of the Marek’s disease virus and the copy number of the virus. The assessment of the presence or absence of methylation, as well as partial methylation, was carried out on the basis of identifying the difference between the threshold cycles dC(t). The presence of unmethylated sites included in the studied promoter sequence was detected on the basis of the ability of methylsensitive restrictases AciI and GlaI. A correlation was found between the concentration of genomic DNA of the Marek’s disease virus serotype 1 strain CVI 988 in cell culture and the presence of demethylated CpG islands in the composition of promoters located at position 9413-9865 bp. and 127943 - 128193 b.p. genomic DNA of the virus. The data obtained make it possible to explain the mechanism of the increase in the pathogenicity of herpesvirus infections under conditions of a decrease in the activity of viral DNA methylation in the body.

Methods of binding antibacterial drugs to the surface of cellulose without the use of oxidizing agents to prevent the occurrence of wound infections have been studied. The immobilization of gentamicin in the complex of partially denatured albumin in the composition with bacterial cellulose has been analyzed. The study was carried out on samples of cellulose synthesized by Gluconacetobacter hansenii. Albumin served as a binding agent, which was used to impregnate cellulose samples, which were then denatured. Using PCR amplifi cation CFX (BioRad), the optimal denaturation temperature was selected. The effectiveness of the immobilization of albumin in the thickness of the cellulose was assessed by staining it with the luminescent dye SYPRO® Ruby Protein Gel Stain, followed by transilluminator detection. Bacterial cellulose impregnated with undenatured albumin was used as a control. Albumin immobilization in bacterial cellulose was observed at temperatures of 65– 95 °C. The antibacterial activity of the complex “cellulose + albumin + gentamicin” was evaluated using a test strain of bacteria Staphylococcus aureus ATCC 25923. The growth inhibition of the test strain of bacteria was observed in all tests with bacterial cellulose in combination with partially denatured albumin and gentamicin. In control samples, in which gentamicin was not immobilized as part of partially denatured albumin, growth inhibition zones of Staphylococcus aureus ATCC 25923 were not noted. It was concluded that by partial denaturation of albumin it is possible to delay antibacterial drugs in the thickness of bacterial cellulose for their further release. A new version of the material suitable for the production of implants and bandages based on bacterial cellulose gel with antibacterial properties is proposed. Dressings based on a composite of bacterial cellulose, albumin and gentamicin are most relevant for the treatment of burns. The presence of gentamicin in their composition is also relevant for the prevention of bacterial infections.