Protective properties of designed samples of a Pseudomonas aeruginosa vaccine (experimental studies)

Abstract

Introduction. One of the main pathogens of purulent and inflammatory diseases, including multi-different serum groups specificity, remains a P. aeruginosa. The pathogen has a wide serogroup landscape, has polyresistance to antibiotics, high resistance to disinfectants, aseptives, external factors. Clear progress in the treatment of this infection is not observed. In a very actual problem of antibiotic resistance, an urgent necessity is the creation of vaccine preparations for the prevention and treatment of pseudomonosis. The search for new approaches to the creation of immune drugs continues in different countries of the world. In Ukraine, vaccine preparations for the prevention and treatment of pseudomonosis infection are absent, so their development and domestic production is promising, relevant and socially grounded. One of the modern directions of research of scientists from different countries is the use of bacteria decontamination technologies  and obtaining immunogens from its by inactivating the original microbial producer with a photodynamic method. We have developed and a patented method for obtaining a synogogeneous vaccine by using bacteriophages adapted to specific freshly used P. aeruginosa strains, use as photosensitizers - vikasol and riboflavin followed by irradiation by light. Materials and methods. For the production of vaccine samples, cultures of freshly branched from various biotopes of patients with purulent inflammatory diseases of P. aeruginosa strains, specific adapted bacteriophages, 0.1% solution of riboflavin and 1.0% vikasol. The irradiation was carried out using a photopolymer lamp "Luxior" and ultraviolet bactericidal lamp in laminar box. The protective properties of vaccine drugs were studied in an experiment on non-inbred mice by determining animal survival rates after control infection with homologous and heterogeneous P. aeruginosa strains. The protective activity of vaccine samples was evaluated in comparison with the control (non-vaccinated) group of infected animals. Statistical methods determined the reliability of the difference in indicators (X2). Results and discussions. In laboratory conditions, 3 series of monovaccines and 2 series of multistrain vaccines (out of 5 strains were obtained P. aeruginosa). The comparative study results of the vaccine monopeparates series received from strains with different baseline characteristics have shown that all of them provided approximately the same protective effect of infection with homologous strains. The high efficiency of vaccination of experimental mice is shown, as a result of which the mortality in the infestation by auto-strain due to different periods after immunization, starting from 3 days, was insignificant (10%) and compared with non-vaccinated - reliably less (P <0.01). Number of animals surviving after infection with heterogeneous strains P. aeruginosa in all experiments was also significantly smaller than in the control (non-vaccinated) group (P <0.05). Taking into account the wide serogroup landscape P. aeruginosa, the main task was to develop a method for obtaining a phagolysate multistrains pseudomonosis vaccine based on the application of the method of photodynamic inactivation of P. aeruginosa candidate strains and determined experimentally with its protective properties. Infection of experimental animals was carried out as strains involved in obtaining a multi-strains vaccine and other heterogeneous strains. In all cases there is a significant difference in comparing survival rates in vaccinated and non-vaccinated animals (p <0.01). The multistrain vaccine protected immunized mice from infection both by autostrain and from heterogeneous strains P. aeruginosa, which were not included in the vaccine. Conclusion. The resulting phagolisis multistrain vaccine has protective properties as relative to homologous and heterogeneous P. aeruginosa strains, was non-toxic and non-reactive. The survival rate of vaccinated mice in infection with a homologous strain has 28.9%, heterogeneous - 78.6%. It is important to emphasize that the strain composition of the developed immunufacturer may vary, supplemented with new, relevant for a particular region or, even, clinical department, etc.

DOI: 10.5281/zenodo.4657888