Experimental study action autostrains Aerococcus viridans on the model Pseudomonas infection

Abstract

The paper presents the results of a study of the action of Aerococcus autostrains on the model of a chronic blue pus infection. For the study of the action of Aerococcus autosymbiont strains on Pseudomonas aeruginosa, three of the most biochemically and antagonistically active isolates were selected: 1) 5m2015 (isolated from mice); 2) 3k2015 (isolated from rats); 3) 3ch2015 (isolated from humans). Experiments were conducted on 84 white outbred mice weighing 16–17 g, 60 were used as the experimental, and 24 as the control group. In the experimental group of animals, infected wounds were treated by Aerococcus autosymbiont strains once daily (0.2 billion ml–1) till recovery. The drug was administered under the eschar with a syringe. In the control animals the wound was treated by isotonic sodium chloride solution (concentration 0.9%) with the same route of administration and for the same period of time. It was found that from the very first days of application of Aerococci autosymbiont strains, perifocal inflammation was less severe in most animals in the research group compared with the control group. Starting from the fourth day of usage of Aerococcus autosymbiont strains the number of pseudomonades, contained in secretions from wounds in the experimental group of mice was significantly lower than in the control animals. It was revealed that in case of application of Aerococcus strain (5m2015) isolated from mice, the animals had better indicators of recovery, dynamics of local clinical signs of inflammation and the number of pseudomonades contained in the wound in comparison with other Aerococcus autostrains isolated from rats and humans. The wounds purified from pus and covered with dry eschar faster. For example, wounds completely healed with dry eschar rejection by the 11th day of observation in 44 of 58 surviving mice (75.9%). In the control group a similar pattern was observed in only 3 of 17 mice (17.6%) by the that period. The number of Pseudomonas aeruginosa (equivalent to 1 ml of secretions wounds), expressed in logarithms, was 5.00 ± 0.16 on average on the 4th day in the treated mice, while the control group had the same amount of pseudomonades detected in the wounds (lg 5.22 ± 0.38; lg 5.12 ± 0.30) only on the 13–14th days of observation. We found different activity of strains, depending on the origin of microorganism and type host. Aerococcus viridians autosymbionts showed higher rates in the study of their activity in terms of the blue pus infection model in the treatment of the host and lower activity in treatment.of other species. The obtained data may warrant further study of application of Aerococcus autostrains for treatment and prevention of wound infection caused by pseudomonades.