EMERGENCY PROPHYLAXIS OF EXPERIMENTAL MELIOIDOSIS USING SYNTHETIC IMMUNOMODULATORS AND HETEROLOGOUS VACCINES

Abstract

Melioidosis is a particularly dangerous infection caused by Burkholderia pseudomallei , against which a vaccine has not yet been created. In this regard, the development of effective treatment regimens and emergency prevention of melioidosis is very relevant. To improve the effectiveness of emergency prophylaxis of melioidosis, synthetic peptides (bestim, imunofan) and thiopoietin preparation glutoxim were used when combined with the antibiotic doxycycline. In addition, in experiments on white mice, the ability of heterologous vaccines (plague and tularemia), used in the emergency prevention mode, to increase the resistance of animals to melioidosis infection was assessed. It was shown that the most effective was imunofan, which, when combined with doxycycline, increased by 20% the survival rate of 5LD50 Burkholderia pseudomallei infection and significantly increased the average life span of mice infected with 5-12 LD50 (p < 0.05). The efficiency of use for stimulation of non-specific resistance to melioidosis of a heterologous plague vaccine EV, once administered 1 day prior to infection, protected 90% of mice from 6 LD50 Burkholderia pseudomallei and 60% - with an increase in the infectious dose of the pathogen of melioidosis up to 15 LD50. The same level of protection from melioidosis was provided by a 3 day course of antibiotic therapy with doxycycline. It was concluded that the tularemia vaccine is not suitable for immunostimulation in melioidosis due to its high residual virulence and reactogenicity.

Keywords

• melioidosis
• immunity
• emergency prophylaxis
• synthetic immunomodulators
• imunofan
• heterologous vaccines