Dynamics of growth of cultures of pathogenic bacterium in conditions of astaticism of thermal factor

Abstract

The purpose. To determine influence of day-night temperature variations upon dynamics of growth of cultures of pathogenic bacterium Erysipelothrix rhusiopathiae. Methods. In model experiments in vitro dynamics of growth of bacteria E. rhusiopathiae in conditions of temperature variations 3, 5, 10, 15 and 20°C is probed at daily average temperature 23°C. Control series was incubated at a constant temperature of 23°C. Results. At periodic fluctuation of ambient temperature within the limits of 3 – 5°C from optimum stationary level (23°C) the content of E. rhusiopathiae in cultures increases in 1,4 – 1,6 times in comparison with the control. At increase of range of temperature variations up to 15°C indexes of growth of bacterial cultures drop in comparison with the maximum ones. Day-night temperature variations (20°C) negatively influenced growth of cultures of experimental sort of microorganisms. Conclusions. Stationary conditions with an index of temperature 23°C are not an ecological optimum for bacteria E. rhusiopathiae. Periodic deflexions rom the mentioned index over the range of 3 – 5°C may be considered as ecological optimum. Astaticism of temperature of water of flat ponds is favorable for growth of pathogenic bacterium E. rhusiopathiae.