EFFECT OF TEMPERATURE ON THE VIABILITY OF PLANKTON CELLS AND MODEL LEGIONELLA PNEUMOPHILA BIOFILMS IN WATER

Abstract

Aim. Study the effect of water temperature from 40 to 70°C on viability of plankton forms and model Legionella pneumophila under experimental conditions. Materials and methods. Monospecies legionella biofilms, obtained in plates for enzyme immunoassay during 96 hours at 28°C, and water suspension of BCYE agar cultivated cells of L.pneumophila at a concentration of 103 - 105 CFU per liter were used in the study for evaluation of bactericidal effect of temperature on various legionella forms. Results. Analysis of effects of various temperature regimens on plankton forms and model legionella biofilms has shown that at a temperature range from 50 to 60°C a significant reduction of quantity of viable legionella cells occurs. Model legionella biofilms have partially conserved viability at a temperature of 60°C and only exposition to a temperature of 70°C resulted in death of legionella biofilms and plankton forms of bacteria. A dependence of viability conservation of legionella from the initial concentration of the causative agent in water and duration of exposition at varying temperature was shown. Conclusion. Short-term heating at a temperature of at least 70°C has the most pronounced bactericidal effect on plankton forms and model L.pneumophila biofilms under experimental conditions. Such temperature regimen could be used as one of the prophylaxis approaches during maintenance of especially dangerous water system and, fist of all, systems of hot water supply.

Keywords

• l.pneumophila
• l.pneumophila
• biofilms
• temperature
• water
• prophylaxis