Survival of Francisella tularensis subsp. Novicida after exposure to different high temperatures

Francisella tularensis is a gram-negative facultative intracellular bacterium that can cause a fatal disease, tularaemia, in human and animals. This organism has been isolated from over 250 wildlife species, including fish, birds, amphibians, rabbits, squirrels, hares, voles, ticks, and flies. It resists harsh environments, and has been shown to survive in water and mud for more than a year. There are four closely related subspecies of F. tularensis: tularensis (type A), holartica (type B), mediasiatica and novicida. The aim of the study was to follow survival of F. tularensis subsp. novicida after exposure to different high temperatures: 42 °C, 55 °C, 60 °C and 65 °C. Our results showed that F. tularensis subsp. novicida survives in all exposed temperatures during 60 minutes of incubation.