Testing the effectiveness of disinfectants 0, 2% Bigvasan, 1% Descocid and 5% Asepsol eko in the destruction of Francisella tularensis subsp. novicida

Francisella tularensis is a highly infectious, facultative gram-negative intracellular bacterium that can cause a deadly disease, tularemia, described in humans and animals. The bacterium is able to survive in different temperature and environmental conditions, while retaining its virulence. There are known four subtypes of Francisella tularensis: tularensis, holartica, mediasiatica and novicida. In this paper, we studied the inhibitory effect of three disinfectants (0, 2% Bigvasan, 1% Descocid and 5% Asepsol eko) on the growth of Francisella tularensis subsp. novicida on Buffered charcoal yeast extract (BCYE) agar during certain time intervals od 10 seconds, 1 minute, 5, 10 and 15 minutes. The results showed one hundred percent efficiency of 5% Asepsol. In all tested intervals there is no increase bacterial colonies, which can be attributed to the sensitivity of F. tularensis subsp. novicida on the bactericidal action of the active substance didecyldimethylammonium chloride and isopropyl alcohol. 1% Descocid and 0, 2% Bigvasan have resulted in an increase in the number of colonies in all time periods, but declining with increasing length of exposure bacterial suspension with solutions of disinfectants. Since the solution of disinfectant prepared in such concentrations that are attributed to use in the laboratory, 5% Asepsol has proven to be best for the complete destruction of Francisella tularensis subsp. novicida, while 0, 2% Bigvasan and 1% Descocid only reduce the number of bacterial colonies.