Features of isolation of the anthrax pathogen depending on the type of nutrient medium

Abstract

The purpose of the work is to develop a nutrient medium for differentiation of bacillus anthracis from soil aerobic bacilli. In order to achieve the set goal, we used the method of introduction into the environment of cultivation of microorganisms separated from animals and objects of external environment (water, soil, feed, air, scrapes from different surfaces suspected of contamination by their bacillus anthracis) of nutrient substrate sucrose, used by bacteria of Bacillus genus for synthesis of levan product of their metabolism,   a sign absent in bacillus anthracis. This feature is essential for identification and differentiation of bacillus anthracis from closely related saprophytes. To identify and differentiate the bacillus anthracis, the microbes isolated from the external environment were cultivated in a nutrient medium consisting of meat-and-peptone agar (MPA) and stimulator (inductor) synthesis of levan sucrose in the amount of 10% to 100 ml of melted agar. The proposed nutrient media was prepared as follows. Meat-peptonic agar (500 ml) was melted at 100⁰C, 10 g of sucrose was added per 100 ml of medium and after the complete dissolution of sucrose, the nutrient medium was poured into Petri dishes and used for sowing the studied material for identification and differentiation of grown crops. For this purpose, soil samples taken from the territory of old cattle cemeteries were fractionally sown on MPA and thermostatted for 16-18 hours at 37⁰C and examined crops for the presence of matte and rough (R-form) colonies.