Three methods of sum DNA isolation were used.The first one is based on the technique recommended by the AmpliSens company (RIBO–sorb kit) (Moscow). In order to remove the cellular debris, the lytic buffer with bacterial mass was centrifuged for 20 min
in the desktop centrifuge at maximal rpm. After adding 25ìl of sorbent to the supernatant, the mixture wascarefully suspended in vortex. Further processing was carried out strictly according to the procedure recommendedby AmpliSens.