BIOFILM FORMATION INDUCED BY CLINICAL ISOLATES OF MYCOBACTERIUM TUBERCULOSIS

The data proving low probability of observing Biofilm Formation (BF) by contemporary clinical strains of M. tuberculosis growing on liquid medium in vitro are discussed. A hypothesis about the role of MDR/XDR development hindering BF production was proposed. It was found that strains capable of producing BF grow on Lewenstein–Jensen medium generated R-form specific colonies shaped as a disk with a convex center, “UFO-colonies”. Sixty seven “UFO”- strains were investigated to BF production, resistance to antibiotics and their belonging to the main epidemics clusters of the Beijing genotype (CC1 and CC2-W148). It was shown that MDR/XDR strains were also capable of BF production that, however, was remarkably more frequent in strains of CC1 and CC2-W148 genotypes. Thus, it was hypothesized that BF production might potentially influence an outcome of chronic forms of TB-infection.