Brief reports on the use of atomic force microscopy in visualization of Mycobacterium tuberculosis

Abstract

Background: By invention of the atomic force microscope (AFM) in 1986, the imaging of surfaces objects at nanometer-scale resolutions becomes possible. Although, in the beginning, AFM was applied almost exclusively to characterize the surfaces of nonbiological materials, at present the application of the AFM to biological and biomedical research has increased exponentially. Methods: In this study, we tried to investigate and visualize Mycobacterium tuberculosis under AFM. The transformation of bacterial shape and the formation of “hard” shell in resistant or dormant conditions were characterized and identified. Results: Application of AFM for the study of antibiotic-resistant forms of M. tuberculosis revealed the presence of round-shaped bacteria along with conventional rod-shaped ones. There has also been concluded changing of the surface charge of the cell membrane for mutated forms since round-shaped bacteria fixed on the charged surface less strongly and can be moved along the surface by a microscope tip with easily. Conclusions: In brief, this article highlights the optimal operation modes and base principal to study dangerous bacilli under AFM.