METHODOLOGICAL ASPECTS OF RESEARCH OF COMPOSITION OF BIOFILMS in vitro, ex vivo, in vivo

UDC 636.5.087.69
doi: 10.36871/vet.san.hyg.ecol.202201009

Authors

Ekaterina M. Lenchenko,
Dmitry A. Blumenkrants,
Vladislav V. Ponomarev,
Moscow State University of Food Production Moscow, Russian Federation
Inna B. Pavlova,
All-Russian Research Institute of Veterinary Sanitation, Hygiene and Ecology – Branch of Federal State Budget Scientific Institution «Federal Scientific Center – K.I. Skryabin, Ya.R. Kovalenko All-Russian Research Institute of Experimental Veterinary Medicine, Russian Academy of Sciences», Moscow, Russian Federation
Galina S. Tolmacheva,
FSBSI «Federal Scientific Center of Food Systems named after V.M. Gorbatov», Moscow, Russian Federation

Abstract

The article presents the general patterns of formation of a three-dimensional multilayer heterogeneous structure biofilms in vitro, ex vivo, in vivo. It was found, that the mass fraction of cells of biofilms was 86,8-91,4%, of the matrix – 8,9-13,2%, which is due to the structure of the cell wall of microorganisms synthesizing the extracellular matrix. The advantages of transmission and scanning electron microscopy are the visualization of L-shapes and the quantitative assessment of the diameter, perimeter, height, area, volume and chemical composition of cells and the extracellular matrix of microorganisms. Laser modulation interference microscopy made it possible to study biofilms in real time without fixing and staining microorganisms; phase-contrast microscopy – intrapopulation and interpopulation interactions depending on changes in the pH of the environment, oxygen content and other chemical and physical factors. Fluorescent microscopy is a promising method for detection of non-culturable viable cells of microorganisms. The use a modified Gram stain, the use of solution of «Crocus sativus» made it possible to differentiate gram-negative and gram-positive microorganisms and to assess the degree of repair of tissue. The developed new methodological approach made it possible to scientifically substantiate and experimentally confirm the effectiveness of the use of nutrient media containing components for the repair of the cell wall of microorganisms.

Keywords

biofilms, pathogenic microorganisms, L-forms, phagocytosis, indication, transmission electron microscopy, scanning electron microscopy, phase contrast microscopy, laser modulation interference microscopy, luminescence microscopy