REGULARITIES OF THE DEVELOPMENT OF BIOFILMS OF BACTERIA ON DIFFERENT PHASES OF THEIR FORMATION IN VITRO

DOI: 10.36871 / vet.san.hyg.ecol.201804009
UDC: 619: 614

Authors

I. B. PAVLOVA, A. B. KONONENKO, D. A. BANNIKOV, G. S. TOLMACHEV
Institute of Veterinary Sanitation, Hygiene and Ecology - BRANCH of FSBI Federal Research Center of the Russian Academy of Science and Technology
E. M. LENCHENKO
MOSCOW STATE UNIVERSITY OF FOOD PRODUCTION

Abstract

The object of research was the bacterial cultures of the genera Salmonella, Escherichia, Pseudomonas, Staphylococcus. The morphology of biofilms and their developmental phases were studied by light and scanning electron microscopy. To study the formation of biofilms in liquid nutrient media, 24-hour cultures of S-form microorganisms grown on solid or in liquid nutrient media were used. The material was incubated for 24 hours at a temperature of 37 ° C. Then, coverslips with biofilms formed on them were removed with tweezers and placed in Petri dishes with filters laid on the bottom (for electron microscopy). In order to preserve the natural architectonics, 25% of glutaraldehyde was fixed intravitally in pairs for 3 ... 5 hours. For contrasting preparations, pairs of a 2 ... 4% solution of osmium acid were used for 2 ... 3 minutes. The regularities of the process of biofilm formation in opportunistic and pathogenic bacteria were experimentally confirmed: adhesion of single cells, combining by an exopolysaccharide matrix into clusters, and the formation of a mature biofilm. The SEM method has shown the possibility of forming a multilayer biofilm structure, which determines the increased resistance of bacteria to antimicrobial agents (antibiotics, disinfectants).

Keywords

enterobacteria, bacterial biofilm, light and electron microscopy.