Identification of Escherichia coli, Escherichia albertii, Proteus vulgaris biofilms detected in poultry with respiratory and gastrointestinal diseases

Introduction. When the body resistance-associated compensatory mechanisms are impaired or evolutionarily developed microbiocenoses are changed the quorum sensing signaling molecules facilitates excessive growth of pathogenic microorganisms. Antibacterial potential of inhibitors of intercellular communication molecule synthesis is achieved through reducing the microorganism adhesion and, consequently, in vivo and in vitro contamination. Objective. Study of the dynamics of morphometric and densitometric parameters of biofilms formed by Escherichia coli, Escherichia albertii, Proteus vulgaris isolates identified in poultry with respiratory and gastrointestinal diseases. Materials and methods. Dynamics of the biofilms formed by reference strains and isolates recovered from pathological samples from ROSS-308 chickens at the age of 40–42 weeks ( n = 20) were studied. The sample optical densities were determined using Immunochem-2100 photometric analyzer (HTI, USA), wavelength 580 nm (OD 580 ). Morphometric parameters were recorded at ≥ 90.0% reliable frequency in the field of view of Н604 Trinocular Unico optical microscope (United Products & Instruments Inc., USA) and Hitachi TM3030 Plus scanning electron microscope (Hitachi, Japan). Results. Escherichia coli, Escherichia albertii, and Proteus vulgaris were isolated from pathological samples from the poultry with catarrhal hemorrhagic aerosacculitis, hemorrhagic enteritis, fibrinous polyserositis and splenomegaly signs and then identified. Direct correlations ( r = 0.91) between morphometric and densitometric parameters depending on the cultivation time were established. Cells with defective cell walls, spheroplasts, needle-like and giant structures as well as revertant cells dominated during heterogeneous population dispersion. Conclusion. General patterns of the heterogeneous microorganism population development are mediated by adhesion, synthesis of exocellular molecules, intensive cell proliferation and differentiation depending on the cell cycle stage.