DOI: 10.36871 / vet.san.hyg.ecol.201903011
UDC 619: 614

Authors

PAVLOVA I.B., KONONENKO A.B., BANNIKOVA D.A., BRITOVA S.V.
Institute of Veterinary Sanitation, Hygiene and Ecology - BRANCH of FSBI Federal Research Center of the Russian Academy of Science and Technology

Abstract

The purpose of the work is to study the biofilm formation of L. monocytogenes in plants and animal feed. Materials and methods. Decontaminated with antibiotics and washed from their debris, oat seeds were germinated. Oat seedlings were placed in the soil and grown for 10 days. The near-root zone was contaminated with a suspension of listeria, and after a certain time, the morphology and biofilm formation of the listeria populations in the vegetative organs of the plants was studied. Granulated mixed feed exogenously contaminated with a suspension of L. monocytogenes was used as feed. The morphological features of bacterial populations and the formation of biofilms were studied by scanning electron microscopy. Research results. It was shown by experimental bacteriological and morphological studies that, as a result of contamination of the near-root zone, the listeria penetrated through the capillary system of the roots into the oat leaf blades and were localized in the chlorenchyma. During scanning electron microscopy studies of preparations obtained from leaves, cells with typical morphology and at different stages of heteromorphism were detected on fragments of the inner part of the oat leaf plate (lacking the epidermis), and the formation of a biofilm was noted. When studying feed using the SEM method, it was shown that at low temperatures (4 ° C) already within the first 24 hours not only the adhesion of individual cells to the surfaces of the feed particles occurs, but also the formation of microcolonies and colonies often with the formation of biofilms, which indicates active reproduction bacteria data. At the same time, it was noted that at a temperature of 37 ° С and exposure for 24 h, the processes of adhesion and colonization of mixed feed particles by listeria cells under the same conditions were slowed down, which is apparently due to the psychrophilicity of listeria.

Keywords

listeria, plants, compound feed, biofilms, heteromorphism.