I. V. Antonevskiy1 , N. A. Leshcheva1, O. V. Sokolova2 , V. I. Pleshakova1 , V. D. Zubareva2 , E. V. Frik1
1 Omsk State Agrarian University named after P. A. Stolypin, Omsk, Russia
2 Ural Federal Agrarian Scientific Research Center of the Ural Branch of the Russian Academy of Sciences, Ekaterinburg, Russia
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Volume 26 No. 4
Date of paper submission: 28.11.2025, date of review: 16.12.2025, date of acceptance: 10.02.2026.
Published: 04/30/2026
Abstract. The increasing prevalence of antibiotic-resistant microorganisms in livestock farming poses a serious threat not only to veterinary medicine but also to human medicine. The formation of biofilms is considered one of the key mechanisms of pathogen resistance, as it reduces the effectiveness of antimicrobial drugs and promotes the persistence of pathogens in the environment and the host organism. However, the relationship between the genetic determinants of biofilm formation, its phenotypic manifestations, and the antibiotic resistance profile in bacteria isolated from animals remains insufficiently studied. The purpose of this study was to establish a relationship between genetic factors, phenotypic ability for biofilm formation, and antibiotic resistance in isolates of Escherichia coli and Staphylococcus spp. isolated from animals. Methods. A total of 155 bacterial isolates of E. coli (n = 85) and Staphylococcus spp. (n = 70) were studied. The phenotypic ability for biofilm formation was determined by measuring the optical density in microtiter plate wells stained with crystal violet. Biofilm-associated genetic determinants for E. coli (csgD, bcsA, fliA) and Staphylococcus spp. (icaD, fnbB, clfB) were detected by PCR. Antibiotic susceptibility was assessed using the disk diffusion method according to EUCAST standards, with the calculation of the multiple antibiotic resistance (MAR) index. The scientific novelty lies in the comprehensive assessment of the combination of genetic and phenotypic traits of biofilm formation with the resistance profile in isolates from animals. Results. A positive correlation was found between the intensity of biofilm formation and the level of antibiotic resistance (E. coli: r = 0.48; Staphylococcus spp.: r = 0.52; p < 0.001). The presence of bcsA, icaD, fnbB, and clfB genes was associated with a pronounced degree of biofilm formation in the studied cultures. Strains with strong biofilm formation exhibited increased resistance to β-lactams and aminoglycosides; among staphylococci, MRSA strains were noted. The obtained data confirm that biofilm formation is a significant factor in multiple antibiotic resistance in bacteria circulating among livestock populations.
Keywords: microbiota, isolates, Escherichia coli, Staphylococcus spp., biofilm formation, antibiotic resistance, genetic determinants, PCR, screening
Acknowledgements. The study was supported by the Russian Science Foundation grant No. 25-26-20048 dated April 17, 2025, https://rscf.ru/project/25-26-20048/
For citation: Antonevskiy I. V., Leshcheva N. A., Sokolova O. V., Pleshakova V. I., Zubareva V. D., Frik E. V. Genetic and phenotypic determinants of biofilm formation and their relationship with antibiotic resistance in Escherichia coli and Staphylococcus spp. Agrarian Bulletin of the Urals. 2926; 26 (04): 631‒642. https://doi.org/10.32417/1997-4868-2026-26-04-631-642 (In Russ.)
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