ÓÄÊ: 579.25: 619:616.98
DOI 10.3861/2071-8020-2025-5-11-15
Original Empirical Research
Tishchenko A.S., Fedorovich S.V., Koshchaev A.G., Sedashev A.P., Terekhov V.I.
Abstract. Toxigenic pathogens of Escherichia coli play a central role in the development of escherichiosis in calves and piglets. They are capable of producing specific exotoxins that disrupt the normal functioning of the intestine, leading to the development of severe forms of diarrhea and other complications, which negatively affects the welfare of animals. Along with the widespread spread of pathogenic E. coli, their antibiotic resistance is of particular concern.
The aim of the work was to screen the toxigenic genetic potential of E. coli isolates isolated from sick calves and piglets in the Krasnodar Territory and to study their sensitivity to antimicrobial drugs.
Materials and methods. 9 isolates of E. coli were used in the work, their morphological and cultural properties were studied, genome-wide sequencing, annotation and assembly of their genomes were carried out. The antibiotic sensitivity of isolated isolates to 24 antibacterial perparates of various pharmacological groups was studied using the discodiffusion method.
Research results. A large number of pathogenicity genes were identified, which ranged from 160 to 239. When analyzing the toxigenicity genes, it was found that all E. coli isolates were dominated by pore-forming exotoxins in the form of various classes of hemolysins. Cytotonic toxin genes (eltA, eltB, stb, astA) prevailed in two strains isolated from piglets. Cytotoxin stx2eB genes were detected in two strains. The cluster of genes responsible for the production of cyclomodulin colibactin prevailed in two strains isolated from calves. The analysis of the antibioticogram of the isolated isolates showed their multiple resistance to most antimicrobial drugs. Of the 24 tested antibacterial drugs belonging to 12 groups, all E. coli isolates remained sensitive only to meropenem. Selective sensitivity was recorded to amoxicillin, ampicillin, levomycetin, levofloxacin, norfloxacin, ofloxacin, ciprofloxacin, cefotaxime, and amikacin.
Conclusion. Toxigenic strains of E. coli act as key pathogens in the occurrence of Escherichia coli in calves and piglets in cattle and pig farms of the Krasnodar Territory. Control of the spread of such strains and new approaches to the treatment and prevention of infection are an important link in ensuring the health and productivity of young animals.
Keywords: escherichiosis, toxigenicity, E. coli, sequencing, antibiotic resistance, calves, piglets.
Author affiliation:
Fedorovich Svyatoslav V., Scientific Researcher of the Center for Molecular Genetic Research of the Kuban State Agrarian University; 13, Kalinina st., Krasnodar, 350044; phone: 8-918-2704727; e-mail: havok11.F@gamail.com.
Koshchaev Andrey G., D.Sc. in Biology, Academician of the Russian Academy of Sciences, Professor, Vice-Rector for Scientific Work of the Kuban State Agrarian University; 13, Kalinina st., Krasnodar, 350044; phone: 8-861-2215637; e-mail: koshhaev.a@kubsau.ru.
Sedashev Artem P., Laboratory Assistant at the Microbiology Laboratory of the Center for Biotechnology of the Kuban State Agrarian University; 13, Kalinina st., Krasnodar, 350044; phone: 8-918-0511691; e-mail: sedashevartem@mail.ru.
Terekhov Vladimir I., D.Sc. in Biology, Professor of the Pashkovsky Agricultural College; 220, Bershanskaya st., Krasnodar, 350910; phone: 8-988-4742115; e-mail: vterekhov@list.ru.
Responsible for correspondence with the editorial board: Tishchenko Alexander S., Ph.D. in Veterinary Medicine, Head of the Microbiology Laboratory of the Center for Biotechnology, Docent of the Department of Microbiology, Epizootology and Virology of the Faculty of Veterinary Medicine of the Kuban State Agrarian University named after I.T. Trubilin; 13, Kalinina st., Krasnodar, 350044; phone: 8-928-4692399; e-mail: mephisto83@inbox.ru.
Authors’ Contribution:
Tishchenko A.S.: methodology development, visualization, discussion of results, drafting the manuscript.
Fedorovich S.V.: sequencing performance, bioinformatic analysis, validation of results.
Koshchaev A.G.: methodology development, reviewing and editing the manuscript.
Sedashev A.P.: antibiotic susceptibility testing, recording of the obtained results.
Terekhov V.I.: conceptualization, validation and discussion of research results.
Conflict of Interest Statement: the authors declare no conflict of interest.
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