Detection and virulent profiles of multidrug-resistant Shiga toxin-producing Escherichia coli (STEC) from horses in Nigeria
DOI:
https://doi.org/10.66585/ohmi.2026.2.0012Schlagwörter:
Horses, Multidrug resistance, Nigeria, Shiga toxin genes, STECAbstract
Shiga toxin-producing Escherichia coli (STEC) are significant zoonotic pathogens worldwide, causing diseases ranging from diarrhea to hemolytic uremic syndrome (HUS). Ruminants, mainly cattle, are considered the primary reservoirs; however, the role of horses in the epidemiology of STEC remains poorly understood in Nigeria. A total of 231 rectal swabs were collected from horses across selected equine facilities in five Nigerian states. Samples were processed following standard procedures, and isolates were confirmed using the Analytical Profile Index (API 20E) kit. Antibiotic susceptibility testing (AST) was performed using the Kirby-Bauer disk diffusion method with a panel of nine antibiotics, and the isolated Escherichia (E.) coli were classified as sensitive or resistant according to CLSI guidelines. The Multiple Antibiotic Resistance (MAR) index was calculated to assess the risk of contamination. The E. coli isolates were screened for selected Shiga toxin genes (stx1, stx2 and eae) using polymerase chain reaction (PCR). Fourteen isolates (6%) were identified as Shiga toxin-producing E. coli; of these, 78.6% (11/14) expressed at least one virulence gene: 42.9% (6/14) carried stx2, 35.7% (5/14) carried eae, and no isolate carried stx1. All confirmed STEC isolates exhibited multidrug resistance (MDR). The isolates showed complete resistance (100%) to cefuroxime and ciprofloxacin, while all were susceptible to ofloxacin. MAR indices ranged from 0.2 to 0.8, with 77.8% of isolates exhibiting MAR indices ≥0.5. This study reports the detection of MDR STEC in horses in Nigeria, revealing high-level resistance to clinically important antibiotics and significant carriage of virulence genes. The high MAR indices indicate high-risk contamination sources. The detection of MDR STEC in this study underscores a significant health risk to horses, with potential for zoonotic transmission to humans and the environment.
Literaturhinweise
1. Ray R, Singh P. Prevalence and implications of Shiga toxin-producing E. coli in farm and wild ruminants. Pathogens. 2022;11(11):1332. https://doi.org/10.3390/pathogens11111332
2. Bryan A, Youngster I, McAdam AJ. Shiga toxin-producing Escherichia coli. Clin Lab Med. 2015;35(2):247-272. https://doi.org
/10.1016/j.cll.2015.02.004
3. Kim JS, Lee MS, Kim JH. Recent updates on outbreaks of Shiga toxin-producing Escherichia coli and its potential reservoirs. Front Cell Infect Microbiol. 2020;10:273. https://doi.org/10.3389/fcimb.
2020.00273
4. Vanselow BA, Krause DO, McSweeney CS. The Shiga toxin-producing Escherichia coli, their ruminant hosts, and potential on-farm interventions: A review. Aust J Agric Res. 2005;56(3):219-244. https://doi.org/10.1071/AR04129
5. Mainil J. Shiga/verocytotoxins and Shiga/verotoxigenic Escherichia coli in animals. Vet Res. 1999;30(2-3):235-257.
6. Pichner R, Sander A, Steinrück H, Gareis M. Occurrence of Salmonella spp. and shigatoxin-producing Escherichia coli (STEC) in horse faeces and horse meat products. Berl Munch Tierarztl Wochenschr. 2005;118(7-8):321-325.
7. Ojo OE, Ajuwape ATP, Otesile EB, Owoade AA, Oyekunle MA, Adetosoye AI. Potentially zoonotic Shiga toxin-producing Escherichia coli serogroups in the faeces and meat of food-producing animals in Ibadan, Nigeria. Int J Food Microbiol. 2010;142(1-2):214-221. https://doi.org/10.1016/j.ijfoodmicro.2010.06.030
8. Ivbade A, Ojo OE, Dipeolu MA. Shiga toxin-producing Escherichia coli O157:H7 in milk and milk products in Ogun State, Nigeria. Vet Ital. 2014;50(3):185-191. https://doi.org/10.12834/VetIt.129.218
7.1
9. Enabulele SA, Nwankiti OO. Shiga toxin (Stx) gene detection and verotoxigenic potentials of non-O157 Escherichia coli isolated from fermented fresh cow milk (Nono) sold in selected cities in Nigeria. Nig J Basic Appl Sci. 2016;24(1):98-105. https://doi.org/10.4314/n
jbas.v24i1.15
10. Persad AK, LeJeune JT. Animal reservoirs of Shiga toxin-producing Escherichia coli. Microbiol Spectr. 2014;2(4):0027-2014. https://doi.org/10.1128/microbiolspec.EHEC-0027-2014
11. Esonu MC, Kwanashie CN, Mamman PH, Esonu DO. Characterization and antibiotic susceptibility of Escherichia coli isolated from selected internal organs of donkeys slaughtered in abattoirs in Kaduna State, Nigeria. Niger Vet J. 2022;43(2):1-11. https://doi.org/10.4314/nvj.v43i2.1
12. Gentle A, Day MR, Hopkins KL, Godbole G, Jenkins C. Antimicrobial resistance in Shiga toxin-producing Escherichia coli other than serotype O157:H7 in England, 2014-2016. J Med Microbiol. 2020;69(3):379-386. https://doi.org/10.1099/jmm.0.001146
13. Reshadi P, Heydari F, Ghanbarpour R, Bagheri M, Jajarmi M, Amiri M, et al. Molecular characterization and antimicrobial resistance of potentially human-pathogenic Escherichia coli strains isolated from riding horses. BMC Vet Res. 2021;17(1):131. https://doi.org/10.11
86/s12917-021-02832-x
14. Day M, Doumith M, Jenkins C, Dallman TJ, Hopkins KL, Elson R, et al. Antimicrobial resistance in Shiga toxin-producing Escherichia coli serogroups O157 and O26 isolated from human cases of diarrhoeal disease in England, 2015. J Antimicrob Chemother. 2017;72(1):145-152. https://doi.org/10.1093/jac/dkw371
15. Rahat A. Multi-hospital surveillance and antibiotic sensitivity among bacterial isolates of acute respiratory and enteric infection in under-five children in Dhaka, Bangladesh. Master’s dissertation. BRAC University. 2015.
16. Barry AL, Badal RE. Rapid identification of Enterobacteriaceae with the micro-ID system versus API 20E and conventional media. J Clin Microbiol. 1979;10(3):293-298. https://doi.org/10.1128/jcm.10.3.
293-298.1979
17. CLSI. Performance standards for antimicrobial susceptibility testing. 34th ed. CLSI supplement M100. Wayne, PA: Clinical and Laboratory Standards Institute; 2024.
18. Magiorakos AP, Srinivasan A, Carey RB, Carmeli Y, Falagas ME, Giske CG, et al. Multidrug-resistant, extensively drug-resistant and pandrug-resistant bacteria: An international expert proposal for interim standard definitions for acquired resistance. Clin Microbiol Infect. 2012;18(3):268-281. https://doi.org/10.1111/j.1469-0691.
2011.03570.x
19. Krumperman PH. Multiple antibiotic resistance indexing of Escherichia coli to identify high-risk sources of fecal contamination of foods. Appl Environ Microbiol. 1983;46(1):165-170. https://doi.org/10.1128/aem.46.1.165-170.1983
20. Trindade LC, Marques E, Lopes DB, Ferreira MASV. Development of a molecular method for detection and identification of Xanthomonas campestris pv. viticola. Summa Phytopathol. 2007;33(1):16-23. https://doi.org/10.1590/S0100-54052007000100002
21. Van Giau V, Nguyen TT, Nguyen TKO, Le TTH, Nguyen TD. A novel multiplex PCR method for the detection of virulence-associated genes of Escherichia coli O157:H7 in food. 3 Biotech. 2016;6(1):5. https://doi.org/10.1007/s13205-015-0319-0
22. Adorján A, Thuma Á, Könyves L, Tóth I. First isolation of atypical enteropathogenic Escherichia coli from geese (Anser anser domestica) and first description of atypical EPEC from turkeys and pigeons in Hungary. BMC Vet Res. 2021;17(1):263. https://doi.org/
10.1186/s12917-021-02968-w
23. Lengacher B, Kline TR, Harpster L, Williams ML, LeJeune JT. Low prevalence of Escherichia coli O157:H7 in horses in Ohio, USA. J Food Prot. 2010;73(11):2089-2092. https://doi.org/10.4315/0362-028X-73.11.2089
24. Wang X, Yu D, Chui L, Zhou T, Feng Y, Cao Y, et al. A comprehensive review on Shiga toxin subtypes and their niche-related distribution characteristics in Shiga toxin-producing E. coli and other bacterial hosts. Microorganisms. 2024;12(4):687. https://doi.org/10.3390/
microorganisms12040687
25. Sokolovic M, Šimpraga B, Amšel-Zelenika T, Berendika M, Krstulović F. Prevalence and characterization of Shiga toxin-producing Escherichia coli isolated from animal feed in Croatia. Microorganisms. 2022;10(9):1839. https://doi.org/10.3390/micro
organisms10091839
26. Arabestani MR, Karami M, Alikhani MY. Antimicrobial resistance in microorganisms. Avicenna J Clin Microbiol Infect. 2014;1(1):e19941. https://doi.org/10.17795/ajcmi-19941
27. Gandham P. A review of multidrug-resistant Acinetobacter baumannii. Int J Curr Microbiol Appl Sci. 2014;3(2):9-13.
28. Wartu JR, Butt AQ, Suleiman U, Adeke M, Tayaza FB, Musa BJ, et al. Multidrug resistance by microorganisms: A review. Sci World J. 2019;14(4):49-56.
29. Khan JA, Mir IA, Soni SS, Maherchandani S. Antibiogram and multiple antibiotic resistance index of Salmonella enterica isolates from poultry. J Pure Appl Microbiol. 2015;9(3):2495-2500.
30. Jemilehin FO, Ogunleye AO, Ajuwape ATP. Plasmid-mediated quinolone resistance (PMQR) determinants in multidrug-resistant, non-ESBL-producing, non-typhoidal Salmonella species isolated from commercial laying chickens. Int J Environ Stud. 2024;81(4):1823-1835. https://doi.org/10.1080/00207233.2023.2
192619
31. Maddox TW, Clegg PD, Diggle PJ, Wedley AL, Dawson S, Pinchbeck GL, et al. Cross-sectional study of antimicrobial-resistant bacteria in horses. Part 1: Prevalence of antimicrobial-resistant Escherichia coli and methicillin-resistant Staphylococcus aureus. Equine Vet J. 2012;44(3):289-296. https://doi.org/10.1111/j.2042-3306.2011.0
0441.x
32. Olowe OA, Aboderin BW, Idris OO, Mabayoje VO, Opaleye OO, Adekunle OC, et al. Genotypes and phenotypes of Shiga toxin-producing Escherichia coli (STEC) in Abeokuta, southwestern Nigeria. Infect Drug Resist. 2014;7:253-259. https://doi.org/10.214
7/IDR.S66268
Veröffentlicht
Versionen
- 2026-04-12 (2)
- 2026-04-15 (1)
Ausgabe
Rubrik
Lizenz
Copyright (c) 2026 Foluke O. Jemilehin, Enoch J. Adetoyan, Adelekan O. Okunlade, Oluwaseyi I. Abiodun-Ojo, Imisioluwa O. Adedayo, Victor O. Azuh, Tolulope C. Harry, Akinlabi O. Ogunleye (Author)
Dieses Werk steht unter der Lizenz Creative Commons Namensnennung - Nicht-kommerziell 4.0 International.
