Antimicrobial Resistance Profiling of Shiga Toxin-Producing Escherichia coli Isolated from Diarrhoeic Cattle
DOI:
https://doi.org/10.48165/ijvsbt.2026.22.06.09Keywords:
Antimicrobial resistance, Multidrug resistance, Resistotyping, STECAbstract
Cattle are recognized as important reservoirs of Shiga toxin-producing Escherichia coli (STEC), contributing to the transmission of antimicrobial-resistant strains through the food chain and environment. The present study investigated the phenotypic and genotypic antimicrobial resistance profiles of 40 molecularly confirmed STEC isolates recovered from diarrhoeic cattle in Jaipur, Rajasthan. Antimicrobial susceptibility testing was performed against 11 antimicrobial agents using the Kirby-Bauer disc diffusion method. The highest susceptibility was observed against ampicillin/sulbactam, doxycycline, imipenem and chloramphenicol (80% each), whereas the highest resistance was detected against ciprofloxacin (97.5%), nitrofurantoin (95%) and co-trimoxazole (90%). Multidrug resistance was observed in 39 (97.5%) isolates, and resistotyping revealed 24 distinct resistance patterns, with R-1 as the predominant profile (25.0%). Molecular analysis detected tetA and blaTEM resistance genes in 17.5% and 15.0% of isolates, respectively. The coexistence of virulence-associated STEC with multidrug resistance highlights the potential public health risk posed by cattle as reservoirs of antimicrobial-resistant zoonotic pathogens. These findings emphasize the importance of antimicrobial stewardship, continuous surveillance and One Health approaches to control the emergence and spread of resistant STEC in livestock populations.
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Amezquita-Lopez, B. A., Quiroz-Gómez, O., Deister-Vega, G. R., & Varela-Hernández, J. J. (2014). Shiga toxin-producing Escherichia coli: Infections, reservoirs, and routes of transmission. Foodborne Pathogens and Diseases, 11(6), 449–456.
Beutin, L., Krause, G., Zimmermann, S., Kaulfuss, S., & Gleier, K. (2004). Characterization of Shiga toxin-producing Escherichia coli strains isolated from human patients in Germany over a 3-year period. Journal of Clinical Microbiology, 42(3), 1099–1108.
Chaudhary, W., Jeph, N. K., Sharma, S. K., Bharia, A., Mandawat, S., Choudhary, A., Jyoti, & Anupriya. (2026). Detection and analysis of Shiga toxin-producing Escherichia coli and serotypes in cattle with diarrhea from Rajasthan. Journal of Pure and Applied Microbiology, 20(3), 2136–2145.
Clinical and Laboratory Standards Institute. (2020). Performance standards for antimicrobial susceptibility testing (30th ed., CLSI Supplement M100). Clinical and Laboratory Standards Institute.
Grif, K., Dierich, M. P., Karch, H., & Allerberger, F. (1998). Strain-specific differences in the amount of Shiga toxin released from enterohemorrhagic Escherichia coli after exposure to antimicrobial agents. The Journal of Infectious Diseases, 178(5), 1453–1460.
Gyles, C. L. (2007). Shiga toxin-producing Escherichia coli (STEC) in sheep and cattle. Animal Health Research Reviews, 8(2), 155–173.
Jajarmi, M., Imani Fooladi, A. A., Badouei, M. A., & Ahmadi, A. (2017). Virulence genes, antimicrobial resistance, and phylogenetic analysis of Shiga toxin-producing Escherichia coli isolated from cattle. Veterinary Research Forum, 8(3), 181–188.
Karmali, M. A., Gannon, V., & Sargeant, J. M. (2010). Verocytotoxin-producing Escherichia coli (VTEC). Veterinary Microbiology, 140(3–4), 360–370.
Maynard, C., Fairbrother, J. M., Bekal, S., Sanschagrin, F., Levesque, R. C., Brousseau, R., Masson, L., Lariviere, S., & Harel, J. (2003). Antimicrobial resistance genes in enterotoxigenic Escherichia coli O149:K91 isolates obtained over a 23-year period from pigs. Antimicrobial Agents and Chemotherapy, 47(10), 3214–3221.
Melton-Celsa, A. R. (2014). Shiga toxin (Stx) classification, structure, and function. Microbiology Spectrum, 2(3), EHEC-0024-2013.
Messele, Y. E., Alkhallawi, M., Veltman, T., Trott, D. J., McMeniman, J. P., Kidd, S. P., Low, W. Y., & Petrovski, K. R. (2022). Phenotypic and genotypic analysis of antimicrobial resistance in Escherichia coli recovered from feedlot beef cattle in Australia. Animals, 12(17), 2256.
Mir, R. A., Weppelmann, T. A., Kang, M., Bliss, T., DiLorenzo, N., Lamb, G. C., & Jeong, K. C. (2019). Association of type II toxin–antitoxin genes with antimicrobial resistance in Shiga toxin-producing Escherichia coli. Frontiers in Microbiology, 10, 706.
Mughini-Gras, L., Franz, E., van Pelt, W., & Heck, M. (2018). Attribution of human infections with Shiga toxin-producing Escherichia coli to animal reservoirs in Europe. Foodborne Pathogens and Disease, 15(6), 370–382.
Mukherjee, S., O’Guin, K., Inwood, S. E., & Manning, S. D. (2021). Antibiotic susceptibility profiles and frequency of resistance genes in clinical Shiga toxin-producing Escherichia coli isolates. Microbiology Spectrum, 9, e00421-21.
Pacheco, A. R., & Sperandio, V. (2012). Shiga toxin in enterohemorrhagic Escherichia coli: Regulation and novel anti-virulence strategies. Frontiers in Cellular and Infection Microbiology, 2, 81.
Paton, A. W., & Paton, J. C. (1998). Detection and characterization of Shiga toxigenic Escherichia coli by using multiplex PCR assays for stx1, stx2, eaeA, enterohemorrhagic E. coli hlyA, rfbO111, and rfbO157. Journal of Clinical Microbiology, 36(2), 598–602.
Randall, L. P., Clouting, C., Horton, R. A., Coldham, N. G., Wu, G., Clifton-Hadley, F. A., Davies, R. H., & Teale, C. J. (2011). Prevalence of Escherichia coli carrying extended-spectrum β-lactamases (CTX-M and TEM-52) from broiler chickens and turkeys in Great Britain between 2006 and 2009. Journal of Antimicrobial Chemotherapy, 66(1), 86–95.
Schierack, P., Rödiger, S., & Wieler, L. H. (2023). The dual evolutionary paths of virulence and antimicrobial resistance in livestock-associated Escherichia coli. Veterinary Microbiology, 278, 109641.
Tello, M., Ocejo, M., Oporto, B., & Hurtado, A. (2020). Prevalence of cefotaxime-resistant Escherichia coli isolates from healthy cattle and sheep in northern Spain: Phenotypic and genome-based characterization of antimicrobial susceptibility. Applied and Environmental Microbiology, 86(15), e00742-20.
Umpierrez, A., Bado, I., Olivera, V., Acquistapace, S., Etcheverría, A., Padola, N. L., Varela, G., & Zunino, P. (2017). Antimicrobial resistance and genomic characterization of Shiga toxin-producing Escherichia coli isolated from cattle. Frontiers in Microbiology, 8, 1361.
Valat, C., Haenni, M., & Madec, J. Y. (2024). Mobile genetic elements driving the plasmidome and resistome evolution in zoonotic Escherichia coli. International Journal of Antimicrobial Agents, 63, 107042.
World Health Organization. (2024). Antimicrobial resistance. https://www.who.int/news-room/fact-sheets/detail/antimicrobial-resistance
Zhao, S., White, D. G., McDermott, P. F., Friedman, S., English, L., Ayers, S., Meng, J., Maurer, J. J., Holland, R., Walker, R. D., & Gaines, S. (2001). Identification and expression of cephamycinase blaCMY genes in Escherichia coli and Salmonella isolates from food animals and ground meat. Antimicrobial Agents and Chemotherapy, 45(12), 3647–3650.
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