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Home▶ Journals▶ Indian Journal of Veterinary Sciences and Biotechnology▶Archive▶Vol. 22 No. 4 (2026)▶Molecular Characterization and Antimicrobial Resistance of…
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Research Article

Molecular Characterization and Antimicrobial Resistance of Escherichia coli Isolated from Mastitis in Dairy Animals

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Akash A. Bothikar — Department of Veterinary Microbiology, KNP College of Veterinary Science, Shirwal, Satara-412801, MAFSU, Maharashtra, India
Prashant P. Mhase — Department of Veterinary Microbiology, KNP College of Veterinary Science, Shirwal, Satara-412801, MAFSU, Maharashtra, India
Pranita G. Manmod — Department of Veterinary Microbiology, KNP College of Veterinary Science, Shirwal, Satara-412801, MAFSU, Maharashtra, India
Uma M. Tumlam — Department of Veterinary Microbiology, KNP College of Veterinary Science, Shirwal, Satara-412801, MAFSU, Maharashtra, India
Prashant D. Pawar — Department of Veterinary Microbiology, KNP College of Veterinary Science, Shirwal, Satara-412801, MAFSU, Maharashtra, India
Sameer N. Jadhav — Department of Veterinary Microbiology, KNP College of Veterinary Science, Shirwal, Satara-412801, MAFSU, Maharashtra, India
Published 10 Jul 2026 Vol. 22 No. 4 (2026), pp. 17-22 ● Open access
❝ How to cite 🔗 https://doi.org/10.48165/ijvsbt.22.4.3
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Abstract

The present study investigated the prevalence of bovine mastitis and antimicrobial resistance patterns of Escherichia coli isolates from dairy animals in Western Maharashtra. A total of 400 lactating cows were screened for mastitis using the California Mastitis Test (CMT) and cultural examination. Of these, 210 (52.50%) animals were confirmed positive, comprising 19.52% (n=41) clinical and 80.47% (n=169) subclinical mastitis cases. Bacteriological analysis revealed Staphylococcus spp. as the predominant pathogen (40.95%), followed by other Gram-positive bacteria, while E. coli accounted for 22.85% (48/210) of the isolates. Antimicrobial susceptibility testing of all bacterial isolates demonstrated highest sensitivity to Amikacin (88.09%) and Ciprofloxacin (82.38%), whereas marked resistance was observed against Gentamicin (69.52%) and Ampicillin-Sulbactam (71.42%). Among E. coli isolates, high susceptibility was recorded for Amikacin (89.58%) and Cefotaxime-Clavulanic acid (83.33%), while resistance to Gentamicin was observed in 68.75% of isolates. MIC50 findings corroborated the disc diffusion results. Molecular confirmation using 16S rRNA PCR yielded a specific 401 bp amplicon. Resistance gene profiling revealed a high prevalence of blaTEM (70.83%), tetA (64.58%), aac(3)-IV (62.50%), qnrA (52.08%), and blaSHV (6.25%). Multidrug resistance was detected in 53.30% of all isolates and 22.91% of E. coli isolates, with common gene combinations including blaTEM+tetA (45.83%) and blaTEM+qnrA (35.41%). The study highlights the alarming emergence of multidrug-resistant E. coli in bovine mastitis and underscores the need for routine antimicrobial surveillance and rational antibiotic use in dairy farms.

KeywordsAntimicrobial resistanceBovine mastitisEscherichia coliMDRResistance genes

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  1. Abed, A. H., Menshawy, A. M. S., Zeinhom, M. M. A., Hossain, D., Khalifa, E., Wareth, G., & Awad, M. F. (2021). Subclinical mastitis in selected bovine dairy herds in North Upper Egypt: Assessment of prevalence, causative bacterial pathogens, antimicrobial resistance and virulence-associated genes. Microorganisms, 9, 1175.
  2. Alfakian, F., Mohseni, N., Hafiz, M., Nikoueian, H., AskariBadouei, M., & RafatiZomorodi, A. (2023). Phenotypic and genotypic investigation of antimicrobial resistance and extended-spectrum beta-lactamase production among Escherichia coli isolated from bovine mastitis. Veterinarski Arhiv, 93(5), 503–512.
  3. Ashraf, A., Imran, M., & Chang, Y. (2018). Antimicrobial resistance of Escherichia coli isolates from mastitic milk and its possible relationship with resistance and virulence genes. Pakistan Journal of Zoology, 50(4), 1435–1441.
  4. CLSI – Clinical and Laboratory Standards Institute. (2018). Performance standards for antimicrobial susceptibility testing: 28th informational supplement (CLSI document M100-S28). Wayne, PA: CLSI.
  5. Emon, A. A., Hossain, H., Chowdhury, M. S. R., Rahman, M. A., Tanni, F. Y., Asha, M. N., Akter, H., Hossain, M. M., Islam, M. R., & Rahman, M. (2024). Prevalence, antimicrobial susceptibility profiles and resistant gene identification of bovine subclinical mastitis pathogens in Bangladesh. Heliyon, 10(14), e34567.
  6. Fesseha, H., Mathewos, M., Aliye, S., & Wolde, A. (2021). Study on prevalence of bovine mastitis and associated risk factors in dairy farms of Modjo town and suburbs, central Oromia, Ethiopia. Veterinary Medicine: Research and Reports, 271–283.
  7. Jagadeesh, D. S., Puttamallappa, R. K., Keregallokoppalu, H. G., & Lakshminarasimhiah, M. (2016). Prevalence of sub-clinical mastitis in cattle and effect on milk quality. Advances in Animal and Veterinary Sciences, 4(5), 237–240.
  8. Janus, A., Deepa, P. M., & Vergis, J. (2023). Epidemiological and clinico-etiological studies in recurrent bovine mastitis. The Pharma Innovation Journal, 12(3), 4213–4216.
  9. Karczmarczyk, M., Abbott, Y., Walsh, C., Leonard, N., & Fanning, S. (2011). Characterization of multidrug-resistant Escherichia coli isolates from animals presenting at a University veterinary hospital. Applied and Environmental Microbiology, 77, 7104–7112.
  10. Kasa, G., Tegegne, B., & Tadesse, B. (2020). Isolation and identification of major pathogenic bacteria from clinical mastitic cows in Asella Town, Ethiopia. Veterinary Medicine International, 2020, 6656755.
  11. Kour, R. (2016). Studies on antibiotic resistance genes among bacterial isolates causing mastitis in dairy animals (MVSc Thesis). Sher-e-Kashmir University of Agricultural Sciences and Technology, Srinagar, Jammu & Kashmir, India.
  12. Kurjogi, M. M., & Kaliwal, B. B. (2014). Epidemiology of bovine mastitis in cows of Dharwad district. International Scholarly Research Notices, 2014, Article ID 968076.
  13. Maynard, C., Fairbrother, J. M., Bekal, S., Sanschagrin, F. O., 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.
  14. Momtaz, H., Rahimi, E., & Moshkelani, S. (2012). Molecular detection of antimicrobial resistance genes in E. coli isolated from slaughtered commercial chickens in Iran. Veterinary Medicine, 57, 193–197.
  15. Mourya, A., Shukla, P. C., Gupta, D. K., Sharma, R. K., Nayak, A., Singh, B., & Pradhan, S. (2020). Prevalence of subclinical mastitis in cows in and around Jabalpur, Madhya Pradesh. Journal of Entomology and Zoology Studies, 8(4), 40–44.
  16. Ombarak, R. A., Awasthi, S. P., Hatanaka, N., & Yamasaki, S. (2021). Detection of plasmid-mediated colistin resistance mcr-1 gene in ESBL-producing Escherichia coli isolated from raw milk hard cheese in Egypt. International Dairy Journal, 117, 104986.
  17. Sadashiv, S. O., & Kaliwal, B. B. (2013). Prevalence of bovine mastitis in North Karnataka, India. International Journal of Pharma and Health Care Research, 1(4), 169–177.
  18. Sambrook, J., & Russell, D. W. (2001). Molecular Cloning: A Laboratory Manual (3rd ed.). Cold Spring Harbor Laboratory Press, New York.
  19. Srinivasan, V., Gillespie, B. E., Lewis, M. J., Nguyen, L. T., Headrick, S. I., Schukken, Y. H., & Oliver, S. P. (2007). Phenotypic and genotypic antimicrobial resistance patterns of Escherichia coli isolated from dairy cows with mastitis. Veterinary Microbiology, 124(3–4), 319–328.
  20. Subhi, A., Saad, A. S., Osman, K., Hashad, M. E., & Deif, H. N. (2023). Prevalence and antibiogram of Escherichia coli isolates recovered from bovine milk. Journal of Applied Veterinary Sciences, 8(3), 82–90.
  21. Vansia, A., Patel, A., & Dudhagara, P. (2021). Analysis of multidrug resistance profile of Escherichia coli from clinical samples from companion animals and bird retrospect to five years (2015–2019): Literature data. Biointerface Research in Applied Chemistry, 11, 12506–12515.
  22. Youssif, N. H., Hafiz, N. M., Halawa, M. A., & Aziz, H. M. (2021). Genes conferring antimicrobial resistance in cattle with subclinical mastitis. Bulgarian Journal of Veterinary Medicine, 24(1), 67–85.

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