Emergence of Methicillin-Resistant Staphylococcus Aureus from Subclinical Mastitis of Cholistani Sheep Posing a Great Threat to the Development of Antibiotic Resistance
Keywords:
Subclinical , Mastitis, Prevalence, Sheep, Antibiotic, MethicillinAbstract
Mastitis is a serious illness that affects dairy sheep. All around the world, dairy farms have been shown to harbour methicillin-resistant S. aureus (MRSA). The study investigated the subclinical mastitis in sheep, associated risk factors, the presence of MRSA its susceptibility against different antibiotics. The positive milk samples were cultured for identification of Staphylococcus aureus on mannitol salt agar and confirmed through biochemical tests and Gram staining. MRSA was identified and confirmed by phenotypic method using oxacillin antibiotic discs through disc diffusion test. A data capture form was used for recording various assumed determinants related to subclinical mastitis in sheep. The study revealed that 12% (48/400) samples were positive for subclinical mastitis, and among these, a majority of the samples (88%, 42/48) were positive for S. aureus. Prevalence of MRSA based on disc diffusion test was 21.42% (9/42). Poor milker care during milking, unhygienic milking, high milk yield, use of teat dips, and mixed type of grazing were significantly (p<0.05) associated with subclinical mastitis in sheep. Results of in-vitro antibiotic susceptibility trials showed that MRSA was 100% resistance to Cefoxitin (30µg), 11.11% to Oxytetracycline (30µg) and Tylosin (30µg), 33.33% to Fusidic acid (10µg) and Vancomycin (30µg), 11.11% to ciprofloxacin (5µg) while it was sensitive to Moxifloxacin (5µg), Trimethoprim + Sulfamethoxazole (1.2µg, 23.75µg) and Linezolid (30µg). The study concluded that subclinical mastitis is an important issue in sheep; the presence of resistant isolate MRSA needs effective treatment to prevent its spread in lambs and humans to reduce antibiotic resistance issues.
References
Ahmed, Z.A., Yousif, A.A. (2021). Molecular and phylogenetic analysis of methicillin-resistant Staphylococcus aureus isolated from subclinical mastitis in lactating ewes. Iraqi Journal of Veterinary Sciences 35, 121-126.
Alba, D. F., da Rosa, G., Hanauer, D., Saldanha, T. F., Souza, C. F., Baldissera, M. D., and Da Silva, A. S. (2019). Subclinical mastitis in Lacaune sheep: Causative agents, impacts on milk production, milk quality, oxidative profiles and treatment efficacy of ceftiofur. Microbial pathogenesis, 137, 103732.
Ali, M., M. Ahmad, K. Muhammad, A. Anjum (2011). Prevalence of subclinical mastitis in dairy buffaloes of Punjab, Pakistan. Journal of Animal and Plant Science, 21(3): 477-480.
Altaf, M., Ijaz, M., Ghaffar, A., Rehman, A., and Avais, M. (2019). Antibiotic susceptibility profile and synergistic effect of non-steroidal anti-inflammatory drugs on antibacterial activity of resistant antibiotics (Oxytetracycline and Gentamicin) against methicillin-resistant Staphylococcus aureus (MRSA). Microbial Pathogenesis, 137, 103755.
Altaf, M., Ijaz, M., Iqbal, M. K., Rehman, A., Avais, M., Ghaffar, A., and Ayyub, R. M. (2020). Molecular Characterization of Methicillin-Resistant Staphylococcus aureus (MRSA) and Associated Risk Factors with the Occurrence of Goat Mastitis. Pakistan Veterinary Journal, 40(1).
Andrade, N. C., Laranjo, M., Costa, M. M., and Queiroga, M. C. (2021). Virulence factors in Staphylococcus associated with small ruminant mastitis: Biofilm production and antimicrobial resistance genes. Antibiotics, 10(6), 633.
Aqib, A. I., Ijaz, M., Anjum, A. A., Malik, M. A. R., Mehmood, K., Farooqi, S. H., and Hussain, K. (2017). Antibiotic susceptibilities and prevalence of Methicillin-resistant Staphylococcus aureus (MRSA) isolated from bovine milk in Pakistan. Acta tropica, 176, 168-172.
Aqib, A. I., Nighat, S., Ahmed, R., Sana, S., Jamal, M. A., Kulyar, M. F. E. A., and Rahman, A. (2019). Drug Susceptibility Profile of Staphylococcus aureus Isolated from Mastitic Milk of Goats and Risk Factors Associated with Goat Mastitis in Pakistan. Pakistan Journal of Zoology, 51(1).
Arsenault, J., Dubreuil, P., Higgins, R., and Bélanger, D. (2008). Risk factors and impacts of clinical and subclinical mastitis in commercial meat-producing sheep flocks in Quebec, Canada. Preventive Veterinary Medicine, 87(3-4), 373-393.
Bachaya, H. A., Iqbal, Z., Muhammad, G., Yousaf, A., and Ali, H. M. (2005). Subclinical mastitis in buffaloes in the Attock district of Punjab (Pakistan). Pakistan Veterinary Journal, 25(3), 134.
Bergonier, D., and Berthelot, X. (2003). New advances in epizootiology and control of ewe mastitis. Livestock Production Science, 79(1), 1-16.
Chambers, H. F., and DeLeo, F. R. (2009). Waves of resistance: Staphylococcus aureus in the antibiotic era. Nature Reviews Microbiology, 7(9), 629-641.
Clinical Laboratory Standards Institute (2015). Performance Standards for Antimicrobial Disk and Dilution Susceptibility Tests for Bacteria Isolated from Animals. Approved Standard M31-A3.
de Almeida, L. M., de Almeida, M. Z. P., de Mendonça, C. L., and Mamizuka, E. M. (2011). Novel sequence types (STS) of Staphylococcus aureus isolates causing clinical and subclinical mastitis in flocks of sheep in the northeast of Brazil. Journal of Dairy Research, 78(3), 373-378.
Fragkou, I. A., Boscos, C. M., & Fthenakis, G. C. (2014). Diagnosis of clinical or subclinical mastitis in ewes. Small Ruminant Research, 118(1-3), 86-92.
Garcia, E. R., Vergara, A., Aziz, F., Narváez, S., Cuesta, G., Hernández, M., and Casals-Pascual, C. (2022). Changes in the gut microbiota and risk of colonisation by multidrug-resistant bacteria, infection, and death in critical care patients. Clinical Microbiology and Infection, 28(7), 975-982.
Iqbal, N., Aslam, S., Hussain, N., Luqman, Z., and Jawad, H. (2020). Dystocia handling by cesarean section in beetal goat in Pakistan: a surgical approach. Journal of Animal Health and Production, 8(3), 134-137.
Jabbar, A., Saleem, M. H., Iqbal, M. Z., Qasim, M., Ashraf, M., Tolba, M. M., and Ahmad, I. (2020). Epidemiology and antibiogram of common mastitis-causing bacteria in Beetal goats. Veterinary world, 13(12), 2596.
Javed, M. U., Ijaz, M., Fatima, Z., Anjum, A. A., Aqib, A. I., Ali, M. M., and Ghaffar, A. (2021). Frequency and antimicrobial susceptibility of methicillin and vancomycin-resistant Staphylococcus aureus from bovine milk. Pakistan Veterinary Journal, 41(4).
Knuth, R. M., Stewart, W. C., Taylor, J. B., Yeoman, C. J., Bisha, B., Page, C. M., and Murphy, T. W. (2019). Subclinical mastitis in sheep: aetiology and association with milk somatic cell count and ewe productivity in three research flocks in the Western United States. Translational Animal Science, 3(Supplement_1), 1739-1743.
Koop, G., Collar, C. A., Toft, N., Nielen, M., van Werven, T., Bacon, D., and Gardner, I. A. (2013). Risk factors for subclinical intramammary infection in dairy goats in two longitudinal field studies were evaluated by Bayesian logistic regression. Preventive Veterinary Medicine, 108(4), 304-312.
Lowy, F. D. (2003). Antimicrobial resistance: the example of Staphylococcus aureus. The Journal of Clinical Investigation, 111(9), 1265-1273.
Maréchal, L., and Loir, L. (2011). Mastitis impact on technological properties of milk and quality of milk products--a review. Dairy Science and Technology, 91(3), 247-282.
Megersa, B., Tadesse, C., Abunna, F., Regassa, A., Mekibib, B., and Debela, E. (2010). Occurrence of mastitis and associated risk factors in lactating goats under pastoral management in Borana, Southern Ethiopia. Tropical animal health and production, 42, 1249-1255.
Minarini, L. A. D. R., Andrade, L. N. D., De Gregorio, E., Grosso, F., Naas, T., Zarrilli, R., and Camargo, I. L. (2020). antimicrobial resistance as a global public health problem: how can we address it?. Frontiers in Public Health, 8, 612844.
Mørk, T., Waage, S., Tollersrud, T., Kvitle, B., and Sviland, S. (2007). Clinical mastitis in ewes: bacteriology, epidemiology, and clinical features. Acta Veterinaria Scandinavica, 49, 1-8.
Nemeghaire, S., Argudín, M. A., Haesebrouck, F., and Butaye, P. (2014). Epidemiology and molecular characterization of methicillin-resistant Staphylococcus aureus nasal carriage isolates from bovines. BMC Veterinary Research, 10, 1-9.
Obaidat, M. M., Bani Salman, A. E., and Roess, A. A. (2018). High prevalence and antimicrobial resistance of meca Staphylococcus aureus in dairy cattle, sheep, and goat bulk tank milk in Jordan. Tropical animal health and production, 50, 405-412.
Pakistan Economic Survey (2022-23) Economic Advisor’s wing, Finance Division: Government of Pakistan.
Pantosti, A., Sanchini, A., and Monaco, M. (2007). Mechanisms of antibiotic resistance in Staphylococcus aureus. Future microbiology, 2(3), 323-334.
Papadopoulos, P., Papadopoulos, T., Angelidis, A. S., Boukouvala, E., Zdragas, A., Papa, A., and Sergelidis, D. (2018). Prevalence of Staphylococcus aureus and methicillin-resistant S. aureus (MRSA) along the production chain of dairy products in north-western Greece. Food microbiology, 69, 43-50.
Queiroga, M. C. (2017). Prevalence and aetiology of sheep mastitis in the Alentejo region of Portugal. Small Ruminant Research, 153, 123-130.
Shahzad, M. A. (2022). The need for national livestock surveillance in Pakistan. Journal of Dairy Research, 89(1), 13-18.
Stastkova, Z., Karpiskova, S., and Karpiskova, R. (2009). Occurrence of methicillin-resistant strains of Staphylococcus aureus at a goat breeding farm. Veterinární medicína, 54(9), 419-426.
Thrusfield, M. (2013). Veterinary epidemiology. John Wiley and Sons.
Turutoglu, H., Hasoksuz, M., Ozturk, D., Yildirim, M., and Sagnak, S. (2009). Methicillin and aminoglycoside resistance in Staphylococcus aureus isolates from bovine mastitis and sequence analysis of their meca genes. Veterinary research communications, 33, 945-956.
Vasileiou, N. G. C., Cripps, P. J., Ioannidi, K. S., Chatzopoulos, D. C., Gougoulis, D. A., Sarrou, S., and Fthenakis, G. C. (2018). Extensive countrywide field investigation of subclinical mastitis in sheep in Greece. Journal of Dairy Science, 101(8), 7297-7310.
Wang, D., Wang, Z., Yan, Z., Wu, J., Ali, T., Li, J., and Han, B. (2015). Bovine mastitis Staphylococcus aureus: Antibiotic susceptibility profile, resistance genes and molecular typing of methicillin-resistant and methicillin-sensitive strains in China. Infection, Genetics and Evolution, 31, 9-16.
Watkins, G. H., Burriel, A. R., and Jones, J. E. T. (1991). A field investigation of subclinical mastitis in sheep in southern England. British Veterinary Journal, 147(5), 413-420.
Additional Files
Published
How to Cite
Issue
Section
License
Copyright (c) 2025 International Journal of Agriculture Innovations and Cutting-Edge Research (HEC Recognised)

This work is licensed under a Creative Commons Attribution-ShareAlike 4.0 International License.
15162394 Canada Inc., ON, Canada