Journal of Animal Science and Veterinary Medicine

JOURNAL OF ANIMAL SCIENCE AND VETERINARY MEDICINE
Integrity Research Journals

ISSN: 2536-7099
Model: Open Access/Peer Reviewed
DOI: 10.31248/JASVM
Start Year: 2016
Email: jasvm@integrityresjournals.org

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Antimicrobial resistance profiles of bacterial isolates associated with subclinical mastitis in crossbred lactating goats in the Forest Zone of Cameroon

https://doi.org/10.31248/JASVM2025.686   |   Article Number: 8E6B45647   |   Vol.11 (5) - October 2026

Received Date: 20 August 2026   |   Accepted Date: 28 September 2026  |   Published Date: 30 October 2026

Authors:  Pierrette Ngo Bahebeck* , Claire Stephane Metsopkeng , Estelle Nnanga Mvondo , Kezeter Claude Noudjio , Clémence Aggy Njehoya , Francis Mwanza and Kingsley Agbor Etchu

Keywords: Antibiotic resistance, dairy goat, extended-spectrum β-lactamases, forest zone, subclinical mastitis.

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This preliminary cross-sectional study aimed to determine the prevalence of subclinical mastitis (SCM), to identify the bacterial isolates associated with CMT-positive milk samples and to assess their susceptibility to antimicrobials in crossbred dairy goats in the forest zone of Cameroon. Screening using the California Mastitis Test (CMT) was carried out on 119 lactating goats from 30 farms and two markets in the Central Region. CMT-positive milk samples were subjected to bacteriological analysis, and the isolates were tested for antimicrobial susceptibility using the disc diffusion method (CLSI M100, 2021). The prevalence of SCM was 23.53% (95% CI: 16.8 - 31.9%), ranging from 6.67% to 38.46% depending on the sampling location (farms or markets). A total of 102 bacterial isolates belonging to six species were isolated, dominated by Staphylococcus aureus (21.57%) and Enterobacteriaceae (60.78% of isolates: Klebsiella pneumoniae, Klebsiella aerogenes, Escherichia coli, Salmonella spp.). Enterobacteria exhibited high rates of resistance to broad-spectrum cephalosporins, suggestive of an extended-spectrum β-lactamase mechanism, whilst staphylococci showed frequent resistance to cefoxitin (a phenotypic surrogate marker for mecA-mediated resistance) and complete resistance to tetracycline in S. aureus. Susceptibility to gentamicin and ciprofloxacin remained largely intact in Klebsiella spp. and staphylococci, but was markedly reduced in E. coli and Salmonella spp., particularly for ciprofloxacin (39% and 0% susceptible, respectively). These results indicate the presence of antimicrobial-resistant bacterial isolates of public health relevance, thereby warranting further epidemiological investigation, and call for larger-scale studies to assess the extent of antibiotic resistance in Cameroon's dairy goat sector.

Abegewi, U. A., Esemu, S., Ndip, R., & Ndip, L. (2022). Prevalence and risk factors of coliform-associated mastitis and antibiotic resistance of coliforms from lactating dairy cows in North West Cameroon. PLOS ONE, 17, e0268247. https://doi.org/10.1371/journal.pone.0268247
https://doi.org/10.1371/journal.pone.0268247
 
Abera, M., Habte, T., Aragaw, K., Asmare, K., & Sheferaw, D. (2012). Major causes of mastitis and associated risk factors in smallholder dairy farms in and around Hawassa, Southern Ethiopia. Tropical Animal Health and Production, 44(6), 1175-1179.
https://doi.org/10.1007/s11250-011-0055-3
 
Altayb, H. N., Elbadawi, H. S., Alzahrani, F. A., Baothman, O., Kazmi, I., Nadeem, M. S., Hosawi, S., & Chaieb, K. (2022). Co-occurrence of β-lactam and aminoglycoside resistance determinants among clinical and environmental isolates of Klebsiella pneumoniae and Escherichia coli: A genomic approach. Pharmaceuticals, 15, 1011.
https://doi.org/10.3390/ph15081011
 
Ambrose, S. J., & Hall, R. M. (2021). dfrA trimethoprim resistance genes found in Gram-negative bacteria: Compilation and unambiguous numbering. Journal of Antimicrobial Chemotherapy, 76, 2748-2756.
https://doi.org/10.1093/jac/dkab212
 
Atoui, A., Cordero-Morales, M. J., Laroussi, A., Abdennebi, M., Ben Salem, F., & Najari, S. (2023). Factors influencing the daily milk production variation in suckling local goats. Journal of Oasis Agriculture and Sustainable Development, 5, 37-44.
https://doi.org/10.56027/JOASD.172023
 
bioMérieux. (2009). API® Staph: Identification system for Staphylococcus, Micrococcus and related organisms. bioMérieux, Marcy-l'Étoile.
 
bioMérieux. (2010). API® 20 E: Identification system for Enterobacteriaceae and other non-fastidious Gram-negative bacilli. bioMérieux, Marcy-l'Étoile.
 
Bissong, M. E. A., Mobey, K. N., Muma, V., & Mkong, P. B. (2023). Reduced susceptibility to carbapenems in Enterobacteriaceae and antimicrobial resistance profile of Escherichia coli strains isolated from clinical and zoonotic sources in the Bamenda Municipality, Cameroon. Pan African Medical Journal, 44, 90.
 
Boz, T. I., Suleymanoglu, A. A., & Aydin, A. (2026). Prevalence of extended-spectrum β-lactamase-producing Escherichia coli in various animal-derived food products. Frontiers in Veterinary Science, 13, 1871688.
https://doi.org/10.3389/fvets.2026.1871688
 
Carattoli, A. (2013). Plasmids and the spread of resistance. International Journal of Medical Microbiology, 303, 298-304.
https://doi.org/10.1016/j.ijmm.2013.02.001
 
Clinical and Laboratory Standards Institute (CLSI). (2021). Performance standards for antimicrobial susceptibility testing (31st ed., CLSI supplement M100). Clinical and Laboratory Standards Institute.
 
Clinical and Laboratory Standards Institute (CLSI). (2023). Performance standards for antimicrobial disk and dilution susceptibility tests for bacteria isolated from animals (6th ed., CLSI supplement VET01S). Clinical and Laboratory Standards Institute.
 
Contreras, A., Luengo, C., Sánchez, A., & Corrales, J. C. (2003). The role of intramammary pathogens in dairy goats. Livestock Production Science, 79, 273-283.
https://doi.org/10.1016/S0301-6226(02)00172-0
 
Contreras, A., Sierra, D., Sánchez, A., Corrales, J. C., Marco, J. C., Paape, M. J., & Gonzalo, C. (2007). Mastitis in small ruminants. Small Ruminant Research, 68, 145-153.
https://doi.org/10.1016/j.smallrumres.2006.09.011
 
Dilek, O., Hulya, T., Faruk-Sahan, P., & Özlem, Y. (2019). Identification of bacteria isolated from dairy goats with subclinical mastitis and investigation of methicillin- and vancomycin-resistant Staphylococcus aureus strains. Ankara University Veterinary Faculty Journal, 66, 191-196.
https://doi.org/10.33988/auvfd.431465
 
Ekwem, D., Morrison, T. A., Reeve, R., Enright, J., Buza, J., Shirima, G., Mwajombe, J. K., Lembo, T., & Hopcraft, J. G. C. (2021). Livestock movement informs the risk of disease spread in traditional production systems in East Africa. Scientific Reports, 11, 16375.
https://doi.org/10.1038/s41598-021-95706-z
 
El-Ashker, M., Monecke, S., Gwida, M., Saad, T., El-Gohary, A., Mohamed, A., Reißig, A., Frankenfeld, K., Gary, D., Müller, E., & Ehricht, R. (2022). Molecular characterisation of methicillin-resistant and methicillin-susceptible Staphylococcus aureus clones isolated from healthy dairy animals and their caretakers in Egypt. Veterinary Microbiology, 267, 109374.
https://doi.org/10.1016/j.vetmic.2022.109374
 
European Food Safety Authority (EFSA), & European Centre for Disease Prevention and Control (ECDC). (2023). The European Union summary report on antimicrobial resistance in zoonotic and indicator bacteria from humans, animals and food in 2020/2021. EFSA Journal, 21(3), e07867. https://doi.org/10.2903/j.efsa.2023.7867
https://doi.org/10.2903/j.efsa.2023.7867
 
Farouk, M. M., El-Molla, A., Salib, F. A., & Soliman, Y. A. (2022). Epidemiology of Salmonella species in diarrheic sheep and goats. Pakistan Journal of Zoology, 54, 381-389.
https://doi.org/10.17582/journal.pjz/20201012161016
 
Founou, L. L., Founou, R. C., Ntshobeni, N., Govinden, U., Bester, L. A., Chenia, H. Y., Djoko, C. F., & Essack, S. Y. (2019). Emergence and spread of extended-spectrum β-lactamase-producing Enterobacteriaceae (ESBL-PE) in pigs and exposed workers: A multicentre comparative study between Cameroon and South Africa. Pathogens, 8, 10.
https://doi.org/10.3390/pathogens8010010
 
Gebremeskel, L., Teklu, T., Kasahun, G. G., & Tuem, K. B. (2023). Antimicrobial resistance pattern of Klebsiella isolated from various clinical samples in Ethiopia: A systematic review and meta-analysis. BMC Infectious Diseases, 23, 643.
https://doi.org/10.1186/s12879-023-08633-x
 
Geldsetzer-Mendoza, S., & Riveros, J. L. (2023). Adaptive capacity and resilience of goats in harsh environments: A review. Small Ruminant Research, 220, 106916.
 
Grace, D. (2015). Food safety in low and middle income countries. International Journal of Environmental Research and Public Health, 12, 10490-10507.
https://doi.org/10.3390/ijerph120910490
 
Ho, J. M.-W., & Juurlink, D. N. (2011). Considerations when prescribing trimethoprim-sulfamethoxazole. Canadian Medical Association Journal, 183, 1851-1858.
https://doi.org/10.1503/cmaj.111152
 
Hogan, J. S., Gonzales, R. N., & Harmon, R. J. (1999). Laboratory handbook on bovine mastitis. National Mastitis Council.
 
Holt, J. G., Krieg, N. R., Sneath, P. H. A., Staley, J. T., & Williams, S. T. (2000). Bergey's manual of determinative bacteriology. Lippincott Williams & Wilkins.
 
Institut National de la Statistique (INS). (2017). Annuaire statistique de la Région du Centre, édition 2017. Institut National de la Statistique.
 
International Organization for Standardization (ISO). (2017). ISO 6887-1: Microbiology of the food chain-Preparation of test samples, initial suspension and decimal dilutions for microbiological examination-Part 1: General rules for the preparation of the initial suspension and decimal dilutions (2nd edition). International Organization for Standardization.
 
Jabbar, A., Saleem, M. H., Iqbal, M. Z., Qasim, M., Ashraf, M., Tolba, M. M., Nasser, H. A., Sajjad, H., Hassan, A., Imran, M., & Ahmad, I. (2020). Epidemiology and antibiogram of common mastitis-causing bacteria in Beetal goats. Veterinary World, 13, 2596-2607.
https://doi.org/10.14202/vetworld.2020.2596-2607
 
Kabui, S., Kimani, J., Ngugi, C., & Kagira, J. (2024). Prevalence and antimicrobial resistance profiles of mastitis-causing bacteria isolated from dairy goats in Mukurweini Sub-County, Nyeri County, Kenya. Veterinary Medicine and Science, 10, e1420.
https://doi.org/10.1002/vms3.1420
 
Kahi, A. K., & Wasike, C. B. (2019). Dairy goat production in sub-Saharan Africa: Current status, constraints and prospects for research and development. Asian-Australasian Journal of Animal Sciences, 32, 1233-1242.
https://doi.org/10.5713/ajas.19.0377
 
Ma, Z., Jiang, X., Guo, X., Zhao, Z., Wang, Y., & Zhang, W. (2014). Prevalence and pathogens of subclinical mastitis in dairy goats in China. Tropical Animal Health and Production, 46, 1737-1742.
 
Mahlangu, P., Maina, N., & Kagira, J. (2018). Prevalence, risk factors, and antibiogram of bacteria isolated from milk of goats with subclinical mastitis in Thika East Subcounty, Kenya. Journal of Veterinary Medicine, 2018, 3801479.
https://doi.org/10.1155/2018/3801479
 
McEwen, S. A., & Collignon, P. J. (2018). Antimicrobial resistance: a one health perspective. Microbiology spectrum, 6(2), 10-1128. https://doi.org/10.1128/microbiolspec.arba-0009-2017
https://doi.org/10.1128/microbiolspec.ARBA-0009-2017
 
Mekonnen, H. M., Asmamaw, K., & Courreau, J. F. (2006). Husbandry practices and health in smallholder dairy farms near Addis Ababa, Ethiopia. Preventive Veterinary Medicine, 74, 99-107.
https://doi.org/10.1016/j.prevetmed.2005.10.004
 
Ministère de la Santé Publique du Cameroun (MINSANTE). (2024). Official WHO record: Cameroon: National Action Plan for the Fight Against Antimicrobial Resistance (2024-2028). MINSANTE.
 
Ministère de l'Élevage, des Pêches et des Industries Animales (MINEPIA). (2023). Situation de la production et des importations du sous-secteu r élevage, pêches et industries animales, 2023. MINEPIA.
 
Mishra, A. K., Sharma, N., Singh, D. D., Gururaj, K., Abhishek, Kumar, V., & Sharma, D. K. (2018). Prevalence and bacterial etiology of subclinical mastitis in goats reared in organized farms. Veterinary World, 11, 20-24.
https://doi.org/10.14202/vetworld.2018.20-24
 
Moroni, P., Pisoni, G., Antonini, M., Ruffo, G., Carli, S., Varisco, G., & Boettcher, P. (2005). Subclinical mastitis and antimicrobial susceptibility of Staphylococcus caprae and Staphylococcus epidermidis isolated from two Italian goat herds. Journal of Dairy Science, 88, 1694-1704.
https://doi.org/10.3168/jds.S0022-0302(05)72841-1
 
Muwonge, K. M., Ndagire, H., Mulindwa, J., & Twesigye, C. K. (2025). Multiple antimicrobial resistance indices of Staphylococcus aureus from the nares of goats and slaughterhouse attendants in Kampala city, Uganda: A cross-sectional study. BMC Microbiology, 25, 162.
https://doi.org/10.1186/s12866-025-03891-y
 
Ndahetuye, J. B., Persson, Y., Nyman, A. K., Tukei, M., Ongol, M. P., & Båge, R. (2019). Aetiology and prevalence of subclinical mastitis in dairy herds in peri-urban areas of Kigali in Rwanda. Tropical Animal Health and Production, 51(7), 2037-2044.
https://doi.org/10.1007/s11250-019-01905-2
 
Neyaz, L. A., Alghamdi, H. S., Alghashmari, R. M., et al. (2026). A comprehensive review on the current status of culture media for routine standardized isolation of Salmonella and Shigella spp. from contaminated food. Journal of Umm Al-Qura University for Applied Sciences, 12, 177-190.
https://doi.org/10.1007/s43994-024-00205-2
 
Njage, P., & Buys, E. M. (2015). Pathogenic and commensal E. coli from irrigation water show potential in the transmission of extended-spectrum and AmpC β-lactamase determinants to isolates from lettuce. Microbial Biotechnology, 8, 462-473.
https://doi.org/10.1111/1751-7915.12234
 
Nordmann, P., Dortet, L., & Poirel, L. (2012). Carbapenem resistance in Enterobacteriaceae: Here is the storm! Trends in Molecular Medicine, 18, 263-272.
https://doi.org/10.1016/j.molmed.2012.03.003
 
Oladele, S. B., Gimba, F. I., & Dawurung, C. J. (2019). Study on prevalence, clinical presentation, and associated bacterial pathogens of goat mastitis in Bauchi, Plateau, and Edo states, Nigeria. Veterinary World, 12, 638-645.
https://doi.org/10.14202/vetworld.2019.638-645
 
Oloo, R. D., Ojango, J. M., Ekine-Dzivenu, C. C., Gebreyohanes, G., Mrode, R., Mwai, O. A., & Chagunda, M. G. (2023). Enhancing individual animal resilience to environmental disturbances to address low productivity in dairy cattle performing in sub-Saharan Africa. Frontiers in Animal Science, 4, 1254877.
https://doi.org/10.3389/fanim.2023.1254877
 
Oyebanji, F., Ajibola, A., Aroyehun, T., Omotara, O., Balogun, T., Lasabi, B., Salako, O., Elegbede, S., & Dokunmu, O. (2023). Hygiene and environmental sanitation consequences on the spread of Klebsiella species and its antibiotic resistance in a ruminant animal farm. Nigerian Veterinary Journal, 43, 16-32.
https://doi.org/10.4314/nvj.v43i3.2
 
Paape, M., Poutrel, B., Contreras, A., Marco, J., & Capuco, A. (2001). Milk somatic cells and lactation in small ruminants. Journal of Dairy Science, 84, 170-179. https://doi.org/10.3168/ jds.S0022-0302(01)70223-8
https://doi.org/10.3168/jds.S0022-0302(01)70223-8
 
Quinn, P. J., Markey, B. K., Leonard, F. C., FitzPatrick, E. S., Fanning, S., & Hartigan, P. J. (2011). Veterinary microbiology and microbial disease (2nd ed.). Wiley-Blackwell.
 
Robinson, T. P., Bu, D. P., Carrique-Mas, J., Fèvre, E. M., Gilbert, M., Grace, D., Hay, S. I., Jiwakanon, J., Kakkar, M., Kariuki, S., Laxminarayan, R., Lubroth, J., Magnusson, U., Thi Ngoc, P., Van Boeckel, T. P., & Woolhouse, M. E. (2016). Antibiotic resistance is the quintessential One Health issue. Transactions of the Royal Society of Tropical Medicine and Hygiene, 110, 377-380.
https://doi.org/10.1093/trstmh/trw048
 
Singh, P. (2024). Potential therapeutic effects of goat milk in treating cardiac diseases, mouth ulcers, and dengue fever: A narrative review. Journal of Dairy Science, 107, 1893-1901.
 
Sizana, L. C., Thekisoe, O., Apenteng, O. O., Lekota, K. E., & Ramatla, T. (2026). Occurrence and antibiotic resistance profiles of mastitis pathogens in North West South African dairy herds. Frontiers in Animal Science, 7, 1834437. https://doi.org/10.3389/fanim.2026.1834437
https://doi.org/10.3389/fanim.2026.1834437
 
Smistad, M., Inglingstad, R. A., & Sølverød, L. (2024). Somatic cell count in dairy goats I: Association with infectious and non-infectious factors. BMC Veterinary Research, 20, 509.
https://doi.org/10.1186/s12917-024-04348-6
 
Soh Wenda, B. D., Nken, H., Takam, H. N., Eloundou, C. E., & Fon, D. E. (2024). Rainforest Alliance-UTZ cocoa certification scheme adoption: Determinants and financial implications for cocoa production in the Centre region of Cameroon. PLOS Sustainability and Transformation, 3, e0000115.
https://doi.org/10.1371/journal.pstr.0000115
 
Thabane, L., Ma, J., Chu, R., Cheng, J., Ismaila, A., Rios, L. P., Robson, R., Thabane, M., Giangregorio, L., & Goldsmith, C. H. (2010). A tutorial on pilot studies: the what, why and how. BMC medical Research Methodology, 10, Article number 1.
https://doi.org/10.1186/1471-2288-10-1
 
Tibebu, A., Teshome, Y., Tamrat, H., Bahiru, A., Yitbarek, T., Moliso, M. M., & Assefa, A. (2026). Mastitis in goats: A comprehensive systematic review and meta-analysis of prevalence and the pathogens. Preventive Veterinary Medicine, 246, 106711.
https://doi.org/10.1016/j.prevetmed.2025.106711
 
Tluanpuii, V., & Mahajan, R. K. (2025). Detection of the mecA gene and its association with antimicrobial resistance among coagulase-negative staphylococci isolated from clinical samples in a tertiary care hospital: A cross-sectional study. Cureus, 17, e81643.
https://doi.org/10.7759/cureus.81643
 
Tomanić, D., Kladar, N., & Kovačević, Z. (2025). Antibiotic residues in milk as a consequence of mastitis treatment: Balancing animal welfare and One Health risks. Veterinary Sciences, 12, 1159.
https://doi.org/10.3390/vetsci12121159
 
Van Boeckel, T. P., Brower, C., Gilbert, M., Grenfell, B. T., Levin, S. A., Robinson, T. P., Teillant, A., & Laxminarayan, R. (2015). Global trends in antimicrobial use in food animals. Proceedings of the National Academy of Sciences of the United States of America, 112, 5649-5654.
https://doi.org/10.1073/pnas.1503141112
 
Verbeek, C. J. R., Xia, S. S., & Whyte, D. (2008). Rheology of the gel formed in the California Mastitis Test. Journal of Dairy Research, 75, 385-391.
https://doi.org/10.1017/S0022029908003397
 
Virdis, S., Scarano, C., Cossu, F., Spanu, V., Spanu, C., & De Santis, E. P. L. (2010). Antibiotic resistance in Staphylococcus aureus and coagulase negative staphylococci isolated from goats with subclinical mastitis. Veterinary Medicine International, 2010, Article ID 517060, 6 pages.
https://doi.org/10.4061/2010/517060
 
Vyletělová, M., Vlková, H., & Manga, I. (2011). Occurrence and characteristics of methicillin-resistant Staphylococcus aureus and methicillin-resistant coagulase-negative staphylococci in raw milk manufacturing. Czech Journal of Food Sciences, 29, 11-16.
https://doi.org/10.17221/4443-CJFS
 
Wilson, E. B. (1927). Probable inference, the law of succession, and statistical inference. Journal of the American Statistical Association, 22, 209-212.
https://doi.org/10.1080/01621459.1927.10502953
 
World Health Organization (WHO). (2019). Critically important antimicrobials for human medicine (6th revision). World Health Organization. https://iris.who.int/handle/10665/312266
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