DOI: https://doi.org/10.17728/jaft.31438

Occurrence and Survival Dynamics of Selected Foodborne Pathogens in Naturally Fermented Milk from Informal Markets in Zimbabwe

*Desmond Tichaona Mugadza orcid  -  Research and Innovation Directorate, Great Zimbabwe University, P. O. Box 1235, Masvingo, Zimbabwe, Zimbabwe
Tsitsi Cythia Mupfeki  -  Department of Food Science and Nutrition, Midlands State University, P Bag 9055, Gweru, Zimbabwe, Zimbabwe
Michael Makoni  -  Department of Food Science and Nutrition, Midlands State University, P Bag 9055, Gweru, Zimbabwe, Zimbabwe
Tafadzwa Matambanadzo  -  Department of Food Science and Nutrition, Midlands State University, P Bag 9055, Gweru, Zimbabwe, Zimbabwe
Talknice Zvamaziva Jombo  -  Department of Food Science and Nutrition, Midlands State University, P Bag 9055, Gweru, Zimbabwe, Zimbabwe
Nomagugu Mpofu  -  Department of Food Science and Nutrition, Midlands State University, P Bag 9055, Gweru, Zimbabwe, Zimbabwe
Rudo Natasha Mugadza  -  Department of Food Science and Nutrition, Midlands State University, P Bag 9055, Gweru, Zimbabwe, Zimbabwe
Ruth Nyoka orcid  -  Department of Food Science and Nutrition, Midlands State University, P Bag 9055, Gweru, Zimbabwe, Zimbabwe
Victor Tatenda Nyanhete  -  Department of Food Science and Nutrition, Midlands State University, P Bag 9055, Gweru, Zimbabwe, Zimbabwe
Open Access Copyright 2026 Journal of Applied Food Technology

Citation Format:
Abstract

Informal markets are important in the supply chain of dairy products in Zimbabwe. The objective of this study was to determine the prevalence of S. aureus, Salmonella spp and E. coli in naturally fermented milk and its survival during controlled milk fermentation. Thirty samples of naturally fermented milk were collected from milk vendors in Harare and Gweru central business districts together with 15 raw milk samples from five dairy farms around two towns. All samples were analysed for pH while naturally fermented milk samples were further analysed for total bacterial count, total coliform, lactic acid bacteria, Salmonella spp., E. coli and S. aureus at 0 h while raw milk samples were analysed for the same parameters at 0, 12 and 24 h during natural fermentation. Four samples of commercial UHT milk were obtained, 2 were inoculated with a starter culture together with S. aureus and E. coli respectively while the other 2 were inoculated with starter culture, allowed to ferment and then inoculated with both E. coli and S. aureus respectively when the milk had set. Samples were tested for pH, E. coli and S. aureus during fermentation at 0, 6, 12, 18 and 24 h. Total bacteria counts of samples from vendors ranged between 6.55±0.31 to 9.00±0.04 log10 CFU/mL while total coliform ranged from 2.06±0.14 to 6.70±0.10 log10CFU/mL. E. coli were enumerated in all samples in the range of 1.33±0.15 to 5.83±0.10 log10CFU/mL. S. aureus was enumerated in 5 of the 10 samples where it ranged between 5.00±0.20 to 6.07±0.25 log10CFU/mL. Both S. aureus and E. coli survived acidic conditions during fermentation. The occurrence and survival of these pathogens raise compliance concerns with Zimbabwean food safety legislation. It is therefore recommended that food business operators producing and or selling naturally fermented milk must adhere to strict hygienic practices. In addition, strengthening enforcement of existing food legislation in Zimbabwe and improving the capacity of national food control systems; particularly for informal and small-scale dairy processors; remain critical priorities, as widely recognised across developing countries.

Fulltext View|Download Email colleagues
Keywords: naturally fermented milk; E.coli; S. aureus; Salmonella spp. ; lactic acid; occurrence; survival
Funding: N/A

Article Metrics:

Article Info
Section: Research Articles
Language : EN
  1. Ahmed, Z. A., Kasim, M. H., Tegegne, B., & Salah, H. M. (2022). Assessment of Hygiene Practices and Bacteriological Quality of Raw Cow Milk of Selected Dairy Farm in Dessie, Ethiopia. American Journal of Aquaculture and Animal Science, 1(1), 27-37. https://doi.org/10.54536/ajaas.v1i1.1071
  2. Aijuka, M., Charimba, G., Hugo, C. J., & Buys, E. M. (2015). Characterization of bacterial pathogens in rural and urban irrigation water. Journal of Water and Health, 13(1), 103-117. https://doi.org/10.2166/wh.2014.228
  3. All, A. A. A., & Dardir, H. A. (2009). Hygienic quality of local traditional fermented skimmed milk (Laban Rayb) sold in Egypt
  4. Aliyo, A.; Teklemariam, Z. (2022) Assessment of Milk Contamination, Associated Risk Factors, and Drug Sensitivity Patterns among Isolated Bacteria from Raw Milk of Borena Zone. Ethiop. J. Trop. Med. 2022, 3577715. https://doi.org/10.1155/2022/3577715
  5. Angelidis, A. S. (2015). The microbiology of raw milk. Dairy Microbiology. A Practical Approach. Taylor & Francis Group, LLC, USA
  6. Argudín MÁ, Mendoza MC, Rodicio MR. (2010) Food poisoning and Staphylococcus aureus enterotoxins. Toxins. 2:1751–73. https://doi.org/10.3390/toxins2071751
  7. Ashraf, R., & Smith, S. C. (2015). Selective enumeration of dairy based strains of probiotic and lactic acid bacteria. International Food Research Journal, 22(6), 2576-2586. ISSN 1985-4668
  8. Bell, V., Guina, J., & Fernandes, T. H. (2023). African fermented foods and beverages. Potential impact on health. Microbial fermentations in nature and as designed processes, 293-322
  9. Bore E, Langsrud S, Langsrud O, Rode TM, Holck A (2007) Acid- shock responses in Staphylococcus aureus investigated by global gene expression analysis. Microbiology 153:2289–2303. https://doi.org/10.1099/mic.0.2007/005942-0
  10. Chimuti, S., Midzi, N., Njage, P. K., & Mugadza, D. T. (2016). Microbial species of safety concern in milk from informal processors in Harare, Zimbabwe. African Journal of Microbiology Research, 10(32), 1257-1262. https://doi.org/10.5897/AJMR2016.8139
  11. Codex Alimentarius, CODEX Standard for Fermented Milks 242-2003, 2nd edition, 2003
  12. Codex Alimentarius Commission (2004). Code of Hygienic Practice for Milk and Milk Products (CAC/RCP 57-2004). Rome: FAO/WHO
  13. Dai, J., Wu, S., Huang, J., Wu, Q., Zhang, F., Zhang, J., Wang, J., Ding, Y., Zhang, S., Yang, X., Lei, T., Xue, L., & Wu, H. (2019). Prevalence and characterization of Staphylococcus aureus isolated from pasteurized Milk in China. Frontiers in Microbiology, 10, 641. https://doi.org/10.3389/fmicb.2019.00641
  14. Darbandi, A., Asadi, A., Mahdizade Ari, M., Ohadi, E., Talebi, M., Halaj Zadeh, M. & Kakanj, M. (2022). Bacteriocins: Properties and potential use as antimicrobials. Journal of Clinical Laboratory Analysis, 36(1). https://doi.org/10.1002/jcla.24093
  15. Dlamini, B. C., & Buys, E. M. (2009). Survival and growth of acid adapted Escherichia coli strains in broth at different pH levels. Journal of food safety, 29(3), 484-497. https://doi.org/10.1111/j.1745-4565.2009.00171.x
  16. Falfán-Cortés, R.N., Mora-Peñaflor, N., Gómez-Aldapa, C.A., Rangel-Vargas, E., Acevedo-Sandoval, O.A., Franco-Fernández, M.J. and Castro-Rosas, J., (2022). Characterization and evaluation of the probiotic potential in vitro and in situ of Lacticaseibacillus paracasei isolated from tenate cheese. Journal of Food Protection, 85(1), pp.112-121. https://doi.org/10.4315/JFP-21-021
  17. FAO & WHO. (2006). Strengthening national food control systems: Guidelines to assess capacity building needs. Rome: FAO/WHO
  18. Fayemi, O. E., & Buys, E. M. (2017). Effect of Lactobacillus plantarum on the survival of acid‐tolerant non‐O157 Shiga toxin‐producing E. coli (STEC) strains in fermented goat's milk. International journal of dairy technology, 70(3), 399-406. https://doi.org/10.1111/1471-0307.12340
  19. Government of Zimbabwe. Food and Food Standards Act [Chapter 15:04]. Harare: Government Printers; Zimbabwe
  20. Government of Zimbabwe. Public Health Act [Chapter 15:17]. Harare: Government Printers; Zimbabwe
  21. Grace D. (2015). Food safety in low and middle income countries. International Journal of Environmental Research and Public Health. 12(9):10490–10507. https://doi.org/10.3390/ijerph120910490
  22. Grispoldi L, Karama M, Armani A, Hadjicharalambous C, & Beniamino T. Cenci-Goga (2021) Staphylococcus aureus enterotoxin in food of animal origin and staphylococcal food poisoning risk assessment from farm to table, Italian Journal of Animal Science, 20:1, 677-690, DOI: 10.1080/1828051X.2020.1871428
  23. Gweshe, W. M. (2018). Determination of prevalence, antimicrobial resistance assessment and screening of virulent genes of Escherichia coli in ready-made meat products and traditionally fermented milk from the formal and informal markets in Harare
  24. Hasan, M. N., Sultan, M. Z., & Mar-E-Um, M. (2014). Significance of fermented food in nutrition and food science. Journal of Scientific Research, 6(2). https://doi.org/10.3329/jsr.v6i2.16530
  25. Hill, A. R., & Kethireddipalli, P. (2013). Dairy Products: Cheese and Yogurt. Chapter 8; Biochemistry of Foods (Third Edition). 319–362
  26. ISO 4833-1:2013 Microbiology of the food chain—Horizontal method for the enumeration of microorganisms—Part 1: Colony count at 30 degrees C by the pour plate technique, https://www.iso.org/standard/53728.html
  27. ISO 4832:2006. Microbiology of food and animal feeding stuffs - Horizontal method for the enumeration
  28. Maoloni, A., Blaiotta, G., Ferrocino, I., Mangia, N. P., Osimani, A., Milanović, V., ... & Aquilanti, L. (2020). Microbiological characterization of Gioddu, an Italian fermented milk. International journal of food microbiology, 323, 108610. https://doi.org/10.1016/j.ijfoodmicro.2020.108610
  29. Martin NH, Trmcic A, Hsieh T-H, Boor K.J, Wiedmann M. (2016). The evolving role of coliforms as indicators of unhygienic processing conditions in dairy foods. Front Microbiol. 7(1549):1–8. https://doi.org/10.3389/ fmicb.2016.01549
  30. Medvedova, A., Gyoriova, R., Lehotová, V., & Valik, L. (2020). Co-cultivation growth of Escherichia coli and Staphylococcus aureus as two common dairy contaminants. Polish Journal of Food and Nutrition Sciences, 70(2). DOI: 10.31883/pjfns/116395
  31. Medveďová, A., & Valík, Ľ. (2012). Staphylococcus aureus: Characterisation and quantitative growth description in milk and artisanal raw milk cheese production. Structure and function of food engineering, 71-102. DOI: 10.5772/48175
  32. Mhone, T. A., Matope, G., & Saidi, P. T. (2011). Aerobic bacterial, coliform, Escherichia coli and Staphylococcus aureus counts of raw and processed milk from selected smallholder dairy farms of Zimbabwe. International Journal of Food Microbiology, 151(2), 223-228. https://doi.org/10.1016/j.ijfoodmicro.2011.08.028
  33. Mugadza, D. T., Feresu, K. W., Jombo, T. Z., Mugombi, J. W., Nyarugwe, S. P., Chimuti, S., ... & Macheka, L. (2025). Food safety governance in Zimbabwe: Challenges, regulatory gaps, and strategies for global compliance. Food Control, 174, 111254
  34. Nahidul-Islam, S.M., Kuda, T., Takahashi, H., Kimura, B., (2018). Bacterial and fungal microbiota in traditional Bangladeshi fermented milk products analysed by culture dependent and culture-independent methods. Food Res. Int. 111, 431–437. https://doi.org/10.1016/j.foodres.2018.05.048
  35. Obioha, P. I., Ouoba, L. I. I., Anyogu, A., Awamaria, B., Atchia, S., Ojimelukwe, P. C., ... & Ghoddusi, H. B. (2021). Identification and characterisation of the lactic acid bacteria associated with the traditional fermentation of dairy fermented product. Brazilian journal of microbiology, 52, 869-881
  36. Pantoja JCF, Reinemann DJ, Ruegg PL. (2009) Associations among milk quality indicators in raw bulk milk. J Dairy Sci. 92:4978–87. https://doi. org/10.3168/jds.2009-2329
  37. Savaiano, D. A., & Hutkins, R. W. (2021). Yogurt, cultured fermented milk, and health: A systematic review. Nutrition reviews, 79(5), 599-614
  38. Schoustra, S., van der Zon, C., Groenenboom, A., Moonga, H. B., Shindano, J., Smid, E. J., & Hazeleger, W. (2022). Microbiological safety of traditionally processed fermented foods based on raw milk, the case of Mabisi from Zambia. LWT, 171, 113997. https://doi.org/10.1016/j.lwt.2022.113997
  39. Sohanang, F. S. N., Coton, M., Debaets, S., Coton, E., Tatsadjieu, L. N., & Mohammadou, B. A. (2021). Bacterial diversity of traditional fermented milks from Cameroon and safety and antifungal activity assessment for selected lactic acid bacteria. LWT, 138, 110635. https://doi.org/10.1016/j.lwt.2020.110635
  40. Tamang, J. P., & Thapa, N. (2022). Beneficial microbiota in ethnic fermented foods and beverages. Good microbes in medicine, food production, biotechnology, bioremediation, and agriculture, 130-148. https://doi.org/10.1002/9781119762621.ch11
  41. Whiting, R.C., Sackitey, S., Calderone, S., Morely, K. and Philips, J.G., 1996. Model for the survival of Staphylococcus aureus in non-growth environments. International Journal of Food Microbiology, 31, 231–243. https://doi.org/10.1016/0168-1605(96)01002-1
  42. Yambayamba, K.E.; Zulu, M.P. (2011) Influence of the milking environment on the microbial quality of raw milk produced by smallholder farmers in Magoye. UNZA J. Sci. Technol. 15, 37–43
  43. Yerlikaya, O. (2023). A review of fermented milks: potential beneficial effects on human nutrition and health. African Health Sciences, 23(4), 498

Last update:

No citation recorded.

Last update:

No citation recorded.