African Journal of
Microbiology Research

  • Abbreviation: Afr. J. Microbiol. Res.
  • Language: English
  • ISSN: 1996-0808
  • DOI: 10.5897/AJMR
  • Start Year: 2007
  • Published Articles: 4875

Full Length Research Paper

Microbial species of safety concern in milk from informal processors in Harare, Zimbabwe

Siyangapi Chimuti
  • Siyangapi Chimuti
  • Department of Food and Microbiology, Government Analyst Laboratory, Harare, Zimbabwe.
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Nicholas Midzi
  • Nicholas Midzi
  • Department of Medical Microbiology, College of Health Sciences, University of Zimbabwe, Zimbabwe.
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Patrick Kamau Njage
  • Patrick Kamau Njage
  • Department of Food and Microbiology, University of Nairobi, Kenya.
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Desmond Tichaona Mugadza
  • Desmond Tichaona Mugadza
  • Department of Food Science and Nutrition, Midlands State University, Gweru, Zimbabwe.
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  •  Received: 01 June 2016
  •  Accepted: 11 July 2016
  •  Published: 28 August 2016

Abstract

In this study, the bacteriological quality and the presence of Staphylococcus aureus, Escherichia coli O157:H7, Bacillus cereus, Salmonella species, and Pseudomonas species were studied in raw milk, cultured milk, milk handlers and packaging containers. A total of 36 samples were collected over 3 months from three different farmers. Samples were analyzed for means of counts per milliliter of milk for total bacterial count (TBC), total coliform count (TCC), total E. coli count (TEC), S. aureus, B. cereus, Salmonella spp. and Pseudomonas spp. Microbial load ranged between 0.81 and 7.6 log10 cfu/ml for various critical sampling locations. Isolates of   E. coli, S. aureus and B. cereus were taken for simple polymerase chain reaction (PCR) to investigate the presence of virulent genes, rfB, sei, and cytK with amplicon sizes of 1.0 kb, 500 bp and 320 bp, respectively. The sei gene was detected in 19% of the samples and 2.8% were found to have the cytK gene. The rfB gene could not be picked in E. coli. The results show poor hygienic practices at the processors and potential risk to the consumers.

Key words: Fresh milk, fermented milk, packaging container, milk handler, pathogens.