East African Medical Journal. 88:46-53.
46 East African Medical Journal February 2011
East Africa Medical Journal Vol. 88 No. 2 February 2011
BACTERIAL CONTAMINATION OF KALE (Brassica oleracea Acephala) ALONG THE SUPPLY CHAIN IN
NAIROBI AND ITS ENVIRONMENT
E. Kutto, BSc, MSc, Department of Veterinary Pathology, Microbiology and Parasitology, M. W. Ngigi, MSc, Department of Agricultural economics, N. Karanja, BSc, MSc, PhD, Department of Land Resource Management and Agricultural Technology, E. Kange’the, Bvm, MSc, PhD, Department of Public Health, Pharmacology and Toxicology, L. C. Bebora, Bvm, MSc, PhD, Department of Veterinary Pathology, Microbiology and Parasitology, University of Nairobi P. O. Box 29052-00625, Kabete Campus, Nairobi, Kenya, C. J. Lagerkvist, BAECON, MAECON, PhD, Swedish University of Agricultural Sciences P.O. Box 7013-75007, Uppsala, Sweden, P. G. Mbuthia, Bvm, MSc, FRVCS(Dip. Path), PhD, Department of Veterinary Pathology, Microbiology and Parasitology, L. W. Njagi, Bvm, MSc, PhD, Department of Veterinary Pathology, Microbiology and Parasitology and J. J. Okello, PhD, Department of Agricultural economics, University of Nairobi, P.O. Box 29052-00625, Kabete Campus, Nairobi, Kenya Request for reprints to: K. E. Kutto, Department of Veterinary Pathology, Microbiology and Parasitology, Kabete Campus, University of Nairobi, P. O. Box 29057-00625, Nairobi, Kenya
BACTERIAL CONTAMINATION OF KALE (Brassica oleracea Acephala)
ALONG THE SUPPLY CHAIN IN NAIROBI AND ITS ENVIRONMENT
E. K. KUTTO, M. W. NGIGI, N. KARANJA, E. KANGE’THE, L. C. BEBORA, C. J. LAGERKVIST, P. G. MBUTHIA, L. W. NJAGI and J. J. OKELLO
ABSTRACT
Objective: To assess the microbiological safety of kale (Brassica oleracea Acephala)
produced from farms and those sold at the markets with special focus on coliforms,
E.coli and Salmonella.
Design: A cross sectional study.
Setting: Peri-Urban farms (in Athi River, Ngong and Wangige), wet markets (in
Kawangware, Kangemi and Githurai), supermarkets and high-end specialty store
both within Nairobi city.
Results: Mean coliform count on vegetables from farms were 2.6x105 ±5.0x105 cfu/g
while those from the wet markets were 4.6x106 ±9.1x106 cfu/g, supermarkets, 2.6x106
±2.7x106 and high-end specialty store 4.7x105 ±8.9x105. Coliform numbers obtained
on kales from the wet markets and supermarkets were significantly higher (p<0.05)
compared to those from farms, while kale samples purchased from high- end specialty
store had similar levels of coliform loads as those from the farms. E. coli prevalence
in the wet markets, supermarkets and high-end specialty store were: 40, 20 and 20%,
respectively. Salmonella was detected on 4.5 and 6.3% of samples collected from the
farms in Wangige and wet market in Kawangware, respectively. Fecal coliforms in
water used on farms (for irrigation) and in the markets (for washing the vegetables)
exceeded levels recommended by World Health Organization (WHO) of 103 organisms
per 100 milliliter while Salmonella was detected in 12.5% of washing water samples
collected from Kangemi market.
Conclusion: Poor cultivation practices and poor handling of vegetables along the
supply chain could increase the risk of pathogen contamination thus puting the health
of the public at risk, therefore good agricultural and handling practices should be
observed.
