Occurrence of pathogens on vegetables harvested from soils irrigated with contaminated streams.
The study assesses the contamination level, the seasonal distribution and the toxigenicity of pathogens isolated from irrigated vegetables and the water used for irrigation. A total of 196 samples of water used for irrigation and 326 irrigated vegetables were obtained from Kawo drain, Sabon Gari drain and River Galma and examined using standard procedures for coliform and viable counts and the presence of E. coli, Salmonella and Vibrio during the dry and wet seasons. Irrigation water from Kawo drain had significantly higher coliform counts by location and season than water from the other two locations. Although all the vegetables had coliform counts higher than the recommended standard (range 3.40-6.38 log(10) cfuml(-1)), amaranthus had significantly higher (P<0.05) counts than other vegetables during the dry season. Salmonella was significantly more likely to be detected during the dry season than during the wet (OR 4.91, 1.07<OR<31.16). Of the 39 enteropathogenic E. coli isolated, 15 (38.5%) were toxigenic by ileal loop test. There is need to educate farmers on the risk involved in the use of waste contaminated water for irrigation. The need to wash and disinfect raw vegetables before consumption is stressed.
Okafo
Cordelia N
CN
Department of Microbiology, Ahmadu Bello University, Zaria, Nigeria.
Umoh
Veronica J
VJ
Galadima
Musa
M
D004926:Escherichia coli / Q000302:isolation & purification*; D005506:Food Contamination; D006801:Humans; D011891:Rain; D018570:Risk Assessment; D012475:Salmonella / Q000302:isolation & purification*; D012621:Seasons; D014675:Vegetables / Q000382:microbiology*; D014733:Vibrio / Q000302:isolation & purification*; D014865:Waste Disposal, Fluid; D014871:Water Microbiology; D014881:Water Supply