PREVALENCE OF SHIGA TOXIN PRODUCING E. COLI IN FRESH PRODUCE FROM ROAD SIDE FRUIT VENDORS AROUND LAGOS AND OGUN STATE

Abstract

Fresh produce constitutes a necessary part of the human diet, it provides essential vitamins, minerals, and fiber. However, the rising consumption of fresh produce has added to an elevated number of illness outbreaks around the world. Fresh produces are often consumed uncooked, therefore; there is increased risk if contaminated with pathogenic microorganisms like E. coli O157:H7 causing foodborne illness and in extreme cases death especially in children. In developing countries like Nigeria, fresh produce is purchased both in closed stores and road side open kiosk and on most occasions are not processed hygienically. This study evaluated the prevalence of Shiga toxin producing E. coli in varieties of fresh produce (Lettuce, Water Melon, Pineapple, Cucumber, Cabbage, Carrot and Pawpaw) from various roadside fruit vendors at different locations around the South-west region of Nigeria precisely Lagos and Ogun state. A total of 64 samples were tested for presence of E. coli using Sorbitol MacConkey Agar and MacConkey Agar plates. All samples had presumptive STEC, molecular identification of selected isolates (n = 21) for STEC virulence genes (stx1 stx2 and eae) using multiplex PCR was done. The total viable count (TVC) for presumptive STEC in the samples was in the range of 4.5 to 7.8 log10cfu/g. Lettuce from Ibafo had the highest total viable count. Using Multiplex PCR, stx1 gene was detected in some of the isolates which confirmed the presence of STEC in the fresh produce. The prevalence of STEC among the isolates (n = 21) was 4.8%. The presence of STEC and a very high microbial count of presumptive STEC poses a threat to public health which could lead to foodborne illnesses including hemorrhagic colitis (HC) or hemolytic uremic syndrome (HUS).