Evaluation of Biofilm Production Capability of Shiga Toxin Producing Escherichia coli Isolated from Milk, Milk Products and Hand Swabs

Background: Food borne pathogens are transmitted to humans through contaminated foods like dairy products, handmade goods and meat. Microbial biofilms are city of microbes in the form of 3D structure and attachment of bacteria with food contact surfaces lead to subsequent development of biofilms that may lead to transmission of disease and food spoilage. This study was designed to evaluate the biofilm production capability of Shiga toxin-producing Escherichia coli (STEC) isolated from milk, milk-based products and hand swabs. Methods: Samples were collected and processed for isolation of E. coli. STEC were detected on the molecular basis through mPCR. Biofilm formation capability of STEC was screened by methods namely Tissue culture plate (TCP), Tube method (TM) and Congo red agar (CRA) assay. Result: The prevalence of E. coli and STEC was found to be 22.50%, 30.55%, 12.5% and 6.25%, 4.86%, 2.08% in retail raw milk, traditional milk products and hand swabs, respectively. The overall prevalence of E. coli, serotype E. coli O157:H7 and STEC was 24.43%, 1.42% and 5.11%, respectively. The biofilm forming STEC revealed by TCP, TM and CRA were 88.88%, 77.77% and 38.88%, respectively.