Dairy products can be contaminated from their surrounding surfaces and equipment with biofilm forming foodborne pathogens such as Escherichia coli(E. coli). Biofilm production is regarded as an adaptive mechanism that enhance microbial growth and proliferation. In sight of these facts, this study aimed toin-vestigateof the prevalence of E. coliin dairy products (kariesh cheese, ice cream, and pasteurized milk), and dairy plant floors, and their contact equipment. Besides, the abilities of the identified E. coliserotypes to produce biofilm were further examined. In a reductiontrial, the use of Nigella sativaand olive oils’ nanoemul-sionsto reduce E. coli-biofilm formation was examined.The obtained results indicated thatthe prevalence rates of E. coliin the examined kariesh cheese, ice cream, pasteurized milk, dairy plant floors, and equipment were 19.05%, 4.76%, 0%, 45.24%, and 30.96%, respectively. Five E. coliserotypes were identified in the cur-rent investigation namely, E. coli O26:H11, E. coli O55:H7, E. coli O78:H-, E. coli O111:H4, and E. coli O127:H6 at variable rates. Molecular identification of the recovered E. coliserotypes revealed that all serotypes har-bored E. coli-specific 16S rRNA, and fim H, biofilm-coding genes. All identified E. coliserotypes had the ability to produce biofilm in the following order:E. coli O26:H11, E. coli O55:H7, E. coli O78:H-, E. coli O111:H4, and E. coli O127:H6, respectively. Nigella sativa,and olive oils’ nanoemulsionsreduced biofilm production in a concentration dependent manner.Keywords:E. coli; biofilm; dairy products; Nigella sativa; olive oil’s nanoemulsionsIntroductionDairy products, despite their high nutritional values (1), are implicated in the transmission of sev-eral foodborne pathogens such as Clostridium botuli-num(2), Staphylococcus aureus (3), Salmonella spp.(4), Bacillus cereus(5),and Escherichia coli(E. coli) (6).Microbial contamination of dairy productsmight occur during any step of their processing due to the unhygienic personal practices, use of contaminated raw materials, or via cross-con-tamination from contaminated equipment or utensils (7, 8).E. coli is oneof the coliforms groupsthat is con-sidered as a common inhabitant of the intestinal tract of the dairy producing animals. Detection of E. coliin dairy productsindicates fecal contamina-tion(6). At the same time, E. coliis implicated in several cases ofhuman illness outbreakssuch as that reported in Colombia (9), Iran(10), India (6), and many African countries(11).E. colihasmore than 100 pathotypesthat play critical roles in E. coli-related foodborne infections such as E. coliO157, O26, O45, O103, O111, O121,and O145(12). There are urgent needs for continuous monitoring