Biofilm Formation among Staphylococcus aureus Strains from Food Contact Surfaces in Households: A Public Health Concern

Abstract

Staphylococcus aureus is a foodborne pathogen of serious public health concern due to its high biofilm formation capability. One of the contributing factors to foodborne illnesses is improper cleaning and sanitization of food contact surfaces This study aimed to determine the prevalence of S. aureus with biofilm formation potential (BFP) from various food contact surfaces. A total of 100 samples were obtained, 20 from each of stainless steel spoons, plastic plates, plastic eating bowls, plastic cutting boards and glass cups. Samples were obtained by surface swabbing. The cotton swabs were streaked onto nutrient agar plates and incubated overnight. Colonies obtained were subjected to Gram staining, coagulase, catalase and DNAse tests for the identification of S. aureus. The identified S. aureus strains were subjected to biofilm formation potential assay using crystal violet assay (CV-assay) in polystyrene 96-well microtitre plates. Out of the 100 samples obtained, 26 were found to harbour S. aureus. Moreover, out of the 20 isolates, 2 (10%) were from stainless steel spoons, 8 (40%) from plastic plates, 5 (25%) from plastic-eating bowls, 10 (50%) from plastic cutting boards and 1 (5%) from glass cups. Additionally, 11 (42%) of the strains had strong BFP, 11 (42%) had moderate BFP, 3 (12%) and 1 (4%) had no BFP. Presence of S. aureus with BFP on food contact surfaces should be checked to avoid foodborne outbreaks due to this organism.