Bacteriophage DW-EC with the capability to destruct and inhibit biofilm formed by several pathogenic bacteria

Abstract

Biofilm formation by pathogenic bacteria is a major challenge in the food industry. Once a biofilm is established, such as on food processing equipment, it becomes more difficult to eradicate. Although physical and chemical treatments are often used to control biofilm formation, these treatments can have significant drawbacks. Alternative biofilm treatments are needed. Phage DW-EC was isolated from dawet, an Indonesian traditional Ready-To-Eat food, which has high specificity for Enterohaemorrhagic Escherichia coli (EHEC), Enteropathogenic E. coli (EPEC), and Enterotoxigenic E. coli (ETEC). Phage DW-EC produces several enzymes that can prevent the development of biofilm and biofilm eradication. Depolymerase enzymes break down the polysaccharides layer on the biofilms can lead to biofilm damage. On the other hand, endolysin and putative like-T4 lysozyme will lyse and kill a bacterial cell, thereby preventing biofilm growth. This research aims to determine the capability of previously identified phage DW-EC to inhibit and destroy biofilms produced by several foodborne pathogens. Phage DW-EC formed plaques on the bacterial lawns of EHEC, EPEC, and ETEC. The efficiency of plating (EOP) values for EHEC, EPEC, ETEC, and Bacillus cereus were 1.06, 0.78. 0.70, and 0.00, demonstrating that DW-EC was effective in controlling pathogenic E. coli populations. Furthermore, phage DW-EC showed anti-biofilm activity against foodborne pathogenic bacteria on polystyrene and stainless-steel substrates. DW-EC biofilm inhibition and destruction activities against pathogenic E. coli were significantly higher than against B. cereus biofilms, which was indicated by a lower density of the biofilm than B. cereus. Microscopic visualization verified that bacteriophage DW-EC effectively controlled EHEC, EPEC, and ETEC biofilms. The results showed that DW-EC could inhibit and destroy biofilm, making it promising to be used as an anti-biofilm candidate for polystyrene and stainless steel equipment in the food industry.