Efficacy of Novel Bacteriophages against Escherichia coli Biofilms on Stainless Steel

Abstract

Biofilm formation by E. coli is a serious threat to meat processing plants. Chemical disinfectants often fail to eliminate biofilms; thus, bacteriophages are a promising alternative to solve this problem, since they are widely distributed, environmentally friendly, and nontoxic to humans. In this study, the biofilm formation of 10 E. coli strains isolated from the meat industry and E. coli ATCC BAA-1430 and ATCC 11303 were evaluated. Three strains, isolated from the meat contact surfaces, showed adhesion ability and produced extracellular polymeric substances. Biofilms of these three strains were developed onto stainless steel (SS) surfaces and enumerated at 2, 12, 24, 48, and 120 h, and were visualized by scanning electron microscopy. Subsequently, three bacteriophages showing podovirus morphology were isolated from ground beef and poultry liver samples, which showed lytic activity against the abovementioned biofilm-forming strains. SS surfaces with biofilms of 2, 14, and 48 h maturity were treated with mixed and individual bacteriophages at 8 and 9 log10 PFU/mL for 1 h. The results showed reductions greater than 6 log10 CFU/cm2 as a result of exposing SS surfaces with biofilms of 24 h maturity to 9 log10 PFU/mL of bacteriophages; however, the E. coli and bacteriophage strains, phage concentration, and biofilm development stage had significant effects on biofilm reduction (p < 0.05). In conclusion, the isolated bacteriophages showed effectiveness at reducing biofilms of isolated E. coli; however, it is necessary to increase the libraries of phages with lytic activity against the strains isolated from production environments.

APTC-EC-2A: A Lytic Phage Targeting Multidrug Resistant E. coli Planktonic Cells and Biofilms

“…For instance, phages have been used widely to protect the food chain and livestock against foodborne pathogens including Shiga toxin-producing E. coli [36,37]. Several studies have demonstrated the efficacy of E. coli phage against planktonic and biofilm forms of E. coli [15,38,39]. In another study, an E. coli phage cocktail demonstrating promise for reducing an E. coli infection efficiently without disrupting the gut microbiota in vivo [40].…”

Controlling of foodborne pathogen biofilms on stainless steel by bacteriophages: A systematic review and meta-analysis

“…aureus , P. fluorescens , P. aeruginosa, and L. monocytogenes contribute significantly to food contamination. These bacteria can form biofilms on food contact surfaces, making their eradication difficult and posing a health risk to consumers [ 65 , [97] , [107] , [112] , [118] , 66 ].…”

“…Chemical methods, for instance, using sanitizers such as chlorine, can make the stainless steel less receptive to biofilm formation, but it can lead to chemical reactions and residue [ 63 , 64 ]. Nowadays, new methods of controlling biofilm on the surface of food industry facilities, such as applying bacteriophages to control biofilm formation, have attracted the attention of researchers [ 65 , 47 , 66 ].…”

Effect of Bacteriophages against Biofilms of Escherichia coli on Food Processing Surfaces

“…The application of lytic phages has also been suggested as a method of mitigating E. coli in foods like milk [ 34 , 35 ], beef [ 36 , 37 , 38 ], tomato [ 38 ], broccoli [ 38 ], spinach [ 38 ], lettuce [ 39 , 40 , 41 ], cantaloupes [ 41 ], lamb and mutton [ 42 ], and bivalves [ 43 , 44 ]. However, there are few studies on the use of phages to control E. coli biofilms on different processing surfaces [ 21 , 45 , 46 , 47 , 48 ].…”