Novel Biocontrol Methods for Listeria monocytogenes Biofilms in Food Production Facilities

Abstract

High mortality and hospitalization rates have seen Listeria monocytogenes as a foodborne pathogen of public health importance for many years and of particular concern for high-risk population groups. Food manufactures face an ongoing challenge in preventing the entry of L. monocytogenes into food production environments (FPEs) due to its ubiquitous nature. In addition to this, the capacity of L. monocytogenes strains to colonize FPEs can lead to repeated identification of L. monocytogenes in FPE surveillance. The contamination of food products requiring product recall presents large economic burden to industry and is further exacerbated by damage to the brand. Poor equipment design, facility layout, and worn or damaged equipment can result in Listeria hotspots and biofilms where traditional cleaning and disinfecting procedures may be inadequate. Novel biocontrol methods may offer FPEs effective means to help improve control of L. monocytogenes and decrease cross contamination of food. Bacteriophages have been used as a medical treatment for many years for their ability to infect and lyse specific bacteria. Endolysins, the hydrolytic enzymes of bacteriophages responsible for breaking the cell wall of Gram-positive bacteria, are being explored as a biocontrol method for food preservation and in nanotechnology and medical applications. Antibacterial proteins known as bacteriocins have been used as alternatives to antibiotics for biopreservation and food product shelf life extension. Essential oils are natural antimicrobials formed by plants and have been used as food additives and preservatives for many years and more recently as a method to prevent food spoilage by microorganisms. Competitive exclusion occurs naturally among bacteria in the environment. However, intentionally selecting and applying bacteria to effect competitive exclusion of food borne pathogens has potential as a biocontrol application. This review discusses these novel biocontrol methods and their use in food safety and prevention of spoilage, and examines their potential to control L. monocytogenes within biofilms in food production facilities.

Listeria Occurrence and Potential Control Strategies in Alternative and Conventional Poultry Processing and Retail

“…Initial reductions of 1.5 log CFU/cm 2 were observed for phage therapy on the cooked turkey. When using LISTEX TM P100 on biofilms formed on stainless steel, 3.5-5.4 log CFU/cm 2 reductions were observed depending on which of the 21 strains were tested (Soni and Nannapaneni, 2010;Gray et al, 2018). Similar reductions were observed by (Monta-ez-Izquierdo et al, 2012), which also tested LISTEX TM P100 biofilms L. monocytogenes on stainless steel.…”

“…Phages are the most abundant organisms on earth and are viruses that infect bacteria for propagation (Pérez Pulido et al, 2016). Phages operate either under a lytic or lysogenic lifecycle, where, in the latter, the prophage may insert itself into the genome of the host and propagate over generations until an environmental stressor triggers unfavorable conditions resulting in a shift to the lytic cycle and lysis of the cell (Gray et al, 2018). In the lytic life cycle, phages, upon attachment and entry to the cell, propagate using host machinery and lyse the cell immediately.…”

“…They are suitable as a biocontrol agent unlike their lysogenic counterparts due to host cell integration of the prophage (Salmond and Fineran, 2015). The underlying mechanisms of phage therapy are discussed in Gray et al (2018). Phages can specifically infect species or strains of bacteria depending on their host range, with those selected for phage therapy replicating within their bacterial hosts and lyse the cell afterward (Shors, 2001).…”

Monitoring of the Listeria spp. identification from the poultry products in the Dnipropetrovsk region

“…На підприємствах харчової промисловості виявлено різноманітні резервуари патогену: підлоги, водостоки, конденсат на трубах і засоби для чищення (губки, щітки), конвеєрні стрічки, пакувальне обладнання, різаки, міксери та ручні інструменти, рукавички, фартухи (Norwood et al, 2000;Weinsetel, 2006). Конструкція приміщення, інвентарю, зношене або пошкоджене обладнання обумовлюють підвищення контамінації Listeria, утворення біоплівок на поверхнях, де традиційні процедури очищення та дезінфекції можуть бути недостатніми (Arevalos-Sánchez et al, 2012;Saraiva et al, 2018;Gray et al, 2018).…”

Quantitative risk assessment of Listeria monocytogenes in a traditional RTE product

“…L. monocytogenes is a bacterium that is common in the environment and can be found in agricultural and food production environments, where once established, it tends to persist through the creation of biofilms (Gray et al., ). Possible entry routes of the bacterium in the final product are both raw material contamination and cross‐contamination during food processing.…”