Location: Meat Safety & Quality ResearchTitle: Consecutive treatments with Sterilex eliminate biofilms by E. coli O157:H7 and Salmonella enterica
|ZHOU, YOU - University Of Nebraska|
|Kalchayanand, Norasak - Nor|
Submitted to: International Association for Food Protection Proceedings
Publication Type: Abstract Only
Publication Acceptance Date: 3/19/2019
Publication Date: N/A
Technical Abstract: Introduction: Biofilms by E. coli O157:H7 and Salmonella enterica pose a serious risk of meat product contamination. The meat industry needs effective sanitizer products to eliminate biofilms on contact surface. Sterilex is a sanitizer product consisting of a proprietary hybrid biocide formulation that can be applied as foam or liquid solution. Three consecutive treatments at 10% are recommended by the manufacture when active biofilms are present. Purpose: To evaluate the effectiveness of consecutive treatments by this product against E. coli O157:H7 and Salmonella biofilms. Methods: Three consecutive treatments with exposure time of 10 m, 20 m, 1 hr, or 2 hrs each treatment were performed using the foam or liquid sanitizer diluted to 2.5%, 5%, or 10%. Log reductions and post-enrichment bacterial prevalence were measured. Scanning electron microscope (SEM) was applied to evaluate post-treatment biofilm removal and bacterial morphology alternation. Results: Liquid or foam sanitizer at 10% reduced viable O157 or Salmonella cells to a non-enumerable level. Low amounts of viable bacteria were observed after 1 or 2 treatments with 2.5% or 5% sanitizer for short exposure time (10 or 20 min each treatment). However, in most cases, 3 consecutive treatments at these low concentrations was also able to reduce both types of bacteria to a non-enumerable level. After enrichment, no O157 prevalence was observed with 3 consecutive treatments at any concentrations. Positive Salmonella prevalence was observed after strong biofilm formers (> 7 Log) were treated, indicating higher tolerance of the strong Salmonella biofilms. SEM revealed significant reduction of the biofilm matrix and a lack of connecting extracellular polysubstance after treatments of both types of bacteria. In addition, disaggregated bacteria with altered morphology and decreased cell length was observed, suggesting membrane damage and loss of cell viability. Significance: Consecutive treatments with Sterliex is effective against E. coli O157:H7 and Salmonella biofilms.