Influence of Biofilm Architecture on Sanitizer Tolerance of Listeria monocytogenes from Vermont Artisanal Cheese Environments
Abstract
Listeria monocytogenes (Lm) persist in food environments by forming biofilms. We explored structural differences that may explain sanitizer tolerance in mature Lm biofilms. Lm cultured in 1X and 1/20X concentrations of brain heart infusion (BHI) were inoculated into stainless steel coupons and incubated statically at 23°C. After 10 days, the coupons were treated with quaternary ammonium compound or sodium hypochlorite and prepared for scanning electron microscopy. At 1/20X BHI, Lm had greater exopolysaccharide development where 1X BHI samples showed denser and more frequent 3D aggregates. Both sanitizers showed incomplete biofilm destruction. Even primitive Lm biofilm architectures impart significant sanitizer tolerance.
Influence of Biofilm Architecture on Sanitizer Tolerance of Listeria monocytogenes from Vermont Artisanal Cheese Environments
Listeria monocytogenes (Lm) persist in food environments by forming biofilms. We explored structural differences that may explain sanitizer tolerance in mature Lm biofilms. Lm cultured in 1X and 1/20X concentrations of brain heart infusion (BHI) were inoculated into stainless steel coupons and incubated statically at 23°C. After 10 days, the coupons were treated with quaternary ammonium compound or sodium hypochlorite and prepared for scanning electron microscopy. At 1/20X BHI, Lm had greater exopolysaccharide development where 1X BHI samples showed denser and more frequent 3D aggregates. Both sanitizers showed incomplete biofilm destruction. Even primitive Lm biofilm architectures impart significant sanitizer tolerance.