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ARS Home » Northeast Area » Beltsville, Maryland (BARC) » Beltsville Agricultural Research Center » Environmental Microbial & Food Safety Laboratory » Research » Publications at this Location » Publication #391210
Research Project: Intervention Strategies to Mitigate the Food Safety Risks Associated with the Fresh Produce Supply Chain

Location: Environmental Microbial & Food Safety Laboratory

Title: Impact of surface topography and shear stress on single and dual species biofilm formation by Listeria monocytogenes in presence of promotor bacteria

Author
item PRABHUKHOT, GRISHMA - University Of Maryland
item Yin, Hsin Bai
item EGGLETON, CHARLES - University Of Maryland
item Patel, Jitu

Submitted to: International Association for Food Protection Proceedings
Publication Type: Abstract Only
Publication Acceptance Date: 3/21/2022
Publication Date: N/A
Citation: N/A

Interpretive Summary:

Technical Abstract: Introduction: Pathogens can form biofilm on equipment surface and subsequently contaminate foods during processing. Promotor bacteria Ralstonia insidiosa may facilitate stronger biofilm formation of pathogens on equipment surface. Purpose: Single and dual species biofilm formation of L. monocytogenes on food contact surfaces under different hydrodynamic shear stresses was investigated. Methods: Biofilms were grown on stainless steel (SS), PTFE, polycarbonate (PC) and EPDM coupons in a CDC bioreactor containing 10% TSB containing L. monocytogenes alone or with R. insidiosa for 48 h. L. monocytogenes and R. insidiosa populations in biofilms from surface coupons (n=144) were determined by spiral plating on MOX and TSA, respectively. The log CFU/cm2 from three individual replicates were analyzed to determine significant differences due to surface material, shear stress, and presence of R. insidiosa. Surface topography of equipment surfaces were measured using profilometer and scanning electron microscopy. Results: L. monocytogenes recovered from dual-species biofilms from SS, PTFE and PC surfaces were significantly higher at the lowest shear stress of 0.013 N/m2 compared to 0.043 and 0.088 N/m2. At the highest shear stress of 0.088 N/m2, L. monocytogenes populations were significantly higher on PTFE (8.17 log CFU/cm2) and EPDM (7.93 log CFU/cm2) compared to SS 316L (7.38 log CFU/cm2) and PC (7.57 log CFU/cm2). R. insidiosa bacterial populations were similar on all the materials at 0.013 N/m2 shear stress. L. monocytogenes recovered in dual-species environment at 0.013 N/m2 (8.21 log CFU/cm2) were significantly higher than in single-species biofilms (4.98 log CFU/cm2); similar trend was observed at other shear stresses. PTFE and PC surface had higher surface roughness (3.17 and 2.36 µm, respectively) compared to EPDM (1.11 µm) and SS 316L (0.71 µm). Significance: Surface topography and shear stress impact L. monocytogenes biofilm formation in a dual species environment. R. insidiosa promotes stronger L. monocytogenes biofilm on surface material.