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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 #313543
Title: Effect of Natural Antimicrobials to reduce Biofilm formed by Environmental Isolates of Salmonella

Author
item Patel, Jitu
item KEELARA, SHIVA - University Of Maryland

Submitted to: Annual Meeting of the Institute of Food Technologists
Publication Type: Abstract Only
Publication Acceptance Date: 3/17/2015
Publication Date: 7/11/2015
Citation: Patel, J.R., Keelara, S. 2015. Effect of Natural Antimicrobials to reduce Biofilm formed by Environmental Isolates of Salmonella. Annual Meeting of the Institute of Food Technologists. p.125-043.

Interpretive Summary:

Technical Abstract: Biofilm formation by enteric pathogens on food and equipment surfaces is a concern because sessile bacteria within biofilms are resistant to cleaning and disinfection. The formation of biofilms by Salmonella enterica on food surfaces has been documented. The purpose of this study was to evaluate the effects of natural antimicrobials in reducing cells in biofilms formed by Salmonella isolated from soil and lagoons near pig farms in North Carolina. Fifteen strains of Salmonella were evaluated for biofilm formation using the MBEC™ HTP assay. The assay consisted of incubation in LB medium w/o salt for 48 h at 25°C, followed by removal of plankotonic cells and subsequent quantification of cell populations in biofilms formed on the MBEC™ polystyrene pegs (n=120). Antimicrobials evaluated included cinnamaldehyde and Sporan at 1000-3000 µg/ml, or chlorine (50 µg/ml); biofilms were treated for 10 min followed by neutralization of antimicrobials, sonication to dislodge cells and spiral plating on XLT4 media. The extent of biofilm formation by Salmonella varied with serotype, strain, and source. In general, bacterial populations in biofilm formed by Salmonella Typhimurium from lagoon (7.89 log CFU) were higher than those recovered from soil isolates of S. Typhimurium (7.32 log CFU). Salmonella Infantis strain S643 was poor biofilm former (6.92 log CFU) on polystyrene pegs. Cinnamaldehyde and Sporan at 2000 µg/ml concentrations significantly reduced Salmonella populations in biofilms (up to 6 log CFU reductions). The efficacy of antimicrobials in reducing cells in biofilm increased with increasing concentrations; Salmonella were undetectable in biofilms when treated with 3000 µg/ml cinnamaldehyde. The efficacy of natural antimicrobials in reducing cells in biofilms was comparable to chlorine treatment. These results suggest that cinnamaldehyde and Sporan have potential in reducing Salmonella in biofilms. These antimicrobials could be used as an effective intervention in organic fresh produce processing.