Biofilm formation by Salmonella spp. on cantaloupe melons

• Published in: Journal of food safety Vol. 25; no. 4; pp. 276 - 287
• Main Authors: Annous, B.A, Solomon, E.B, Cooke, P.H, Burke, A
• Format: Journal Article
• Language: English
• Published: Oxford, UK and Malden, USA Blackwell Science Inc 01-11-2005; Blackwell
• Subjects: bacterial adhesion; bacterial contamination; biofilm; Biological and medical sciences; cantaloupes; Cucumis melo; food contamination; Food industries; Food microbiology; food pathogens; Fruit and vegetable industries; Fundamental and applied biological sciences. Psychology; inoculum density; peels; Salmonella; Salmonella enterica; scanning electron microscopy; serotypes; surface area; Salmonella; Fruit; Dicotyledones; Angiospermae; Cucurbitaceae; Biofilm; Bacteria; Spermatophyta; Cucumis melo; Enterobacteriaceae; Melon
• ISSN: 0149-6085; 1745-4565
• DOI: 10.1111/j.1745-4565.2005.00024.x

The ability of two strains of Salmonella to form biofilms on whole cantaloupe melons was investigated. Ten microliters of bacterial suspensions was spot-inoculated onto cantaloupe melon rinds in pre-marked areas, and the cantaloupe melons were held at either 10 or 20C. Biofilm formation was monitored using scanning electron microscopy on excised portions of the cantaloupe melon rind at 2, 24, 48, 72 and 144 h postinoculation. Micrographs indicated that biofilm formation occurred rapidly following introduction of cells (2 h at 20C) onto the cantaloupe melon rind. A fibrillar material was visible after just 2 h at 20C, and cells were embedded in extracellular polymeric material after 24 h at either temperature. These results indicate that a human pathogen is capable of forming a biofilm on plant tissue and that biofilm formation may be responsible for the increased recalcitrance of bacteria to aqueous sanitizers.