ARS | Publication request: Interventions for control of Salmonella: Clearance of Microbial growth from rubber picker fingers

Submitted to: Poultry Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: January 31, 2009
Publication Date: June 1, 2009
Citation: Arnold, J.W., Yates, I.E. 2009. Interventions for control of Salmonella: clearance of microbial growth from rubber picker fingers. Poultry Science. 88(6):1292-1298.

Interpretive Summary: A study was conducted to determine if a material with antimicrobial properties combined with an effective disinfectant could achieve total clearance of bacterial contamination from a surface. Bacteria found on new rubber material (rubber picker fingers) before use in defeathering machinery were identified, and no foodborne pathogens were present. In separate experiments, new (unused) rubber picker fingers from three manufacturers were exposed to broiler carcass rinses, and the amount of bacterial attachment to the material was measured. Multiple concentrations of bacteria were exposed to picker finger sections and compared hourly with controls to evaluate inhibition. The new rubber finger material from three manufacturers significantly inhibited bacterial growth, without the aid of antibacterial additives. We improved an assay for testing effectiveness of disinfectants against growth of pathogens, and determined the activity of five disinfectant compounds used in the poultry industry. Two of the compounds were effective against five types of bacteria, and one of the compounds was used to further test Salmonella. Specialized microscopy confirmed the levels of Salmonella before and after treatment. The most effective compound completely removed Salmonella contamination from the surface.

Technical Abstract: A study was conducted to determine if a surface material with antimicrobial properties combined with an effective disinfectant could achieve total clearance of bacterial contamination. Prior to beginning the project, new rubber picker fingers collected from three processing facilities were tested for endogenous microflora. Five species of bacteria common to soil and human handling were present: Bacillus amyloliquefaciens, B. cereus/thuringiensis, Staphylococcus epidermidis, S. hominis ss novobiosepticus, and S. intermedius. In separate experiments, new (unused) rubber picker fingers from three manufacturers were exposed to broiler carcass rinses, and the kinetics of bacterial attachment to finger material was determined. Turbidity of the bacterial suspensions at varying dilutions containing picker finger sections was compared hourly with controls to evaluate inhibition. New rubber finger material from the three manufacturers significantly inhibited bacterial growth (P < 0.05), without the aid of antibacterial additives. We improved an assay for screening disinfectants against growth of pathogens, and determined the activity of five disinfectant compounds. Two of the compounds were most effective against Pseudomonas aeruginosa, Listeria monocytogenes, Staphylococcus aureus, Salmonella enteritidis, and Escherichia coli, and one of the compounds was selected for further study with S. enteritidis. Scanning electron microscopy confirmed the levels of S. enteritidis before and after treatment. The most effective compound completely cleared S. enteritidis contamination from the rubber picker finger surface.