Master of Science (MS)
School of Nutrition and Food Sciences
The antibacterial properties of copper ions against Listeria spp., Pseudomonas spp., Escherichia coli and other coliforms, and total aerobic bacteria have been investigated in seafood processing environments. Our hypothesis was that drains fabricated from copper and coatings and concrete containing copper ions that have been used for sealing floors and walls could be utilized in crawfish and crab processing facilities as an effective means of controlling Listeria spp. and other unwanted bacteria. Copper in the form of copper sulfate pentahydrate was incorporated into coatings and concrete at the salt concentration of 25 ppm (6.36 ppm Cu++). Sampling sites were selected in multiple areas of the processing facilities. Sampling was performed in the course of two-month seafood production period. Bacterial counts were determined by using microbiological selective media. In addition, PCR analysis was applied to detect the presence of Listeria monocytogenes in the environmental samples. Copper drains were found to be quite effective against some of the tested bacteria. The counts of Listeria spp. and total aerobic bacteria were over one log CFU/cm2 lower on the copper drains than those detected on the control sites. Neither copper coatings nor copper concrete exerted antimicrobial activity against any microorganisms tested. Additionally, almost all PCR samples were negative for the presence of Listeria monocytogenes, suggesting that black colonies grown on Oxford media represented the other species of Listeria family. Based on the overall results, the copper-fabricated drains could be used in the seafood processing facilities as one of other approaches for reducing environmental contamination by foodborne pathogens. Regarding the application of copper coatings and concrete at the seafood production plants, future research should be conducted to find the most effective bactericidal copper forms and, subsequently, their effective minimal inhibitory concentrations.
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Rogovskyy, Artem S., "Control of Listeria species and other bacteria in crawfish and crab processing facilities, utilizing copper drains, coatings and concrete, containing copper ions" (2006). LSU Master's Theses. 591.
Marlene E. Janes