Attachment of Listeria monocytogenes, Escherichia coli O157:H7 and Pseudomonas aeruginosa on Food Soiled Plastic Surfaces

This study investigated the ability of three different pathogens, Escherichia coli O157:H7, Listeria monocytogenes and Pseudomonas aeruginosa, to attach food soiled (salad dressing, cooking oil, milk and yogurt) polyvinyl chloride (PVC) plastic. The pre-soiled PVC coupons were incubated with 10(8) CFU/cm2 of each bacterium in 50% tryptic soy broth for 6 h to allow attachment. It was found that the effect of food products was not significant while the effect of bacterial strain was highly significant (p = 0.0005). Mean attachment ofP. aeruginosa (5.5 log CFU/cm2) to pre-soiled coupons was the highest (p < 0.05), compared to L. monocytogenes (5.0 log CFU/cm2) and E. coli O157:H7 (4.5 log CFU/cm2). This study indicates the capability of each bacterial pathogen, E. coli O157:H7, L. monocytogenes or P. aeruginosa, to equally attach to different pre-soiled PVC surfaces. P. aeruginosa showed the greatest potential to attach to PVC when compared to E. coli O157:H7 and L. monocytogenes.