Microbial ecology of meat slicers as determined by denaturing gradient gel electrophoresis

Cross-contamination of pathogens and spoilage bacteria during slicing of ready to eat meats is an important factor that has been shown to impact both food quality and consumersʹ safety. In this study we analyzed the microbial diversity and total microbiological ecology of different niches on 8 deli meat slicers using standard plate counts as well as culture-independent PCR-denaturing gradient gel electrophoresis (DGGE) analysis. Using aerobic plate counts it was determined that areas underneath the slicer and on the back plate had the highest total bacterial populations. There was slight similarity between total aerobic plate counts by slicer and the number of bacterial genera/species determined by DGGE. The DGGE analysis demonstrated that members of the genus Pseudomonas were the most common bacteria to be found on slicers. This may serve as an estimate of the effectiveness of current cleaning and sanitizing practices to remove biofilms, a possible role for competitive inhibition in preventing colonization by pathogens and an indication of the range and diversity of non-pathogens on these food contact surfaces.