Several identified knowledge gaps were further addressed. The concentration of coliforms and Escherichia coli and prevalence of E. coli O157:H7, Salmonella spp., Shigella spp. and Listeria monocytogenes in spianch before and after minimal processing under commercial conditions was investigated. A total of 1356 spinach samples were collected daily in two processing plants over a period of 14 months. The proportion of coliform positive samples increased from 53% before to 79% after minimal processing. Generic E. coli prevalence was 8.9% (mean 1.81 ± 0.14 log CFU/g) with no difference after processing. Salmonella spp. and L. monocytogenes were isolated from 0.4% and 0.7% of samples, respectively. The contribution of each commercial processing step to generic E. coli, coliform, and total aerobic bacterial load on fresh-cut lettuce and food contact surfaces in a processing plant were further quantified. Plausible bacterial populations on fresh-cut, minimally processed lettuce using T-RFLP analysis were identified. Washing initially decreased coliforms on lettuce but microbial populations increased during subsequent steps. Peak contamination on food contact surfaces was detected after two hours of processing, then declined after 4-6h of processing without intermediate sanitation interventions. No association between coliform increase on lettuce and contact-surfaces was found. Removal of outer leaves was the single most effective step of large-scale minimal processing. T-RFLP analysis identified representatives of 12 phyla/classes of bacteria on minimally processed lettuce.