The microbial quality of five types of fresh produce obtained at the retail level was determined by standard quantitative techniques. These techniques included aerobic plate count (APC), total coliform counts, Escherichia coli counts, and yeast and mold counts. Three different methods were used to determine total coliform counts, which consisted of MacConkey agar plate counts, Colicomplete most probable number counts, and Petrifilm E. coli (EC) plate counts. The mean APCs for sprouts, lettuce, celery, cauliflower, and broccoli were 8.7, 8.6, 7.5, 7.4. and 6.3 log10 CFU/g, respectively. MacConkey agar counts indicated that 89 to 96% of the APCs consisted of gram-negative bacteria. Yeast and mold counts were in a range expected of fresh produce. Fresh produce was also analyzed for human pathogens. Samples were analyzed for Staphylococcus spp., Bacillus spp., Salmonella spp., Listeria spp., and Campylobacter spp. One isolate of Staphylococcus was found to be enterotoxigenic, and one species of Bacillus was also toxigenic. Neither Salmonella spp. nor Campylobacter spp. were detected in any of the produce samples. A variety of Listeria spp., including Listeria monocytogenes, were found in fresh produce.

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Thirty‐two foodborne bacterial isolates were tested as potential competitors of Listeria monocytogenes strain LM82 during enrichment because of their resistance to the selective agents in Listeria enrichment and isolation media. Competitive ability of each isolate was classified as weak, moderate, or strong by determining the ratio at which it masked identification of LM82 at an inoculation concentration of 10 colony forming units (CFU)/10 mL of Listeria enrichment broth. Of the competitive isolates identified, six were Enterococcus spp., two were Staphylococcus spp., and one was a Corynebacterium sp. Although several strains of Enterococcus faecium were examined, not all were competitive. Of six other bacterial strains associated with food fermentations and tested for competitiveness with LM82, one, a Gram‐positive tetrad, was competitive. This study showed that although food microfloral strains that are able to survive in enrichment and isolation environments are fairly common, they do not necessarily compete with Listeria. Not all strains in a competitive species are necessarily competitive.