Listeria Species in Commercially Broken Raw Liquid Whole Egg .

Commercially broken raw liquid whole egg (LWE) was obtained from 11 processing establishments across the United States on 3 or 4 occasions over an eight-month period. The samples were evaluated for the presence of Listeria species by the FDA, USDA, and cold enrichment procedures. Forty-five Listeria isolates were obtained from 15 of 42 (36%) egg samples. Both the USDA and FDA methods were useful for isolation of Listeria species, resulting in 12 and 8 positive samples, respectively. Six samples were positive by both procedures. Listeria was isolated from one sample by cold enrichment. The most frequently isolated species was L. innocua , which was found in all () of the listeriae-positive samples. L. monocytogenes was the only other species isolated and was obtained from 5% () of the egg samples. The USDA and FDA procedures each yielded one L. monocytogenes -positive sample. The two L. monocytogenes -positive samples contained estimated populations of 1 and 8 CFU L. monocytogenes /ml and were obtained from the same plant during the spring and early summer sampling times. Twelve (80%) of the 15 Listeria -positive samples were solids-adjusted LWE. Thus, Listeria species, including the psychrotrophic pathogen L. monocytogenes , are present in commercially broken raw LWE.