Leasor Susan B, Foegeding Peggy M
Department of Food Science, Box 7624, North Carolina State University, Raleigh, NC 27695-7624.
J Food Prot. 1989 Nov;52(11):777-780. doi: 10.4315/0362-028X-52.11.777.
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.
在八个月的时间里，从美国各地的11家加工企业分3至4次获取了商业破损的生液态全蛋液（LWE）。美国食品药品监督管理局（FDA）、美国农业部（USDA）以及冷增菌程序对这些样本进行了李斯特菌属检测。从42个鸡蛋样本中的15个（36%）获得了45株李斯特菌分离株。USDA和FDA的方法都有助于分离李斯特菌属，分别得到12个和8个阳性样本。两种程序都有6个样本呈阳性。通过冷增菌从一个样本中分离出了李斯特菌。最常分离出的菌种是无害李斯特菌，在所有李斯特菌阳性样本中均有发现。单核细胞增生李斯特菌是唯一分离出的其他菌种，从5%的鸡蛋样本中获得。USDA和FDA的程序各产生了一个单核细胞增生李斯特菌阳性样本。这两个单核细胞增生李斯特菌阳性样本中单核细胞增生李斯特菌的估计菌量分别为1 CFU/ml和8 CFU/ml，且是在春季和初夏采样时从同一工厂获得的。15个李斯特菌阳性样本中有12个（80%）是经过固体调整的LWE。因此，包括嗜冷病原菌单核细胞增生李斯特菌在内的李斯特菌属存在于商业破损的生LWE中。
