Wagner M, Auer B, Trittremmel C, Hein I, Schoder D
Department for Veterinary Public Health, Institute for Milk Hygiene, Milk Technology and Food Science, University of Veterinary Medicine, Veterinärplatz 1, 1210 Vienna, Austria.
Zoonoses Public Health. 2007;54(1):16-22. doi: 10.1111/j.1863-2378.2007.00982.x.
Qualitative and quantitative contamination of ready-to-eat food-stuffs with the pathogen Listeria monocytogenes was studied in 1586 samples collected from 103 supermarkets (n = 946) and 61 households (n = 640) in Vienna, Austria. Seventeen groups of ready-to-eat foods were classified into three risk categories for contamination (CP1-CP3). Three to four samples were randomly collected at the retail level from each CP. Regarding the households, the sampling procedure was started with food items of CP1, and if not available, was continued with sampling of food items of CP2 and finally of CP3. Additionally, 184 environmental samples (swabs from the kitchen area, dust samples from the vacuum cleaner) and faecal samples (household members and pet animals) were included. One-hundred and twenty-four (13.1%) and 45 (4.8%) samples out of 946 food samples collected from food retailers tested positive for Listeria spp. and L. monocytogenes, respectively, with five smoked fish samples exceeding the tolerated limit of 100 CFU/g food. Food-stuffs associated with the highest risk of contamination were twice as frequently contaminated with L. monocytogenes as food-stuffs associated with a medium risk of contamination. Products showing the highest contamination rate were fish and seafood (19.4%), followed by raw meat sausages (6.3%), soft cheese (5.5%) and cooked meat products/patés (4.5%). The overall contamination rate of foods collected at the household level was more than two times lower. Only 5.6% and 1.7% of 640 food-stuffs analysed tested positive for Listeria spp. and L. monocytogenes, respectively. However, CP1 foods were rarely collected. Pulsed-field gel electrophoresis (PFGE) typing of the collected L. monocytogenes isolates revealed a high degree of diversity between the isolates, with some exceptions. PFGE typing of isolates harvested from green-veined cheese revealed a match among strains, although the manufacturer seemed to be distinguishable. Typing of household strains revealed an epidemiological link within one family. In this case, food-stuffs and the kitchen environment were contaminated by an indistinguishable isolate. In addition, the same isolate was collected from a pooled faecal sample of the household members suggesting that consumption of even low contaminated food items (<100 CFU/g) results in Listeria shedding after the passage through the gut.
对从奥地利维也纳103家超市（n = 946）和61户家庭（n = 640）采集的1586份样本中的即食食品受单核细胞增生李斯特菌病原体的定性和定量污染情况进行了研究。将十七类即食食品分为三类污染风险类别（CP1 - CP3）。从每个CP在零售层面随机采集三到四个样本。对于家庭，采样程序从CP1的食品项目开始，如果没有，则继续对CP2的食品项目进行采样，最后是CP3的食品项目。此外，还纳入了184份环境样本（厨房区域拭子、吸尘器灰尘样本）和粪便样本（家庭成员和宠物）。从食品零售商处采集的946份食品样本中，分别有124份（13.1%）和45份（4.8%）单核细胞增生李斯特菌属和单核细胞增生李斯特菌检测呈阳性，其中有五份烟熏鱼样本超过了100 CFU/g食品的耐受限量。与最高污染风险相关的食品被单核细胞增生李斯特菌污染的频率是与中等污染风险相关食品的两倍。污染率最高的产品是鱼类和海鲜（19.4%），其次是生肉香肠（6.3%）、软奶酪（5.5%）和熟肉制品/肉酱（4.5%）。在家庭层面采集的食品的总体污染率要低两倍多。在分析的640份食品中，分别只有5.6%和1.7%的单核细胞增生李斯特菌属和单核细胞增生李斯特菌检测呈阳性。然而，CP1食品很少被采集到。对采集的单核细胞增生李斯特菌分离株进行脉冲场凝胶电泳（PFGE）分型显示，分离株之间存在高度多样性，但有一些例外。从绿纹奶酪中分离出的菌株的PFGE分型显示菌株之间存在匹配，尽管制造商似乎是可区分的。对家庭菌株的分型显示一个家庭内存在流行病学联系。在这种情况下，食品和厨房环境被一种无法区分的分离株污染。此外，从家庭成员的混合粪便样本中也采集到了相同的分离株，这表明即使食用污染程度低的食品（<100 CFU/g）在通过肠道后也会导致李斯特菌排出。
