河南省6类食品中肠出血性大肠埃希氏菌O157：H7污染状况调查

调查肠出血性大肠埃希氏菌O157:H在河南省6类食品中的分布特征和污染状况，了解季节因素对于肠出血性大肠埃希氏菌O157:H7分布的影响，以预防和控制食品污染保证食品安全。依据河南省自然地理概况，分5个采样区域，按夏季和冬季在销售环节随机抽取样品，选择性增菌培养后，用O157胶体金试剂筛查，免疫磁珠富集后分离病原菌，应用bioMerieux VITEK32 AMS system,GNI^ 和血清学的方法进行鉴定。结果显示1463份食品中共检出肠出血性大肠埃希氏菌O157:H7 28株，检出率为1．9％，其中鲜肉和生食蔬菜检出率最高，为3．3％和3．2％，酸奶中未检出。夏季检出率(2．5％)明显高于冬季检出率(1．1％)。结果提示，肠出血性大肠埃希氏菌O157：H7在食品中的污染程度较为严重，其检出率的高低与O157:H7感染性腹泻的流行强度呈正相关。应引起有关部门的足够重视，加强畜禽屠宰、蔬菜生产和销售环节的监督和监测，预防食源性疾病的爆发流行。

Pollution of EHEC O157:H7 in six types of food in Henan Province]

In order to investigate the distribution of contamination of EHEC O157:H7 in 6 types of food in Henan Province and characterize the effect of seasonal factors on distribution of O157:H7 contamination so as to prevent and control food contamination, Henan Province was divided into five sampling areas according to the natural geographical features. Samples were taken randomly in summer and winter sales links. After selective culture of increasing reproduction of O157:H7, it was screened by immuno-gold reagent, and pathogenic bacterium were isolated after accumulation of immunomagnetic. Then, it was identified by the bioMérieux VITEK32 AMS system, GNI+ and sero-reaction. Results showed that 28 EHEC O157:H7 were isolated in 1463 samples among which the positive rate of raw meat and fresh vegetable was 3.3% and 3.2% respectively (the highest of all), and EHEC O157:H7 was not found in yogurt. The positive rate in summer (2.5%) was obviously higher than that in winter (1.1%). It could be concluded that the contamination of EHEC O157:H7 in food was serious. Its positive rate was positively correlated with the epidemic of infective diarrhea. Therefore, attention should be given by relevant departments concerned and spervision and testing should be strengthened in livestock and farmyard bird slaughtering link, vegetable production link and sales link for better prevention of the breaking out and epidemic of food born diseases.