福建省2003-2005年食品中空肠和结肠弯曲菌的监测与分析

目的系统分析福建省食品中空肠和结肠弯曲菌的污染现状、分布特征,建立和完善食源性致病菌监测网络,为制定相关的食品卫生干预措施提供可靠的基础数据。方法2003-2005年选择福建省的8个地级市和南北2个贫困县的农贸市场为监测点,采集生畜禽肉类、生牛奶、生食蔬菜、鸡蛋、水产品5大类共730份食品样品。按照WHO推荐并作为《全国食品污染物监测相关实验室操作手册(食源性致病菌部分)》的弯曲菌检验方法,用加有生长促进剂和特定配方抗生素的布氏肉汤增菌,将增菌液划线接种至弯曲菌选择性琼脂CCDA平板,挑取可疑菌落转种在哥伦比亚血琼脂平板上纯化。纯化的可疑菌落做革兰染色镜检,湿片观察动力,同时做过氧化氢酶试验、氧化酶试验、马尿酸盐水解试验、吲哚乙酸酯试验等生化鉴定。结果检出弯曲菌阳性的样品39件,总的阳性率为5·34%。分离到空肠和结肠弯曲菌47株,其中空肠弯曲菌34株、结肠弯曲菌13株。不同种类的食品阳性率不同,阳性率最高的为生肉6·72%(36/536),其次为生食蔬菜5·88%(2/34),水产品0·95%(1/105),生牛奶与鸡蛋中均未检出。生肉类中阳性率最高的为鸡肉7·31%(19/260)。结论福建省市售食品中存在着不同程度的弯曲菌污染,应加强食品中空肠和结肠弯曲菌的监测,加强禽畜养殖、屠宰、运输和加工过程的卫生管理,防止交叉污染,有效地预防和控制弯曲菌感染的暴发和流行。

Surveillance and Analysis on Food Contamination by C. jejuni and C. coli in Fujian Province from 2003 to 2005

Objective To explore systemically the extent and distribution of C.jejuni and C.coli contamination in food products, to establish and improve the surveillance network for food-born pathogens and to provide fundamental information for policy makers to work out related intervention program.Method Free markets in 8 cities and 2 counties were chosen as surveillance spots according to their geographic locations and their economic levels. Samples of 5 categories of foods were collected, including raw meat, raw milk, vegetable, eggs and aquatic products. According to the testing methods recommended by WHO and the national laboratory manual for monitoring food pollutants, samples were pre-enriched in Preston broth containing campylobacter growth supplement and specific antibiotics. Enriched broth was inoculated in selective agar CCDA plates. Suspected colonies were purified on Columbia blood agar plates. The isolates were Gram stained and tested by motility test, catalase test, oxidase test, hippurate hydrolysis and indoxyl acetate hydrolysis.Results 730 samples were examined and the overall positive rate was 5.34%( 39/730 ). 34 strains of C.jejuni isolates and 13 strains of C.coli were isolated. Positive rates varied in different categories of foods, with the highest (6.72%) in raw meats, followed by vegetables 5.88% and aquatic foods (0.95%). The pathogens were not found in raw milk and eggs. The highest positive rate among various raw meats 7.34%( 19/260 ) was found in chicken. Conclusion This study indicated that foods in Fujian Province were contaminated by Campylobacters in different degrees. Surveillance and management should be improved in the process of farming, slaughtering and transportation to prevent cross-contamination, outbreak and prevailing of campylobacters infection.