Pei Xiao Yan, Yan Lin, Zhu Jiang Hui, Li Ning, Guo Yun Chang, Fu Ping, Jia Hua Yun, Zhang Xiu Li, Yang Xiao Rong, Yang Da Jin
China National Center for Food Safety Risk Assessment, Beijing 100022, China.
Hunan Province Center for Disease Control and Prevention, Changsha 410000, Hunan, China.
Biomed Environ Sci. 2016 Feb;29(2):99-106. doi: 10.3967/bes2016.011.
To determine Cronobacter spp. contamination in infant and follow-up powdered formula in China.
All of 2282 samples were collected from the retail markets in China from January 2012 to December 2012, and analyzed for Cronobacter spp. by the Chinese National Food Safety Standard. Characterization of the isolates was analyzed by pulsed-field gel electrophoresis (PFGE) with XbaI and SpeI restriction enzymes.
Cronobacter spp. strains were isolated from 25 samples, and the positive rates in infant powdered formulas and follow-up powdered formulas were 0.90% (10/1011) and 1.18% (15/1271), respectively. Analysis of variable data regarding different purchasing store formats, seasonality, and production locations as well as comparison of infant versus follow-up formulas did not reveal statistically significant factors. During the sampling period, one of six surveillance zones did exhibit a statistically significant trend towards higher positive rate. PFGE characterization of Cronobacter spp. to elucidate genetic diversity revealed only three pairs of Cronobacter spp. out of 25 having the same PFGE patterns.
The current investigation indicated a lower positive rate of Cronobacter spp. in the powdered formula in China. This evidence suggested contamination originating from multiple different sources during the manufacturing process.
测定中国婴儿配方奶粉和后续配方奶粉中阪崎肠杆菌属的污染情况。
2012年1月至2012年12月期间，从中国零售市场采集了2282份样本，并按照中国国家食品安全标准对阪崎肠杆菌属进行分析。使用XbaI和SpeI限制性内切酶通过脉冲场凝胶电泳（PFGE）对分离株进行特征分析。
从25份样本中分离出阪崎肠杆菌属菌株，婴儿配方奶粉和后续配方奶粉中的阳性率分别为0.90%（10/1011）和1.18%（15/1271）。对不同购买店铺形式、季节性、生产地点等可变数据的分析以及婴儿配方奶粉与后续配方奶粉的比较，均未发现具有统计学意义的因素。在采样期间，六个监测区域中的一个确实呈现出阳性率较高的统计学显著趋势。对阪崎肠杆菌属进行PFGE特征分析以阐明遗传多样性，结果显示在25株中有三对阪崎肠杆菌属具有相同的PFGE图谱。
当前调查表明中国配方奶粉中阪崎肠杆菌属的阳性率较低。这一证据表明在制造过程中污染源自多个不同来源。
