婴幼儿羊奶粉及米粉中的细菌多样性分析

为探究婴幼儿奶粉和米粉辅食中细菌群落结构,对婴幼儿食品生产质量控制和监管提供理论依据,本研究采用Ion torrent PGM二代高通量测序平台对14个婴幼儿食品样本中细菌16Sr RNA的V4~V5可变区进行了测序分析。测序共获得13805个不同的OTU,隶属于2界、10门、20纲、50目、84科、144属。分析结果表明,婴幼儿羊奶粉样品比米粉样品具有更高的群落多样性,奶粉样品组内差异较米粉样品小。羊奶粉样品中占绝对优势菌群隶属于厚壁菌门(65.58%)和变形菌门(16.01%),在属水平上以链球菌属(24.86%)和乳球菌属(21.44%)为主;而米粉样品中蓝藻菌门(41.79%)占有绝对优势,厚壁菌门(30.99%)和变形菌门(24.48%)次之,推测主要与两种产品的原料不同有关。另外,沙门氏菌(8.75%)、李斯特氏菌(3.61%)等与食源性疾病相关的细菌种类在米粉样品组中普遍存在,经组间差异性分析表明与奶粉样品中相应丰度有统计学差异(p<0.05),提示婴幼儿米粉产品存在潜在的食品安全隐患,其原料和生产加工环节的质量控制亟需引起生产企业和食品监管部门的重视。

Bacterial Diversity Analysis of Infant Food Based on 16S rRNA High-throughput Sequencing

In order to investigate the bacterial community structure in infant formula milk and rice flour, and provide theoretical basis for the quality control and supervision of infant food production, the 16S rRNA V4-V5 regions of bacteria from 14 infant food samples were sequenced based on ion torrent PGM platform. A total of 13,805 different OTUs were obtained by sequencing analysis, belonging to 2 kindoms, 10 phyla, 20 classes, 50 orders, 84 families and 144 genera. The results showed that the bacterial community diversity of the infant milk powder samples was higher than that of the rice flour, and the difference within group of milk powder was smaller than that of rice flour. The absolute dominant flora in goat milk powder belonged to Fimicutes (65.58%) and Proteobacteria (16.01%) on phylum level, Streptococcus (24.86%) and Lactococcus (21.44%) on genus level. While, Cyanobacteria (41.79%) was the most dominant in rice flour samples, followed by Fimicutes (30.99%) and Proteobacteria (24.48%), which might be related to the different raw materials of two products. In addition, foodborne pathogens such as Salmonella (8.75%) and Listeria (3.61%) existed in most of the rice flour samples, and the difference of abundance was significant (p<0.05) between the milk powder and rice flour samples, which indicated that infant rice flour products might have potential food safety risks. Therefore, the enterprises and food supervision department should pay more attention to the quality control of infant rice flour production.