Kim M, Kuehn L A, Bono J L, Berry E D, Kalchayanand N, Freetly H C, Benson A K, Wells J E
U.S. Meat Animal Research Center, USDA, ARS, Clay Center, NE, USA.
Department of Food Science and Technology, University of Nebraska-Lincoln, Lincoln, NE, USA.
J Appl Microbiol. 2017 Oct;123(4):1027-1042. doi: 10.1111/jam.13545. Epub 2017 Sep 11.
The objective of this study was to determine if the faecal microbiome has an association with Escherichia coli O157:H7 prevalence and enumeration.
Pyrosequencing analysis of faecal microbiome was performed from feedlot cattle fed one of three diets: (i) 94 heifers fed low concentrate (LC) diet, (ii) 142 steers fed moderate concentrate (MC) diet, and (iii) 132 steers fed high concentrate (HC) diet. A total of 322 585 OTUs were calculated from 2,411,122 high-quality sequences obtained from 368 faecal samples. In the LC diet group, OTUs assigned to the orders Clostridiales and RF39 (placed within the class Mollicutes) were positively correlated with both E. coli O157:H7 prevalence and enumeration. In the MC diet group, OTUs assigned to Prevotella copri were positively correlated with both E. coli O157:H7 prevalence and enumeration, whereas OTUs assigned to Prevotella stercorea were negatively correlated with both E. coli O157:H7 prevalence and enumeration. In both the MC diet group and the HC diet group, OTUs assigned to taxa placed within Clostridiales were both positively and negatively correlated with both E. coli O157:H7 prevalence and enumeration. However, all correlations were weak. In both the MC diet group and the HC diet group, stepwise linear regression through backward elimination analyses indicated that these OTUs were significantly correlated (P < 0·001) with prevalence or enumeration, explaining as much as 50% of variability in E. coli O157:H7 prevalence or enumeration.
Individual colonic bacterial species have little impact on E. coli O157:H7 shedding but collectively groups of bacteria were strongly associated with pathogen shedding.
Bacterial groups in the bovine colon may impact faecal shedding of the zoonotic pathogen E. coli O157:H7, and manipulation of the intestinal microbiota to alter these bacteria may reduce shedding of this pathogen and foodborne illnesses.
本研究的目的是确定粪便微生物群与大肠杆菌O157:H7的流行率和计数是否有关联。
对饲养场中喂食三种日粮之一的牛进行粪便微生物群焦磷酸测序分析：（i）94头小母牛喂食低精料（LC）日粮，（ii）142头阉牛喂食中等精料（MC）日粮，（iii）132头阉牛喂食高精料（HC）日粮。从368份粪便样本获得的2,411,122条高质量序列中，共计算出322585个操作分类单元（OTU）。在LC日粮组中，属于梭菌目和RF39（属于柔膜菌纲）的OTU与大肠杆菌O157:H7的流行率和计数均呈正相关。在MC日粮组中，属于普氏粪杆菌的OTU与大肠杆菌O157:H7的流行率和计数均呈正相关，而属于硬结普氏菌的OTU与大肠杆菌O157:H7的流行率和计数均呈负相关。在MC日粮组和HC日粮组中，属于梭菌目的分类单元的OTU与大肠杆菌O157:H7的流行率和计数均呈正相关和负相关。然而，所有相关性都很弱。在MC日粮组和HC日粮组中，通过向后逐步消除分析的逐步线性回归表明，这些OTU与流行率或计数显著相关（P < 0·001），解释了大肠杆菌O157:H7流行率或计数中高达50%的变异性。
单个结肠细菌物种对大肠杆菌O157:H7的排出影响很小，但细菌群体总体上与病原体排出密切相关。
牛结肠中的细菌群体可能影响人畜共患病原体大肠杆菌O157:H7的粪便排出，通过操纵肠道微生物群来改变这些细菌可能会减少该病原体的排出和食源性疾病。
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