Intestinal microbiota mediates Enterotoxigenic Escherichia coli-induced diarrhea in piglets

Peng Bin,Shaojuan Liu,Zhiyi Tang,Shuai Chen,Yaoyao Xia,Hucong Wu,Jiaqi Liu,Guoqiang Zhu

doi:10.1186/s12917-018-1704-9

Abstract

BackgroundEnterotoxigenic Escherichia coli (ETEC) causes diarrhea in humans, cows, and pigs. The gut microbiota underlies pathology of several infectious diseases yet the role of the gut microbiota in the pathogenesis of ETEC-induced diarrhea is unknown.ResultsBy using an ETEC induced diarrheal model in piglet, we profiled the jejunal and fecal microbiota using metagenomics and 16S rRNA sequencing. A jejunal microbiota transplantation experiment was conducted to determine the role of the gut microbiota in ETEC-induced diarrhea. ETEC-induced diarrhea influenced the structure and function of gut microbiota. Diarrheal piglets had lower Bacteroidetes: Firmicutes ratio and microbiota diversity in the jejunum and feces, and lower percentage of Prevotella in the feces, but higher Lactococcus in the jejunum and higher Escherichia-Shigella in the feces. The transplantation of the jejunal microbiota from diarrheal piglets to uninfected piglets leaded to diarrhea after transplantation. Microbiota transplantation experiments also supported the notion that dysbiosis of gut microbiota is involved in the immune responses in ETEC-induced diarrhea.ConclusionWe conclude that ETEC infection influences the gut microbiota and the dysbiosis of gut microbiota after ETEC infection mediates the immune responses in ETEC infection.

Highlights

Enterotoxigenic Escherichia coli (ETEC) causes diarrhea in humans, cows, and pigs
Piglets which challenged with LB medium were defined as control group; piglets which developed watery diarrhea were marked during the whole experiment, and the marked piglets were regarded as recovered piglets if they recovered from diarrhea, otherwise were considered as diarrheal piglets; piglets those challenged with ETEC but not suffered from diarrhea were regarded as resistant piglets
ETEC-induced diarrhea was associated with alterations in intestinal microbiota We characterized the jejnunal microbiota in piglets using metagenomics sequencing (Fig. 1a)

Summary

Introduction

Enterotoxigenic Escherichia coli (ETEC) causes diarrhea in humans, cows, and pigs. The etiology and epidemiology of diarrhea in piglets is very complicated, and the Enterotoxigenic Escherichia coli (ETEC) is the most common food-borne epidemical pathogen which causes diarrhea. Mechanism of ETEC-induced diarrhea depends on the fimbrial adhesins and enterotoxin, which promotes the pathogen bacteria to adhere on the intestinal epithelial cells of piglets and lead to the fluid-electrolytes disturbance and acid-base imbalance of piglets, respectively [14, 15]. Our previous investigation found that about 50% of piglets develop diarrhea after ETEC infection [17]. Whether the intestinal microbiota is related to the susceptibility of individuals and pigs to ETEC infection and development of diarrhea is unknown

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Discussion

Conclusion