RT Journal Article SR Electronic T1 Human intestinal tract serves as an alternative infection route for Middle East respiratory syndrome coronavirus JF Science Advances JO Sci Adv FD American Association for the Advancement of Science SP eaao4966 DO 10.1126/sciadv.aao4966 VO 3 IS 11 A1 Zhou, Jie A1 Li, Cun A1 Zhao, Guangyu A1 Chu, Hin A1 Wang, Dong A1 Yan, Helen Hoi-Ning A1 Poon, Vincent Kwok-Man A1 Wen, Lei A1 Wong, Bosco Ho-Yin A1 Zhao, Xiaoyu A1 Chiu, Man Chun A1 Yang, Dong A1 Wang, Yixin A1 Au-Yeung, Rex K. H. A1 Chan, Ivy Hau-Yee A1 Sun, Shihui A1 Chan, Jasper Fuk-Woo A1 To, Kelvin Kai-Wang A1 Memish, Ziad A. A1 Corman, Victor M. A1 Drosten, Christian A1 Hung, Ivan Fan-Ngai A1 Zhou, Yusen A1 Leung, Suet Yi A1 Yuen, Kwok-Yung YR 2017 UL http://advances.sciencemag.org/content/3/11/eaao4966.abstract AB Middle East respiratory syndrome coronavirus (MERS-CoV) has caused human respiratory infections with a high case fatality rate since 2012. However, the mode of virus transmission is not well understood. The findings of epidemiological and virological studies prompted us to hypothesize that the human gastrointestinal tract could serve as an alternative route to acquire MERS-CoV infection. We demonstrated that human primary intestinal epithelial cells, small intestine explants, and intestinal organoids were highly susceptible to MERS-CoV and can sustain robust viral replication. We also identified the evidence of enteric MERS-CoV infection in the stool specimen of a clinical patient. MERS-CoV was considerably resistant to fed-state gastrointestinal fluids but less tolerant to highly acidic fasted-state gastric fluid. In polarized Caco-2 cells cultured in Transwell inserts, apical MERS-CoV inoculation was more effective in establishing infection than basolateral inoculation. Notably, direct intragastric inoculation of MERS-CoV caused a lethal infection in human DPP4 transgenic mice. Histological examination revealed MERS-CoV enteric infection in all inoculated mice, as shown by the presence of virus-positive cells, progressive inflammation, and epithelial degeneration in small intestines, which were exaggerated in the mice pretreated with the proton pump inhibitor pantoprazole. With the progression of the enteric infection, inflammation, virus-positive cells, and live viruses emerged in the lung tissues, indicating the development of sequential respiratory infection. Taken together, these data suggest that the human intestinal tract may serve as an alternative infection route for MERS-CoV.