Jingwan Zhang1, Emily C Hoedt2, Qin Liu1, Erwin Berendsen3, Jing Jie Teh3, Amy Hamilton4, Amy Wilson O' Brien4, Jessica Y L Ching1, Hong Wei5, Keli Yang1, Zhilu Xu1, Sunny H Wong6, Joyce W Y Mak1, Joseph J Y Sung1, Mark Morrison7, Jun Yu8, Michael A Kamm9, Siew C Ng10. 1. Department of Medicine and Therapeutics, Institute of Digestive Disease, State Key Laboratory of Digestive Diseases, Li Ka Shing Institute of Health Science, The Chinese University of Hong Kong, Hong Kong, China. 2. The University of Queensland Diamantina Institute, Faculty of Medicine, Brisbane, Australia; APC Microbiome Ireland, University College Cork, Cork, Ireland. 3. The University of Queensland Diamantina Institute, Faculty of Medicine, Brisbane, Australia. 4. Department of Gastroenterology, St Vincent's Hospital, Melbourne, Australia; Department of Medicine, The University of Melbourne, Melbourne, Australia. 5. Department of Laboratory Animal Science at the Third Military Medical University in Chongqing, China. 6. Department of Medicine and Therapeutics, Institute of Digestive Disease, State Key Laboratory of Digestive Diseases, Li Ka Shing Institute of Health Science, The Chinese University of Hong Kong, Hong Kong, China; Center for Gut Microbiota Research, Department of Medicine and Therapeutics, The Chinese University of Hong Kong, Hong Kong, China. 7. The University of Queensland Diamantina Institute, Faculty of Medicine, Brisbane, Australia. Electronic address: m.morrison1@uq.edu.au. 8. Department of Medicine and Therapeutics, Institute of Digestive Disease, State Key Laboratory of Digestive Diseases, Li Ka Shing Institute of Health Science, The Chinese University of Hong Kong, Hong Kong, China; Center for Gut Microbiota Research, Department of Medicine and Therapeutics, The Chinese University of Hong Kong, Hong Kong, China. Electronic address: junyu@cuhk.edu.hk. 9. Department of Gastroenterology, St Vincent's Hospital, Melbourne, Australia; Department of Medicine, The University of Melbourne, Melbourne, Australia. Electronic address: mkamm@unimelb.edu.au. 10. Department of Medicine and Therapeutics, Institute of Digestive Disease, State Key Laboratory of Digestive Diseases, Li Ka Shing Institute of Health Science, The Chinese University of Hong Kong, Hong Kong, China; Center for Gut Microbiota Research, Department of Medicine and Therapeutics, The Chinese University of Hong Kong, Hong Kong, China. Electronic address: siewchienng@cuhk.edu.hk.
Abstract
BACKGROUND & AIMS: Proteus spp, Gram-negative facultative anaerobic bacilli, have recently been associated with Crohn's disease (CD) recurrence after intestinal resection. We investigated the genomic and functional role of Proteus as a gut pathogen in CD. METHODS: Proteus spp abundance was assessed by ure gene-specific polymerase chain in 54 pairs of fecal samples and 101 intestinal biopsies from patients with CD and healthy controls. The adherence, invasion, and intracellular presence of 2 distinct isolates of Proteus mirabilis in epithelial cells were evaluated using immunofluorescence and electron microscopy. Intracellular gene expression profiles and regulated pathways were analyzed by RNA sequencing and KEGG pathway analysis. Biologic functions of 2 isolates of P mirabilis were determined by in vitro cell culture, and in vivo using conventional mice and germ-free mice. RESULTS: Proteus spp were significantly more prevalent and abundant in fecal samples and colonic tissue of patients with CD than controls. A greater abundance of the genus Fusobacterium and a lesser abundance of the genus Faecalibacterium were seen in patients with CD with a high Proteus spp abundance. All 24 Proteus monoclones isolated from patients with CD belonged to members of P mirabilis lineages and 2 isolates, recovered from stool or mucosa, were used in further studies. Mice gavaged with either P mirabilis strain had more severe colonic inflammation. Co-culture of the isolates with epithelial cell lines showed bacterial adherence, invasion, increased production of pro-inflammatory cytokines IL-18 and IL-1α, and cell necrosis. Both isolates induced key pro-inflammatory pathways, including NOD-like receptor signaling, Jak-STAT signaling, and MAPK signaling, and induced pro-inflammatory genes and activated inflammation-related pathways in gnotobiotic mice. CONCLUSIONS: P mirabilis in the gut is associated with CD and can induce inflammation in cells and animal models of colitis. P mirabilis can act as a pathobiont and play a crucial role in the pathogenesis of CD.
BACKGROUND & AIMS:Proteus spp, Gram-negative facultative anaerobic bacilli, have recently been associated with Crohn's disease (CD) recurrence after intestinal resection. We investigated the genomic and functional role of Proteus as a gut pathogen in CD. METHODS:Proteus spp abundance was assessed by ure gene-specific polymerase chain in 54 pairs of fecal samples and 101 intestinal biopsies from patients with CD and healthy controls. The adherence, invasion, and intracellular presence of 2 distinct isolates of Proteus mirabilis in epithelial cells were evaluated using immunofluorescence and electron microscopy. Intracellular gene expression profiles and regulated pathways were analyzed by RNA sequencing and KEGG pathway analysis. Biologic functions of 2 isolates of P mirabilis were determined by in vitro cell culture, and in vivo using conventional mice and germ-free mice. RESULTS:Proteus spp were significantly more prevalent and abundant in fecal samples and colonic tissue of patients with CD than controls. A greater abundance of the genus Fusobacterium and a lesser abundance of the genus Faecalibacterium were seen in patients with CD with a high Proteus spp abundance. All 24 Proteus monoclones isolated from patients with CD belonged to members of P mirabilis lineages and 2 isolates, recovered from stool or mucosa, were used in further studies. Mice gavaged with either P mirabilis strain had more severe colonic inflammation. Co-culture of the isolates with epithelial cell lines showed bacterial adherence, invasion, increased production of pro-inflammatory cytokines IL-18 and IL-1α, and cell necrosis. Both isolates induced key pro-inflammatory pathways, including NOD-like receptor signaling, Jak-STAT signaling, and MAPK signaling, and induced pro-inflammatory genes and activated inflammation-related pathways in gnotobiotic mice. CONCLUSIONS: P mirabilis in the gut is associated with CD and can induce inflammation in cells and animal models of colitis. P mirabilis can act as a pathobiont and play a crucial role in the pathogenesis of CD.
Authors: Maria Joanna Niemiec; Mario Kapitan; Maximilian Himmel; Kristina Döll; Thomas Krüger; Tobias G Köllner; Isabel Auge; Franziska Kage; Christopher J Alteri; Harry L T Mobley; Tor Monsen; Susanne Linde; Sandor Nietzsche; Olaf Kniemeyer; Axel A Brakhage; Ilse D Jacobsen Journal: Front Cell Infect Microbiol Date: 2022-05-16 Impact factor: 6.073