1
|
McCoy R, Oldroyd S, Yang W, Wang K, Hoven D, Bulmer D, Zilbauer M, Owens RM. In Vitro Models for Investigating Intestinal Host-Pathogen Interactions. ADVANCED SCIENCE (WEINHEIM, BADEN-WURTTEMBERG, GERMANY) 2024; 11:e2306727. [PMID: 38155358 PMCID: PMC10885678 DOI: 10.1002/advs.202306727] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/15/2023] [Revised: 12/01/2023] [Indexed: 12/30/2023]
Abstract
Infectious diseases are increasingly recognized as a major threat worldwide due to the rise of antimicrobial resistance and the emergence of novel pathogens. In vitro models that can adequately mimic in vivo gastrointestinal physiology are in high demand to elucidate mechanisms behind pathogen infectivity, and to aid the design of effective preventive and therapeutic interventions. There exists a trade-off between simple and high throughput models and those that are more complex and physiologically relevant. The complexity of the model used shall be guided by the biological question to be addressed. This review provides an overview of the structure and function of the intestine and the models that are developed to emulate this. Conventional models are discussed in addition to emerging models which employ engineering principles to equip them with necessary advanced monitoring capabilities for intestinal host-pathogen interrogation. Limitations of current models and future perspectives on the field are presented.
Collapse
Affiliation(s)
- Reece McCoy
- Department of Chemical Engineering and BiotechnologyUniversity of CambridgeCambridgeCB3 0ASUK
| | - Sophie Oldroyd
- Department of Chemical Engineering and BiotechnologyUniversity of CambridgeCambridgeCB3 0ASUK
| | - Woojin Yang
- Department of Chemical Engineering and BiotechnologyUniversity of CambridgeCambridgeCB3 0ASUK
- Wellcome‐MRC Cambridge Stem Cell InstituteUniversity of CambridgeCambridgeCB2 0AWUK
| | - Kaixin Wang
- Department of Chemical Engineering and BiotechnologyUniversity of CambridgeCambridgeCB3 0ASUK
| | - Darius Hoven
- Department of Chemical Engineering and BiotechnologyUniversity of CambridgeCambridgeCB3 0ASUK
| | - David Bulmer
- Department of PharmacologyUniversity of CambridgeCambridgeCB2 1PDUK
| | - Matthias Zilbauer
- Wellcome‐MRC Cambridge Stem Cell InstituteUniversity of CambridgeCambridgeCB2 0AWUK
| | - Róisín M. Owens
- Department of Chemical Engineering and BiotechnologyUniversity of CambridgeCambridgeCB3 0ASUK
| |
Collapse
|
2
|
Doranga S, Krogfelt KA, Cohen PS, Conway T. Nutrition of Escherichia coli within the intestinal microbiome. EcoSal Plus 2024:eesp00062023. [PMID: 38417452 DOI: 10.1128/ecosalplus.esp-0006-2023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2023] [Accepted: 11/03/2023] [Indexed: 03/01/2024]
Abstract
In this chapter, we update our 2004 review of "The Life of Commensal Escherichia coli in the Mammalian Intestine" (https://doi.org/10.1128/ecosalplus.8.3.1.2), with a change of title that reflects the current focus on "Nutrition of E. coli within the Intestinal Microbiome." The earlier part of the previous two decades saw incremental improvements in understanding the carbon and energy sources that E. coli and Salmonella use to support intestinal colonization. Along with these investigations of electron donors came a better understanding of the electron acceptors that support the respiration of these facultative anaerobes in the gastrointestinal tract. Hundreds of recent papers add to what was known about the nutrition of commensal and pathogenic enteric bacteria. The fact that each biotype or pathotype grows on a different subset of the available nutrients suggested a mechanism for succession of commensal colonizers and invasion by enteric pathogens. Competition for nutrients in the intestine has also come to be recognized as one basis for colonization resistance, in which colonized strain(s) prevent colonization by a challenger. In the past decade, detailed investigations of fiber- and mucin-degrading anaerobes added greatly to our understanding of how complex polysaccharides support the hundreds of intestinal microbiome species. It is now clear that facultative anaerobes, which usually cannot degrade complex polysaccharides, live in symbiosis with the anaerobic degraders. This concept led to the "restaurant hypothesis," which emphasizes that facultative bacteria, such as E. coli, colonize the intestine as members of mixed biofilms and obtain the sugars they need for growth locally through cross-feeding from polysaccharide-degrading anaerobes. Each restaurant represents an intestinal niche. Competition for those niches determines whether or not invaders are able to overcome colonization resistance and become established. Topics centered on the nutritional basis of intestinal colonization and gastrointestinal health are explored here in detail.
Collapse
Affiliation(s)
- Sudhir Doranga
- Department of Microbiology and Molecular Genetics, Oklahoma State University, Stillwater, Oklahoma, USA
| | - Karen A Krogfelt
- Department of Science and Environment, Pandemix Center Roskilde University, Roskilde, Denmark
| | - Paul S Cohen
- Department of Cell and Molecular Biology, University of Rhode Island, Kingston, Rhode Island, USA
| | - Tyrrell Conway
- Department of Microbiology and Molecular Genetics, Oklahoma State University, Stillwater, Oklahoma, USA
| |
Collapse
|
3
|
Gao H, He C, Xin S, Hua R, Du Y, Wang B, Gong F, Yu X, Pan L, Liang C, Gao L, Shang H, Xu JD. Rhubarb extract rebuilding the mucus homeostasis and regulating mucin-associated flora to relieve constipation. Exp Biol Med (Maywood) 2023; 248:2449-2463. [PMID: 38073524 PMCID: PMC10903230 DOI: 10.1177/15353702231211859] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2023] [Accepted: 08/21/2023] [Indexed: 01/23/2024] Open
Abstract
In clinical trials, rhubarb extract (Rb) was demonstrated to efficiently alleviate constipation. We would like to find out the underlying mechanism of rhubarb relieving constipation. However, there are few studies on the effects of rhubarb on colonic mucus secretion and constipation. The aim of this study was to investigate the effects of rhubarb on colonic mucus secretion and its underlying mechanism. The mice were randomly divided into four groups. Group I was the control group and Group II was the rhubarb control group, with Rb (24 g/kg body weight [b.w.]) administered through intragastric administration for three days. Group III mice were given diphenoxylate (20 mg/kg b.w.) for five days via gavage to induce constipation. Group IV received diphenoxylate lasting five days before undergoing Rb administration for three days. The condition of the colon was evaluated using an endoscope. Particularly, the diameter of blood vessels in the colonic mucosa expanded considerably in constipation mice along with diminishing mucus output, which was in line with the observation via scanning electron microscope (SEM) and transmission electron microscope (TEM). We also performed metagenomic analysis to reveal the microbiome related to mucin gene expression level referring to mucin secretion. In conclusion, Rb relieves constipation by rebuilding mucus homeostasis and regulating the microbiome.
Collapse
Affiliation(s)
- Han Gao
- Department of Physiology and Pathophysiology, School of Basic Medical Sciences, Capital Medical University, Beijing 100069, China
- Department of Clinical Laboratory, Aerospace Center Hospital, Beijing 100039, China
| | - Chengwei He
- Department of Physiology and Pathophysiology, School of Basic Medical Sciences, Capital Medical University, Beijing 100069, China
| | - Shuzi Xin
- Department of Physiology and Pathophysiology, School of Basic Medical Sciences, Capital Medical University, Beijing 100069, China
| | - Rongxuan Hua
- Department of Clinical Medicine, School of Basic Medical Sciences, Capital Medical University, Beijing 100069, China
| | - Yixuan Du
- Department of Oral Medicine, School of Basic Medical Sciences, Capital Medical University, Beijing 100069, China
| | - Boya Wang
- Key laboratory of Carcinogenesis and Translational Research (Ministry of Education/Beijing), Department of Gastrointestinal Oncology, Peking University Cancer Hospital & Institute, Beijing 100142, China
| | - Fengrong Gong
- Department of Clinical Medicine, School of Basic Medical Sciences, Capital Medical University, Beijing 100069, China
| | - Xinyi Yu
- Department of Clinical Medicine, School of Basic Medical Sciences, Capital Medical University, Beijing 100069, China
| | - Luming Pan
- Department of Clinical Medicine, School of Basic Medical Sciences, Capital Medical University, Beijing 100069, China
| | - Chen Liang
- Department of Clinical Medicine, School of Basic Medical Sciences, Capital Medical University, Beijing 100069, China
| | - Lei Gao
- Department of Biomedical Informatics, School of Biomedical Engineering, Capital Medical University, Beijing 100069, China
| | - Hongwei Shang
- Experimental Center for Morphological Research Platform, School of Basic Medical Sciences, Capital Medical University, Beijing 100069, China
| | - Jing-dong Xu
- Department of Physiology and Pathophysiology, School of Basic Medical Sciences, Capital Medical University, Beijing 100069, China
| |
Collapse
|
4
|
Ortiz Y, Heredia N, García S. Boundaries That Prevent or May Lead Animals to be Reservoirs of Escherichia coli O104:H4. J Food Prot 2023; 86:100053. [PMID: 36916560 DOI: 10.1016/j.jfp.2023.100053] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2022] [Revised: 01/18/2023] [Accepted: 01/21/2023] [Indexed: 02/05/2023]
Abstract
Escherichia coli O104:H4, a hybrid serotype carrying virulence factors from enteroaggregative (EAEC) and Shiga toxin-producing (STEC) pathotypes, is the reported cause of a multicountry outbreak in 2011. Evaluation of potential routes of human contamination revealed that this strain is a foodborne pathogen. In contrast to STEC strains, whose main reservoir is cattle, serotype O104:H4 has not been commonly isolated from animals or related environments, suggesting an inability to naturally colonize the gut in hosts other than humans. However, contrary to this view, this strain has been shown to colonize the intestines of experimental animals in infectious studies. In this minireview, we provide a systematic summary of reports highlighting potential evolutionary changes that could facilitate the colonization of new reservoirs by these bacteria.
Collapse
Affiliation(s)
- Yaraymi Ortiz
- Departamento de Microbiología e Inmunología, Facultad de Ciencias Biológicas, Universidad Autónoma de Nuevo León, Ciudad Universitaria, San Nicolás de los Garza, NL 66455, Mexico
| | - Norma Heredia
- Departamento de Microbiología e Inmunología, Facultad de Ciencias Biológicas, Universidad Autónoma de Nuevo León, Ciudad Universitaria, San Nicolás de los Garza, NL 66455, Mexico
| | - Santos García
- Departamento de Microbiología e Inmunología, Facultad de Ciencias Biológicas, Universidad Autónoma de Nuevo León, Ciudad Universitaria, San Nicolás de los Garza, NL 66455, Mexico.
| |
Collapse
|
5
|
Bournonville L, Askri D, Arafah K, Voisin SN, Bocquet M, Bulet P. Unraveling the Bombus terrestris Hemolymph, an Indicator of the Immune Response to Microbial Infections, through Complementary Mass Spectrometry Approaches. Int J Mol Sci 2023; 24:ijms24054658. [PMID: 36902086 PMCID: PMC10003634 DOI: 10.3390/ijms24054658] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2023] [Revised: 02/20/2023] [Accepted: 02/22/2023] [Indexed: 03/04/2023] Open
Abstract
Pollinators, including Bombus terrestris, are crucial for maintaining biodiversity in ecosystems and for agriculture. Deciphering their immune response under stress conditions is a key issue for protecting these populations. To assess this metric, we analyzed the B. terrestris hemolymph as an indicator of their immune status. Hemolymph analysis was carried out using mass spectrometry, MALDI molecular mass fingerprinting was used for its effectiveness in assessing the immune status, and high-resolution mass spectrometry was used to measure the impact of experimental bacterial infections on the "hemoproteome". By infecting with three different types of bacteria, we observed that B. terrestris reacts in a specific way to bacterial attacks. Indeed, bacteria impact survival and stimulate an immune response in infected individuals, visible through changes in the molecular composition of their hemolymph. The characterization and label-free quantification of proteins involved in specific signaling pathways in bumble bees by bottom-up proteomics revealed differences in protein expression between the non-experimentally infected and the infected bees. Our results highlight the alteration of pathways involved in immune and defense reactions, stress, and energetic metabolism. Lastly, we developed molecular signatures reflecting the health status of B. terrestris to pave the way for diagnosis/prognosis tools in response to environmental stress.
Collapse
Affiliation(s)
- Lorène Bournonville
- Platform BioPark Archamps, 218 Avenue Marie Curie ArchParc, 74160 Archamps, France
- Department of Molecular and Cellular Biology, University of Geneva, Sciences III, 30 Quai Ernest-Ansermet, 1211 Geneva, Switzerland
| | - Dalel Askri
- Platform BioPark Archamps, 218 Avenue Marie Curie ArchParc, 74160 Archamps, France
| | - Karim Arafah
- Platform BioPark Archamps, 218 Avenue Marie Curie ArchParc, 74160 Archamps, France
| | - Sébastien N. Voisin
- Platform BioPark Archamps, 218 Avenue Marie Curie ArchParc, 74160 Archamps, France
- Phylogene S.A. 62 RN113, 30620 Bernis, France
| | - Michel Bocquet
- Michel Bocquet, Apimedia, 82 Route de Proméry, Pringy, 74370 Annecy, France
| | - Philippe Bulet
- Platform BioPark Archamps, 218 Avenue Marie Curie ArchParc, 74160 Archamps, France
- Institute for Advanced Biosciences, Inserm U 1209, CNRS UMR 5309, University Grenoble Alpes, 38000 Grenoble, France
- Correspondence: ; Tel.: +33-4-50-43-25-21
| |
Collapse
|
6
|
Garimano N, Scalise ML, Gómez F, Amaral MM, Ibarra C. Intestinal mucus-derived metabolites modulate virulence of a clade 8 enterohemorrhagic Escherichia coli O157:H7. Front Cell Infect Microbiol 2022; 12:975173. [PMID: 36004327 PMCID: PMC9393340 DOI: 10.3389/fcimb.2022.975173] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2022] [Accepted: 07/20/2022] [Indexed: 11/24/2022] Open
Abstract
The human colonic mucus is mainly composed of mucins, which are highly glycosylated proteins. The normal commensal colonic microbiota has mucolytic activity and is capable of releasing the monosaccharides contained in mucins, which can then be used as carbon sources by pathogens such as Enterohemorrhagic Escherichia coli (EHEC). EHEC can regulate the expression of some of its virulence factors through environmental sensing of mucus-derived sugars, but its implications regarding its main virulence factor, Shiga toxin type 2 (Stx2), among others, remain unknown. In the present work, we have studied the effects of five of the most abundant mucolytic activity-derived sugars, Fucose (L-Fucose), Galactose (D-Galactose), N-Gal (N-acetyl-galactosamine), NANA (N-Acetyl-Neuraminic Acid) and NAG (N-Acetyl-D-Glucosamine) on EHEC growth, adhesion to epithelial colonic cells (HCT-8), and Stx2 production and translocation across a polarized HCT-8 monolayer. We found that bacterial growth was maximum when using NAG and NANA compared to Galactose, Fucose or N-Gal, and that EHEC adhesion was inhibited regardless of the metabolite used. On the other hand, Stx2 production was enhanced when using NAG and inhibited with the rest of the metabolites, whilst Stx2 translocation was only enhanced when using NANA, and this increase occurred only through the transcellular route. Overall, this study provides insights on the influence of the commensal microbiota on the pathogenicity of E. coli O157:H7, helping to identify favorable intestinal environments for the development of severe disease.
Collapse
|
7
|
Lange ME, Uwiera RRE, Inglis GD. Enteric Escherichia coli O157:H7 in Cattle, and the Use of Mice as a Model to Elucidate Key Aspects of the Host-Pathogen-Microbiota Interaction: A Review. Front Vet Sci 2022; 9:937866. [PMID: 35898542 PMCID: PMC9310005 DOI: 10.3389/fvets.2022.937866] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2022] [Accepted: 06/02/2022] [Indexed: 11/24/2022] Open
Abstract
Enterohemorrhagic Escherichia coli (EHEC) serotype O157:H7 is responsible for foodborne disease outbreaks, typically associated with the consumption of undercooked foods contaminated with cattle manure containing the bacterium. At present, effective mitigations do not exist. Many of the factors regulating enteric colonization by E. coli O157:H7 in cattle, and how cattle respond to the bacterium are unknown. In this regard, intestinal colonization locations, shedding patterns, interactions with the enteric microbiota, and host immune responses to infection are current knowledge gaps. As disturbances to host homeostasis are believed to play an important role in the enteric survival of the bacterium, it is important to consider the potential importance of stress during cattle production. Husbandry logistics, cost, and the high genetic, physiological, and microbial heterogeneity in cattle has greatly hampered the ability of researchers to elucidate key aspects of the host-pathogen-microbiota interaction. Although mice have not been extensively used as a cattle model, the utilization of murine models has the potential to identify mechanisms to facilitate hypothesis formulation and efficacy testing in cattle. Murine models have been effectively used to mechanistically examine colonization of the intestine, host responses to infection, and to interactively ascertain how host physiological status (e.g., due to physiological stress) and the enteric microbiota influences colonization and disease. In addition to reviewing the relevant literature on intestinal colonization and pathogenesis, including existing knowledge gaps, the review provides information on how murine models can be used to elucidate mechanisms toward the development of rationale-based mitigations for E. coli O157:H7 in cattle.
Collapse
Affiliation(s)
- Maximo E. Lange
- Agriculture and Agri-Food Canada, Lethbridge Research and Development Centre, Lethbridge, AB, Canada
| | - Richard R. E. Uwiera
- Department of Agricultural, Food and Nutritional Science, University of Alberta, Edmonton, AB, Canada
| | - G. Douglas Inglis
- Agriculture and Agri-Food Canada, Lethbridge Research and Development Centre, Lethbridge, AB, Canada
| |
Collapse
|
8
|
Effects of Yellow Light on Airborne Microbial Composition and on the Transcriptome of Typical Marker Strain in Ward. DISEASE MARKERS 2022; 2022:8762936. [PMID: 35634440 PMCID: PMC9132710 DOI: 10.1155/2022/8762936] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/01/2022] [Accepted: 04/27/2022] [Indexed: 11/25/2022]
Abstract
Airborne diseases are transmitted by pathogens in the air. The complex microbial environment in wards is usually considered a major cause of nosocomial infection of various diseases which greatly influences the health of patients with chronic diseases, whereas the illuminant of wards impacts on the microbe especially the disease marker strain is seldom studied. In the present study, high-throughput sequencing was used to study the effect of yellow light on airborne microbial composition, and changes of transcriptome of marker strains Escherichia coli, Staphylococcus aureus and Pseudomonas aeruginosa, which were isolated from wards, were further studied after the irradiation by yellow light. High-throughput sequencing results indicated that yellow light significantly decreased α-diversity. The relative abundance of Firmicutes at the phylum level, and Clostridium sensu stricto 1, Paraclostridium at the genus level were significantly reduced. RNA sequencing results declared that yellow light significantly downregulated the genes associated with flagella, heme transport system and carbohydrate, amino acid metabolism in E. coli, and the genes related to arginine biosynthesis and the biosynthesis of isoleucine, leucine, and valine in S. aureus. Meanwhile, yellow light significantly upregulated the genes relating to porphyrin metabolism in P. aeruginosa. In conclusion, our work reveals the impacts of yellow light on the microbe in wards, pointing out the application value of yellow light in the prevention of infectious diseases in clinical practice.
Collapse
|
9
|
Sy BM, Tree JJ. The Small RNA CyaR Activates Translation of the Outer Membrane Haem Receptor chuA in Enterohemorrhagic Escherichia coli. Front Microbiol 2022; 13:821196. [PMID: 35422774 PMCID: PMC9002310 DOI: 10.3389/fmicb.2022.821196] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2021] [Accepted: 02/10/2022] [Indexed: 12/22/2022] Open
Abstract
To sense the transition from environment to host, bacteria use a range of environmental cues to control expression of virulence genes. Iron is tightly sequestered in host tissues and in the human pathogen enterohemorrhagic Escherichia coli (EHEC) iron-limitation induces transcription of the outer membrane haem transporter encoded by chuAS. ChuA expression is post-transcriptionally activated at 37°C by a FourU RNA thermometer ensuring that the haem receptor is only expressed under low iron, high temperature conditions that indicate the host. Here we demonstrate that expression of chuA is also independently regulated by the cAMP-responsive small RNA (sRNA) CyaR and transcriptional terminator Rho. These results indicate that chuAS expression is regulated at the transcription initiation, transcript elongation, and translational level. We speculate that additional sensing of the gluconeogenic environment allows further precision in determining when EHEC is at the gastrointestinal epithelium of the host. With previous studies, it appears that the chuAS transcript is controlled by eight regulatory inputs that control expression through six different transcriptional and post-transcriptional mechanisms. The results highlight the ability of regulatory sRNAs to integrate multiple environmental signals into a layered hierarchy of signal input.
Collapse
Affiliation(s)
- Brandon M Sy
- School of Biotechnology and Biomolecular Sciences, University of New South Wales, Sydney, NSW, Australia
| | - Jai J Tree
- School of Biotechnology and Biomolecular Sciences, University of New South Wales, Sydney, NSW, Australia
| |
Collapse
|
10
|
Segura A, Bertin Y, Durand A, Benbakkar M, Forano E. Transcriptional analysis reveals specific niche factors and response to environmental stresses of enterohemorrhagic Escherichia coli O157:H7 in bovine digestive contents. BMC Microbiol 2021; 21:284. [PMID: 34663220 PMCID: PMC8524897 DOI: 10.1186/s12866-021-02343-7] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2021] [Accepted: 09/24/2021] [Indexed: 02/08/2023] Open
Abstract
Background Enterohemorrhagic Escherichia coli (EHEC) are responsible for severe diseases in humans, and the ruminant digestive tract is considered as their main reservoir. Their excretion in bovine feces leads to the contamination of foods and the environment. Thus, providing knowledge of processes used by EHEC to survive and/or develop all along the bovine gut represents a major step for strategies implementation. Results We compared the transcriptome of the reference EHEC strain EDL933 incubated in vitro in triplicate samples in sterile bovine rumen, small intestine and rectum contents with that of the strain grown in an artificial medium using RNA-sequencing (RNA-seq), focusing on genes involved in stress response, adhesion systems including the LEE, iron uptake, motility and chemotaxis. We also compared expression of these genes in one digestive content relative to the others. In addition, we quantified short chain fatty acids and metal ions present in the three digestive contents. RNA-seq data first highlighted response of EHEC EDL933 to unfavorable physiochemical conditions encountered during its transit through the bovine gut lumen. Seventy-eight genes involved in stress responses including drug export, oxidative stress and acid resistance/pH adaptation were over-expressed in all the digestive contents compared with artificial medium. However, differences in stress fitness gene expression were observed depending on the digestive segment, suggesting that these differences were due to distinct physiochemical conditions in the bovine digestive contents. EHEC activated genes encoding three toxin/antitoxin systems in rumen content and many gene clusters involved in motility and chemotaxis in rectum contents. Genes involved in iron uptake and utilization were mostly down-regulated in all digestive contents compared with artificial medium, but feo genes were over-expressed in rumen and small intestine compared with rectum. The five LEE operons were more expressed in rectum than in rumen content, and LEE1 was also more expressed in rectum than in small intestine content. Conclusion Our results highlight various strategies that EHEC may implement to survive in the gastrointestinal environment of cattle. These data could also help defining new targets to limit EHEC O157:H7 carriage and shedding by cattle. Supplementary Information The online version contains supplementary material available at 10.1186/s12866-021-02343-7.
Collapse
Affiliation(s)
- Audrey Segura
- Université Clermont Auvergne, INRAE, MEDIS 0454, F-63000, Clermont-Ferrand, France
| | - Yolande Bertin
- Université Clermont Auvergne, INRAE, MEDIS 0454, F-63000, Clermont-Ferrand, France
| | - Alexandra Durand
- Université Clermont Auvergne, INRAE, MEDIS 0454, F-63000, Clermont-Ferrand, France
| | - Mhammed Benbakkar
- Université Clermont Auvergne, CNRS, IRD, OPGC, Laboratoire Magmas et Volcans, F-63000, Clermont-Ferrand, France
| | - Evelyne Forano
- Université Clermont Auvergne, INRAE, MEDIS 0454, F-63000, Clermont-Ferrand, France.
| |
Collapse
|
11
|
Mucolytic bacteria: prevalence in various pathological diseases. World J Microbiol Biotechnol 2021; 37:176. [PMID: 34519941 DOI: 10.1007/s11274-021-03145-9] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2021] [Accepted: 09/07/2021] [Indexed: 02/07/2023]
Abstract
All mucins are highly glycosylated and a key constituent of the mucus layer that is vigilant against pathogens in many organ systems of animals and humans. The viscous layer is organized in bilayers, i.e., an outer layer that is loosely arranged, variable in thickness, home to the commensal microbiota that grows in the complex environment, and an innermost layer that is stratified, non-aspirated, firmly adherent to the epithelial cells and devoid of any microorganisms. The O-glycosylation moiety represents the site of adhesion for pathogens and due to the increase of motility, mucolytic activity, and upregulation of virulence factors, some microorganisms can circumvent the component of the mucus layer and cause disruption in organ homeostasis. A dysbiotic microbiome, defective mucus barrier, and altered immune response often result in various diseases. In this review, paramount emphasis is given to the role played by the bacterial species directly or indirectly involved in mucin degradation, alteration in mucus secretion or its composition or mucin gene expression, which instigates many diseases in the digestive, respiratory, and other organ systems. A systematic view can help better understand the etiology of some complex disorders such as cystic fibrosis, ulcerative colitis and expand our knowledge about mucin degraders to develop new therapeutic approaches to correct ill effects caused by these mucin-dwelling pathogens.
Collapse
|
12
|
Sauvaitre T, Etienne-Mesmin L, Sivignon A, Mosoni P, Courtin CM, Van de Wiele T, Blanquet-Diot S. Tripartite relationship between gut microbiota, intestinal mucus and dietary fibers: towards preventive strategies against enteric infections. FEMS Microbiol Rev 2021; 45:5918835. [PMID: 33026073 DOI: 10.1093/femsre/fuaa052] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2020] [Accepted: 10/05/2020] [Indexed: 02/06/2023] Open
Abstract
The human gut is inhabited by a large variety of microorganims involved in many physiological processes and collectively referred as to gut microbiota. Disrupted microbiome has been associated with negative health outcomes and especially could promote the onset of enteric infections. To sustain their growth and persistence within the human digestive tract, gut microbes and enteric pathogens rely on two main polysaccharide compartments, namely dietary fibers and mucus carbohydrates. Several evidences suggest that the three-way relationship between gut microbiota, dietary fibers and mucus layer could unravel the capacity of enteric pathogens to colonise the human digestive tract and ultimately lead to infection. The review starts by shedding light on similarities and differences between dietary fibers and mucus carbohydrates structures and functions. Next, we provide an overview of the interactions of these two components with the third partner, namely, the gut microbiota, under health and disease situations. The review will then provide insights into the relevance of using dietary fibers interventions to prevent enteric infections with a focus on gut microbial imbalance and impaired-mucus integrity. Facing the numerous challenges in studying microbiota-pathogen-dietary fiber-mucus interactions, we lastly describe the characteristics and potentialities of currently available in vitro models of the human gut.
Collapse
Affiliation(s)
- Thomas Sauvaitre
- Université Clermont Auvergne, UMR 454 INRAe, Microbiology, Digestive Environment and Health (MEDIS), Clermont-Ferrand, France.,Ghent University, Faculty of Bioscience Engineering, Center for Microbial Ecology and Technology (CMET), Ghent, Belgium
| | - Lucie Etienne-Mesmin
- Université Clermont Auvergne, UMR 454 INRAe, Microbiology, Digestive Environment and Health (MEDIS), Clermont-Ferrand, France
| | - Adeline Sivignon
- Université Clermont Auvergne, UMR 1071 Inserm, USC-INRAe 2018, Microbes, Intestin, Inflammation et Susceptibilité de l'Hôte (M2iSH), Clermont-Ferrand, France
| | - Pascale Mosoni
- Université Clermont Auvergne, UMR 454 INRAe, Microbiology, Digestive Environment and Health (MEDIS), Clermont-Ferrand, France
| | - Christophe M Courtin
- KU Leuven, Faculty of Bioscience Engineering, Laboratory of Food Chemistry and Biochemistry & Leuven Food Science and Nutrition Research Centre (LFoRCe), Leuven, Belgium
| | - Tom Van de Wiele
- Ghent University, Faculty of Bioscience Engineering, Center for Microbial Ecology and Technology (CMET), Ghent, Belgium
| | - Stéphanie Blanquet-Diot
- Université Clermont Auvergne, UMR 454 INRAe, Microbiology, Digestive Environment and Health (MEDIS), Clermont-Ferrand, France
| |
Collapse
|
13
|
Liang Q, Vallance BA. What's for dinner? How Citrobacter rodentium's metabolism helps it thrive in the competitive gut. Curr Opin Microbiol 2021; 63:76-82. [PMID: 34243134 DOI: 10.1016/j.mib.2021.06.004] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2021] [Revised: 06/16/2021] [Accepted: 06/21/2021] [Indexed: 01/04/2023]
Abstract
Enteric bacterial infections impose a significant and global health burden on society, and their threat is increasing in concert with a rise in antibiotic resistance. There is thus a great need to quickly develop new antimicrobial treatments and interest is growing in targeting pathogen nutrition and metabolism. In this review, we highlight recent research on the metabolism of Citrobacter rodentium, a murine-specific relative of enteropathogenic Escherichia coli (EPEC) and enterohemorrhagic E. coli (EHEC). We focus on the mechanisms by which C. rodentium acquires nutrients as well as the distinct metabolic strategies that C. rodentium employs in varying spatiotemporal niches. We propose that identifying and targeting nutrients found essential for bacterial pathogenesis is an attractive anti-microbial approach in the new post-antibiotic era.
Collapse
Affiliation(s)
- Qiaochu Liang
- Division of Gastroenterology, Hepatology and Nutrition, Department of Pediatrics, BC Children's Hospital and University of British Columbia, Vancouver, British Columbia, Canada
| | - Bruce A Vallance
- Division of Gastroenterology, Hepatology and Nutrition, Department of Pediatrics, BC Children's Hospital and University of British Columbia, Vancouver, British Columbia, Canada.
| |
Collapse
|
14
|
Engevik MA, Engevik AC, Engevik KA, Auchtung JM, Chang-Graham AL, Ruan W, Luna RA, Hyser JM, Spinler JK, Versalovic J. Mucin-Degrading Microbes Release Monosaccharides That Chemoattract Clostridioides difficile and Facilitate Colonization of the Human Intestinal Mucus Layer. ACS Infect Dis 2021; 7:1126-1142. [PMID: 33176423 DOI: 10.1021/acsinfecdis.0c00634] [Citation(s) in RCA: 45] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
It is widely accepted that the pathogen Clostridioides difficile exploits an intestinal environment with an altered microbiota, but the details of these microbe-microbe interactions are unclear. Adherence and colonization of mucus has been demonstrated for several enteric pathogens and it is possible that mucin-associated microbes may be working in concert with C. difficile. We showed that C. difficile ribotype-027 adheres to MUC2 glycans and using fecal bioreactors, we identified that C. difficile associates with several mucin-degrading microbes. C. difficile was found to chemotax toward intestinal mucus and its glycan components, demonstrating that C. difficile senses the mucus layer. Although C. difficile lacks the glycosyl hydrolases required to degrade mucin glycans, coculturing C. difficile with the mucin-degrading Akkermansia muciniphila, Bacteroides thetaiotaomicron, and Ruminococcus torques allowed C. difficile to grow in media that lacked glucose but contained purified MUC2. Collectively, these studies expand our knowledge on how intestinal microbes support C. difficile.
Collapse
Affiliation(s)
- Melinda A. Engevik
- Department of Pathology & Immunology, Baylor College of Medicine Houston Texas 77030, United States
- Department of Pathology, Texas Children’s Hospital Houston Texas 77030, United States
| | - Amy C. Engevik
- Department of Surgery, Vanderbilt University School of Medicine, Nashville Tennessee 37232, United States
- Epithelial Biology Center, Vanderbilt University School of Medicine, Nashville Tennessee 37232, United States
| | - Kristen A. Engevik
- Department of Molecular Virology and Microbiology, Baylor College of Medicine Houston Texas 77030, United States
| | - Jennifer M. Auchtung
- Department of Molecular Virology and Microbiology, Baylor College of Medicine Houston Texas 77030, United States
- Department of Food Science and Technology, University of Nebraska—Lincoln, Lincoln Nebraska 68588, United States
| | - Alexandra L. Chang-Graham
- Department of Molecular Virology and Microbiology, Baylor College of Medicine Houston Texas 77030, United States
| | - Wenly Ruan
- Department of Pathology & Immunology, Baylor College of Medicine Houston Texas 77030, United States
- Department of Pathology, Texas Children’s Hospital Houston Texas 77030, United States
| | - Ruth Ann Luna
- Department of Pathology & Immunology, Baylor College of Medicine Houston Texas 77030, United States
- Department of Pathology, Texas Children’s Hospital Houston Texas 77030, United States
| | - Joseph M. Hyser
- Department of Molecular Virology and Microbiology, Baylor College of Medicine Houston Texas 77030, United States
| | - Jennifer K. Spinler
- Department of Pathology & Immunology, Baylor College of Medicine Houston Texas 77030, United States
- Department of Pathology, Texas Children’s Hospital Houston Texas 77030, United States
| | - James Versalovic
- Department of Pathology & Immunology, Baylor College of Medicine Houston Texas 77030, United States
- Department of Pathology, Texas Children’s Hospital Houston Texas 77030, United States
| |
Collapse
|
15
|
Pan Q, Li Z, Ju X, Hou C, Xiao Y, Shi R, Fu C, Danchin A, You C. Escherichia coli segments its controls on carbon-dependent gene expression into global and specific regulations. Microb Biotechnol 2021; 14:1084-1106. [PMID: 33650807 PMCID: PMC8085971 DOI: 10.1111/1751-7915.13776] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2020] [Revised: 02/05/2021] [Accepted: 02/05/2021] [Indexed: 01/20/2023] Open
Abstract
How bacteria adjust gene expression to cope with variable environments remains open to question. Here, we investigated the way global gene expression changes in E. coli correlated with the metabolism of seven carbon substrates chosen to trigger a large panel of metabolic pathways. Coarse-grained analysis of gene co-expression identified a novel regulation pattern: we established that the gene expression trend following immediately the reduction of growth rate (GR) was correlated to its initial expression level. Subsequent fine-grained analysis of co-expression demonstrated that the Crp regulator, coupled with a change in GR, governed the response of most GR-dependent genes. By contrast, the Cra, Mlc and Fur regulators governed the expression of genes responding to non-glycolytic substrates, glycolytic substrates or phosphotransferase system transported sugars following an idiosyncratic way. This work allowed us to expand additional genes in the panel of gene complement regulated by each regulator and to elucidate the regulatory functions of each regulator comprehensively. Interestingly, the bulk of genes controlled by Cra and Mlc were, respectively, co-regulated by Crp- or GR-related effect and our quantitative analysis showed that each factor took turns to work as the primary one or contributed equally depending on the conditions.
Collapse
Affiliation(s)
- Qing Pan
- Shenzhen Key Laboratory of Microbial Genetic EngineeringCollege of Life Sciences and OceanologyShenzhen UniversityShenzhen, GuangdongChina
- Shandong Provincial Key Laboratory of Energy GeneticsKey Laboratory of BiofuelsQingdao Engineering Research Center of Biomass Resources and EnvironmentQingdao Institute of Bioenergy and Bioprocess TechnologyChinese Academy of SciencesQingdao, ShandongChina
| | - Zongjin Li
- Shenzhen Key Laboratory of Microbial Genetic EngineeringCollege of Life Sciences and OceanologyShenzhen UniversityShenzhen, GuangdongChina
| | - Xian Ju
- Shenzhen Key Laboratory of Microbial Genetic EngineeringCollege of Life Sciences and OceanologyShenzhen UniversityShenzhen, GuangdongChina
| | - Chaofan Hou
- Shenzhen Key Laboratory of Microbial Genetic EngineeringCollege of Life Sciences and OceanologyShenzhen UniversityShenzhen, GuangdongChina
| | - Yunzhu Xiao
- Shenzhen Key Laboratory of Microbial Genetic EngineeringCollege of Life Sciences and OceanologyShenzhen UniversityShenzhen, GuangdongChina
| | - Ruoping Shi
- Shenzhen Key Laboratory of Microbial Genetic EngineeringCollege of Life Sciences and OceanologyShenzhen UniversityShenzhen, GuangdongChina
| | - Chunxiang Fu
- Shandong Provincial Key Laboratory of Energy GeneticsKey Laboratory of BiofuelsQingdao Engineering Research Center of Biomass Resources and EnvironmentQingdao Institute of Bioenergy and Bioprocess TechnologyChinese Academy of SciencesQingdao, ShandongChina
| | - Antoine Danchin
- Kodikos Labs/Stellate TherapeuticsInstitut Cochin24 rue du Faubourg Saint‐JacquesParis75014France
| | - Conghui You
- Shenzhen Key Laboratory of Microbial Genetic EngineeringCollege of Life Sciences and OceanologyShenzhen UniversityShenzhen, GuangdongChina
| |
Collapse
|
16
|
Hailemariam S, Zhao S, Wang J. Complete Genome Sequencing and Transcriptome Analysis of Nitrogen Metabolism of Succinivibrio dextrinosolvens Strain Z6 Isolated From Dairy Cow Rumen. Front Microbiol 2020; 11:1826. [PMID: 33013723 PMCID: PMC7507024 DOI: 10.3389/fmicb.2020.01826] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2020] [Accepted: 07/10/2020] [Indexed: 02/02/2023] Open
Abstract
The unclassified Succinivibrionaceae lineages are abundant in high yielding multiparous cows, and their presence is positively correlated with milk yield and fat percentage and reduces methane emissions. However, it is still unclear which species are associated with the most efficient feed nutrient utilization and productivity. Here, we used integrated whole genome sequencing and matrix-assisted laser desorption/ionization mass spectrometry, coupled with phenotypic and chemotaxonomic analysis, to characterize S. dextrinosolvens Z6, a species in Succinivibrionaceae isolated from the rumen. To assess the role of S. dextrinosolvens Z6 in nitrogen metabolism, cells grown in different nitrogen sources were analyzed by RNA sequencing. The whole genome sequence result revealed a genome size of 3.47 Mbp with 38.9% of G + C content. A total of 2993 encoding sequences account for 98%. The genes for regulating carbohydrate (10.6%) and amino acid (9%) transport and metabolism were the most abundant. ANI (Average nucleotide identity) showed that SD-Z6 was most closely related to SD-22B (99.96%). The whole genome alignment of SD-Z6 with SD-22B showed a more than 0.34 Mb nucleotide difference. Growth of SD-Z6 occurred at a temperature 36–42°C with an optimum at 39.7°C, pH 6–8; the optimum pH was 6.9 and with 0–1% (w/v) NaCl. The maximum growth (OD600 0.825 ± 0.12) and microbial crude protein (MCP) (178.2 μg/ml) were observed in cells grown in amino acid. The maximum concentration of ammonia (3.96 ± 1.2) was observed in urea containing media and 1.06 mM (26.7% of the produced) remained after 24 h incubation. Activities of urease and glutamine synthase (P < 0.01) and glutamate dehydrogenase (P < 0.05) were significantly different in nitrogen and growth phase. Glutamate synthetase (P < 0.01) was significantly different only at different growth phases. In total, 1246 differentially expressed genes (DEGs) were identified in all nitrogen. Among DEGs, 33 were related to nitrogen metabolism. Their expression correlated with nitrogen sources and the intensity of enzyme activity. This result enhances our understanding of the roles of Succinivibrionaceae in the efficient nitrogen utilization and on environmental protection.
Collapse
Affiliation(s)
- Samson Hailemariam
- State Key Laboratory of Animal Nutrition, Institute of Animal Sciences, Chinese Academy of Agricultural Sciences, Beijing, China
| | - Shengguo Zhao
- State Key Laboratory of Animal Nutrition, Institute of Animal Sciences, Chinese Academy of Agricultural Sciences, Beijing, China
| | - Jiaqi Wang
- State Key Laboratory of Animal Nutrition, Institute of Animal Sciences, Chinese Academy of Agricultural Sciences, Beijing, China
| |
Collapse
|
17
|
Sapountzis P, Segura A, Desvaux M, Forano E. An Overview of the Elusive Passenger in the Gastrointestinal Tract of Cattle: The Shiga Toxin Producing Escherichia coli. Microorganisms 2020; 8:microorganisms8060877. [PMID: 32531983 PMCID: PMC7355788 DOI: 10.3390/microorganisms8060877] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2020] [Revised: 06/05/2020] [Accepted: 06/07/2020] [Indexed: 02/07/2023] Open
Abstract
For approximately 10,000 years, cattle have been our major source of meat and dairy. However, cattle are also a major reservoir for dangerous foodborne pathogens that belong to the Shiga toxin-producing Escherichia coli (STEC) group. Even though STEC infections in humans are rare, they are often lethal, as treatment options are limited. In cattle, STEC infections are typically asymptomatic and STEC is able to survive and persist in the cattle GIT by escaping the immune defenses of the host. Interactions with members of the native gut microbiota can favor or inhibit its persistence in cattle, but research in this direction is still in its infancy. Diet, temperature and season but also industrialized animal husbandry practices have a profound effect on STEC prevalence and the native gut microbiota composition. Thus, exploring the native cattle gut microbiota in depth, its interactions with STEC and the factors that affect them could offer viable solutions against STEC carriage in cattle.
Collapse
Affiliation(s)
- Panagiotis Sapountzis
- Université Clermont Auvergne, INRAE, UMR 0454 MEDIS, 63000 Clermont-Ferrand, France; (A.S.); (M.D.); (E.F.)
- Correspondence:
| | - Audrey Segura
- Université Clermont Auvergne, INRAE, UMR 0454 MEDIS, 63000 Clermont-Ferrand, France; (A.S.); (M.D.); (E.F.)
- Chr. Hansen Animal Health & Nutrition, 2970 Hørsholm, Denmark
| | - Mickaël Desvaux
- Université Clermont Auvergne, INRAE, UMR 0454 MEDIS, 63000 Clermont-Ferrand, France; (A.S.); (M.D.); (E.F.)
| | - Evelyne Forano
- Université Clermont Auvergne, INRAE, UMR 0454 MEDIS, 63000 Clermont-Ferrand, France; (A.S.); (M.D.); (E.F.)
| |
Collapse
|
18
|
Josenhans C, Müthing J, Elling L, Bartfeld S, Schmidt H. How bacterial pathogens of the gastrointestinal tract use the mucosal glyco-code to harness mucus and microbiota: New ways to study an ancient bag of tricks. Int J Med Microbiol 2020; 310:151392. [DOI: 10.1016/j.ijmm.2020.151392] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2019] [Revised: 11/28/2019] [Accepted: 12/06/2019] [Indexed: 12/13/2022] Open
|
19
|
Gardette M, Le Hello S, Mariani-Kurkdjian P, Fabre L, Gravey F, Garrivier A, Loukiadis E, Jubelin G. Identification and prevalence of in vivo-induced genes in enterohaemorrhagic Escherichia coli. Virulence 2019; 10:180-193. [PMID: 30806162 PMCID: PMC6550539 DOI: 10.1080/21505594.2019.1582976] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2018] [Revised: 01/25/2019] [Accepted: 02/06/2019] [Indexed: 12/14/2022] Open
Abstract
Enterohaemorrhagic Escherichia coli (EHEC) are food-borne pathogens responsible for bloody diarrhoea and renal failure in humans. While Shiga toxin (Stx) is the cardinal virulence factor of EHEC, its production by E. coli is not sufficient to cause disease and many Shiga-toxin producing E. coli (STEC) strains have never been implicated in human infection. So far, the pathophysiology of EHEC infection is not fully understood and more knowledge is needed to characterize the "auxiliary" factors that enable a STEC strain to cause disease in humans. In this study, we applied a recombinase-based in vivo expression technology (RIVET) to the EHEC reference strain EDL933 in order to identify genes specifically induced during the infectious process, using mouse as an infection model. We identified 31 in vivo-induced (ivi) genes having functions related to metabolism, stress adaptive response and bacterial virulence or fitness. Eight of the 31 ivi genes were found to be heterogeneously distributed in EHEC strains circulating in France these last years. In addition, they are more prevalent in strains from the TOP seven priority serotypes and particularly strains carrying significant virulence determinants such as Stx2 and intimin adhesin. This work sheds further light on bacterial determinants over-expressed in vivo during infection that may contribute to the potential of STEC strains to cause disease in humans.
Collapse
Affiliation(s)
- Marion Gardette
- UCA, INRA, UMR454 MEDIS, Clermont-Ferrand, France
- Laboratoire d’écologie microbienne de Lyon, Université de Lyon, CNRS, INRA, UCBL, VetAgro Sup, Marcy l’Etoile, France
| | - Simon Le Hello
- Centre de Référence National des Escherichia coli, Shigella et Salmonella, Institut Pasteur, Paris, France
- Université de Normandie, EA 2656 GRAM 2.0, UNICAEN, Caen, France
| | - Patricia Mariani-Kurkdjian
- Service de Microbiologie, Centre National de Référence associé Escherichia coli, Hôpital Robert-Debré, AP-HP, Paris, France
| | - Laetitia Fabre
- Centre de Référence National des Escherichia coli, Shigella et Salmonella, Institut Pasteur, Paris, France
| | - François Gravey
- Centre de Référence National des Escherichia coli, Shigella et Salmonella, Institut Pasteur, Paris, France
- Université de Normandie, EA 2656 GRAM 2.0, UNICAEN, Caen, France
| | | | - Estelle Loukiadis
- Laboratoire d’écologie microbienne de Lyon, Université de Lyon, CNRS, INRA, UCBL, VetAgro Sup, Marcy l’Etoile, France
- Laboratoire national de référence des E. coli, Université de Lyon, VetAgro Sup, Marcy l’Etoile, France
| | | |
Collapse
|
20
|
A Clonal Shiga Toxin–Producing Escherichia coli O121:H19 Population Exhibits Diverse Carbon Utilization Patterns. Foodborne Pathog Dis 2019; 16:384-393. [DOI: 10.1089/fpd.2018.2567] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
|
21
|
Segura A, Bertoni M, Auffret P, Klopp C, Bouchez O, Genthon C, Durand A, Bertin Y, Forano E. Transcriptomic analysis reveals specific metabolic pathways of enterohemorrhagic Escherichia coli O157:H7 in bovine digestive contents. BMC Genomics 2018; 19:766. [PMID: 30352567 PMCID: PMC6199705 DOI: 10.1186/s12864-018-5167-y] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2018] [Accepted: 10/15/2018] [Indexed: 11/12/2022] Open
Abstract
Background The cattle gastrointestinal tract (GIT) is the main enterohemorrhagic Escherichia coli (EHEC) reservoir. In order to identify nutrients required for the survival or multiplication of EHEC in the bovine GIT, we compared the transcriptomes of the EHEC O157:H7 reference strain EDL933 cultured in vitro in bovine digestive contents (DCs) (rumen, small intestine and rectum) using RNA-sequencing. Results Gene expression profiles showed that EHEC EDL933 activated common but also specific metabolic pathways to survive in the different bovine DCs. Mucus-derived carbohydrates seem important in EHEC nutrition in posterior DCs (small intestine and rectum) but not in rumen content. Additional carbohydrates (xylose, ribose, mannitol, galactitol) as well as gluconeogenic substrates (aspartate, serine, glycerol) would also be used by EHEC as carbon and/or nitrogen sources all along the bovine GIT including the rumen. However, xylose, GalNac, ribose and fucose transport and/or assimilation encoding genes were over-expressed during incubation in rectum content compared with rumen and intestine contents, and genes coding for maltose transport were only induced in rectum. This suggests a role for these carbohydrates in the colonization of the cattle rectum, considered as the major site for EHEC multiplication. In contrast, the transcription of the genes associated with the assimilation of ethanolamine, an important nitrogen source for EHEC, was poorly induced in EHEC growing in rectum content, suggesting that ethanolamine is mainly assimilated in the cattle rumen and small intestine. Respiratory flexibility would also be required for EHEC survival because of the redundancy of dehydrogenases and reductases simultaneously induced in the bovine DCs, probably in response to the availability of electron donors and acceptors. Conclusion EHEC EDL933 showed a high flexibility in the activation of genes involved in respiratory pathways and assimilation of carbon and nitrogen sources, most of them from animal origin. This may allow the bacterium to adapt and survive in the various bovine GIT compartments. Obtaining a better understanding of EHEC physiology in bovine GIT is a key step to ultimately propose strategies to limit EHEC carriage and shedding by cattle. Electronic supplementary material The online version of this article (10.1186/s12864-018-5167-y) contains supplementary material, which is available to authorized users.
Collapse
Affiliation(s)
- Audrey Segura
- Université Clermont Auvergne, INRA, UMR 0454 MEDIS, F-63000, Clermont-Ferrand, France
| | - Marine Bertoni
- Université Clermont Auvergne, INRA, UMR 0454 MEDIS, F-63000, Clermont-Ferrand, France.,Present address : Institut National de Police Scientifique - Laboratoire de Police Scientifique de Marseille, Marseille, France
| | - Pauline Auffret
- Université Clermont Auvergne, INRA, UMR 0454 MEDIS, F-63000, Clermont-Ferrand, France.,Present address : Ifremer, UMR 241 EIO, Tahiti, French Polynesia
| | - Christophe Klopp
- Plateforme Bioinformatique Toulouse, Midi-Pyrénées UBIA, INRA, Auzeville, Castanet-Tolosan, France
| | - Olivier Bouchez
- INRA, US 1426, GeT-PlaGe, Genotoul, Castanet-Tolosan, France
| | | | - Alexandra Durand
- Université Clermont Auvergne, INRA, UMR 0454 MEDIS, F-63000, Clermont-Ferrand, France
| | - Yolande Bertin
- Université Clermont Auvergne, INRA, UMR 0454 MEDIS, F-63000, Clermont-Ferrand, France
| | - Evelyne Forano
- Université Clermont Auvergne, INRA, UMR 0454 MEDIS, F-63000, Clermont-Ferrand, France.
| |
Collapse
|
22
|
De-O-Acetylation of mucin-derived sialic acids by recombinant NanS-p esterases of Escherichia coli O157:H7 strain EDL933. Int J Med Microbiol 2018; 308:1113-1120. [PMID: 30340996 PMCID: PMC7106450 DOI: 10.1016/j.ijmm.2018.10.001] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2018] [Revised: 09/27/2018] [Accepted: 10/05/2018] [Indexed: 01/11/2023] Open
Abstract
Enterohemorrhagic Escherichia coli (EHEC) O157:H7 strain EDL933 encodes the single chromosomal 9-O-acetylesterase NanS, and several copies of prophage-encoded 9-O-acetylesterases (NanS-p). These enzymes have recently been shown to cleave 5-N-acetyl-9-O-acetyl neuraminic acid (Neu5,9Ac2) to yield de-O-acetylated Neu5Ac, the latter of which may serve as a carbon and/or nitrogen source. In the current study, we investigated the NanS- and NanS-p-mediated digestion of synthetic O-acetylated neuraminic acids and bovine submaxillary glands mucin (BSM)-derived O-acetylneuraminic acids by high-performance thin-layer chromatography (HPTLC) and nano electrospray ionization mass spectrometry (nanoESI MS). Initial HPTLC analyses showed the expected activity of NanS and NanS-p variants for Neu5,9Ac2. However, all tested enzymes were unable to de-O-acetylate 5-N-acetyl-4-O-acetylneuraminic acid (Neu5,4 Ac2) in our test system. The nanoESI MS analysis of neuraminic acids after treatment of BSM with NanS-p gave evidence that NanS-p variants of EHEC O157:H7 strain EDL933 cleave off O-acetyl groups from mono-, di-, and tri-O-acetylated Neu5Ac and N-glycolylneuraminic acid (Neu5Gc), regardless of the carbon positions C7, C8 or C9 of the acetate esters. This enzyme activity leads to neuraminidase-accessible Neu5Ac and Neu5Gc on mucin glycans. Moreover, we could demonstrate by HPTLC analyses that recombinant Bacteroides thetaiotaomicron sialidase (BTSA-His) was able to cleave Neu5Ac and Neu5,9Ac2 from BSM and that the combination of BTSA-His with both NanS-His and NanS-p-His derivatives enhanced the release of de-O-acetylated core Neu5Ac and Neu5Gc from mammalian mucin O-glycans. Growth experiments with EHEC wildtype strain EDL933, its nanS and nanS/nanS-p1a-p7 mutant and exogenous BTSA-His in BSM demonstrated that the presence of BTSA-His enhanced growth of EDL933 and the nanS deletion mutant but not the nanS/nanS-p1a-p7 mutant. Thus, we hypothesize that the expression of sialic acid O-acetylesterases with a broad specificity could be an advantage in competition with the gut microbiota for nutrients and facilitate EHEC colonization in the human large intestine.
Collapse
|
23
|
Bertin Y, Segura A, Jubelin G, Dunière L, Durand A, Forano E. Aspartate metabolism is involved in the maintenance of enterohaemorrhagicEscherichia coliO157:H7 in bovine intestinal content. Environ Microbiol 2018; 20:4473-4485. [DOI: 10.1111/1462-2920.14380] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2018] [Revised: 07/20/2018] [Accepted: 08/09/2018] [Indexed: 11/28/2022]
Affiliation(s)
- Yolande Bertin
- Université Clermont Auvergne, INRA, MEDIS F‐63000 Clermont‐Ferrand France
| | - Audrey Segura
- Université Clermont Auvergne, INRA, MEDIS F‐63000 Clermont‐Ferrand France
| | - Gregory Jubelin
- Université Clermont Auvergne, INRA, MEDIS F‐63000 Clermont‐Ferrand France
| | - Lysiane Dunière
- Université Clermont Auvergne, INRA, MEDIS F‐63000 Clermont‐Ferrand France
- Lallemand Animal Nutrition Blagnac France
| | - Alexandra Durand
- Université Clermont Auvergne, INRA, MEDIS F‐63000 Clermont‐Ferrand France
| | - Evelyne Forano
- Université Clermont Auvergne, INRA, MEDIS F‐63000 Clermont‐Ferrand France
| |
Collapse
|
24
|
Sicard JF, Vogeleer P, Le Bihan G, Rodriguez Olivera Y, Beaudry F, Jacques M, Harel J. N-Acetyl-glucosamine influences the biofilm formation of Escherichia coli. Gut Pathog 2018; 10:26. [PMID: 29977346 PMCID: PMC6013987 DOI: 10.1186/s13099-018-0252-y] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/03/2018] [Accepted: 06/18/2018] [Indexed: 12/14/2022] Open
Abstract
Background The intestinal mucous layer is a physical barrier that limits the contact between bacteria and host epithelial cells. There is growing evidence that microbiota-produced metabolites can also be specifically sensed by gut pathogens as signals to induce or repress virulence genes. Many E. coli, including adherent and invasive (AIEC) strains, can form biofilm. This property can promote their intestinal colonization and resistance to immune mechanisms. We sought to evaluate the impact of mucus-derived sugars on biofilm formation of E. coli. Results We showed that the mucin sugar N-acetyl-glucosamine (NAG) can reduce biofilm formation of AIEC strain LF82. We demonstrated that the inactivation of the regulatory protein NagC, by addition of NAG or by mutation of nagC gene, reduced the biofilm formation of LF82 in static condition. Interestingly, real-time monitoring of biofilm formation of LF82 using microfluidic system showed that the mutation of nagC impairs the early process of biofilm development of LF82. Thus, NAG sensor NagC is involved in the early steps of biofilm formation of AIEC strain LF82 under both static and dynamic conditions. Its implication is partly due to the activation of type 1 fimbriae. NAG can also influence biofilm formation of other intestinal E. coli strains. Conclusions This study highlights how catabolism can be involved in biofilm formation of E. coli. Mucus-derived sugars can influence virulence properties of pathogenic E. coli and this study will help us better understand the mechanisms used to prevent colonization of the intestinal mucosa by pathogens. Electronic supplementary material The online version of this article (10.1186/s13099-018-0252-y) contains supplementary material, which is available to authorized users.
Collapse
Affiliation(s)
- Jean-Félix Sicard
- 1Groupe de Recherche sur les Maladies Infectieuses en Production Animale, Centre de Recherche en Infectiologie Porcine et Avicole, Faculté de Médecine Vétérinaire, Université de Montréal, St-Hyacinthe, QC J2S 2M2 Canada
| | - Philippe Vogeleer
- 1Groupe de Recherche sur les Maladies Infectieuses en Production Animale, Centre de Recherche en Infectiologie Porcine et Avicole, Faculté de Médecine Vétérinaire, Université de Montréal, St-Hyacinthe, QC J2S 2M2 Canada
| | - Guillaume Le Bihan
- 1Groupe de Recherche sur les Maladies Infectieuses en Production Animale, Centre de Recherche en Infectiologie Porcine et Avicole, Faculté de Médecine Vétérinaire, Université de Montréal, St-Hyacinthe, QC J2S 2M2 Canada
| | - Yaindrys Rodriguez Olivera
- 1Groupe de Recherche sur les Maladies Infectieuses en Production Animale, Centre de Recherche en Infectiologie Porcine et Avicole, Faculté de Médecine Vétérinaire, Université de Montréal, St-Hyacinthe, QC J2S 2M2 Canada
| | - Francis Beaudry
- 1Groupe de Recherche sur les Maladies Infectieuses en Production Animale, Centre de Recherche en Infectiologie Porcine et Avicole, Faculté de Médecine Vétérinaire, Université de Montréal, St-Hyacinthe, QC J2S 2M2 Canada
| | - Mario Jacques
- 2Regroupement de Recherche Pour un Lait de Qualité Optimale (Op+Lait), Faculté de Médecine Vétérinaire, Université de Montréal, Saint-Hyacinthe, QC J2S 2M2 Canada
| | - Josée Harel
- 1Groupe de Recherche sur les Maladies Infectieuses en Production Animale, Centre de Recherche en Infectiologie Porcine et Avicole, Faculté de Médecine Vétérinaire, Université de Montréal, St-Hyacinthe, QC J2S 2M2 Canada
| |
Collapse
|
25
|
Quintana-Hayashi MP, Padra M, Padra JT, Benktander J, Lindén SK. Mucus-Pathogen Interactions in the Gastrointestinal Tract of Farmed Animals. Microorganisms 2018; 6:E55. [PMID: 29912166 PMCID: PMC6027344 DOI: 10.3390/microorganisms6020055] [Citation(s) in RCA: 40] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2018] [Revised: 06/09/2018] [Accepted: 06/15/2018] [Indexed: 12/29/2022] Open
Abstract
Gastrointestinal infections cause significant challenges and economic losses in animal husbandry. As pathogens becoming resistant to antibiotics are a growing concern worldwide, alternative strategies to treat infections in farmed animals are necessary in order to decrease the risk to human health and increase animal health and productivity. Mucosal surfaces are the most common route used by pathogens to enter the body. The mucosal surface that lines the gastrointestinal tract is covered by a continuously secreted mucus layer that protects the epithelial surface. The mucus layer is the first barrier the pathogen must overcome for successful colonization, and is mainly composed of densely glycosylated proteins called mucins. The vast array of carbohydrate structures present on the mucins provide an important setting for host-pathogen interactions. This review summarizes the current knowledge on gastrointestinal mucins and their role during infections in farmed animals. We examine the interactions between mucins and animal pathogens, with a focus on how pathogenic bacteria can modify the mucin environment in the gut, and how this in turn affects pathogen adhesion and growth. Finally, we discuss analytical challenges and complexities of the mucus-based defense, as well as its potential to control infections in farmed animals.
Collapse
Affiliation(s)
- Macarena P Quintana-Hayashi
- Department of Medical Biochemistry and Cell biology, Institute of Biomedicine, Sahlgrenska Academy, University of Gothenburg, Box 440, 405 30 Gothenburg, Sweden.
| | - Médea Padra
- Department of Medical Biochemistry and Cell biology, Institute of Biomedicine, Sahlgrenska Academy, University of Gothenburg, Box 440, 405 30 Gothenburg, Sweden.
| | - János Tamás Padra
- Department of Medical Biochemistry and Cell biology, Institute of Biomedicine, Sahlgrenska Academy, University of Gothenburg, Box 440, 405 30 Gothenburg, Sweden.
| | - John Benktander
- Department of Medical Biochemistry and Cell biology, Institute of Biomedicine, Sahlgrenska Academy, University of Gothenburg, Box 440, 405 30 Gothenburg, Sweden.
| | - Sara K Lindén
- Department of Medical Biochemistry and Cell biology, Institute of Biomedicine, Sahlgrenska Academy, University of Gothenburg, Box 440, 405 30 Gothenburg, Sweden.
| |
Collapse
|
26
|
Segura A, Auffret P, Bibbal D, Bertoni M, Durand A, Jubelin G, Kérourédan M, Brugère H, Bertin Y, Forano E. Factors Involved in the Persistence of a Shiga Toxin-Producing Escherichia coli O157:H7 Strain in Bovine Feces and Gastro-Intestinal Content. Front Microbiol 2018; 9:375. [PMID: 29593666 PMCID: PMC5854682 DOI: 10.3389/fmicb.2018.00375] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2017] [Accepted: 02/19/2018] [Indexed: 11/28/2022] Open
Abstract
Healthy cattle are the primary reservoir for O157:H7 Shiga toxin-producing E. coli responsible for human food-borne infections. Because farm environment acts as a source of cattle contamination, it is important to better understand the factors controlling the persistence of E. coli O157:H7 outside the bovine gut. The E. coli O157:H7 strain MC2, identified as a persistent strain in French farms, possessed the characteristics required to cause human infections and genetic markers associated with clinical O157:H7 isolates. Therefore, the capacity of E. coli MC2 to survive during its transit through the bovine gastro-intestinal tract (GIT) and to respond to stresses potentially encountered in extra-intestinal environments was analyzed. E. coli MC2 survived in rumen fluids, grew in the content of posterior digestive compartments and survived in bovine feces at 15°C predicting a successful transit of the bacteria along the bovine GIT and its persistence outside the bovine intestine. E. coli MC2 possessed the genetic information encoding 14 adherence systems including adhesins with properties related to colonization of the bovine intestine (F9 fimbriae, EhaA and EspP autotransporters, HCP pilus, FdeC adhesin) reflecting the capacity of the bacteria to colonize different segments of the bovine GIT. E. coli MC2 was also a strong biofilm producer when incubated in fecal samples at low temperature and had a greater ability to form biofilms than the bovine commensal E. coli strain BG1. Furthermore, in contrast to BG1, E. coli MC2 responded to temperature stresses by inducing the genes cspA and htrA during its survival in bovine feces at 15°C. E. coli MC2 also activated genes that are part of the GhoT/GhoS, HicA/HicB and EcnB/EcnA toxin/antitoxin systems involved in the response of E. coli to nutrient starvation and chemical stresses. In summary, the large number of colonization factors known to bind to intestinal epithelium and to biotic or abiotic surfaces, the capacity to produce biofilms and to activate stress fitness genes in bovine feces could explain the persistence of E. coli MC2 in the farm environment.
Collapse
Affiliation(s)
- Audrey Segura
- Institut National de la Recherche Agronomique, UMR-MEDIS, Université Clermont Auvergne, Clermont-Ferrand, France
| | - Pauline Auffret
- Institut National de la Recherche Agronomique, UMR-MEDIS, Université Clermont Auvergne, Clermont-Ferrand, France
| | - Delphine Bibbal
- IRSD, Institut National de la Santé Et de la Recherche Médicale, Institut National de la Recherche Agronomique, ENVT, UPS, Université de Toulouse, Toulouse, France
| | - Marine Bertoni
- Institut National de la Recherche Agronomique, UMR-MEDIS, Université Clermont Auvergne, Clermont-Ferrand, France
| | - Alexandra Durand
- Institut National de la Recherche Agronomique, UMR-MEDIS, Université Clermont Auvergne, Clermont-Ferrand, France
| | - Grégory Jubelin
- Institut National de la Recherche Agronomique, UMR-MEDIS, Université Clermont Auvergne, Clermont-Ferrand, France
| | - Monique Kérourédan
- IRSD, Institut National de la Santé Et de la Recherche Médicale, Institut National de la Recherche Agronomique, ENVT, UPS, Université de Toulouse, Toulouse, France
| | - Hubert Brugère
- IRSD, Institut National de la Santé Et de la Recherche Médicale, Institut National de la Recherche Agronomique, ENVT, UPS, Université de Toulouse, Toulouse, France
| | - Yolande Bertin
- Institut National de la Recherche Agronomique, UMR-MEDIS, Université Clermont Auvergne, Clermont-Ferrand, France
| | - Evelyne Forano
- Institut National de la Recherche Agronomique, UMR-MEDIS, Université Clermont Auvergne, Clermont-Ferrand, France
| |
Collapse
|
27
|
Abstract
Enteric pathogens with low infectious doses rely on the ability to orchestrate the expression of virulence and metabolism-associated genes in response to environmental cues for successful infection. Accordingly, the human pathogen enterohemorrhagic Escherichia coli (EHEC) employs a complex multifaceted regulatory network to link the expression of type III secretion system (T3SS) components to nutrient availability. While phosphorylation of histidine and aspartate residues on two-component system response regulators is recognized as an integral part of bacterial signaling, the involvement of phosphotyrosine-mediated control is minimally explored in Gram-negative pathogens. Our recent phosphotyrosine profiling study of E. coli identified 342 phosphorylated proteins, indicating that phosphotyrosine modifications in bacteria are more prevalent than previously anticipated. The present study demonstrates that tyrosine phosphorylation of a metabolite-responsive LacI/GalR family regulator, Cra, negatively affects T3SS expression under glycolytic conditions that are typical for the colonic lumen environment where production of the T3SS is unnecessary. Our data suggest that Cra phosphorylation affects T3SS expression by modulating the expression of ler, which encodes the major activator of EHEC virulence gene expression. Phosphorylation of the Cra Y47 residue diminishes DNA binding to fine-tune the expression of virulence-associated genes, including those of the locus of enterocyte effacement pathogenicity island that encode the T3SS, and thereby negatively affects the formation of attaching and effacing lesions. Our data indicate that tyrosine phosphorylation provides an additional mechanism to control the DNA binding of Cra and other LacI/GalR family regulators, including LacI and PurR. This study describes an initial effort to unravel the role of global phosphotyrosine signaling in the control of EHEC virulence potential. Enterohemorrhagic Escherichia coli (EHEC) causes outbreaks of hemorrhagic colitis and the potentially fatal hemolytic-uremic syndrome. Successful host colonization by EHEC relies on the ability to coordinate the expression of virulence factors in response to environmental cues. A complex network that integrates environmental signals at multiple regulatory levels tightly controls virulence gene expression. We demonstrate that EHEC utilizes a previously uncharacterized phosphotyrosine signaling pathway through Cra to fine-tune the expression of virulence-associated genes to effectively control T3SS production. This study demonstrates that tyrosine phosphorylation negatively affects the DNA-binding capacity of Cra, which affects the expression of genes related to virulence and metabolism. We demonstrate for the first time that phosphotyrosine-mediated control affects global transcription in EHEC. Our data provide insight into a hitherto unexplored regulatory level of the global network controlling EHEC virulence gene expression.
Collapse
|
28
|
Carlson-Banning KM, Sperandio V. Enterohemorrhagic Escherichia coli outwits hosts through sensing small molecules. Curr Opin Microbiol 2018; 41:83-88. [PMID: 29258058 PMCID: PMC5862742 DOI: 10.1016/j.mib.2017.12.002] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2017] [Revised: 11/29/2017] [Accepted: 12/05/2017] [Indexed: 02/07/2023]
Abstract
Small molecules help intestinal pathogens navigate the complex human gastrointestinal tract to exploit favorable microhabitats. These small molecules provide spatial landmarks for pathogens to regulate synthesis of virulence caches and are derived from the host, ingested plant and animal material, and the microbiota. Their concentrations and fluxes vary along the length of the gut and provide molecular signatures that are beginning to be explored through metabolomics and genetics. However, while many small molecules have been identified and are reviewed here, there are undoubtedly others that may also profoundly affect how enteric pathogens infect their hosts.
Collapse
Affiliation(s)
- Kimberly M Carlson-Banning
- Departments of Microbiology, University of Texas Southwestern Medical Center, Dallas, TX, USA; Department of Biochemistry, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Vanessa Sperandio
- Departments of Microbiology, University of Texas Southwestern Medical Center, Dallas, TX, USA; Department of Biochemistry, University of Texas Southwestern Medical Center, Dallas, TX, USA.
| |
Collapse
|
29
|
Kerangart S, Cournoyer B, Loukiadis E. C-source metabolic profilings of foodborne Shiga-toxin producing E. coli match serogroup differentiations and highlight functional adaptations. Int J Food Microbiol 2017; 266:324-336. [PMID: 29217302 DOI: 10.1016/j.ijfoodmicro.2017.10.018] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2017] [Revised: 10/05/2017] [Accepted: 10/13/2017] [Indexed: 01/07/2023]
Abstract
The tropism of pathogenic STEC for foodstuffs and cattle reservoir is related to functional specializations. An investigation of C-source utilization patterns among and between STEC serogroups was performed using omnilog phenotypic microarrays (OM). OM functional groupings were compared with STEC phylogroups, seropathotypes, EFSA's molecular risk assessment groups and serogroups. OM INT reduction activities of 37 STEC strains growing on 190 C-substrates were compared. Each strain had its own specific C-utilization profile but 23% of the substrates was used by all strains, 47% by none, and 30% was variably metabolized. Galactose, mannose, N-acetyl-glucosamine (GlcNAc), and N-acetyl neuraminic acid (Neu5Ac) found in the mucus layer of the bovine small intestine were metabolized by all strains. The 56 most informative substrates divided the C-utilization patterns (CP) into three clusters with: (A) harboring all O157 and O145 strains; (B) all O26 strains, and (C) strains of the other serogroups. Significant correlations between INT reduction values of pair of strains per CP group supported these differentiations. CP of group A and B strains were respectively defective in the use of galactonic acid-γ-lactone and rhamnose. Most CP group C strains grew with l-lyxose. Adjusted Wallace coefficients analyses of the datasets indicated high probabilities for the prediction of the use of glycolic acid, β-hydroxybutyric acid, l-lyxose and d-galactonic acid-γ-lactone and 5-keto-d-gluconic acid by a serogroup. The use of a C-substrate could be predicted from the classification of a strain into a phylogroup or seropathotype. Significantly lower numbers of C-substrates were used by seropathotype A strains like O157 ones. Improvements of STEC identification keys were proposed using the most discriminant C-substrates found in this study.
Collapse
Affiliation(s)
- Stéphane Kerangart
- University of Lyon, Research group on "Bacterial Opportunistic Pathogens and Environment", UMR Ecologie Microbienne, CNRS 5557, INRA 1418, University Lyon 1, VetAgro Sup, 69280 Marcy L'Etoile, France
| | - Benoit Cournoyer
- University of Lyon, Research group on "Bacterial Opportunistic Pathogens and Environment", UMR Ecologie Microbienne, CNRS 5557, INRA 1418, University Lyon 1, VetAgro Sup, 69280 Marcy L'Etoile, France.
| | - Estelle Loukiadis
- University of Lyon, Research group on "Bacterial Opportunistic Pathogens and Environment", UMR Ecologie Microbienne, CNRS 5557, INRA 1418, University Lyon 1, VetAgro Sup, 69280 Marcy L'Etoile, France; University of Lyon, VetAgro Sup, LMAP, National Reference Laboratory for Escherichia coli (including VTEC), Marcy L'Etoile, France
| |
Collapse
|
30
|
Bertin Y, Habouzit C, Dunière L, Laurier M, Durand A, Duchez D, Segura A, Thévenot-Sergentet D, Baruzzi F, Chaucheyras-Durand F, Forano E. Lactobacillus reuteri suppresses E. coli O157:H7 in bovine ruminal fluid: Toward a pre-slaughter strategy to improve food safety? PLoS One 2017; 12:e0187229. [PMID: 29091926 PMCID: PMC5665532 DOI: 10.1371/journal.pone.0187229] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2017] [Accepted: 10/16/2017] [Indexed: 12/14/2022] Open
Abstract
The bovine gastrointestinal tract (GIT) is the main reservoir for enterohaemorrhagic Escherichia coli (EHEC) responsible for food-borne infections. Therefore, it is crucial to develop strategies, such as EHEC suppression by antagonistic microorganisms, to reduce EHEC survival in the GIT of cattle and to limit shedding and food contamination. Most human-derived Lactobacillus reuteri strains produce hydroxypropionaldehyde (HPA), an antimicrobial compound, during anaerobic reduction of glycerol. The capacity of L. reuteri LB1-7, a strain isolated from raw bovine milk, to produce HPA and its antimicrobial activity against an O157:H7 EHEC strain (FCH6) were evaluated in bovine rumen fluid (RF) under strict anaerobiosis. EHEC was totally suppressed when incubated in RF inoculated with L. reuteri LB1-7 and supplemented with 80 mM glycerol (RF-Glyc80). The addition of LB1-7 or glycerol alone did not modify EHEC survival in RF. Glycerol was converted to HPA (up to 14 mM) by LB1-7 during incubation in RF-Glyc80, and HPA production appeared to be responsible for EHEC suppression. The bactericidal activity of L. reuteri LB1-7, the concentration of glycerol required and the level of HPA produced depended on physiological and ecological environments. In vitro experiments also showed that EHEC inoculated in rumen fluid and exposed to L. reuteri and glycerol had a very limited growth in rectal contents. However, L. reuteri exerted an antimicrobial activity against the rumen endogenous microbiota and perturbed feedstuff degradation in the presence of glycerol. The potential administration of L. reuteri and glycerol in view of application to finishing beef cattle at the time of slaughter is discussed. Further in vivo studies will be important to confirm the efficiency of L. reuteri and glycerol supplementation against EHEC shedding in ruminants.
Collapse
Affiliation(s)
- Yolande Bertin
- Université Clermont Auvergne, INRA, MEDIS, Clermont-Ferrand, France
- * E-mail:
| | - Chloé Habouzit
- Université Clermont Auvergne, INRA, MEDIS, Clermont-Ferrand, France
| | - Lysiane Dunière
- Université Clermont Auvergne, INRA, MEDIS, Clermont-Ferrand, France
- Lallemand SAS, Blagnac, France
| | - Marie Laurier
- Université Clermont Auvergne, INRA, MEDIS, Clermont-Ferrand, France
| | - Alexandra Durand
- Université Clermont Auvergne, INRA, MEDIS, Clermont-Ferrand, France
| | - David Duchez
- Institut Pascal—Axe GePEB, Polytech Clermont-Ferrand, Université Blaise Pascal, Aubière, France
| | - Audrey Segura
- Université Clermont Auvergne, INRA, MEDIS, Clermont-Ferrand, France
| | - Delphine Thévenot-Sergentet
- Research Group on Bacterial Opportunistic Pathogens and Environment, UMR, Ecologie Microbienne, CNRS, VetAgro Sup, INRA and Université Lyon 1, Villeurbanne, France
- Laboratoire d'Étude des Microorganismes pathogènes, French Laboratory for Shiga Toxin-Producing Escherichia coli, VetAgro Sup, Campus vétérinaire, Marcy L’Etoile, France
| | - Federico Baruzzi
- Institute of Sciences of Food Production, National Research Council of Italy, Bari, Italy
| | | | - Evelyne Forano
- Université Clermont Auvergne, INRA, MEDIS, Clermont-Ferrand, France
| |
Collapse
|
31
|
Segura A, Auffret P, Klopp C, Bertin Y, Forano E. Draft genome sequence and characterization of commensal Escherichia coli strain BG1 isolated from bovine gastro-intestinal tract. Stand Genomic Sci 2017; 12:61. [PMID: 29046740 PMCID: PMC5634895 DOI: 10.1186/s40793-017-0272-0] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2017] [Accepted: 09/21/2017] [Indexed: 11/16/2022] Open
Abstract
Escherichia coli is the most abundant facultative anaerobic bacteria in the gastro-intestinal tract of mammals but can be responsible for intestinal infection due to acquisition of virulence factors. Genomes of pathogenic E. coli strains are widely described whereas those of bovine commensal E. coli strains are very scarce. Here, we report the genome sequence, annotation, and features of the commensal E. coli BG1 isolated from the gastro-intestinal tract of cattle. Whole genome sequencing analysis showed that BG1 has a chromosome of 4,782,107 bp coding for 4465 proteins and 97 RNAs. E. coli BG1 belonged to the serotype O159:H21, was classified in the phylogroup B1 and possessed the genetic information encoding "virulence factors" such as adherence systems, iron acquisition and flagella synthesis. A total of 12 adherence systems were detected reflecting the potential ability of BG1 to colonize different segments of the bovine gastro-intestinal tract. E. coli BG1 is unable to assimilate ethanolamine that confers a nutritional advantage to some pathogenic E. coli in the bovine gastro-intestinal tract. Genome analysis revealed the presence of i) 34 amino acids change due to non-synonymous SNPs among the genes encoding ethanolamine transport and assimilation, and ii) an additional predicted alpha helix inserted in cobalamin adenosyltransferase, a key enzyme required for ethanolamine assimilation. These modifications could explain the incapacity of BG1 to use ethanolamine. The BG1 genome can now be used as a reference (control strain) for subsequent evolution and comparative studies.
Collapse
Affiliation(s)
- Audrey Segura
- Université Clermont Auvergne, INRA, MEDIS, F-63000 Clermont-Ferrand, France
| | - Pauline Auffret
- Université Clermont Auvergne, INRA, MEDIS, F-63000 Clermont-Ferrand, France
| | - Christophe Klopp
- Plateforme Bioinformatique Toulouse, Midi-Pyrénées UBIA, INRA, Auzeville Castanet-Tolosan, France
| | - Yolande Bertin
- Université Clermont Auvergne, INRA, MEDIS, F-63000 Clermont-Ferrand, France
| | - Evelyne Forano
- Université Clermont Auvergne, INRA, MEDIS, F-63000 Clermont-Ferrand, France
| |
Collapse
|
32
|
Sicard JF, Le Bihan G, Vogeleer P, Jacques M, Harel J. Interactions of Intestinal Bacteria with Components of the Intestinal Mucus. Front Cell Infect Microbiol 2017; 7:387. [PMID: 28929087 PMCID: PMC5591952 DOI: 10.3389/fcimb.2017.00387] [Citation(s) in RCA: 279] [Impact Index Per Article: 39.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2017] [Accepted: 08/18/2017] [Indexed: 12/19/2022] Open
Abstract
The human gut is colonized by a variety of large amounts of microbes that are collectively called intestinal microbiota. Most of these microbial residents will grow within the mucus layer that overlies the gut epithelium and will act as the first line of defense against both commensal and invading microbes. This mucus is essentially formed by mucins, a family of highly glycosylated protein that are secreted by specialize cells in the gut. In this Review, we examine how commensal members of the microbiota and pathogenic bacteria use mucus to their advantage to promote their growth, develop biofilms and colonize the intestine. We also discuss how mucus-derived components act as nutrient and chemical cues for adaptation and pathogenesis of bacteria and how bacteria can influence the composition of the mucus layer.
Collapse
Affiliation(s)
- Jean-Félix Sicard
- Centre de Recherche en Infectiologie Porcine et Aviaire, Faculté de Médecine Vétérinaire, Université de MontréalSaint-Hyacinthe, QC, Canada
| | - Guillaume Le Bihan
- Centre de Recherche en Infectiologie Porcine et Aviaire, Faculté de Médecine Vétérinaire, Université de MontréalSaint-Hyacinthe, QC, Canada
| | - Philippe Vogeleer
- Centre de Recherche en Infectiologie Porcine et Aviaire, Faculté de Médecine Vétérinaire, Université de MontréalSaint-Hyacinthe, QC, Canada
| | - Mario Jacques
- Regroupement de Recherche Pour un Lait de Qualité Optimale (Op+Lait), Faculté de Médecine Vétérinaire, Université de MontréalSaint-Hyacinthe, QC, Canada
| | - Josée Harel
- Centre de Recherche en Infectiologie Porcine et Aviaire, Faculté de Médecine Vétérinaire, Université de MontréalSaint-Hyacinthe, QC, Canada
| |
Collapse
|
33
|
Le Bihan G, Sicard JF, Garneau P, Bernalier-Donadille A, Gobert AP, Garrivier A, Martin C, Hay AG, Beaudry F, Harel J, Jubelin G. The NAG Sensor NagC Regulates LEE Gene Expression and Contributes to Gut Colonization by Escherichia coli O157:H7. Front Cell Infect Microbiol 2017; 7:134. [PMID: 28484684 PMCID: PMC5401889 DOI: 10.3389/fcimb.2017.00134] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2017] [Accepted: 03/31/2017] [Indexed: 11/16/2022] Open
Abstract
Enterohemorrhagic Escherichia coli (EHEC) O157:H7 are human pathogens responsible for bloody diarrhea and renal failures. EHEC employ a type 3 secretion system to attach directly to the human colonic epithelium. This structure is encoded by the locus of enterocyte effacement (LEE) whose expression is regulated in response to specific nutrients. In this study, we show that the mucin-derived sugars N-acetylglucosamine (NAG) and N-acetylneuraminic acid (NANA) inhibit EHEC adhesion to epithelial cells through down-regulation of LEE expression. The effect of NAG and NANA is dependent on NagC, a transcriptional repressor of the NAG catabolism in E. coli. We show that NagC is an activator of the LEE1 operon and a critical regulator for the colonization of mice intestine by EHEC. Finally, we demonstrate that NAG and NANA as well as the metabolic activity of Bacteroides thetaiotaomicron affect the in vivo fitness of EHEC in a NagC-dependent manner. This study highlights the role of NagC in coordinating metabolism and LEE expression in EHEC and in promoting EHEC colonization in vivo.
Collapse
Affiliation(s)
- Guillaume Le Bihan
- Faculté de Médecine Vétérinaire, Centre de Recherche en Infectiologie Porcine et Aviaire, Université de MontréalSaint-Hyacinthe, QC, Canada
| | - Jean-Félix Sicard
- Faculté de Médecine Vétérinaire, Centre de Recherche en Infectiologie Porcine et Aviaire, Université de MontréalSaint-Hyacinthe, QC, Canada
| | - Philippe Garneau
- Faculté de Médecine Vétérinaire, Centre de Recherche en Infectiologie Porcine et Aviaire, Université de MontréalSaint-Hyacinthe, QC, Canada
| | | | - Alain P Gobert
- INRA, Université Clermont Auvergne, MEDISClermont-Ferrand, France
| | - Annie Garrivier
- INRA, Université Clermont Auvergne, MEDISClermont-Ferrand, France
| | - Christine Martin
- INRA, Université Clermont Auvergne, MEDISClermont-Ferrand, France
| | - Anthony G Hay
- Department of Microbiology, Cornell UniversityIthaca, NY, USA
| | - Francis Beaudry
- Groupe de Recherche en Pharmacologie Animal du Québec, Département de Biomédecine Vétérinaire, Faculté de Médecine Vétérinaire, Université de MontréalSaint-Hyacinthe, QC, Canada
| | - Josée Harel
- Faculté de Médecine Vétérinaire, Centre de Recherche en Infectiologie Porcine et Aviaire, Université de MontréalSaint-Hyacinthe, QC, Canada
| | - Grégory Jubelin
- INRA, Université Clermont Auvergne, MEDISClermont-Ferrand, France
| |
Collapse
|
34
|
Allosteric Activation of Escherichia coli Glucosamine-6-Phosphate Deaminase (NagB) In Vivo Justified by Intracellular Amino Sugar Metabolite Concentrations. J Bacteriol 2016; 198:1610-1620. [PMID: 27002132 DOI: 10.1128/jb.00870-15] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2015] [Accepted: 03/15/2016] [Indexed: 01/01/2023] Open
Abstract
UNLABELLED We have investigated the impact of growth on glucosamine (GlcN) and N-acetylglucosamine (GlcNAc) on cellular metabolism by quantifying glycolytic metabolites in Escherichia coli Growth on GlcNAc increased intracellular pools of both GlcNAc6P and GlcN6P 10- to 20-fold compared to growth on glucose. Growth on GlcN produced a 100-fold increase in GlcN6P but only a slight increase in GlcNAc6P. Changes to the amounts of downstream glycolytic intermediates were minor compared to growth on glucose. The enzyme glucosamine-6P deaminase (NagB) is required for growth on both GlcN and GlcNAc. It is an allosteric enzyme in E. coli, displaying sigmoid kinetics with respect to its substrate, GlcN6P, and is allosterically activated by GlcNAc6P. The high concentration of GlcN6P, accompanied by the small increase in GlcNAc6P, drives E. coli NagB (NagBEc) into its high activity state, as observed during growth on GlcN (L. I. Álvarez-Añorve, I. Bustos-Jaimes, M. L. Calcagno, and J. Plumbridge, J Bacteriol 191:6401-6407, 2009, http://dx.doi.org/10.1128/JB.00633-09). The slight increase in GlcNAc6P during growth on GlcN is insufficient to displace NagC, the GlcNAc6P-responsive repressor of the nag genes, from its binding sites, so there is only a small increase in nagB expression. We replaced the gene for the allosteric NagBEc enzyme with that of the nonallosteric, B. subtilis homologue, NagBBs We detected no effects on growth rates or competitive fitness on glucose or the amino sugars, nor did we detect any effect on the concentrations of central metabolites, thus demonstrating the robustness of amino sugar metabolism and leaving open the question of the role of allostery in the regulation of NagB. IMPORTANCE Chitin, the polymer of N-acetylglucosamine, is an abundant biomaterial, and both glucosamine and N-acetylglucosamine are valuable nutrients for bacteria. The amino sugars are components of numerous essential macromolecules, including bacterial peptidoglycan and mammalian glycosaminoglycans. Controlling the biosynthetic and degradative pathways of amino sugar metabolism is important in all organisms to avoid loss of nitrogen and energy via a futile cycle of synthesis and breakdown. The enzyme glucosamine-6P deaminase (NagB) is central to this control, and N-acetylglucosamine-6P is the key signaling molecule regulating amino sugar utilization in Escherichia coli Here, we investigate how the metabolic status of the bacteria impacts on the activity of NagBEc and the N-acetylglucosamine-6P-sensitive transcriptional repressor, NagC.
Collapse
|
35
|
Enteric Pathogens Exploit the Microbiota-generated Nutritional Environment of the Gut. Microbiol Spectr 2016; 3. [PMID: 26185079 DOI: 10.1128/microbiolspec.mbp-0001-2014] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
Host bacterial associations have a profound impact on health and disease. The human gastrointestinal (GI) tract is inhabited by trillions of commensal bacteria that aid in the digestion of food and vitamin production and play crucial roles in human physiology. Disruption of these relationships and the structure of the bacterial communities that inhabit the gut can contribute to dysbiosis, leading to disease. This fundamental relationship between the host and microbiota relies on chemical signaling and nutrient availability and exchange. GI pathogens compete with the endogenous microbiota for a colonization niche (1, 2). The ability to monitor nutrients and combine this information with the host physiological state is important for the pathogen to precisely program the expression of its virulence repertoire. A major nutrient source is carbon, and although the impact of carbon nutrition on the colonization of the gut by the microbiota has been extensively studied, the extent to which carbon sources affect the regulation of virulence factors by invading pathogens has not been fully defined. The GI pathogen enterohemorrhagic E. coli (EHEC) gages sugar sources as an important cue to regulate expression of its virulence genes. EHEC senses whether it is in a gluconeogenic versus a glycolytic environment, as well as fluctuations of fucose levels to fine tune regulation of its virulence repertoire.
Collapse
|
36
|
Abstract
Sialic acids, or the more broad term nonulosonic acids, comprise a family of nine-carbon keto-sugars ubiquitous on mammalian mucous membranes as terminal modifications of mucin glycoproteins. Sialic acids have a limited distribution among bacteria, and the ability to catabolize sialic acids is mainly confined to pathogenic and commensal species. This ability to utilize sialic acid as a carbon source is correlated with bacterial virulence, especially, in the sialic acid rich environment of the oral cavity, respiratory, intestinal, and urogenital tracts. This chapter discusses the distribution of sialic acid catabolizers among the sequenced bacterial genomes and examines the studies that have linked sialic acid catabolism with increased in vivo fitness in a number of species using several animal models. This chapter presents the most recent findings in sialobiology with a focus on sialic acid catabolism, which demonstrates an important relationship between the catabolism of sialic acid and bacterial pathogenesis.
Collapse
|
37
|
Host-Derived Sialic Acids Are an Important Nutrient Source Required for Optimal Bacterial Fitness In Vivo. mBio 2016; 7:e02237-15. [PMID: 27073099 PMCID: PMC4959520 DOI: 10.1128/mbio.02237-15] [Citation(s) in RCA: 50] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
A major challenge facing bacterial intestinal pathogens is competition for nutrient sources with the host microbiota. Vibrio cholerae is an intestinal pathogen that causes cholera, which affects millions each year; however, our knowledge of its nutritional requirements in the intestinal milieu is limited. In this study, we demonstrated that V. cholerae can grow efficiently on intestinal mucus and its component sialic acids and that a tripartite ATP-independent periplasmic SiaPQM strain, transporter-deficient mutant NC1777, was attenuated for colonization using a streptomycin-pretreated adult mouse model. In in vivo competition assays, NC1777 was significantly outcompeted for up to 3 days postinfection. NC1777 was also significantly outcompeted in in vitro competition assays in M9 minimal medium supplemented with intestinal mucus, indicating that sialic acid uptake is essential for fitness. Phylogenetic analyses demonstrated that the ability to utilize sialic acid was distributed among 452 bacterial species from eight phyla. The majority of species belonged to four phyla, Actinobacteria (members of Actinobacillus, Corynebacterium, Mycoplasma, and Streptomyces), Bacteroidetes (mainly Bacteroides, Capnocytophaga, and Prevotella), Firmicutes (members of Streptococcus, Staphylococcus, Clostridium, and Lactobacillus), and Proteobacteria (including Escherichia, Shigella, Salmonella, Citrobacter, Haemophilus, Klebsiella, Pasteurella, Photobacterium, Vibrio, and Yersinia species), mostly commensals and/or pathogens. Overall, our data demonstrate that the ability to take up host-derived sugars and sialic acid specifically allows V. cholerae a competitive advantage in intestinal colonization and that this is a trait that is sporadic in its occurrence and phylogenetic distribution and ancestral in some genera but horizontally acquired in others. Sialic acids are nine carbon amino sugars that are abundant on all mucous surfaces. The deadly human pathogen Vibrio cholerae contains the genes required for scavenging, transport, and catabolism of sialic acid. We determined that the V. cholerae SiaPQM transporter is essential for sialic acid transport and that this trait allows the bacterium to outcompete noncatabolizers in vivo. We also showed that the ability to take up and catabolize sialic acid is prevalent among both commensals and pathogens that colonize the oral cavity and the respiratory, intestinal, and urogenital tracts. Phylogenetic analysis determined that the sialic acid catabolism phenotype is ancestral in some genera such as Yersinia, Streptococcus, and Staphylococcus and is acquired by horizontal gene transfer in others such as Vibrio, Aeromonas, and Klebsiella. The data demonstrate that this trait has evolved multiple times in different lineages, indicating the importance of specialized metabolism to niche expansion.
Collapse
|
38
|
Contributions of EspA Filaments and Curli Fimbriae in Cellular Adherence and Biofilm Formation of Enterohemorrhagic Escherichia coli O157:H7. PLoS One 2016; 11:e0149745. [PMID: 26900701 PMCID: PMC4764202 DOI: 10.1371/journal.pone.0149745] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2015] [Accepted: 02/04/2016] [Indexed: 12/14/2022] Open
Abstract
In Escherichia coli O157:H7 (O157), the filamentous structure of the type III secretion system is produced from the polymerization of the EspA protein. EspA filaments are essential for O157 adherence to epithelial cells. In previous studies, we demonstrated that O157 hha deletion mutants showed increased adherence to HEp-2 cells and produced abundant biofilms. Transcriptional analysis revealed increased expression of espA as well as the csgA gene, which encodes curli fimbriae that are essential for biofilm formation. In the present study, we constructed hha espA, hha csgA, and hha csgA espA deletion mutants to determine the relative importance of EspA and CsgA in O157 adherence to HEp-2 cells and biofilm formation. In vitro adherence assays, conducted at 37°C in a tissue culture medium containing 0.1% glucose, showed that HEp-2 cell adherence required EspA because hha espA and hha csgA espA mutants adhered to HEp-2 cells at higher levels only when complemented with an espA-expressing plasmid. Biofilm assays performed at 28°C in a medium lacking glucose showed dependency of biofilm formation on CsgA; however EspA was not produced under these conditions. Despite production of detectable levels of EspA at 37°C in media supplemented with 0.1% glucose, the biofilm formation occurred independent of EspA. These results indicate dependency of O157 adherence to epithelial cells on EspA filaments, while CsgA promoted biofilm formation under conditions mimicking those found in the environment (low temperature with nutrient limitations) and in the digestive tract of an host animal (higher temperature and low levels of glucose).
Collapse
|
39
|
Porcheron G, Schouler C, Dozois CM. Survival games at the dinner table: regulation of Enterobacterial virulence through nutrient sensing and acquisition. Curr Opin Microbiol 2016; 30:98-106. [PMID: 26871481 DOI: 10.1016/j.mib.2016.01.008] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2015] [Revised: 01/12/2016] [Accepted: 01/19/2016] [Indexed: 10/22/2022]
Abstract
The ability of bacterial pathogens to colonize specific host niches is largely dependent on acquisition of essential metabolites and co-factors for growth and sensing and adapting in response to specific environmental cues. Nutrient availability in host environments is strongly influenced by host physiology and immunity, diet, and competition with other members of the host microbiota. Rapid adaptation to environmental cues and nutrient availability is a hallmark of bacterial fitness and virulence. This adaptability requires complex regulatory networks that tightly link sensing of nutrient availability to expression of virulence genes accordingly. This review focuses on recent findings highlighting the ability of bacterial pathogens to compete for nutrient acquisition in the host-microbiota environment, and emphasizes key aspects mediating the multi-tiered regulatory cascades that coordinately control nutrient sensing and expression of virulence genes in pathogenic Enterobacteria.
Collapse
Affiliation(s)
- Gaëlle Porcheron
- INRS-Institut Armand Frappier, Laval, Québec, Canada; Centre de Recherche en Infectiologie Porcine et Avicole (CRIPA), Université de Montréal, Faculté de Médecine Vétérinaire, Saint-Hyacinthe, Québec, Canada
| | - Catherine Schouler
- INRA, UMR1282 Infectiologie et Santé Publique, 37 380 Nouzilly, France; Université François Rabelais de Tours, UMR1282 Infectiologie et Santé Publique, 37 000 Tours, France
| | - Charles M Dozois
- INRS-Institut Armand Frappier, Laval, Québec, Canada; Centre de Recherche en Infectiologie Porcine et Avicole (CRIPA), Université de Montréal, Faculté de Médecine Vétérinaire, Saint-Hyacinthe, Québec, Canada.
| |
Collapse
|
40
|
Vitamin B12 Uptake by the Gut Commensal Bacteria Bacteroides thetaiotaomicron Limits the Production of Shiga Toxin by Enterohemorrhagic Escherichia coli. Toxins (Basel) 2016; 8:toxins8010014. [PMID: 26742075 PMCID: PMC4728536 DOI: 10.3390/toxins8010014] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2015] [Revised: 12/17/2015] [Accepted: 12/29/2015] [Indexed: 01/11/2023] Open
Abstract
Enterohemorrhagic Escherichia coli (EHEC) are foodborne pathogens responsible for the development of bloody diarrhea and renal failure in humans. Many environmental factors have been shown to regulate the production of Shiga toxin 2 (Stx2), the main virulence factor of EHEC. Among them, soluble factors produced by human gut microbiota and in particular, by the predominant species Bacteroides thetaiotaomicron (B. thetaiotaomicron), inhibit Stx2 gene expression. In this study, we investigated the molecular mechanisms underlying the B. thetaiotaomicron-dependent inhibition of Stx2 production by EHEC. We determined that Stx2-regulating molecules are resistant to heat treatment but do not correspond to propionate and acetate, two short-chain fatty acids produced by B. thetaiotaomicron. Moreover, screening of a B. thetaiotaomicron mutant library identified seven mutants that do not inhibit Stx2 synthesis by EHEC. One mutant has impaired production of BtuB, an outer membrane receptor for vitamin B12. Together with restoration of Stx2 level after vitamin B12 supplementation, these data highlight vitamin B12 as a molecule produced by gut microbiota that modulates production of a key virulence factor of EHEC and consequently may affect the outcome of an infection.
Collapse
|
41
|
In J, Foulke-Abel J, Zachos NC, Hansen AM, Kaper JB, Bernstein HD, Halushka M, Blutt S, Estes MK, Donowitz M, Kovbasnjuk O. Enterohemorrhagic Escherichia coli reduce mucus and intermicrovillar bridges in human stem cell-derived colonoids. Cell Mol Gastroenterol Hepatol 2015; 2:48-62.e3. [PMID: 26855967 PMCID: PMC4740923 DOI: 10.1016/j.jcmgh.2015.10.001] [Citation(s) in RCA: 180] [Impact Index Per Article: 20.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
BACKGROUND AND AIMS Enterohemorrhagic E. coli (EHEC) causes over 70,000 episodes of foodborne diarrhea annually in the USA. The early sequence of events which precede life-threatening hemorrhagic colitis and hemolytic uremic syndrome are not fully understood due to the initial asymptomatic phase of the disease and the lack of a suitable animal model. The aim of this study was to determine the initial molecular events in the interaction between EHEC and human colonic epithelium. METHODS Human colonoids derived from adult proximal colonic stem cells were developed into monolayers to study EHEC-epithelial interactions. Monolayer confluency and differentiation were monitored by transepithelial electrical resistance (TER) measurements. The monolayers were apically infected with EHEC and the progression of epithelial damage over time was assessed using biochemical and imaging approaches. RESULTS Human colonoid cultures recapitulate the differential protein expression patterns characteristic of the crypt and surface colonocytes. Mucus-producing differentiated colonoid monolayers are preferentially colonized by EHEC. Upon colonization, EHEC forms characteristic attaching and effacing lesions on the apical surface of colonoid monolayers. Mucin 2, a main component of colonic mucus, and protocadherin 24 (PCDH24), a microvillar resident protein, are targeted by EHEC at early stages of infection. The EHEC secreted serine protease, EspP, initiates brush border damage through PCDH24 reduction. CONCLUSIONS Human colonoid monolayers are a relevant pathophysiological model which allows the study of early molecular events during enteric infections. Colonoid monolayers provide access to both apical and basolateral surfaces, thus providing an advantage over 3D cultures to study host-pathogen interactions in a controllable and tractable manner. EHEC reduces colonic mucus and affects the brush border cytoskeleton in the absence of commensal bacteria.
Collapse
Affiliation(s)
- Julie In
- Department of Medicine, Division of Gastroenterology and Hepatology, Johns Hopkins University, School of Medicine, Baltimore, Maryland
| | - Jennifer Foulke-Abel
- Department of Medicine, Division of Gastroenterology and Hepatology, Johns Hopkins University, School of Medicine, Baltimore, Maryland
| | - Nicholas C. Zachos
- Department of Medicine, Division of Gastroenterology and Hepatology, Johns Hopkins University, School of Medicine, Baltimore, Maryland
| | - Anne-Marie Hansen
- Department of Microbiology and Immunology, University of Maryland School of Medicine, Baltimore, Maryland
| | - James B. Kaper
- Department of Microbiology and Immunology, University of Maryland School of Medicine, Baltimore, Maryland
| | - Harris D. Bernstein
- Genetics and Biochemistry Branch, National Institutes of Diabetes and Digestive and Kidney Disease, National Institutes of Health, Bethesda, Maryland
| | - Marc Halushka
- Department of Pathology, Johns Hopkins University School of Medicine, Baltimore, Maryland
| | - Sarah Blutt
- Department of Molecular Virology and Microbiology, Baylor College of Medicine, Houston, Texas
| | - Mary K. Estes
- Department of Molecular Virology and Microbiology, Baylor College of Medicine, Houston, Texas
| | - Mark Donowitz
- Department of Medicine, Division of Gastroenterology and Hepatology, Johns Hopkins University, School of Medicine, Baltimore, Maryland
| | - Olga Kovbasnjuk
- Department of Medicine, Division of Gastroenterology and Hepatology, Johns Hopkins University, School of Medicine, Baltimore, Maryland,Correspondence Address correspondence to: Olga Kovbasnjuk, PhD, Division of Gastroenterology and Hepatology, Johns Hopkins University School of Medicine, 943 Ross Research Building, 720 Rutland Avenue, Baltimore, Maryland 21205.Division of Gastroenterology and HepatologyJohns Hopkins University School of Medicine943 Ross Research Building720 Rutland AvenueBaltimoreMaryland 21205
| |
Collapse
|
42
|
Yang B, Feng L, Wang F, Wang L. Enterohemorrhagic Escherichia coli senses low biotin status in the large intestine for colonization and infection. Nat Commun 2015; 6:6592. [PMID: 25791315 PMCID: PMC4382993 DOI: 10.1038/ncomms7592] [Citation(s) in RCA: 72] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2014] [Accepted: 02/10/2015] [Indexed: 12/17/2022] Open
Abstract
Enterohemorrhagic Escherichia coli (EHEC) is an important foodborne pathogen that infects humans by colonizing the large intestine. Here we identify a virulence-regulating pathway in which the biotin protein ligase BirA signals to the global regulator Fur, which in turn activates LEE (locus of enterocyte effacement) genes to promote EHEC adherence in the low-biotin large intestine. LEE genes are repressed in the high-biotin small intestine, thus preventing adherence and ensuring selective colonization of the large intestine. The presence of this pathway in all nine EHEC serotypes tested indicates that it is an important evolutionary strategy for EHEC. The pathway is incomplete in closely related small-intestinal enteropathogenic E. coli due to the lack of the Fur response to BirA. Mice fed with a biotin-rich diet show significantly reduced EHEC adherence, indicating that biotin might be useful to prevent EHEC infection in humans. Enterohaemorrhagic Escherichia coli (EHEC) is an important foodborne pathogen that colonizes the large intestine. Here, the authors identify a signalling pathway that controls EHEC adherence to host cells in response to variations in biotin levels, ensuring selective colonization of the large intestine.
Collapse
Affiliation(s)
- Bin Yang
- 1] TEDA Institute of Biological Sciences and Biotechnology, Nankai University, TEDA, Tianjin 300457, P.R. China [2] Key Laboratory of Molecular Microbiology and Technology, Ministry of Education, Tianjin 300071, P.R. China
| | - Lu Feng
- 1] TEDA Institute of Biological Sciences and Biotechnology, Nankai University, TEDA, Tianjin 300457, P.R. China [2] Key Laboratory of Molecular Microbiology and Technology, Ministry of Education, Tianjin 300071, P.R. China [3] Tianjin Key Laboratory of Microbial Functional Genomics, Tianjin 300457, P.R. China [4] State Key Laboratory of Medicinal Chemical Biology, Nankai University, Tianjin 300071, P.R. China [5] SynBio Research Platform, Collaborative Innovation Center of Chemical Science and Engineering (Tianjin), Tianjin 300072, P.R. China
| | - Fang Wang
- 1] TEDA Institute of Biological Sciences and Biotechnology, Nankai University, TEDA, Tianjin 300457, P.R. China [2] Key Laboratory of Molecular Microbiology and Technology, Ministry of Education, Tianjin 300071, P.R. China
| | - Lei Wang
- 1] TEDA Institute of Biological Sciences and Biotechnology, Nankai University, TEDA, Tianjin 300457, P.R. China [2] Key Laboratory of Molecular Microbiology and Technology, Ministry of Education, Tianjin 300071, P.R. China [3] Tianjin Key Laboratory of Microbial Functional Genomics, Tianjin 300457, P.R. China [4] State Key Laboratory of Medicinal Chemical Biology, Nankai University, Tianjin 300071, P.R. China
| |
Collapse
|
43
|
The Metabolism of Polysaccharide from Atractylodes macrocephala Koidz and Its Effect on Intestinal Microflora. EVIDENCE-BASED COMPLEMENTARY AND ALTERNATIVE MEDICINE 2014; 2014:926381. [PMID: 25505927 PMCID: PMC4258363 DOI: 10.1155/2014/926381] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/23/2014] [Accepted: 11/06/2014] [Indexed: 12/16/2022]
Abstract
An active polysaccharide from the rhizome of Atractylodes macrocephala Koidz (PAM) was identified to improve and adjust disordered intestinal flora. High-performance gel permeation chromatography (HPGPC) and gas chromatography-mass spectrometry (GC-MS) were employed to identify the components of PAM as rhamnose, glucose, mannose, xylose, and galactose at a ratio of 0.03 : 0.25 : 0.15 : 0.41 : 0.15. PAM metabolized in gastrointestinal tract when incubated with artificial gastric and intestinal juices. Anaerobic incubation of PAM on intestinal flora confirmed that PAM promoted the ability of intestinal bacteria to digest reducing sugar. Based on the Shannon index and similarity coefficient index of enterobacterial repetitive intergenic consensus-PCR (ERIC-PCR) fingerprinting of the total intestinal bacteria DNA, we concluded that PAM can significantly improve disordered intestinal flora and may be used as an oral adjuvant to regulate intestinal flora.
Collapse
|
44
|
Transcriptome analysis of Escherichia coli O157:H7 grown in vitro in the sterile-filtrated cecal content of human gut microbiota associated rats reveals an adaptive expression of metabolic and virulence genes. Microbes Infect 2014; 17:23-33. [PMID: 25290220 DOI: 10.1016/j.micinf.2014.09.008] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2014] [Revised: 09/19/2014] [Accepted: 09/19/2014] [Indexed: 12/12/2022]
Abstract
In developed countries, enterohemorrhagic Escherichia coli (EHEC) O157:H7 is a leading cause of bloody diarrhea and renal failures in human. Understanding strategies employed by EHEC to colonize the intestine is of major importance since to date no cure exists to eradicate the pathogen. In this study, the adaptive response of EHEC to the intestinal milieu conditioned by a human microbiota was examined. A transcriptomic analysis was performed on the EHEC strain EDL933 incubated in vitro in the sterile-filtrated cecal content of human microbiota-associated rats (HMC) compared with EDL933 incubated in the sterile-filtrated cecal content of germ-free rat (GFC). EDL933 switches from a glycolytic metabolic profile in the GFC to an anaplerotic metabolic profile in HMC. The expression of several catabolism genes was strongly affected such as those involved in the utilization of sugars, glycerol, N-acetylneuraminic acid, amino acids and secondary metabolites. Interestingly, expression level of critical EHEC O157:H7 virulence genes including genes from the locus of enterocyte effacement was reduced in HMC. Altogether, these results contribute to the understanding of EHEC adaptive response to a digestive content and highlight the ability of the microbiota to repress EHEC virulence gene expression.
Collapse
|
45
|
Bertin Y, Deval C, de la Foye A, Masson L, Gannon V, Harel J, Martin C, Desvaux M, Forano E. The gluconeogenesis pathway is involved in maintenance of enterohaemorrhagic Escherichia coli O157:H7 in bovine intestinal content. PLoS One 2014; 9:e98367. [PMID: 24887187 PMCID: PMC4041753 DOI: 10.1371/journal.pone.0098367] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2014] [Accepted: 05/01/2014] [Indexed: 11/19/2022] Open
Abstract
Enterohaemorrhagic Escherichia coli (EHEC) are responsible for outbreaks of food- and water-borne illness. The bovine gastrointestinal tract (GIT) is thought to be the principle reservoir of EHEC. Knowledge of the nutrients essential for EHEC growth and survival in the bovine intestine may help in developing strategies to limit their shedding in bovine faeces thus reducing the risk of human illnesses. To identify specific metabolic pathways induced in the animal GIT, the transcriptome profiles of EHEC O157:H7 EDL933 during incubation in bovine small intestine contents (BSIC) and minimal medium supplemented with glucose were compared. The transcriptome analysis revealed that genes responsible for the assimilation of ethanolamine, urea, agmatine and amino acids (Asp, Thr, Gly, Ser and Trp) were strongly up-regulated suggesting that these compounds are the main nitrogen sources for EHEC in BSIC. A central role for the gluconeogenesis pathway and assimilation of gluconeogenic substrates was also pinpointed in EHEC incubated in BSIC. Our results suggested that three amino acids (Asp, Ser and Trp), glycerol, glycerol 3-phosphate, L-lactate and C4-dicarboxylates are important carbon sources for EHEC in BSIC. The ability to use gluconeogenic substrates as nitrogen sources (amino acids) and/or carbon sources (amino acids, glycerol and lactate) may provide a growth advantage to the bacteria in intestinal fluids. Accordingly, aspartate (2.4 mM), serine (1.9 mM), glycerol (5.8 mM) and lactate (3.6 mM) were present in BSIC and may represent the main gluconeogenic substrates potentially used by EHEC. A double mutant of E. coli EDL933 defective for phosphoenolpyruvate synthase (PpsA) and phosphoenolpyruvate carboxykinase (PckA), unable to utilize tricarboxylic acid (TCA) intermediates was constructed. Growth competition experiments between EHEC EDL933 and the isogenic mutant strain in BSIC clearly showed a significant competitive growth advantage of the wild-type strain further illustrating the importance of the gluconeogenesis pathway in maintaining EHEC in the bovine GIT.
Collapse
Affiliation(s)
- Yolande Bertin
- Institut National de la Recherche Agronomique, UR454 Microbiologie, Saint-Genès-Champanelle, France
- * E-mail:
| | - Christiane Deval
- Institut National de la Recherche Agronomique, UMR 1019, Unité de Nutrition Humaine, Centre de Recherche en Nutrition Humaine d’Auvergne, Clermont-Ferrand, France; Clermont Université, Université d’Auvergne, Unité de Nutrition Humaine, BP 10448, Clermont-Ferrand, France
| | - Anne de la Foye
- Institut National de la Recherche Agronomique, UMR1213 Herbivores, Plate-Forme d’Exploration du Métabolisme, Saint-Genès-Champanelle, France
| | - Luke Masson
- Biotechnology Research Institute, National Research Council of Canada, Montreal, Quebec, Canada
| | - Victor Gannon
- Laboratory for Foodborne Zoonoses, Public Health Agency of Canada, Lethbridge, Alberta, Canada
| | - Josée Harel
- Groupe de Recherche sur les Maladies Infectieuses du Porc, Université de Montréal, Faculté de Médecine Vétérinaire, Saint-Hyacinthe, Québec, Canada
| | - Christine Martin
- Institut National de la Recherche Agronomique, UR454 Microbiologie, Saint-Genès-Champanelle, France
| | - Mickaël Desvaux
- Institut National de la Recherche Agronomique, UR454 Microbiologie, Saint-Genès-Champanelle, France
| | - Evelyne Forano
- Institut National de la Recherche Agronomique, UR454 Microbiologie, Saint-Genès-Champanelle, France
| |
Collapse
|
46
|
Ferreyra JA, Ng KM, Sonnenburg JL. The Enteric Two-Step: nutritional strategies of bacterial pathogens within the gut. Cell Microbiol 2014; 16:993-1003. [PMID: 24720567 DOI: 10.1111/cmi.12300] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/27/2014] [Indexed: 01/20/2023]
Abstract
The gut microbiota is a dense and diverse microbial community governed by dynamic microbe-microbe and microbe-host interactions, the status of which influences whether enteric pathogens can cause disease. Here we review recent insights into the key roles that nutrients play in bacterial pathogen exploitation of the gut microbial ecosystem. We synthesize recent findings to support a five-stage model describing the transition between a healthy microbiota and one dominated by a pathogen and disease. Within this five-stage model, two stages are critical to the pathogen: (i) an initial expansion phase that must occur in the absence of pathogen-induced inflammation, followed by (ii) pathogen-promoting physiological changes such as inflammation and diarrhoea. We discuss how this emerging paradigm of pathogen life within the lumen of the gut is giving rise to novel therapeutic strategies.
Collapse
Affiliation(s)
- Jessica A Ferreyra
- Department of Microbiology and Immunology, Stanford University School of Medicine, Stanford, CA, 94305, USA
| | | | | |
Collapse
|
47
|
Bacteriophage 933W encodes a functional esterase downstream of the Shiga toxin 2a operon. Int J Med Microbiol 2014; 304:269-74. [DOI: 10.1016/j.ijmm.2013.10.008] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2013] [Revised: 09/26/2013] [Accepted: 10/20/2013] [Indexed: 11/19/2022] Open
|
48
|
Capacity of the bovine intestinal mucus and its components to support growth of Escherichia coli O157:H7. Animal 2014; 8:731-7. [PMID: 24606840 DOI: 10.1017/s1751731114000147] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Colonization of the gastrointestinal tract of cattle by Shiga toxin-producing Escherichia coli increases the risk of contamination of food products at slaughter. Our study aimed to shed more light on the mechanisms used by E. coli O157:H7 to thrive and compete with other bacteria in the gastrointestinal tract of cattle. We evaluated, in vitro, bovine intestinal mucus and its constituents in terms of their capacity to support growth of E. coli O157:H7 in presence or absence of fecal inoculum, with and without various enzymes. Growth of E. coli O157:H7 and total anaerobic bacteria were proportionate to the amount of mucus added as substrate. Growth of E. coli O157:H7 was similar for small and large intestinal mucus as substrate, and was partially inhibited with addition of fecal inoculum to cultures, presumably due to competition from other organisms. Whole mucus stimulated growth to the greatest degree compared with other compounds evaluated, but the pathogen was capable of utilizing all substrates to some extent. Addition of enzymes to cultures failed to impact growth of E. coli O157:H7 except for neuraminidase, which resulted in greater growth of E. coli O157 when combined with sialic acid as substrate. In conclusion, E. coli O157 has capacity to utilize small or large intestinal mucus, and growth is greatest with whole mucus compared with individual mucus components. There are two possible explanations for these findings (i) multiple substrates are needed to optimize growth, or alternatively, (ii) a component of mucus not evaluated in this experiment is a key ingredient for optimal growth of E. coli O157:H7.
Collapse
|
49
|
Hopkins AP, Hawkhead JA, Thomas GH. Transport and catabolism of the sialic acids N-glycolylneuraminic acid and 3-keto-3-deoxy-D-glycero-D-galactonononic acid by Escherichia coli K-12. FEMS Microbiol Lett 2013; 347:14-22. [PMID: 23848303 DOI: 10.1111/1574-6968.12213] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2013] [Revised: 06/21/2013] [Accepted: 07/05/2013] [Indexed: 11/29/2022] Open
Abstract
Escherichia coli can transport and catabolize the common sialic acid, N-acetylneuraminic acid (Neu5Ac), as a sole source of carbon and nitrogen, which is an important mucus-derived carbon source in the mammalian gut. Herein we demonstrate that E. coli can also grow efficiently on the related sialic acids, N-glycolylneuraminic acid (Neu5Gc) and 3-keto-3-deoxy-D-glycero-D-galactonononic acid (KDN), which are transported via the sialic acid transporter NanT and catabolized using the sialic acid aldolase NanA. Catabolism of Neu5Gc uses the same pathway as Neu5Ac, likely producing glycolate instead and acetate during its breakdown and catabolism of KDN requires NanA activity, while other components of the Neu5Ac catabolism pathway are non-essential. We also demonstrate that these two sialic acids can support growth of an E. coli ∆nanT strain expressing sialic acid transporters from two bacterial pathogens, namely the tripartite ATP-independent periplasmic transporter SiaPQM from Haemophilus influenzae and the sodium solute symport transporter STM1128 from Salmonella enterica ssp. Typhimurium, suggesting that the ability to use Neu5Gc and KDN in addition to Neu5Ac is present in a number of human pathogens.
Collapse
Affiliation(s)
- Adam P Hopkins
- Department of Biology, University of York, Heslington, York, UK
| | | | | |
Collapse
|
50
|
Stecher B, Berry D, Loy A. Colonization resistance and microbial ecophysiology: using gnotobiotic mouse models and single-cell technology to explore the intestinal jungle. FEMS Microbiol Rev 2013; 37:793-829. [PMID: 23662775 DOI: 10.1111/1574-6976.12024] [Citation(s) in RCA: 76] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2013] [Revised: 04/11/2013] [Accepted: 04/18/2013] [Indexed: 12/14/2022] Open
Abstract
The highly diverse intestinal microbiota forms a structured community engaged in constant communication with itself and its host and is characterized by extensive ecological interactions. A key benefit that the microbiota affords its host is its ability to protect against infections in a process termed colonization resistance (CR), which remains insufficiently understood. In this review, we connect basic concepts of CR with new insights from recent years and highlight key technological advances in the field of microbial ecology. We present a selection of statistical and bioinformatics tools used to generate hypotheses about synergistic and antagonistic interactions in microbial ecosystems from metagenomic datasets. We emphasize the importance of experimentally testing these hypotheses and discuss the value of gnotobiotic mouse models for investigating specific aspects related to microbiota-host-pathogen interactions in a well-defined experimental system. We further introduce new developments in the area of single-cell analysis using fluorescence in situ hybridization in combination with metabolic stable isotope labeling technologies for studying the in vivo activities of complex community members. These approaches promise to yield novel insights into the mechanisms of CR and intestinal ecophysiology in general, and give researchers the means to experimentally test hypotheses in vivo at varying levels of biological and ecological complexity.
Collapse
Affiliation(s)
- Bärbel Stecher
- Max von Pettenkofer Institute of Hygiene and Medical Microbiology, Ludwig-Maximilians-University of Munich, Munich, Germany.
| | | | | |
Collapse
|