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Hotinger JA, Campbell IW, Hullahalli K, Osaki A, Waldor MK. Quantification of Salmonella enterica serovar Typhimurium Population Dynamics in Murine Infection Using a Highly Diverse Barcoded Library. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.06.28.601246. [PMID: 38979326 PMCID: PMC11230369 DOI: 10.1101/2024.06.28.601246] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/10/2024]
Abstract
Murine models are often used to study the pathogenicity and dissemination of the enteric pathogen Salmonella enterica serovar Typhimurium. Here, we quantified S. Typhimurium population dynamics in mice using the STAMPR analytic pipeline and a highly diverse S . Typhimurium barcoded library containing ∼55,000 unique strains distinguishable by genomic barcodes by enumerating S . Typhimurium founding populations and deciphering routes of spread in mice. We found that a severe bottleneck allowed only one in a million cells from an oral inoculum to establish a niche in the intestine. Furthermore, we observed compartmentalization of pathogen populations throughout the intestine, with few barcodes shared between intestinal segments and feces. This severe bottleneck widened and compartmentalization was reduced after streptomycin treatment, suggesting the microbiota plays a key role in restricting the pathogen's colonization and movement within the intestine. Additionally, there was minimal sharing between the intestine and extraintestinal organ populations, indicating dissemination to extraintestinal sites occurs rapidly, before substantial pathogen expansion in the intestine. Bypassing the intestinal bottleneck by inoculating mice via intravenous or intraperitoneal injection revealed that Salmonella re-enters the intestine after establishing niches in extraintestinal sites by at least two distinct pathways. One pathway results in a diverse intestinal population. The other re-seeding pathway is through the bile, where the pathogen is often clonal, leading to clonal intestinal populations and correlates with gallbladder pathology. Together, these findings deepen our understanding of Salmonella population dynamics. Significance Statement Salmonella is a prevalent food-borne pathogen that infects hundreds of millions of people worldwide. Here, we created a highly complex barcoded Salmonella enterica serovar Typhimurium library containing ∼55,000 barcodes to further understand and quantify Salmonella population dynamics in experimental murine infection. Through comparisons of barcode abundance and frequency in different samples and following different routes of inoculation, we quantify key facets of Salmonella infection, including bottleneck sizes and dissemination patterns, and uncover hidden routes of spread that drive heterogeneity in infection outcome. These observations provide a detailed map of Salmonella infection and demonstrate the power of high-diversity barcoded libraries in deciphering microbial population dynamics.
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Felipe-López A, Hansmeier N, Hensel M. Destruction of the brush border by Salmonella enterica sv. Typhimurium subverts resorption by polarized epithelial cells. Front Microbiol 2024; 15:1329798. [PMID: 38894970 PMCID: PMC11183102 DOI: 10.3389/fmicb.2024.1329798] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2023] [Accepted: 05/06/2024] [Indexed: 06/21/2024] Open
Abstract
Salmonella enterica serovar Typhimurium is an invasive, facultative intracellular gastrointestinal pathogen that destroys the brush border of polarized epithelial cells (PEC). The brush border is critical for the functions of PEC because it resorbs nutrients from the intestinal lumen and builds a physical barrier to infecting pathogens. The manipuation of PEC during infection by Salmonella was investigated by live-cell imaging and ultrastructural analysed of the brush border. We demonstrate that the destruction of the brush border by Salmonella significantly reduces the resorption surface of PEC along with the abrogation of endocytosis at the apical side of PEC. Both these changes in the physiology of PEC were associated with the translocation of type III secretion system effector protein SopE. Additionally, the F-actin polymerization rate at the apical side of PEC was highly altered by SopE, indicating that reduced endocytosis observed in infected PEC is related to the manipulation of F-actin polymerization mediated by SopE and, to a lesser extent, by effectors SopE2 or SipA. We further observed that in the absence of SopE, Salmonella effaced microvilli and induced reticular F-actin by bacterial accumulation during prolonged infection periods. In contrast to strains translocating SopE, strains lacking SopE did not alter resorption by PEC. Finally, we observed that after engulfment of Salmonella, ezrin was lost from the apical side of PEC and found later in early endosomes containing Salmonella. Our observations suggest that the destruction of the brush border by Salmonella may contribute to the pathogenesis of diarrhea.
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Affiliation(s)
| | | | - Michael Hensel
- Abt. Mikrobiologie, Universität Osnabrück, Osnabrück, Germany
- CellNanOs—Center of Cellular Nanoanalytics Osnabrück, Universität Osnabrück, Osnabrück, Germany
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3
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Gu D, Li A, Zang X, Huang T, Guo Y, Jiao X, Pan Z. Salmonella Enteritidis antitoxin DinJ inhibits NLRP3-dependent canonical inflammasome activation in macrophages. Infect Immun 2024; 92:e0050523. [PMID: 38477589 PMCID: PMC11003228 DOI: 10.1128/iai.00505-23] [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: 12/06/2023] [Accepted: 02/09/2024] [Indexed: 03/14/2024] Open
Abstract
The inflammasome is a pivotal component of the innate immune system, acting as a multiprotein complex that plays an essential role in detecting and responding to microbial infections. Salmonella Enteritidis have evolved multiple mechanisms to regulate inflammasome activation and evade host immune system clearance. Through screening S. Enteritidis C50336ΔfliC transposon mutant library, we found that the insertion mutant of dinJ increased inflammasome activation. In this study, we demonstrated the genetic connection between the antitoxin DinJ and the toxin YafQ in S. Enteritidis, confirming their co-transcription. The deletion mutant ΔfliCΔdinJ increased cell death and IL-1β secretion in J774A.1 cells. Western blotting analysis further showed elevated cleaved Caspase-1 product (p10 subunits) and IL-1β secretion in cells infected with ΔfliCΔdinJ compared to cells infected with ΔfliC. DinJ was found to inhibit canonical inflammasome activation using primary bone marrow-derived macrophages (BMDMs) from Casp-/- C57BL/6 mice. Furthermore, DinJ specifically inhibited NLRP3 inflammasome activation, as demonstrated in BMDMs from Nlrp3-/- and Nlrc4-/- mice. Fluorescence resonance energy transfer (FRET) experiments confirmed the translocation of DinJ into host cells during infection. Finally, we revealed that DinJ could inhibit the secretion of IL-1β and IL-18 in vivo, contributing to S. Enteritidis evading host immune clearance. In summary, our findings provide insights into the role of DinJ in modulating the inflammasome response during S. Enteritidis infection, highlighting its impact on inhibiting inflammasome activation and immune evasion.
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Affiliation(s)
- Dan Gu
- Jiangsu Key Laboratory of Zoonosis/Jiangsu Co-innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou University, Yangzhou, Jiangsu, China
- Key Laboratory of Prevention and Control of Biological Hazard Factors (Animal Origin) for Agrifood Safety and Quality, Ministry of Agriculture of China, Yangzhou University, Yangzhou, Jiangsu, China
- Joint International Research Laboratory of Agriculture and Agri-product Safety of the Ministry of Education, Yangzhou University, Yangzhou, Jiangsu, China
| | - Ang Li
- Jiangsu Key Laboratory of Zoonosis/Jiangsu Co-innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou University, Yangzhou, Jiangsu, China
- Key Laboratory of Prevention and Control of Biological Hazard Factors (Animal Origin) for Agrifood Safety and Quality, Ministry of Agriculture of China, Yangzhou University, Yangzhou, Jiangsu, China
- Joint International Research Laboratory of Agriculture and Agri-product Safety of the Ministry of Education, Yangzhou University, Yangzhou, Jiangsu, China
| | - Xirui Zang
- Jiangsu Key Laboratory of Zoonosis/Jiangsu Co-innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou University, Yangzhou, Jiangsu, China
- Key Laboratory of Prevention and Control of Biological Hazard Factors (Animal Origin) for Agrifood Safety and Quality, Ministry of Agriculture of China, Yangzhou University, Yangzhou, Jiangsu, China
- Joint International Research Laboratory of Agriculture and Agri-product Safety of the Ministry of Education, Yangzhou University, Yangzhou, Jiangsu, China
| | - Tingting Huang
- Jiangsu Key Laboratory of Zoonosis/Jiangsu Co-innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou University, Yangzhou, Jiangsu, China
- Key Laboratory of Prevention and Control of Biological Hazard Factors (Animal Origin) for Agrifood Safety and Quality, Ministry of Agriculture of China, Yangzhou University, Yangzhou, Jiangsu, China
- Joint International Research Laboratory of Agriculture and Agri-product Safety of the Ministry of Education, Yangzhou University, Yangzhou, Jiangsu, China
| | - Yaxin Guo
- Jiangsu Key Laboratory of Zoonosis/Jiangsu Co-innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou University, Yangzhou, Jiangsu, China
- Key Laboratory of Prevention and Control of Biological Hazard Factors (Animal Origin) for Agrifood Safety and Quality, Ministry of Agriculture of China, Yangzhou University, Yangzhou, Jiangsu, China
- Joint International Research Laboratory of Agriculture and Agri-product Safety of the Ministry of Education, Yangzhou University, Yangzhou, Jiangsu, China
| | - Xinan Jiao
- Jiangsu Key Laboratory of Zoonosis/Jiangsu Co-innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou University, Yangzhou, Jiangsu, China
- Key Laboratory of Prevention and Control of Biological Hazard Factors (Animal Origin) for Agrifood Safety and Quality, Ministry of Agriculture of China, Yangzhou University, Yangzhou, Jiangsu, China
- Joint International Research Laboratory of Agriculture and Agri-product Safety of the Ministry of Education, Yangzhou University, Yangzhou, Jiangsu, China
| | - Zhiming Pan
- Jiangsu Key Laboratory of Zoonosis/Jiangsu Co-innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou University, Yangzhou, Jiangsu, China
- Key Laboratory of Prevention and Control of Biological Hazard Factors (Animal Origin) for Agrifood Safety and Quality, Ministry of Agriculture of China, Yangzhou University, Yangzhou, Jiangsu, China
- Joint International Research Laboratory of Agriculture and Agri-product Safety of the Ministry of Education, Yangzhou University, Yangzhou, Jiangsu, China
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Zhang K, Repnik U, Diab N, Friske D, Pütz A, Bachmann AZ, Gubbi NMKP, Hensel M, Förstner KU, Westermann AJ, Dupont A, Hornef MW. Non-professional efferocytosis of Salmonella-infected intestinal epithelial cells in the neonatal host. J Exp Med 2024; 221:e20231237. [PMID: 38305765 PMCID: PMC10837083 DOI: 10.1084/jem.20231237] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2023] [Revised: 12/04/2023] [Accepted: 01/08/2024] [Indexed: 02/03/2024] Open
Abstract
The intestinal epithelium is the first line of defense against enteric pathogens. Removal of infected cells by exfoliation prevents mucosal translocation and systemic infection in the adult host, but is less commonly observed in the neonatal intestine. Instead, here, we describe non-professional efferocytosis of Salmonella-infected enterocytes by neighboring epithelial cells in the neonatal intestine. Intestinal epithelial stem cell organoid cocultures of neonatal and adult cell monolayers with damaged enterocytes replicated this observation, confirmed the age-dependent ability of intestinal epithelial cells for efferocytosis, and identified the involvement of the "eat-me" signals and adaptors phosphatidylserine and C1q as well as the "eat-me" receptors integrin-αv (CD51) and CD36 in cellular uptake. Consistent with this, massive epithelial cell membrane protrusions and CD36 accumulation at the contact site with apoptotic cells were observed in the infected neonatal host in vivo. Efferocytosis of infected small intestinal enterocytes by neighboring epithelial cells may represent a previously unrecognized mechanism of neonatal antimicrobial host defense to maintain barrier integrity.
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Affiliation(s)
- Kaiyi Zhang
- Institute of Medical Microbiology, RWTH Aachen University Hospital , Aachen, Germany
| | - Urska Repnik
- Department of Biology, Central Microscopy Unit, University of Kiel, Kiel, Germany
- Department of Biosciences, University of Oslo, Oslo, Norway
| | - Nour Diab
- Institute of Medical Microbiology, RWTH Aachen University Hospital , Aachen, Germany
| | - Daniel Friske
- Institute of Medical Microbiology, RWTH Aachen University Hospital , Aachen, Germany
| | - Andreas Pütz
- Institute of Medical Microbiology, RWTH Aachen University Hospital , Aachen, Germany
| | - Alina Z Bachmann
- Institute of Medical Microbiology, RWTH Aachen University Hospital , Aachen, Germany
| | | | - Michael Hensel
- Division of Microbiology, University of Osnabrück, Osnabrück, Germany
| | - Konrad U Förstner
- Institute of Molecular Infection Biology, University of Würzburg , Würzburg, Germany
| | - Alexander J Westermann
- Institute of Molecular Infection Biology, University of Würzburg , Würzburg, Germany
- Helmholtz Institute for RNA-based Infection Research, Helmholtz Centre for Infection Research , Würzburg, Germany
- Department of Microbiology, Biocentre, University of Würzburg, Würzburg, Germany
| | - Aline Dupont
- Institute of Medical Microbiology, RWTH Aachen University Hospital , Aachen, Germany
| | - Mathias W Hornef
- Institute of Medical Microbiology, RWTH Aachen University Hospital , Aachen, Germany
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Berni M, Bolzoni L, Menozzi I, Dodi A, Bracchi C, Morganti M, Scaltriti E, Pongolini S, Tambassi M. Salmonella Derby adaptation to swine and simultaneous attenuation for humans go through decay of Salmonella Pathogenicity Island I. Microbiol Spectr 2023; 11:e0189923. [PMID: 37800927 PMCID: PMC10715017 DOI: 10.1128/spectrum.01899-23] [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: 05/19/2023] [Accepted: 08/09/2023] [Indexed: 10/07/2023] Open
Abstract
IMPORTANCE This study integrated population data with in vitro assessment of virulence phenotypes to unveil that a considerable part of the global population of Salmonella Derby is evolving to enhance its host adaptation to the swine host and that this evolution is simultaneously increasing its attenuation for humans. The study shows that the fixation of deleterious mutations in SPI-1 has a role in this process. This evidence indicates that SPI-1 has a key role for S. Derby virulence in humans but not for its circulation in swine. The results show that genes generally considered essential for Salmonella pathogenesis do not play the same key role for all Salmonella serovars or lineages and/or all hosts. The study helps in understanding the molecular mechanisms underlying the ecology and host adaptation of Salmonella showing that the adaptation process can vary for different types of Salmonella and hosts.
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Affiliation(s)
- Melissa Berni
- Risk Analysis and Genomic Epidemiology Unit, Istituto Zooprofilattico Sperimentale della Lombardia e dell'Emilia-Romagna (IZSLER), Parma, Italy
| | - Luca Bolzoni
- Risk Analysis and Genomic Epidemiology Unit, Istituto Zooprofilattico Sperimentale della Lombardia e dell'Emilia-Romagna (IZSLER), Parma, Italy
| | - Ilaria Menozzi
- Risk Analysis and Genomic Epidemiology Unit, Istituto Zooprofilattico Sperimentale della Lombardia e dell'Emilia-Romagna (IZSLER), Parma, Italy
| | - Alessandra Dodi
- Risk Analysis and Genomic Epidemiology Unit, Istituto Zooprofilattico Sperimentale della Lombardia e dell'Emilia-Romagna (IZSLER), Parma, Italy
| | - Chiara Bracchi
- Risk Analysis and Genomic Epidemiology Unit, Istituto Zooprofilattico Sperimentale della Lombardia e dell'Emilia-Romagna (IZSLER), Parma, Italy
| | - Marina Morganti
- Risk Analysis and Genomic Epidemiology Unit, Istituto Zooprofilattico Sperimentale della Lombardia e dell'Emilia-Romagna (IZSLER), Parma, Italy
| | - Erika Scaltriti
- Risk Analysis and Genomic Epidemiology Unit, Istituto Zooprofilattico Sperimentale della Lombardia e dell'Emilia-Romagna (IZSLER), Parma, Italy
| | - Stefano Pongolini
- Risk Analysis and Genomic Epidemiology Unit, Istituto Zooprofilattico Sperimentale della Lombardia e dell'Emilia-Romagna (IZSLER), Parma, Italy
| | - Martina Tambassi
- Risk Analysis and Genomic Epidemiology Unit, Istituto Zooprofilattico Sperimentale della Lombardia e dell'Emilia-Romagna (IZSLER), Parma, Italy
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6
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Mikolajczyk-Martinez A, Ugorski M. Unraveling the role of type 1 fimbriae in Salmonella pathogenesis: insights from a comparative analysis of Salmonella Enteritidis and Salmonella Gallinarum. Poult Sci 2023; 102:102833. [PMID: 37356296 PMCID: PMC10404763 DOI: 10.1016/j.psj.2023.102833] [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: 03/19/2023] [Revised: 05/21/2023] [Accepted: 05/31/2023] [Indexed: 06/27/2023] Open
Abstract
Significant differences in pathogenicity between Salmonella Enteritidis and Salmonella Gallinarum exist despite the fact that S. Gallinarum is a direct descendant of S. Enteritidis. It was hypothesized that such various properties may be in part the result of differences in structure and functions of type 1 fimbriae (T1Fs). In S. Enteritidis, T1Fs bind to oligomannosidic structures carried by host cell glycoproteins and are called mannose-sensitive T1Fs (MST1F). In S. Gallinarum, T1Fs lost ability to bind such carbohydrate chains, and were named mannose-resistant MRT1Fs (MRT1F). Therefore, the present study was undertaken to evaluate the role of MST1Fs and MRT1Fs in the adhesion, invasion, intracellular survival and cytotoxicity of S. Enteritidis and S. Gallinarum toward chicken intestinal CHIC8-E11cells and macrophage-like HD11 cells. Using mutant strains: S. Enteritidis fimH::kan and S. Gallinarum fimH::kan devoid of T1Fs and in vitro assays the following observations were made. MST1Fs have a significant impact on the chicken cell invasion by S. Enteritidis as MST1F-mediated adhesion facilitates direct and stable contact of bacteria with host cells, in contrast to MRT1Fs expressed by S. Gallinarum. MST1Fs as well as MRT1Fs did not affected intracellular viability of S. Enteritidis and S. Gallinarum. However, absolute numbers of intracellular viable wild-type S. Enteritidis were significantly higher than S. Enteritidis fimH::kan mutant and wild-type S. Gallinarum and S. Gallinarum fimH::kan mutant. These differences, reflecting the numbers of adherent and invading bacteria, underline the importance of MST1Fs in the pathogenicity of S. Enteritidis infections. The cytotoxicity of wild-type S. Enteritidis and its mutant devoid of MST1Fs to HD11 cells was essentially the same, despite the fact that the number of viable intracellular bacteria was significantly lower in the mutated strain. Using HD11 cells with similar number of intracellular wild-type S. Enteritidis and S. Enteritidis fimH::kan mutant, it was found that the lack of MST1Fs did not affect directly the cytotoxicity, suggesting that the increase in cytotoxicity of S. Enteritidis devoid of MST1Fs may be associated with crosstalk between T1Fs and other virulence factors.
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Affiliation(s)
- Agata Mikolajczyk-Martinez
- Department of Biochemistry and Molecular Biology, Faculty of Veterinary Medicine, Wroclaw University of Environmental and Life Sciences, Wroclaw, Poland
| | - Maciej Ugorski
- Department of Biochemistry and Molecular Biology, Faculty of Veterinary Medicine, Wroclaw University of Environmental and Life Sciences, Wroclaw, Poland.
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Xiong D, Song L, Chen Y, Jiao X, Pan Z. Salmonella Enteritidis activates inflammatory storm via SPI-1 and SPI-2 to promote intracellular proliferation and bacterial virulence. Front Cell Infect Microbiol 2023; 13:1158888. [PMID: 37325511 PMCID: PMC10266283 DOI: 10.3389/fcimb.2023.1158888] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2023] [Accepted: 05/18/2023] [Indexed: 06/17/2023] Open
Abstract
Salmonella Enteritidis is an important intracellular pathogen, which can cause gastroenteritis in humans and animals and threaten life and health. S. Enteritidis proliferates in host macrophages to establish systemic infection. In this study, we evaluated the effects of Salmonella pathogenicity island-1 (SPI-1) and SPI-2 to S. Enteritidis virulence in vitro and in vivo, as well as the host inflammatory pathways affected by SPI-1 and SPI-2. Our results show that S. Enteritidis SPI-1 and SPI-2 contributed to bacterial invasion and proliferation in RAW264.7 macrophages, and induced cytotoxicity and cellular apoptosis of these cells. S. Enteritidis infection induced multiple inflammatory responses, including mitogen-activated protein kinase (ERK-mediated) and Janus kinase-signal transducer and activator of transcript (STAT) (STAT2-mediated) pathways. Both SPI-1 and SPI-2 were necessary to induce robust inflammatory responses and ERK/STAT2 phosphorylation in macrophages. In a mouse infection model, both SPIs, especially SPI-2, resulted in significant production of inflammatory cytokines and various interferon-stimulated genes in the liver and spleen. Activation of the ERK- and STAT2-mediated cytokine storm was largely affected by SPI-2. S. Enteritidis ΔSPI-1-infected mice displayed moderate histopathological damage and drastically reduced bacterial loads in tissues, whereas only slight damage and no bacteria were observed in ΔSPI-2- and ΔSPI-1/SPI-2-infected mice. A survival assay showed that ΔSPI-1 mutant mice maintained a medium level of virulence, while SPI-2 plays a decisive role in bacterial virulence. Collectively, our findings indicate that both SPIs, especially SPI-2, profoundly contributed to S. Enteritidis intracellular localization and virulence by activating multiple inflammatory pathways.
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Affiliation(s)
- Dan Xiong
- Jiangsu Key Laboratory of Zoonosis, Yangzhou University, Yangzhou, China
- Jiangsu Co-Innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou University, Yangzhou, China
- Key Laboratory of Prevention and Control of Biological Hazard Factors (Animal Origin) for Agrifood Safety and Quality, Ministry of Agriculture and Rural Affairs, Yangzhou University, Yangzhou, China
| | - Li Song
- Jiangsu Key Laboratory of Zoonosis, Yangzhou University, Yangzhou, China
- Jiangsu Co-Innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou University, Yangzhou, China
- Key Laboratory of Prevention and Control of Biological Hazard Factors (Animal Origin) for Agrifood Safety and Quality, Ministry of Agriculture and Rural Affairs, Yangzhou University, Yangzhou, China
| | - Yushan Chen
- Jiangsu Key Laboratory of Zoonosis, Yangzhou University, Yangzhou, China
- Jiangsu Co-Innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou University, Yangzhou, China
- Key Laboratory of Prevention and Control of Biological Hazard Factors (Animal Origin) for Agrifood Safety and Quality, Ministry of Agriculture and Rural Affairs, Yangzhou University, Yangzhou, China
| | - Xinan Jiao
- Jiangsu Key Laboratory of Zoonosis, Yangzhou University, Yangzhou, China
- Jiangsu Co-Innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou University, Yangzhou, China
- Key Laboratory of Prevention and Control of Biological Hazard Factors (Animal Origin) for Agrifood Safety and Quality, Ministry of Agriculture and Rural Affairs, Yangzhou University, Yangzhou, China
| | - Zhiming Pan
- Jiangsu Key Laboratory of Zoonosis, Yangzhou University, Yangzhou, China
- Jiangsu Co-Innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou University, Yangzhou, China
- Key Laboratory of Prevention and Control of Biological Hazard Factors (Animal Origin) for Agrifood Safety and Quality, Ministry of Agriculture and Rural Affairs, Yangzhou University, Yangzhou, China
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Davidson A, Hume PJ, Greene NP, Koronakis V. Salmonella invasion of a cell is self-limiting due to effector-driven activation of N-WASP. iScience 2023; 26:106643. [PMID: 37168569 PMCID: PMC10164908 DOI: 10.1016/j.isci.2023.106643] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2023] [Revised: 03/10/2023] [Accepted: 04/06/2023] [Indexed: 05/13/2023] Open
Abstract
Salmonella Typhimurium drives uptake into non-phagocytic host cells by injecting effector proteins that reorganize the actin cytoskeleton. The host actin regulator N-WASP has been implicated in bacterial entry, but its precise role is not clear. We demonstrate that Cdc42-dependent N-WASP activation, instigated by the Cdc42-activating effector SopE2, strongly impedes Salmonella uptake into host cells. This inhibitory pathway is predominant later in invasion, with the ubiquitin ligase activity of the effector SopA specifically interfering with negative Cdc42-N-WASP signaling at early stages. The cell therefore transitions from being susceptible to invasion, into a state almost completely recalcitrant to bacterial uptake, providing a mechanism to limit the number of internalized Salmonella. Our work raises the possibility that Cdc42-N-WASP, known to be activated by numerous bacterial and viral species during infection and commonly assumed to promote pathogen uptake, is used to limit the entry of multiple pathogens.
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Affiliation(s)
| | - Peter J. Hume
- Department of Pathology, University of Cambridge, Cambridge, UK
| | | | - Vassilis Koronakis
- Department of Pathology, University of Cambridge, Cambridge, UK
- Corresponding author
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9
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García-Reyes RA, García-Cancino A, Arrevillaga-Boni G, Espinoza-Monje M, Gutiérrez-Zamorano C, Arrizon J, González-Avila M. Identification and Characterization of Probiotic Lactiplantibacillus plantarum BI-59.1 Isolated from tejuino and Its Capacity to Produce Biofilms. Curr Microbiol 2023; 80:220. [PMID: 37204589 DOI: 10.1007/s00284-023-03319-8] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2022] [Accepted: 04/30/2023] [Indexed: 05/20/2023]
Abstract
Tejuino is a popular and traditional beverage consumed in north and western of Mexico, due to its biological properties, it is considered a natural source of probiotics. Nevertheless, few studies have been performed on Tejuino microbiota. In this work, the probiotic potential of the tejuino isolated Lactiplantibacillus plantarum BI-59.1 strain was investigated. Its effectiveness was compared with a commercial Lactobacillus spp and identified by 16S rDNA sequence homology. Lactiplantibacillus plantarum BI-59.1 strain showed probiotic properties, i.e., production of antimicrobial compounds (lactic acid and presence of plantaricin A gene), inhibition of entero-pathogens by planktonic cells and metabolites (Salmonella enterica serovar Typhimurium inhibition to HT29-MTX adhesion), biofilm formation, bacterial adhesion (HT29-MTX, 3.96 CFU/cell), and tolerance to stimulated gastrointestinal conditions (tolerance to pH 3 and bile salts). The strain was gamma hemolytic, susceptible to most antibiotics and negative for gelatinase production; thus, the Lactiplantibacillus. plantarum BI-59.1 strain is suitable for its use as a probiotic for nutraceutical or pharmaceutical formulations.
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Affiliation(s)
- Rudy Antonio García-Reyes
- Ex-Vivo Digestion Laboratory, Medical and Pharmaceutical Biotechnology Unit, Center for Research and Applied Technology in Jalisco (CIATEJ), Normalistas 800, Colinas de La Normal, 44270, Guadalajara, Jalisco, Mexico
| | - Apolinaria García-Cancino
- Laboratory of Bacterial Pathogenicity, Faculty of Biological Sciences, University of Concepcion, Chacabuco, 4030000, Concepción, Bío-Bío, Chile
| | - Gerardo Arrevillaga-Boni
- Ex-Vivo Digestion Laboratory, Medical and Pharmaceutical Biotechnology Unit, Center for Research and Applied Technology in Jalisco (CIATEJ), Normalistas 800, Colinas de La Normal, 44270, Guadalajara, Jalisco, Mexico
| | - Marcela Espinoza-Monje
- Laboratory of Bacterial Pathogenicity, Faculty of Biological Sciences, University of Concepcion, Chacabuco, 4030000, Concepción, Bío-Bío, Chile
| | - Cristian Gutiérrez-Zamorano
- Laboratory of Bacterial Pathogenicity, Faculty of Biological Sciences, University of Concepcion, Chacabuco, 4030000, Concepción, Bío-Bío, Chile
| | - Javier Arrizon
- Industrial Biotechnology Unit, Center for Research and Applied Technology in Jalisco (CIATEJ), Camino Arenero 1227, El Bajío del Arenal, 45019, Zapopan, Jalisco, Mexico
| | - Marisela González-Avila
- Ex-Vivo Digestion Laboratory, Medical and Pharmaceutical Biotechnology Unit, Center for Research and Applied Technology in Jalisco (CIATEJ), Normalistas 800, Colinas de La Normal, 44270, Guadalajara, Jalisco, Mexico.
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10
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Rogers AP, Mileto SJ, Lyras D. Impact of enteric bacterial infections at and beyond the epithelial barrier. Nat Rev Microbiol 2023; 21:260-274. [PMID: 36175770 DOI: 10.1038/s41579-022-00794-x] [Citation(s) in RCA: 28] [Impact Index Per Article: 28.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/23/2022] [Indexed: 11/09/2022]
Abstract
The mucosal lining of the gut has co-evolved with a diverse microbiota over millions of years, leading to the development of specialized mechanisms to actively limit the invasion of pathogens. However, some enteric microorganisms have adapted against these measures, developing ways to hijack or overcome epithelial micro-integrity mechanisms. This breach of the gut barrier not only enables the leakage of host factors out of circulation but can also initiate a cascade of detrimental systemic events as microbiota, pathogens and their affiliated secretions passively leak into extra-intestinal sites. Under normal circumstances, gut damage is rapidly repaired by intestinal stem cells. However, with substantial and deep perturbation to the gut lining and the systemic dissemination of gut contents, we now know that some enteric infections can cause the impairment of host regenerative processes. Although these local and systemic aspects of enteric disease are often studied in isolation, they heavily impact one another. In this Review, by examining the journey of enteric infections from initial establishment to systemic sequelae and how, or if, the host can successfully repair damage, we will tie together these complex interactions to provide a holistic overview of the impact of enteric infections at and beyond the epithelial barrier.
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Affiliation(s)
- Ashleigh P Rogers
- Infection and Immunity Program, Monash Biomedicine Discovery Institute, Monash University, Melbourne, Victoria, Australia.,Department of Microbiology, Monash University, Melbourne, Victoria, Australia
| | - Steven J Mileto
- Infection and Immunity Program, Monash Biomedicine Discovery Institute, Monash University, Melbourne, Victoria, Australia.,Department of Microbiology, Monash University, Melbourne, Victoria, Australia
| | - Dena Lyras
- Infection and Immunity Program, Monash Biomedicine Discovery Institute, Monash University, Melbourne, Victoria, Australia. .,Department of Microbiology, Monash University, Melbourne, Victoria, Australia.
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11
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Elpers L, Lüken L, Lange F, Hensel M. Factors Required for Adhesion of Salmonella enterica Serovar Typhimurium to Lactuca sativa (Lettuce). Microbiol Spectr 2023; 11:e0343622. [PMID: 36533955 PMCID: PMC9927257 DOI: 10.1128/spectrum.03436-22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2022] [Accepted: 11/29/2022] [Indexed: 12/23/2022] Open
Abstract
Salmonella enterica serovar Typhimurium is a major cause of foodborne gastroenteritis. Recent outbreaks of infections by S. enterica serovar Typhimurium are often associated with non-animal-related food, i.e., vegetables, fruits, herbs, sprouts, and nuts. One main problem related to the consumption of fresh produce is the minimal processing, especially for leafy green salads. In this study, we focused on butterhead lettuce (Lactuca sativa) to which S. enterica serovar Typhimurium adheres at higher rates compared to Valerianella locusta, resulting in prolonged persistence. Here, we systematically analyzed factors contributing to adhesion of S. enterica serovar Typhimurium to L. sativa leaves. Application of a reductionist, synthetic approach, including the controlled surface expression of specific adhesive structures of S. enterica serovar Typhimurium, one at a time, enabled the identification of relevant fimbrial and nonfimbrial adhesins, the O-antigen of lipopolysaccharide, the flagella, and chemotaxis being involved in binding to L. sativa leaves. The analyses revealed contributions of Lpf fimbriae, Sti fimbriae, autotransported adhesin MisL, T1SS-secreted BapA, intact lipopolysaccharide (LPS), and flagella-mediated motility to adhesion of S. enterica serovar Typhimurium to L. sativa leaves. In addition, we identified BapA as a potential adhesin involved in binding to V. locusta and L. sativa leaf surfaces. IMPORTANCE The number of produce-associated outbreaks by gastrointestinal pathogens is increasing and underlines the relevance to human health. The mechanisms involved in the colonization of, persistence on, and transmission by, fresh produce are poorly understood. Here, we investigated the contribution of adhesive factors of S. enterica serovar Typhimurium in the initial phase of plant colonization, i.e., the binding to the plant surface. We used the previously established reductionist, synthetic approach to identify factors that contribute to the surface binding of S. enterica serovar Typhimurium to leaves of L. sativa by expressing all known adhesive structures by remote control expression system.
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Affiliation(s)
- Laura Elpers
- Abt. Mikrobiologie, Universität Osnabrück, Osnabrück, Germany
| | - Lena Lüken
- Abt. Mikrobiologie, Universität Osnabrück, Osnabrück, Germany
| | - Fabio Lange
- Abt. Mikrobiologie, Universität Osnabrück, Osnabrück, Germany
| | - Michael Hensel
- Abt. Mikrobiologie, Universität Osnabrück, Osnabrück, Germany
- Center for Cellular Nanoanalytics (CellNanOs), Universität Osnabrück, Osnabrück, Germany
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12
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A Small RNA, SaaS, Promotes Salmonella Pathogenicity by Regulating Invasion, Intracellular Growth, and Virulence Factors. Microbiol Spectr 2023; 11:e0293822. [PMID: 36688642 PMCID: PMC9927236 DOI: 10.1128/spectrum.02938-22] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023] Open
Abstract
Salmonella enterica serovar Enteritidis is a common foodborne pathogen that infects both humans and animals. The S. Enteritidis virulence regulation network remains largely incomplete, and knowledge regarding the specific virulence phenotype of small RNAs (sRNAs) is limited. Here, we investigated the role of a previously identified sRNA, Salmonella adhesive-associated sRNA (SaaS), in the virulence phenotype of S. Enteritidis by constructing mutant (ΔsaaS) and complemented (ΔsaaS/psaaS) strains. SaaS did not affect S. Enteritidis; it was activated in the simulated intestinal environment (SIE), regulating the expression of virulence target genes. We discovered that it directly binds ssaV mRNA. Caco-2 and RAW 264.7 cell assays revealed that SaaS promoted S. Enteritidis invasion and damage to epithelial cells while suppressing macrophage overgrowth and destruction. Furthermore, a BALB/c mouse model demonstrated that the deletion of SaaS significantly reduced mortality and attenuated the deterioration of pathophysiology, bacterial dissemination into systemic circulation, and systemic inflammation. Our findings indicate that SaaS is required for S. Enteritidis virulence and further highlight its biological role in bacterial pathogenesis. IMPORTANCE Salmonella is a zoonotic pathogen with high virulence worldwide, and sRNAs have recently been discovered to play important roles. We explored the biological characteristics of the sRNA SaaS and developed two cell infection models and a mouse infection model. SaaS is an SIE-responsive sRNA that regulates the expression of virulence-targeted genes. Additionally, it differentially mediates invasion and intracellular growth for survival and infection of the epithelium and macrophages. We further found that SaaS enhanced bacterial virulence by promoting lethality, colonization, and inflammatory response. These findings provide a better understanding of the critical role of sRNA in bacterial virulence.
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13
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Herzog MKM, Cazzaniga M, Peters A, Shayya N, Beldi L, Hapfelmeier S, Heimesaat MM, Bereswill S, Frankel G, Gahan CG, Hardt WD. Mouse models for bacterial enteropathogen infections: insights into the role of colonization resistance. Gut Microbes 2023; 15:2172667. [PMID: 36794831 PMCID: PMC9980611 DOI: 10.1080/19490976.2023.2172667] [Citation(s) in RCA: 12] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/02/2022] [Accepted: 01/18/2023] [Indexed: 02/17/2023] Open
Abstract
Globally, enteropathogenic bacteria are a major cause of morbidity and mortality.1-3 Campylobacter, Salmonella, Shiga-toxin-producing Escherichia coli, and Listeria are among the top five most commonly reported zoonotic pathogens in the European Union.4 However, not all individuals naturally exposed to enteropathogens go on to develop disease. This protection is attributable to colonization resistance (CR) conferred by the gut microbiota, as well as an array of physical, chemical, and immunological barriers that limit infection. Despite their importance for human health, a detailed understanding of gastrointestinal barriers to infection is lacking, and further research is required to investigate the mechanisms that underpin inter-individual differences in resistance to gastrointestinal infection. Here, we discuss the current mouse models available to study infections by non-typhoidal Salmonella strains, Citrobacter rodentium (as a model for enteropathogenic and enterohemorrhagic E. coli), Listeria monocytogenes, and Campylobacter jejuni. Clostridioides difficile is included as another important cause of enteric disease in which resistance is dependent upon CR. We outline which parameters of human infection are recapitulated in these mouse models, including the impact of CR, disease pathology, disease progression, and mucosal immune response. This will showcase common virulence strategies, highlight mechanistic differences, and help researchers from microbiology, infectiology, microbiome research, and mucosal immunology to select the optimal mouse model.
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Affiliation(s)
- Mathias K.-M. Herzog
- Department of Biology, Institute of Microbiology, ETH Zurich, Zurich, Switzerland
| | - Monica Cazzaniga
- APC Microbiome Ireland, University College Cork, Cork, Ireland
- School of Microbiology, University College Cork, Cork, Ireland
| | - Audrey Peters
- Department of Life Sciences, MRC Centre for Molecular Bacteriology and Infection, Imperial College London, London, UK
| | - Nizar Shayya
- Institute of Microbiology, Infectious Diseases and Immunology, Charité - University Medicine Berlin, Berlin, Germany
| | - Luca Beldi
- Institute for Infectious Diseases, University of Bern, Bern, Switzerland
| | | | - Markus M. Heimesaat
- Institute of Microbiology, Infectious Diseases and Immunology, Charité - University Medicine Berlin, Berlin, Germany
| | - Stefan Bereswill
- Institute of Microbiology, Infectious Diseases and Immunology, Charité - University Medicine Berlin, Berlin, Germany
| | - Gad Frankel
- Department of Life Sciences, MRC Centre for Molecular Bacteriology and Infection, Imperial College London, London, UK
| | - Cormac G.M. Gahan
- APC Microbiome Ireland, University College Cork, Cork, Ireland
- School of Microbiology, University College Cork, Cork, Ireland
- School of Pharmacy, University College Cork, Cork, Ireland
| | - Wolf-Dietrich Hardt
- Department of Biology, Institute of Microbiology, ETH Zurich, Zurich, Switzerland
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14
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Wang M, Xiong D, Wang X, Gu D, Meng C, Jiao X, Pan Z. The DNA adenine methylase of Salmonella Enteritidis promotes their intracellular replication by inhibiting arachidonic acid metabolism pathway in macrophages. Front Microbiol 2023; 14:1080851. [PMID: 36937256 PMCID: PMC10018194 DOI: 10.3389/fmicb.2023.1080851] [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: 10/26/2022] [Accepted: 01/23/2023] [Indexed: 03/06/2023] Open
Abstract
Macrophages can participate in immune responses by altering their metabolism, and play important roles in controlling bacterial infections. However, Salmonella Enteritidis can survive and proliferate in macrophages. After the deletion of DNA adenine methylase (Dam), the proliferation of Salmonella Enteritidis in macrophages decreased, the molecular mechanism is still unclear. After infecting macrophages with Salmonella Enteritidis wild type and dam gene deletion strains, intracellular metabolites were extracted and detected by non-targeted metabolomics and fatty acid targeted metabolomics. We found Dam had significant effects on arachidonic acid and related metabolic pathways in macrophages. The dam gene can promote the proliferation of Salmonella Enteritidis in macrophages by inhibiting the metabolic pathway of cytosolic phospholipase A2-mediated arachidonic acid production and conversion to prostaglandin E2 in macrophages, reducing the secretion of the pro-inflammatory factors IL-1β and IL-6. In addition, inhibition of arachidonic acid-related pathways in macrophages by Arachidonyl trifluoromethyl ketone could restore the proliferation of dam gene deletion strains in macrophages. This study explored the role of Dam in the process of Salmonella Enteritidis invading host cells from the perspective of host cell metabolism, and provides new insights into the immune escape mechanism of Salmonella Enteritidis.
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Affiliation(s)
- Ming Wang
- Jiangsu Key Laboratory of Zoonosis, Yangzhou University, Yangzhou, Jiangsu, China
- Jiangsu Co-innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou University, Yangzhou, Jiangsu, China
- Key Laboratory of Prevention and Control of Biological Hazard Factors (Animal Origin) for Agrifood Safety and Quality, Ministry of Agriculture and Rural Affairs, Yangzhou University, Yangzhou, Jiangsu, China
- Joint International Research Laboratory of Agriculture and Agri-product Safety of the Ministry of Education, Yangzhou University, Yangzhou, China
| | - Dan Xiong
- Jiangsu Key Laboratory of Zoonosis, Yangzhou University, Yangzhou, Jiangsu, China
- Jiangsu Co-innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou University, Yangzhou, Jiangsu, China
- Key Laboratory of Prevention and Control of Biological Hazard Factors (Animal Origin) for Agrifood Safety and Quality, Ministry of Agriculture and Rural Affairs, Yangzhou University, Yangzhou, Jiangsu, China
- Joint International Research Laboratory of Agriculture and Agri-product Safety of the Ministry of Education, Yangzhou University, Yangzhou, China
| | - Xinwei Wang
- Jiangsu Key Laboratory of Zoonosis, Yangzhou University, Yangzhou, Jiangsu, China
- Jiangsu Co-innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou University, Yangzhou, Jiangsu, China
- Key Laboratory of Prevention and Control of Biological Hazard Factors (Animal Origin) for Agrifood Safety and Quality, Ministry of Agriculture and Rural Affairs, Yangzhou University, Yangzhou, Jiangsu, China
- Joint International Research Laboratory of Agriculture and Agri-product Safety of the Ministry of Education, Yangzhou University, Yangzhou, China
| | - Dan Gu
- Jiangsu Key Laboratory of Zoonosis, Yangzhou University, Yangzhou, Jiangsu, China
- Jiangsu Co-innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou University, Yangzhou, Jiangsu, China
- Key Laboratory of Prevention and Control of Biological Hazard Factors (Animal Origin) for Agrifood Safety and Quality, Ministry of Agriculture and Rural Affairs, Yangzhou University, Yangzhou, Jiangsu, China
- Joint International Research Laboratory of Agriculture and Agri-product Safety of the Ministry of Education, Yangzhou University, Yangzhou, China
| | - Chuang Meng
- Jiangsu Key Laboratory of Zoonosis, Yangzhou University, Yangzhou, Jiangsu, China
- Jiangsu Co-innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou University, Yangzhou, Jiangsu, China
- Key Laboratory of Prevention and Control of Biological Hazard Factors (Animal Origin) for Agrifood Safety and Quality, Ministry of Agriculture and Rural Affairs, Yangzhou University, Yangzhou, Jiangsu, China
- Joint International Research Laboratory of Agriculture and Agri-product Safety of the Ministry of Education, Yangzhou University, Yangzhou, China
| | - Xinan Jiao
- Jiangsu Key Laboratory of Zoonosis, Yangzhou University, Yangzhou, Jiangsu, China
- Jiangsu Co-innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou University, Yangzhou, Jiangsu, China
- Key Laboratory of Prevention and Control of Biological Hazard Factors (Animal Origin) for Agrifood Safety and Quality, Ministry of Agriculture and Rural Affairs, Yangzhou University, Yangzhou, Jiangsu, China
- Joint International Research Laboratory of Agriculture and Agri-product Safety of the Ministry of Education, Yangzhou University, Yangzhou, China
- *Correspondence: Xinan Jiao,
| | - Zhiming Pan
- Jiangsu Key Laboratory of Zoonosis, Yangzhou University, Yangzhou, Jiangsu, China
- Jiangsu Co-innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou University, Yangzhou, Jiangsu, China
- Key Laboratory of Prevention and Control of Biological Hazard Factors (Animal Origin) for Agrifood Safety and Quality, Ministry of Agriculture and Rural Affairs, Yangzhou University, Yangzhou, Jiangsu, China
- Joint International Research Laboratory of Agriculture and Agri-product Safety of the Ministry of Education, Yangzhou University, Yangzhou, China
- Zhiming Pan,
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15
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Newson JP, Gaissmaier MS, McHugh SC, Hardt WD. Studying antibiotic persistence in vivo using the model organism Salmonella Typhimurium. Curr Opin Microbiol 2022; 70:102224. [PMID: 36335713 DOI: 10.1016/j.mib.2022.102224] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2022] [Revised: 09/22/2022] [Accepted: 10/02/2022] [Indexed: 11/06/2022]
Abstract
Antibiotic persistence permits a subpopulation of susceptible bacteria to survive lethal concentrations of bactericidal antibiotics. This prolongs antibiotic therapy, promotes the evolution of antibiotic-resistant pathogen strains and can select for pathogen virulence within infected hosts. Here, we review the literature exploring antibiotic persistence in vivo, and describe the consequences of recalcitrant subpopulations, with a focus on studies using the model pathogen Salmonella Typhimurium. In vitro studies have established a concise set of features distinguishing true persisters from other forms of bacterial recalcitrance to bactericidal antibiotics. We discuss how animal infection models are useful for exploring these features in vivo, and describe how technical challenges can sometimes prevent the conclusive identification of true antibiotic persistence within infected hosts. We propose using two complementary working definitions for studying antibiotic persistence in vivo: the strict definition for studying the mechanisms of persister formation, and an operative definition for functional studies assessing the links between invasive virulence and persistence as well as the consequences for horizontal gene transfer, or the emergence of antibiotic-resistant mutants. This operative definition will enable further study of how antibiotic persisters arise in vivo, and of how surviving populations contribute to diverse downstream effects such as pathogen transmission, horizontal gene transfer and the evolution of virulence and antibiotic resistance. Ultimately, such studies will help to improve therapeutic control of antibiotic- recalcitrant populations.
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Affiliation(s)
- Joshua Pm Newson
- Institute of Microbiology, Department of Biology, ETH Zürich, Zürich, Switzerland
| | - Marla S Gaissmaier
- Institute of Microbiology, Department of Biology, ETH Zürich, Zürich, Switzerland
| | - Sarah C McHugh
- Department of Fundamental Microbiology, University of Lausanne, Lausanne, Switzerland
| | - Wolf-Dietrich Hardt
- Institute of Microbiology, Department of Biology, ETH Zürich, Zürich, Switzerland.
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16
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Gautier T, Olivieiro N, Ferron S, Le Pogam P, David-Le Gall S, Sauvager A, Leroyer P, Cannie I, Dion S, Sweidan A, Loréal O, Tomasi S, Bousarghin L. Bacteroides fragilis derived metabolites, identified by molecular networking, decrease Salmonella virulence in mice model. Front Microbiol 2022; 13:1023315. [DOI: 10.3389/fmicb.2022.1023315] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2022] [Accepted: 10/26/2022] [Indexed: 11/12/2022] Open
Abstract
In the gut microbiota, resident bacteria prevent pathogens infection by producing specific metabolites. Among bacteria belonging to phylum Bacteroidota, we have previously shown that Bacteroides fragilis or its cell-free supernatant inhibited in vitro Salmonella Heidelberg translocation. In the present study, we have analyzed this supernatant to identify bioactive molecules after extraction and subsequent fractionation using a semi-preparative reversed-phase Liquid Chromatography High-Resolution Tandem Mass Spectrometry (LC-HRMS/MS). The results indicated that only two fractions (F3 and F4) strongly inhibited S. Heidelberg translocation in a model mimicking the intestinal epithelium. The efficiency of the bioactive fractions was evaluated in BALB/c mice, and the results showed a decrease of S. Heidelberg in Peyer’s patches and spleen, associated with a decrease in inflammatory cytokines and neutrophils infiltration. The reduction of the genus Alistipes in mice receiving the fractions could be related to the anti-inflammatory effects of bioactive fractions. Furthermore, these bioactive fractions did not alter the gut microbiota diversity in mice. To further characterize the compounds present in these bioactive fractions, Liquid Chromatography High-Resolution Tandem Mass Spectrometry (LC-HRMS/MS) data were analyzed through molecular networking, highlighting cholic acid (CA) and deoxycholic acid. In vitro, CA had inhibitory activity against the translocation of S. Heidelberg by significantly decreasing the expression of Salmonella virulence genes such as sipA. The bioactive fractions also significantly downregulated the flagellar gene fliC, suggesting the involvement of other active molecules. This study showed the interest to characterize better the metabolites produced by B. fragilis to make them means of fighting pathogenic bacteria by targeting their virulence factor without modifying the gut microbiota.
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17
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Mechanisms for the Invasion and Dissemination of Salmonella. CANADIAN JOURNAL OF INFECTIOUS DISEASES AND MEDICAL MICROBIOLOGY 2022; 2022:2655801. [PMID: 35722038 PMCID: PMC9203224 DOI: 10.1155/2022/2655801] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/26/2021] [Revised: 05/15/2022] [Accepted: 05/30/2022] [Indexed: 11/25/2022]
Abstract
Salmonella enterica is a gastroenteric Gram-negative bacterium that can infect both humans and animals and causes millions of illnesses per year around the world. Salmonella infections usually occur after the consumption of contaminated food or water. Infections with Salmonella species can cause diseases ranging from enterocolitis to typhoid fever. Salmonella has developed multiple strategies to invade and establish a systemic infection in the host. Different cell types, including epithelial cells, macrophages, dendritic cells, and M cells, are important in the infection process of Salmonella. Dissemination throughout the body and colonization of remote organs are hallmarks of Salmonella infection. There are several routes for the dissemination of Salmonella typhimurium. This review summarizes the current understanding of the infection mechanisms of Salmonella. Additionally, different routes of Salmonella infection will be discussed. In this review, the strategies used by Salmonella enterica to establish persistent infection will be discussed. Understanding both the bacterial and host factors leading to the successful colonization of Salmonella enterica may enable the rational design of effective therapeutic strategies.
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18
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Walpole GFW, Pacheco J, Chauhan N, Clark J, Anderson KE, Abbas YM, Brabant-Kirwan D, Montaño-Rendón F, Liu Z, Zhu H, Brumell JH, Deiters A, Stephens LR, Hawkins PT, Hammond GRV, Grinstein S, Fairn GD. Kinase-independent synthesis of 3-phosphorylated phosphoinositides by a phosphotransferase. Nat Cell Biol 2022; 24:708-722. [PMID: 35484249 PMCID: PMC9107517 DOI: 10.1038/s41556-022-00895-y] [Citation(s) in RCA: 19] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2021] [Accepted: 03/08/2022] [Indexed: 01/10/2023]
Abstract
Despite their low abundance, phosphoinositides play a central role in membrane traffic and signalling. PtdIns(3,4,5)P3 and PtdIns(3,4)P2 are uniquely important, as they promote cell growth, survival and migration. Pathogenic organisms have developed means to subvert phosphoinositide metabolism to promote successful infection and their survival in host organisms. We demonstrate that PtdIns(3,4)P2 is a major product generated in host cells by the effectors of the enteropathogenic bacteria Salmonella and Shigella. Pharmacological, gene silencing and heterologous expression experiments revealed that, remarkably, the biosynthesis of PtdIns(3,4)P2 occurs independently of phosphoinositide 3-kinases. Instead, we found that the Salmonella effector SopB, heretofore believed to be a phosphatase, generates PtdIns(3,4)P2 de novo via a phosphotransferase/phosphoisomerase mechanism. Recombinant SopB is capable of generating PtdIns(3,4,5)P3 and PtdIns(3,4)P2 from PtdIns(4,5)P2 in a cell-free system. Through a remarkable instance of convergent evolution, bacterial effectors acquired the ability to synthesize 3-phosphorylated phosphoinositides by an ATP- and kinase-independent mechanism, thereby subverting host signalling to gain entry and even provoke oncogenic transformation.
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Affiliation(s)
- Glenn F W Walpole
- Division of Cell Biology, Hospital for Sick Children, Toronto, Ontario, Canada
- Department of Biochemistry, University of Toronto, Toronto, Ontario, Canada
| | - Jonathan Pacheco
- Department of Cell Biology, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA
| | - Neha Chauhan
- Keenan Research Centre for Biomedical Science, St. Michael's Hospital, Toronto, Ontario, Canada
| | | | | | - Yazan M Abbas
- Molecular Medicine Program, Hospital for Sick Children, Toronto, Ontario, Canada
| | | | - Fernando Montaño-Rendón
- Division of Cell Biology, Hospital for Sick Children, Toronto, Ontario, Canada
- Institute of Medical Sciences, University of Toronto, Toronto, Ontario, Canada
| | - Zetao Liu
- Division of Cell Biology, Hospital for Sick Children, Toronto, Ontario, Canada
- Department of Biochemistry, University of Toronto, Toronto, Ontario, Canada
| | - Hongxian Zhu
- Division of Cell Biology, Hospital for Sick Children, Toronto, Ontario, Canada
- Department of Molecular Genetics, University of Toronto, Toronto, Ontario, Canada
| | - John H Brumell
- Division of Cell Biology, Hospital for Sick Children, Toronto, Ontario, Canada
- Institute of Medical Sciences, University of Toronto, Toronto, Ontario, Canada
- Department of Molecular Genetics, University of Toronto, Toronto, Ontario, Canada
| | - Alexander Deiters
- Department of Chemistry, University of Pittsburgh, Pittsburgh, PA, USA
| | | | | | - Gerald R V Hammond
- Department of Cell Biology, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA
| | - Sergio Grinstein
- Division of Cell Biology, Hospital for Sick Children, Toronto, Ontario, Canada.
- Department of Biochemistry, University of Toronto, Toronto, Ontario, Canada.
- Keenan Research Centre for Biomedical Science, St. Michael's Hospital, Toronto, Ontario, Canada.
- Institute of Medical Sciences, University of Toronto, Toronto, Ontario, Canada.
| | - Gregory D Fairn
- Department of Biochemistry, University of Toronto, Toronto, Ontario, Canada.
- Keenan Research Centre for Biomedical Science, St. Michael's Hospital, Toronto, Ontario, Canada.
- Institute of Medical Sciences, University of Toronto, Toronto, Ontario, Canada.
- Department of Pathology, Dalhousie University, Halifax, Nova Scotia, Canada.
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19
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Ek V, Fattinger SA, Florbrant A, Hardt WD, Di Martino ML, Eriksson J, Sellin ME. A Motile Doublet Form of Salmonella Typhimurium Diversifies Target Search Behaviour at the Epithelial Surface. Mol Microbiol 2022; 117:1156-1172. [PMID: 35332598 PMCID: PMC9325389 DOI: 10.1111/mmi.14898] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2021] [Revised: 02/24/2022] [Accepted: 03/21/2022] [Indexed: 12/01/2022]
Abstract
The behaviors of infectious bacteria are commonly studied in bulk. This is effective to define the general properties of a given isolate, but insufficient to resolve subpopulations and unique single‐microbe behaviors within the bacterial pool. We here employ microscopy to study single‐bacterium characteristics among Salmonella enterica serovar Typhimurium (S.Tm), as they prepare for and launch invasion of epithelial host cells. We find that during the bacterial growth cycle, S.Tm populations switch gradually from fast planktonic growth to a host cell‐invasive phenotype, characterized by flagellar motility and expression of the Type‐three‐secretion‐system‐1. The indistinct nature of this shift leads to the establishment of a transient subpopulation of S.Tm “doublets”—waist‐bearing bacteria anticipating cell division—which simultaneously express host cell invasion machinery. In epithelial cell culture infections, these S.Tm doublets outperform their “singlet” brethren and represent a hyperinvasive subpopulation. Atop both glass and enteroid‐derived monolayers, doublets swim along markedly straighter trajectories than singlets, thereby diversifying search patterns and improving the surface exploration capacity of the total bacterial population. The straighter swimming, combined with an enhanced cell‐adhesion propensity, suffices to account for the hyperinvasive doublet phenotype. This work highlights bacterial cell length heterogeneity as a key determinant of target search patterns atop epithelia.
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Affiliation(s)
- Viktor Ek
- Science for Life Laboratory, Department of Medical Biochemistry and Microbiology, Uppsala University, Sweden
| | - Stefan A Fattinger
- Science for Life Laboratory, Department of Medical Biochemistry and Microbiology, Uppsala University, Sweden.,Institute of Microbiology, Department of Biology, ETH, Zurich, Zurich, Switzerland
| | - Alexandra Florbrant
- Science for Life Laboratory, Department of Medical Biochemistry and Microbiology, Uppsala University, Sweden
| | - Wolf-Dietrich Hardt
- Institute of Microbiology, Department of Biology, ETH, Zurich, Zurich, Switzerland
| | - Maria Letizia Di Martino
- Science for Life Laboratory, Department of Medical Biochemistry and Microbiology, Uppsala University, Sweden
| | - Jens Eriksson
- Science for Life Laboratory, Department of Medical Biochemistry and Microbiology, Uppsala University, Sweden
| | - Mikael E Sellin
- Science for Life Laboratory, Department of Medical Biochemistry and Microbiology, Uppsala University, Sweden
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20
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Fang Z, Méresse S. Endomembrane remodeling and dynamics in Salmonella infection. MICROBIAL CELL (GRAZ, AUSTRIA) 2022; 9:24-41. [PMID: 35127930 PMCID: PMC8796136 DOI: 10.15698/mic2022.02.769] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/16/2021] [Revised: 12/08/2021] [Accepted: 12/10/2021] [Indexed: 11/13/2022]
Abstract
Salmonellae are bacteria that cause moderate to severe infections in humans, depending on the strain and the immune status of the infected host. These pathogens have the particularity of residing in the cells of the infected host. They are usually found in a vacuolar compartment that the bacteria shape with the help of effector proteins. Following invasion of a eukaryotic cell, the bacterial vacuole undergoes maturation characterized by changes in localization, composition and morphology. In particular, membrane tubules stretching over the microtubule cytoskeleton are formed from the bacterial vacuole. Although these tubules do not occur in all infected cells, they are functionally important and promote intracellular replication. This review focuses on the role and significance of membrane compartment remodeling observed in infected cells and the bacterial and host cell pathways involved.
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Affiliation(s)
- Ziyan Fang
- Aix Marseille University, CNRS, INSERM, CIML, Marseille, France
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21
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Fulde M, van Vorst K, Zhang K, Westermann AJ, Busche T, Huei YC, Welitschanski K, Froh I, Pägelow D, Plendl J, Pfarrer C, Kalinowski J, Vogel J, Valentin-Weigand P, Hensel M, Tedin K, Repnik U, Hornef MW. SPI2 T3SS effectors facilitate enterocyte apical to basolateral transmigration of Salmonella-containing vacuoles in vivo. Gut Microbes 2022; 13:1973836. [PMID: 34542008 PMCID: PMC8475570 DOI: 10.1080/19490976.2021.1973836] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
Salmonella pathogenicity island (SPI) 2 type three secretion system (T3SS)-mediated effector molecules facilitate bacterial survival in phagocytes but their role in the intestinal epithelium in vivo remains ill-defined. Using our neonatal murine infection model in combination with SPI2 reporter technology and RNA-Seq of sorted primary enterocytes, we demonstrate expression of SPI2 effector molecules by intraepithelial Salmonella Typhimurium (S. Typhimurium). Contrary to expectation, immunostaining revealed that infection with SPI2 T3SS-mutants resulted in significantly enlarged intraepithelial Salmonella-containing vacuoles (SCV) with altered cellular positioning, suggesting impaired apical to basolateral transmigration. Also, infection with isogenic tagged S. Typhimurium strains revealed a reduced spread of intraepithelial SPI2 T3SS mutant S. Typhimurium to systemic body sites. These results suggest that SPI2 T3SS effector molecules contribute to enterocyte apical to basolateral transmigration of the SCV during the early stage of the infection.
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Affiliation(s)
- Marcus Fulde
- Department of Veterinary Medicine, Freie Universität Berlin, Institute of Microbiology and Epizootics, Berlin, Germany,CONTACT Mathias Hornef Institute for Medical Microbiology; RWTH University Hospital; Pauwelsstr. 30, Aachen, D-52074, Germany
| | - Kira van Vorst
- Department of Veterinary Medicine, Freie Universität Berlin, Institute of Microbiology and Epizootics, Berlin, Germany
| | - Kaiyi Zhang
- Institute of Medical Microbiology, Rwth University Hospital Aachen, Aachen, Germany
| | - Alexander J. Westermann
- Institute of Molecular Infection Biology (IMIB), University of Würzburg, Würzburg, Germany,Helmholtz Institute for RNA-based Infection Research (HIRI), Helmholtz Centre for Infection Research (HZI), Würzburg, Germany
| | - Tobias Busche
- Technology Platform Genomics, Center for Biotechnology (Cebitec), Bielefeld University, Bielefeld, Germany
| | - Yong Chiun Huei
- Institute of Medical Microbiology, Rwth University Hospital Aachen, Aachen, Germany
| | - Katharina Welitschanski
- Hannover Medical School, Institute for Medical Microbiology and Hospital Epidemiology, Hannover, Germany
| | - Isabell Froh
- Hannover Medical School, Institute for Medical Microbiology and Hospital Epidemiology, Hannover, Germany
| | - Dennis Pägelow
- Department of Veterinary Medicine, Freie Universität Berlin, Institute of Microbiology and Epizootics, Berlin, Germany
| | - Johanna Plendl
- Department of Veterinary Medicine, Freie Universität Berlin, Institute of Veterinary Anatomy, Berlin, Germany
| | - Christiane Pfarrer
- Institute for Anatomy, University of Veterinary Medicine Hannover, Foundation, Hannover, Germany
| | - Jörn Kalinowski
- Technology Platform Genomics, Center for Biotechnology (Cebitec), Bielefeld University, Bielefeld, Germany
| | - Jörg Vogel
- Institute of Molecular Infection Biology (IMIB), University of Würzburg, Würzburg, Germany,Helmholtz Institute for RNA-based Infection Research (HIRI), Helmholtz Centre for Infection Research (HZI), Würzburg, Germany
| | - Peter Valentin-Weigand
- Institute of Microbiology, University of Veterinary Medicine Hannover, Foundation, Hannover, Germany
| | - Michael Hensel
- Division of Microbiology, University of Osnabrück, Osnabrück, Germany
| | - Karsten Tedin
- Department of Veterinary Medicine, Freie Universität Berlin, Institute of Microbiology and Epizootics, Berlin, Germany
| | - Urska Repnik
- Department of Biosciences, University of Oslo, Oslo, Norway
| | - Mathias W. Hornef
- Institute of Medical Microbiology, Rwth University Hospital Aachen, Aachen, Germany
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22
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Stabilization but no functional influence of HIF-1α expression in the intestinal epithelium during Salmonella Typhimurium infection. Infect Immun 2022; 90:e0022221. [PMID: 34978927 DOI: 10.1128/iai.00222-21] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The hypoxia-inducible transcription factor 1 (HIF-1) has been shown to enhance microbial killing and to ameliorate the course of bacterial infections. While the impact of HIF-1 on inflammatory diseases of the gut has been studied intensively, its function in bacterial infections of the gastrointestinal tract remains largely elusive. With the help of a publicly available gene expression data set, we could infer significant activation of HIF-1 after oral infection of mice with Salmonella Typhimurium. Immunohistochemistry and western blot analysis confirmed marked HIF-1α protein stabilization, especially in the intestinal epithelium. This prompted us to analyze conditional Hif1a-deficient mice to examine cell type-specific functions of HIF-1 in this model. Our results demonstrate enhanced non-canonical induction of HIF-1 activity upon Salmonella infection in the intestinal epithelium as well as in macrophages. Surprisingly, Hif1a deletion in intestinal epithelial cells did not impact on inflammatory gene expression, bacterial spread or disease outcome. In contrast, Hif1a deletion in myeloid cells enhanced intestinal Cxcl2 expression and reduced the cecal Salmonella load. In vitro, HIF-1α-deficient macrophages showed an overall impaired transcription of mRNA encoding pro-inflammatory factors, however, intracellular survival of Salmonella was not impacted by HIF-1α deficiency.
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23
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Raman V, Van Dessel N, Hall CL, Wetherby VE, Whitney SA, Kolewe EL, Bloom SMK, Sharma A, Hardy JA, Bollen M, Van Eynde A, Forbes NS. Intracellular delivery of protein drugs with an autonomously lysing bacterial system reduces tumor growth and metastases. Nat Commun 2021; 12:6116. [PMID: 34675204 PMCID: PMC8531320 DOI: 10.1038/s41467-021-26367-9] [Citation(s) in RCA: 55] [Impact Index Per Article: 18.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2020] [Accepted: 10/01/2021] [Indexed: 12/25/2022] Open
Abstract
Critical cancer pathways often cannot be targeted because of limited efficiency crossing cell membranes. Here we report the development of a Salmonella-based intracellular delivery system to address this challenge. We engineer genetic circuits that (1) activate the regulator flhDC to drive invasion and (2) induce lysis to release proteins into tumor cells. Released protein drugs diffuse from Salmonella containing vacuoles into the cellular cytoplasm where they interact with their therapeutic targets. Control of invasion with flhDC increases delivery over 500 times. The autonomous triggering of lysis after invasion makes the platform self-limiting and prevents drug release in healthy organs. Bacterial delivery of constitutively active caspase-3 blocks the growth of hepatocellular carcinoma and lung metastases, and increases survival in mice. This success in targeted killing of cancer cells provides critical evidence that this approach will be applicable to a wide range of protein drugs for the treatment of solid tumors.
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Affiliation(s)
- Vishnu Raman
- Department of Chemical Engineering, University of Massachusetts, Amherst, Amherst, MA, USA
- Ernest Pharmaceuticals, LLC, Hadley, MA, USA
| | - Nele Van Dessel
- Department of Chemical Engineering, University of Massachusetts, Amherst, Amherst, MA, USA
- Ernest Pharmaceuticals, LLC, Hadley, MA, USA
| | - Christopher L Hall
- Department of Chemical Engineering, University of Massachusetts, Amherst, Amherst, MA, USA
- Ernest Pharmaceuticals, LLC, Hadley, MA, USA
| | | | - Samantha A Whitney
- Department of Chemical Engineering, University of Massachusetts, Amherst, Amherst, MA, USA
| | - Emily L Kolewe
- Department of Chemical Engineering, University of Massachusetts, Amherst, Amherst, MA, USA
| | - Shoshana M K Bloom
- Department of Chemical Engineering, University of Massachusetts, Amherst, Amherst, MA, USA
| | - Abhinav Sharma
- Department of Chemical Engineering, University of Massachusetts, Amherst, Amherst, MA, USA
| | - Jeanne A Hardy
- Department of Chemistry, University of Massachusetts, Amherst, Amherst, MA, USA
- Molecular and Cell Biology Program, University of Massachusetts, Amherst, Amherst, MA, USA
- Institute for Applied Life Science, University of Massachusetts, Amherst, Amherst, MA, USA
| | - Mathieu Bollen
- Laboratory of Biosignaling & Therapeutics, Department of Cellular and Molecular Medicine, KU Leuven, Leuven, Belgium
| | - Aleyde Van Eynde
- Laboratory of Biosignaling & Therapeutics, Department of Cellular and Molecular Medicine, KU Leuven, Leuven, Belgium
| | - Neil S Forbes
- Department of Chemical Engineering, University of Massachusetts, Amherst, Amherst, MA, USA.
- Ernest Pharmaceuticals, LLC, Hadley, MA, USA.
- Molecular and Cell Biology Program, University of Massachusetts, Amherst, Amherst, MA, USA.
- Institute for Applied Life Science, University of Massachusetts, Amherst, Amherst, MA, USA.
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24
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Chen D, Burford WB, Pham G, Zhang L, Alto LT, Ertelt JM, Winter MG, Winter SE, Way SS, Alto NM. Systematic reconstruction of an effector-gene network reveals determinants of Salmonella cellular and tissue tropism. Cell Host Microbe 2021; 29:1531-1544.e9. [PMID: 34536347 DOI: 10.1016/j.chom.2021.08.012] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2020] [Revised: 06/24/2021] [Accepted: 08/20/2021] [Indexed: 11/17/2022]
Abstract
The minimal genetic requirements for microbes to survive within multiorganism communities, including host-pathogen interactions, remain poorly understood. Here, we combined targeted gene mutagenesis with phenotype-guided genetic reassembly to identify a cooperative network of SPI-2 T3SS effector genes that are sufficient for Salmonella Typhimurium (STm) to cause disease in a natural host organism. Five SPI-2 effector genes support pathogen survival within the host cell cytoplasm by coordinating bacterial replication with Salmonella-containing vacuole (SCV) division. Unexpectedly, this minimal genetic repertoire does not support STm systemic infection of mice. In vivo screening revealed a second effector-gene network, encoded by the spv operon, that expands the life cycle of STm from growth in cells to deep-tissue colonization in a murine model of typhoid fever. Comparison between Salmonella infection models suggests how cooperation between effector genes drives tissue tropism in a pathogen group.
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Affiliation(s)
- Didi Chen
- Department of Microbiology, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | - Wesley B Burford
- Department of Microbiology, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | - Giang Pham
- Division of Infectious Diseases, Center for Inflammation and Tolerance, Cincinnati Children's Hospital Medical Center, University of Cincinnati College of Medicine, Cincinnati, OH 45229, USA
| | - Lishu Zhang
- Department of Microbiology, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | - Laura T Alto
- Department of Microbiology, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | - James M Ertelt
- Division of Infectious Diseases, Center for Inflammation and Tolerance, Cincinnati Children's Hospital Medical Center, University of Cincinnati College of Medicine, Cincinnati, OH 45229, USA
| | - Maria G Winter
- Department of Microbiology, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | - Sebastian E Winter
- Department of Microbiology, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | - Sing Sing Way
- Division of Infectious Diseases, Center for Inflammation and Tolerance, Cincinnati Children's Hospital Medical Center, University of Cincinnati College of Medicine, Cincinnati, OH 45229, USA
| | - Neal M Alto
- Department of Microbiology, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA.
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25
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Fattinger SA, Sellin ME, Hardt WD. Salmonella effector driven invasion of the gut epithelium: breaking in and setting the house on fire. Curr Opin Microbiol 2021; 64:9-18. [PMID: 34492596 DOI: 10.1016/j.mib.2021.08.007] [Citation(s) in RCA: 32] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2021] [Revised: 08/10/2021] [Accepted: 08/17/2021] [Indexed: 12/15/2022]
Abstract
Salmonella Typhimurium (S.Tm) is a major cause of diarrheal disease. The invasion into intestinal epithelial cells (IECs) is a central step in the infection cycle. It is associated with gut inflammation and thought to benefit S.Tm proliferation also in the intestinal lumen. Importantly, it is still not entirely clear how inflammation is elicited and to which extent it links to IEC invasion efficiency in vivo. In this review, we summarize recent findings explaining IEC invasion by type-three-secretion-system-1 (TTSS-1) effector proteins and discuss their effects on invasion and gut inflammation. In non-polarized tissue culture cells, the TTSS-1 effectors (mainly SopB/E/E2) elicit large membrane ruffles fueling cooperative invasion, and can directly trigger pro-inflammatory signaling. By contrast, in the murine gut, we observe discreet-invasion (mainly via the TTSS-1 effector SipA) and a prominent pro-inflammatory role of the host?"s epithelial inflammasome(s), which sense pathogen associated molecular patterns (PAMPs). We discuss why it has remained a major challenge to tease apart direct and indirect inflammatory effects of TTSS-1 effectors and explain why further research will be needed to fully determine their inflammation-modulating role(s).
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Affiliation(s)
- Stefan A Fattinger
- Institute of Microbiology, Department of Biology, ETH Zurich, Zurich, Switzerland; Science for Life Laboratory, Department of Medical Biochemistry and Microbiology, Uppsala University, Uppsala, Sweden.
| | - Mikael E Sellin
- Science for Life Laboratory, Department of Medical Biochemistry and Microbiology, Uppsala University, Uppsala, Sweden.
| | - Wolf-Dietrich Hardt
- Institute of Microbiology, Department of Biology, ETH Zurich, Zurich, Switzerland.
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26
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Boddy KC, Zhu H, D'Costa VM, Xu C, Beyrakhova K, Cygler M, Grinstein S, Coyaud E, Laurent EMN, St-Germain J, Raught B, Brumell JH. Salmonella effector SopD promotes plasma membrane scission by inhibiting Rab10. Nat Commun 2021; 12:4707. [PMID: 34349110 PMCID: PMC8339009 DOI: 10.1038/s41467-021-24983-z] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2019] [Accepted: 07/16/2021] [Indexed: 12/17/2022] Open
Abstract
Salmonella utilizes translocated virulence proteins (termed effectors) to promote host cell invasion. The effector SopD contributes to invasion by promoting scission of the plasma membrane, generating Salmonella-containing vacuoles. SopD is expressed in all Salmonella lineages and plays important roles in animal models of infection, but its host cell targets are unknown. Here we show that SopD can bind to and inhibit the small GTPase Rab10, through a C-terminal GTPase activating protein (GAP) domain. During infection, Rab10 and its effectors MICAL-L1 and EHBP1 are recruited to invasion sites. By inhibiting Rab10, SopD promotes removal of Rab10 and recruitment of Dynamin-2 to drive scission of the plasma membrane. Together, our study uncovers an important role for Rab10 in regulating plasma membrane scission and identifies the mechanism used by a bacterial pathogen to manipulate this function during infection.
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Affiliation(s)
- Kirsten C Boddy
- Cell Biology Program, Hospital for Sick Children, Toronto, ON, Canada.,Institute of Medical Science, University of Toronto, Toronto, ON, Canada
| | - Hongxian Zhu
- Cell Biology Program, Hospital for Sick Children, Toronto, ON, Canada.,Department of Molecular Genetics, University of Toronto, Toronto, ON, Canada
| | - Vanessa M D'Costa
- Cell Biology Program, Hospital for Sick Children, Toronto, ON, Canada.,Department of Biochemistry, Microbiology and Immunology, University of Ottawa, Ottawa, ON, Canada.,Centre for Infection, Immunity and Inflammation, University of Ottawa, Ottawa, Canada
| | - Caishuang Xu
- Department of Biochemistry, Microbiology and Immunology, University of Saskatchewan, Saskatoon, SK, Canada
| | - Ksenia Beyrakhova
- Department of Biochemistry, Microbiology and Immunology, University of Saskatchewan, Saskatoon, SK, Canada
| | - Miroslaw Cygler
- Department of Biochemistry, Microbiology and Immunology, University of Saskatchewan, Saskatoon, SK, Canada
| | - Sergio Grinstein
- Cell Biology Program, Hospital for Sick Children, Toronto, ON, Canada.,Institute of Medical Science, University of Toronto, Toronto, ON, Canada.,Department of Biochemistry, University of Toronto, Toronto, ON, Canada
| | - Etienne Coyaud
- Princess Margaret Cancer Centre, University Health Network, Toronto, ON, Canada
| | - Estelle M N Laurent
- Princess Margaret Cancer Centre, University Health Network, Toronto, ON, Canada
| | - Jonathan St-Germain
- Princess Margaret Cancer Centre, University Health Network, Toronto, ON, Canada
| | - Brian Raught
- Princess Margaret Cancer Centre, University Health Network, Toronto, ON, Canada.,Department of Medical Biophysics, University of Toronto, Toronto, ON, Canada
| | - John H Brumell
- Cell Biology Program, Hospital for Sick Children, Toronto, ON, Canada. .,Institute of Medical Science, University of Toronto, Toronto, ON, Canada. .,Department of Molecular Genetics, University of Toronto, Toronto, ON, Canada. .,SickKids IBD Centre, Hospital for Sick Children, Toronto, ON, Canada.
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27
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ARHGEF26 enhances Salmonella invasion and inflammation in cells and mice. PLoS Pathog 2021; 17:e1009713. [PMID: 34242364 PMCID: PMC8294491 DOI: 10.1371/journal.ppat.1009713] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2020] [Revised: 07/21/2021] [Accepted: 06/14/2021] [Indexed: 11/25/2022] Open
Abstract
Salmonella hijack host machinery in order to invade cells and establish infection. While considerable work has described the role of host proteins in invasion, much less is known regarding how natural variation in these invasion-associated host proteins affects Salmonella pathogenesis. Here we leveraged a candidate cellular GWAS screen to identify natural genetic variation in the ARHGEF26 (Rho Guanine Nucleotide Exchange Factor 26) gene that renders lymphoblastoid cells susceptible to Salmonella Typhi and Typhimurium invasion. Experimental follow-up redefined ARHGEF26’s role in Salmonella epithelial cell infection. Specifically, we identified complex serovar-by-host interactions whereby ARHGEF26 stimulation of S. Typhi and S. Typhimurium invasion into host cells varied in magnitude and effector-dependence based on host cell type. While ARHGEF26 regulated SopB- and SopE-mediated S. Typhi (but not S. Typhimurium) infection of HeLa cells, the largest effect of ARHGEF26 was observed with S. Typhimurium in polarized MDCK cells through a SopB- and SopE2-independent mechanism. In both cell types, knockdown of the ARHGEF26-associated protein DLG1 resulted in a similar phenotype and serovar specificity. Importantly, we show that ARHGEF26 plays a critical role in S. Typhimurium pathogenesis by contributing to bacterial burden in the enteric fever murine model, as well as inflammation in the colitis infection model. In the enteric fever model, SopB and SopE2 are required for the effects of Arhgef26 deletion on bacterial burden, and the impact of sopB and sopE2 deletion in turn required ARHGEF26. In contrast, SopB and SopE2 were not required for the impacts of Arhgef26 deletion on colitis. A role for ARHGEF26 on inflammation was also seen in cells, as knockdown reduced IL-8 production in HeLa cells. Together, these data reveal pleiotropic roles for ARHGEF26 during infection and highlight that many of the interactions that occur during infection that are thought to be well understood likely have underappreciated complexity. During infection, Salmonella manipulates host cells into engulfing the bacteria and establishing an intracellular niche. While many studies have identified genes involved in different stages of this Salmonella invasion process, few studies have examined how differences between human hosts contribute to infection susceptibility. Here we leveraged a candidate genetic screen to identify natural genetic variation in the human ARHGEF26 gene that correlates with Salmonella invasion. Springboarding from this result, we experimentally tested and redefined ARHGEF26’s role in Salmonella invasion, discovered a new role for ARHGEF26 in regulating inflammation during Salmonella disease, and demonstrated the relevance of these findings in mouse models. Building on how ARHGEF26 functions in other contexts, we implicated two ARHGEF26-interacting host proteins as contributors to Salmonella pathobiology. Collectively, these results identify a potential source of inter-person diversity in susceptibility to Salmonella disease and expand our molecular understanding of Salmonella infection to include a multifaceted role for ARHGEF26. They further identify important future directions in understanding how Salmonella recruit and manipulate ARHGEF26 as well as how ARHGEF26 is able to drive Salmonella-beneficial processes.
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28
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Schultz BM, Melo-Gonzalez F, Salazar GA, Porto BN, Riedel CA, Kalergis AM, Bueno SM. New Insights on the Early Interaction Between Typhoid and Non-typhoid Salmonella Serovars and the Host Cells. Front Microbiol 2021; 12:647044. [PMID: 34276584 PMCID: PMC8282409 DOI: 10.3389/fmicb.2021.647044] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2020] [Accepted: 06/08/2021] [Indexed: 11/13/2022] Open
Abstract
Salmonella enterica is a common source of food and water-borne infections, causing a wide range of clinical ailments in both human and animal hosts. Immunity to Salmonella involves an interplay between different immune responses, which are rapidly initiated to control bacterial burden. However, Salmonella has developed several strategies to evade and modulate the host immune responses. In this sense, the main knowledge about the pathogenicity of this bacterium has been obtained by the study of mouse models with non-typhoidal serovars. However, this knowledge is not representative of all the pathologies caused by non-typhoidal serovars in the human. Here we review the most important features of typhoidal and non-typhoidal serovars and the diseases they cause in the human host, describing the virulence mechanisms used by these pathogens that have been identified in different models of infection.
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Affiliation(s)
- Bárbara M Schultz
- Departamento de Genética Molecular y Microbiología, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Santiago, Chile
| | - Felipe Melo-Gonzalez
- Departamento de Genética Molecular y Microbiología, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Santiago, Chile
| | - Geraldyne A Salazar
- Departamento de Genética Molecular y Microbiología, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Santiago, Chile
| | - Bárbara N Porto
- Laboratory of Clinical and Experimental Immunology, School of Medicine, Pontifical Catholic University of Rio Grande do Sul, Porto Alegre, Brazil.,Program in Translational Medicine, Hospital for Sick Children, Toronto, ON, Canada
| | - Claudia A Riedel
- Departamento de Ciencias Biológicas, Facultad de Ciencias de la Vida, Millennium Institute on Immunology and Immunotherapy, Universidad Andrés Bello, Santiago, Chile
| | - Alexis M Kalergis
- Departamento de Genética Molecular y Microbiología, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Santiago, Chile.,Departamento de Endocrinología, Facultad de Medicina, Pontificia Universidad Católica de Chile, Santiago, Chile
| | - Susan M Bueno
- Departamento de Genética Molecular y Microbiología, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Santiago, Chile
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29
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Riba A, Hassani K, Walker A, van Best N, von Zezschwitz D, Anslinger T, Sillner N, Rosenhain S, Eibach D, Maiga-Ascofaré O, Rolle-Kampczyk U, Basic M, Binz A, Mocek S, Sodeik B, Bauerfeind R, Mohs A, Trautwein C, Kiessling F, May J, Klingenspor M, Gremse F, Schmitt-Kopplin P, Bleich A, Torow N, von Bergen M, Hornef MW. Disturbed gut microbiota and bile homeostasis in Giardia-infected mice contributes to metabolic dysregulation and growth impairment. Sci Transl Med 2021; 12:12/565/eaay7019. [PMID: 33055245 DOI: 10.1126/scitranslmed.aay7019] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2019] [Revised: 01/06/2020] [Accepted: 05/11/2020] [Indexed: 12/11/2022]
Abstract
Although infection with the human enteropathogen Giardia lamblia causes self-limited diarrhea in adults, infant populations in endemic areas experience persistent pathogen carriage in the absence of diarrhea. The persistence of this protozoan parasite in infants has been associated with reduced weight gain and linear growth (height-for-age). The mechanisms that support persistent infection and determine the different disease outcomes in the infant host are incompletely understood. Using a neonatal mouse model of persistent G. lamblia infection, we demonstrate that G. lamblia induced bile secretion and used the bile constituent phosphatidylcholine as a substrate for parasite growth. In addition, we show that G. lamblia infection altered the enteric microbiota composition, leading to enhanced bile acid deconjugation and increased expression of fibroblast growth factor 15. This resulted in elevated energy expenditure and dysregulated lipid metabolism with reduced adipose tissue, body weight gain, and growth in the infected mice. Our results indicate that this enteropathogen's modulation of bile acid metabolism and lipid metabolism in the neonatal mouse host led to an altered body composition, suggesting how G. lamblia infection could contribute to growth restriction in infants in endemic areas.
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Affiliation(s)
- Ambre Riba
- Institute of Medical Microbiology, RWTH University Hospital, 52074 Aachen, Germany
| | - Kasra Hassani
- Institute of Medical Microbiology and Hospital Epidemiology, Hannover Medical School, 30625 Hannover, Germany
| | - Alesia Walker
- Research Unit Analytical BioGeoChemistry, Helmholtz Zentrum München, 85764 Neuherberg, Germany
| | - Niels van Best
- Institute of Medical Microbiology, RWTH University Hospital, 52074 Aachen, Germany.,Department of Medical Microbiology and NUTRIM, Maastricht University, Maastricht, Netherlands
| | - Dunja von Zezschwitz
- Institute of Medical Microbiology, RWTH University Hospital, 52074 Aachen, Germany
| | - Teresa Anslinger
- Institute of Medical Microbiology, RWTH University Hospital, 52074 Aachen, Germany
| | - Nina Sillner
- Research Unit Analytical BioGeoChemistry, Helmholtz Zentrum München, 85764 Neuherberg, Germany.,ZIEL Institute for Food and Health, Technical University of Munich, 85354 Freising, Germany
| | - Stefanie Rosenhain
- Institute for Experimental Molecular Imaging, University Hospital Aachen, 52074 Aachen, Germany
| | - Daniel Eibach
- Department of Infectious Disease Epidemiology, Bernhard Nocht Institute for Tropical Medicine, 20359 Hamburg, Germany
| | | | - Ulrike Rolle-Kampczyk
- Helmholtz Centre for Environmental Research, Department of Molecular Systems Biology, 04318 Leipzig, Germany
| | - Marijana Basic
- Institute for Laboratory Animal Science, Hannover Medical School, 30625 Hannover, Germany
| | - Anne Binz
- Institute of Virology, Hannover Medical School, 30625 Hannover, Germany
| | - Sabine Mocek
- Chair for Molecular Nutritional Medicine, School of Life Sciences, Technical University of Munich, 85354 Freising, Germany
| | - Beate Sodeik
- Institute of Virology, Hannover Medical School, 30625 Hannover, Germany
| | - Rudolf Bauerfeind
- Research Core Unit for Laser Microscopy, Hannover Medical School, 30625 Hannover, Germany
| | - Antje Mohs
- Medizinische Klinik III, RWTH University Hospital, Aachen, 52074 Aachen, Germany
| | - Christian Trautwein
- Medizinische Klinik III, RWTH University Hospital, Aachen, 52074 Aachen, Germany
| | - Fabian Kiessling
- Institute for Experimental Molecular Imaging, University Hospital Aachen, 52074 Aachen, Germany.,Helmholtz Institute for Biomedical Engineering, RWTH Aachen University, Aachen, Germany.,Fraunhofer Institute for Digital Medicine MEVIS, Bremen, Germany
| | - Jürgen May
- Department of Infectious Disease Epidemiology, Bernhard Nocht Institute for Tropical Medicine, 20359 Hamburg, Germany
| | - Martin Klingenspor
- Chair for Molecular Nutritional Medicine, School of Life Sciences, Technical University of Munich, 85354 Freising, Germany
| | - Felix Gremse
- Institute for Experimental Molecular Imaging, University Hospital Aachen, 52074 Aachen, Germany.,Software Tools for Computational Engineering, RWTH Aachen University, 52072 Aachen, Germany.,Gremse-IT GmbH, 52068 Aachen, Germany
| | - Philippe Schmitt-Kopplin
- Research Unit Analytical BioGeoChemistry, Helmholtz Zentrum München, 85764 Neuherberg, Germany.,ZIEL Institute for Food and Health, Technical University of Munich, 85354 Freising, Germany.,Analytical Food Chemistry, Technical University of Munich, 85354 Freising, Germany
| | - André Bleich
- Institute for Laboratory Animal Science, Hannover Medical School, 30625 Hannover, Germany
| | - Natalia Torow
- Institute of Medical Microbiology, RWTH University Hospital, 52074 Aachen, Germany
| | - Martin von Bergen
- Helmholtz Centre for Environmental Research, Department of Molecular Systems Biology, 04318 Leipzig, Germany.,Institute of Biochemistry, Faculty of Life Sciences, University of Leipzig, Bruderstrase 34, D-04103 Leipzig, Germany
| | - Mathias W Hornef
- Institute of Medical Microbiology, RWTH University Hospital, 52074 Aachen, Germany.
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Wagner C, Torow N, Hornef MW, Lelouard H. Spatial and temporal key steps in early-life intestinal immune system development and education. FEBS J 2021; 289:4731-4757. [PMID: 34076962 DOI: 10.1111/febs.16047] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2021] [Revised: 04/15/2021] [Accepted: 06/01/2021] [Indexed: 12/15/2022]
Abstract
Education of our intestinal immune system early in life strongly influences adult health. This education strongly relies on series of events that must occur in well-defined time windows. From initial colonization by maternal-derived microbiota during delivery to dietary changes from mother's milk to solid foods at weaning, these early-life events have indeed long-standing consequences on our immunity, facilitating tolerance to environmental exposures or, on the contrary, increasing the risk of developing noncommunicable diseases such as allergies, asthma, obesity, and inflammatory bowel diseases. In this review, we provide an outline of the recent advances in our understanding of these events and how they are mechanistically related to intestinal immunity development and education. First, we review the susceptibility of neonates to infections and inflammatory diseases, related to their immune system and microbiota changes. Then, we highlight the maternal factors involved in protection and education of the mucosal immune system of the offspring, the role of the microbiota, and the nature of neonatal immune system until weaning. We also present how the development of some immune responses is intertwined in temporal and spatial windows of opportunity. Finally, we discuss pending questions regarding the neonate particular immune status and the activation of the intestinal immune system at weaning.
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Affiliation(s)
- Camille Wagner
- Aix Marseille Univ, CNRS, INSERM, CIML, Marseille, France
| | - Natalia Torow
- Institute of Medical Microbiology, RWTH University Hospital, Aachen, Germany
| | - Mathias W Hornef
- Institute of Medical Microbiology, RWTH University Hospital, Aachen, Germany
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31
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Bacterial detection by NAIP/NLRC4 elicits prompt contractions of intestinal epithelial cell layers. Proc Natl Acad Sci U S A 2021; 118:2013963118. [PMID: 33846244 PMCID: PMC8072224 DOI: 10.1073/pnas.2013963118] [Citation(s) in RCA: 25] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
The gut epithelium serves to maximize the surface for nutrient and fluid uptake, but at the same time must provide a tight barrier to pathogens and remove damaged intestinal epithelial cells (IECs) without jeopardizing barrier integrity. How the epithelium coordinates these tasks remains a question of significant interest. We used imaging and an optical flow analysis pipeline to study the dynamicity of untransformed murine and human intestinal epithelia, cultured atop flexible hydrogel supports. Infection with the pathogen Salmonella Typhimurium (STm) within minutes elicited focal contractions with inward movements of up to ∼1,000 IECs. Genetics approaches and chimeric epithelial monolayers revealed contractions to be triggered by the NAIP/NLRC4 inflammasome, which sensed type-III secretion system and flagellar ligands upon bacterial invasion, converting the local tissue into a contraction epicenter. Execution of the response required swift sublytic Gasdermin D pore formation, ion fluxes, and the propagation of a myosin contraction pulse across the tissue. Importantly, focal contractions preceded, and could be uncoupled from, the death and expulsion of infected IECs. In both two-dimensional monolayers and three-dimensional enteroids, multiple infection-elicited contractions coalesced to produce shrinkage of the epithelium as a whole. Monolayers deficient for Caspase-1(-11) or Gasdermin D failed to elicit focal contractions but were still capable of infected IEC death and expulsion. Strikingly, these monolayers lost their integrity to a markedly higher extent than wild-type counterparts. We propose that prompt NAIP/NLRC4/Caspase-1/Gasdermin D/myosin-dependent contractions allow the epithelium to densify its cell packing in infected regions, thereby preventing tissue disintegration due to the subsequent IEC death and expulsion process.
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32
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Hotinger JA, Pendergrass HA, May AE. Molecular Targets and Strategies for Inhibition of the Bacterial Type III Secretion System (T3SS); Inhibitors Directly Binding to T3SS Components. Biomolecules 2021; 11:biom11020316. [PMID: 33669653 PMCID: PMC7922566 DOI: 10.3390/biom11020316] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2021] [Revised: 02/16/2021] [Accepted: 02/17/2021] [Indexed: 01/01/2023] Open
Abstract
The type III secretion system (T3SS) is a virulence apparatus used by many Gram-negative pathogenic bacteria to cause infections. Pathogens utilizing a T3SS are responsible for millions of infections yearly. Since many T3SS knockout strains are incapable of causing systemic infection, the T3SS has emerged as an attractive anti-virulence target for therapeutic design. The T3SS is a multiprotein molecular syringe that enables pathogens to inject effector proteins into host cells. These effectors modify host cell mechanisms in a variety of ways beneficial to the pathogen. Due to the T3SS’s complex nature, there are numerous ways in which it can be targeted. This review will be focused on the direct targeting of components of the T3SS, including the needle, translocon, basal body, sorting platform, and effector proteins. Inhibitors will be considered a direct inhibitor if they have a binding partner that is a T3SS component, regardless of the inhibitory effect being structural or functional.
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33
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Jiang L, Wang P, Song X, Zhang H, Ma S, Wang J, Li W, Lv R, Liu X, Ma S, Yan J, Zhou H, Huang D, Cheng Z, Yang C, Feng L, Wang L. Salmonella Typhimurium reprograms macrophage metabolism via T3SS effector SopE2 to promote intracellular replication and virulence. Nat Commun 2021; 12:879. [PMID: 33563986 PMCID: PMC7873081 DOI: 10.1038/s41467-021-21186-4] [Citation(s) in RCA: 60] [Impact Index Per Article: 20.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2020] [Accepted: 01/11/2021] [Indexed: 12/14/2022] Open
Abstract
Salmonella Typhimurium establishes systemic infection by replicating in host macrophages. Here we show that macrophages infected with S. Typhimurium exhibit upregulated glycolysis and decreased serine synthesis, leading to accumulation of glycolytic intermediates. The effects on serine synthesis are mediated by bacterial protein SopE2, a type III secretion system (T3SS) effector encoded in pathogenicity island SPI-1. The changes in host metabolism promote intracellular replication of S. Typhimurium via two mechanisms: decreased glucose levels lead to upregulated bacterial uptake of 2- and 3-phosphoglycerate and phosphoenolpyruvate (carbon sources), while increased pyruvate and lactate levels induce upregulation of another pathogenicity island, SPI-2, known to encode virulence factors. Pharmacological or genetic inhibition of host glycolysis, activation of host serine synthesis, or deletion of either the bacterial transport or signal sensor systems for those host glycolytic intermediates impairs S. Typhimurium replication or virulence. Salmonella Typhimurium establishes systemic infection by replicating in host macrophages. Here, Jiang et al. show that infected macrophages exhibit upregulated glycolysis and decreased serine synthesis, leading to accumulation of glycolytic intermediates that promote intracellular replication and virulence of S. Typhimurium.
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Affiliation(s)
- Lingyan Jiang
- The Key Laboratory of Molecular Microbiology and Technology, Ministry of Education, Nankai University, Tianjin, China.,TEDA Institute of Biological Sciences and Biotechnology, Tianjin Key Laboratory of Microbial Functional Genomics, Nankai University, Tianjin, China
| | - Peisheng Wang
- The Key Laboratory of Molecular Microbiology and Technology, Ministry of Education, Nankai University, Tianjin, China.,TEDA Institute of Biological Sciences and Biotechnology, Tianjin Key Laboratory of Microbial Functional Genomics, Nankai University, Tianjin, China
| | - Xiaorui Song
- The Key Laboratory of Molecular Microbiology and Technology, Ministry of Education, Nankai University, Tianjin, China.,TEDA Institute of Biological Sciences and Biotechnology, Tianjin Key Laboratory of Microbial Functional Genomics, Nankai University, Tianjin, China
| | - Huan Zhang
- The Key Laboratory of Molecular Microbiology and Technology, Ministry of Education, Nankai University, Tianjin, China.,TEDA Institute of Biological Sciences and Biotechnology, Tianjin Key Laboratory of Microbial Functional Genomics, Nankai University, Tianjin, China
| | - Shuangshuang Ma
- The Key Laboratory of Molecular Microbiology and Technology, Ministry of Education, Nankai University, Tianjin, China.,TEDA Institute of Biological Sciences and Biotechnology, Tianjin Key Laboratory of Microbial Functional Genomics, Nankai University, Tianjin, China
| | - Jingting Wang
- The Key Laboratory of Molecular Microbiology and Technology, Ministry of Education, Nankai University, Tianjin, China.,TEDA Institute of Biological Sciences and Biotechnology, Tianjin Key Laboratory of Microbial Functional Genomics, Nankai University, Tianjin, China
| | - Wanwu Li
- The Key Laboratory of Molecular Microbiology and Technology, Ministry of Education, Nankai University, Tianjin, China.,TEDA Institute of Biological Sciences and Biotechnology, Tianjin Key Laboratory of Microbial Functional Genomics, Nankai University, Tianjin, China
| | - Runxia Lv
- The Key Laboratory of Molecular Microbiology and Technology, Ministry of Education, Nankai University, Tianjin, China.,TEDA Institute of Biological Sciences and Biotechnology, Tianjin Key Laboratory of Microbial Functional Genomics, Nankai University, Tianjin, China
| | - Xiaoqian Liu
- The Key Laboratory of Molecular Microbiology and Technology, Ministry of Education, Nankai University, Tianjin, China.,TEDA Institute of Biological Sciences and Biotechnology, Tianjin Key Laboratory of Microbial Functional Genomics, Nankai University, Tianjin, China
| | - Shuai Ma
- The Key Laboratory of Molecular Microbiology and Technology, Ministry of Education, Nankai University, Tianjin, China.,TEDA Institute of Biological Sciences and Biotechnology, Tianjin Key Laboratory of Microbial Functional Genomics, Nankai University, Tianjin, China
| | - Jiaqi Yan
- College of Life Sciences, Nankai University, Tianjin, China
| | - Haiyan Zhou
- CAS-Key Laboratory of Synthetic Biology, CAS Center for Excellence in Molecular Plant Sciences, Shanghai Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai, China
| | - Di Huang
- The Key Laboratory of Molecular Microbiology and Technology, Ministry of Education, Nankai University, Tianjin, China.,TEDA Institute of Biological Sciences and Biotechnology, Tianjin Key Laboratory of Microbial Functional Genomics, Nankai University, Tianjin, China
| | - Zhihui Cheng
- The Key Laboratory of Molecular Microbiology and Technology, Ministry of Education, Nankai University, Tianjin, China.,College of Life Sciences, Nankai University, Tianjin, China
| | - Chen Yang
- CAS-Key Laboratory of Synthetic Biology, CAS Center for Excellence in Molecular Plant Sciences, Shanghai Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai, China
| | - Lu Feng
- The Key Laboratory of Molecular Microbiology and Technology, Ministry of Education, Nankai University, Tianjin, China. .,TEDA Institute of Biological Sciences and Biotechnology, Tianjin Key Laboratory of Microbial Functional Genomics, Nankai University, Tianjin, China.
| | - Lei Wang
- The Key Laboratory of Molecular Microbiology and Technology, Ministry of Education, Nankai University, Tianjin, China. .,TEDA Institute of Biological Sciences and Biotechnology, Tianjin Key Laboratory of Microbial Functional Genomics, Nankai University, Tianjin, China. .,The Institute of Translational Medicine Research, Tianjin Union Medical Center, Nankai University Affiliated Hospital, Nankai University, Tianjin, China.
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Salmonella enterica Serovar Typhimurium Exploits Cycling through Epithelial Cells To Colonize Human and Murine Enteroids. mBio 2021; 12:mBio.02684-20. [PMID: 33436434 PMCID: PMC7844539 DOI: 10.1128/mbio.02684-20] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Enterobacterial pathogens infect the gut by a multistep process, resulting in colonization of both the lumen and the mucosal epithelium. Due to experimental constraints, it remains challenging to address how luminal and epithelium-lodged pathogen populations cross-feed each other in vivo Enteroids are cultured three-dimensional miniature intestinal organs with a single layer of primary intestinal epithelial cells (IECs) surrounding a central lumen. They offer new opportunities to study enterobacterial infection under near-physiological conditions, at a temporal and spatial resolution not attainable in animal models, but remain poorly explored in this context. We employed microinjection, time-lapse microscopy, bacterial genetics, and barcoded consortium infections to describe the complete infection cycle of Salmonella enterica serovar Typhimurium in both human and murine enteroids. Flagellar motility and type III secretion system 1 (TTSS-1) promoted Salmonella Typhimurium targeting of the intraepithelial compartment and breaching of the epithelial barrier. Strikingly, however, TTSS-1 also potently boosted colonization of the enteroid lumen. By tracing the infection over time, we identified a cycle(s) of TTSS-1-driven IEC invasion, intraepithelial replication, and reemergence through infected IEC expulsion as a key mechanism for Salmonella Typhimurium luminal colonization. These findings suggest a positive feed-forward loop, through which IEC invasion by planktonic bacteria fuels further luminal population expansion, thereby ensuring efficient colonization of both the intraepithelial and luminal niches.IMPORTANCE Pathogenic gut bacteria are common causes of intestinal disease. Enteroids-cultured three-dimensional replicas of the mammalian gut-offer an emerging model system to study disease mechanisms under conditions that recapitulate key features of the intestinal tract. In this study, we describe the full life cycle of the prototype gut pathogen Salmonella enterica serovar Typhimurium within human and mouse enteroids. We map the consecutive steps and define the bacterial virulence factors that drive colonization of luminal and epithelial compartments, as well as breaching of the epithelial barrier. Strikingly, our work reveals how bacterial colonization of the epithelium potently fuels expansion also in the luminal compartment, through a mechanism involving the death and expulsion of bacterium-infected epithelial cells. These findings have repercussions for our understanding of the Salmonella infection cycle. Moreover, our work provides a comprehensive foundation for the use of microinjected enteroids to model gut bacterial diseases.
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Epithelium-autonomous NAIP/NLRC4 prevents TNF-driven inflammatory destruction of the gut epithelial barrier in Salmonella-infected mice. Mucosal Immunol 2021; 14:615-629. [PMID: 33731826 PMCID: PMC8075861 DOI: 10.1038/s41385-021-00381-y] [Citation(s) in RCA: 41] [Impact Index Per Article: 13.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2020] [Revised: 11/26/2020] [Accepted: 01/19/2021] [Indexed: 02/04/2023]
Abstract
The gut epithelium is a critical protective barrier. Its NAIP/NLRC4 inflammasome senses infection by Gram-negative bacteria, including Salmonella Typhimurium (S.Tm) and promotes expulsion of infected enterocytes. During the first ~12-24 h, this reduces mucosal S.Tm loads at the price of moderate enteropathy. It remained unknown how this NAIP/NLRC4-dependent tradeoff would develop during subsequent infection stages. In NAIP/NLRC4-deficient mice, S.Tm elicited severe enteropathy within 72 h, characterized by elevated mucosal TNF (>20 pg/mg) production from bone marrow-derived cells, reduced regeneration, excessive enterocyte loss, and a collapse of the epithelial barrier. TNF-depleting antibodies prevented this destructive pathology. In hosts proficient for epithelial NAIP/NLRC4, a heterogeneous enterocyte death response with both apoptotic and pyroptotic features kept S.Tm loads persistently in check, thereby preventing this dire outcome altogether. Our results demonstrate that immediate and selective removal of infected enterocytes, by locally acting epithelium-autonomous NAIP/NLRC4, is required to avoid a TNF-driven inflammatory hyper-reaction that otherwise destroys the epithelial barrier.
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36
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Tambassi M, Berni M, Bracchi C, Scaltriti E, Morganti M, Bolzoni L, Tanner JR, Thilliez G, Kingsley RA, Pongolini S, Casadei G. Mutation of hilD in a Salmonella Derby lineage linked to swine adaptation and reduced risk to human health. Sci Rep 2020; 10:21539. [PMID: 33299016 PMCID: PMC7726570 DOI: 10.1038/s41598-020-78443-7] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2020] [Accepted: 11/18/2020] [Indexed: 12/11/2022] Open
Abstract
AbstractSalmonella enterica variants exhibit diverse host adaptation, outcome of infection, and associated risk to food safety. Analysis of the distribution of Salmonella enterica serovar Derby (S. Derby) subtypes in human and swine identified isolates with a distinct PFGE profile that were significantly under-represented in human infections, consistent with further host adaptation to swine. Here we show that isolates with this PFGE profile form a distinct phylogenetic sub-clade within S. Derby and exhibit a profound reduction in invasion of human epithelial cells, and a relatively small reduction in swine epithelial cells. A single missense mutation in hilD, that encodes the master-regulator of the Salmonella Pathogenicity Island 1 (SPI-1), was present in the adapted lineage. The missense mutation resulted in a loss of function of HilD that accounted for reduced invasion in human epithelial cells. The relatively small impact of the mutation on interaction with swine cells was consistent with an alternative mechanism of invasion in this pathogen-host combination.
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37
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Fattinger SA, Sellin ME, Hardt WD. Epithelial inflammasomes in the defense against Salmonella gut infection. Curr Opin Microbiol 2020; 59:86-94. [PMID: 33128958 DOI: 10.1016/j.mib.2020.09.014] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2020] [Revised: 09/15/2020] [Accepted: 09/22/2020] [Indexed: 02/06/2023]
Abstract
The gut epithelium prevents bacterial access to the host's tissues and coordinates a number of mucosal defenses. Here, we review the function of epithelial inflammasomes in the infected host and focus on their role in defense against Salmonella Typhimurium. This pathogen employs flagella to swim towards the epithelium and a type III secretion system (TTSS) to dock and invade intestinal epithelial cells. Flagella and TTSS components are recognized by the canonical NAIP/NLRC4 inflammasome, while LPS activates the non-canonical Caspase-4/11 inflammasome. The relative contributions of these inflammasomes, the activated cell death pathways and the elicited mucosal defenses are subject to environmental control and appear to change along the infection trajectory. It will be an important future task to explain how this may enable defense against the challenges imposed by diverse bacterial enteropathogens.
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Affiliation(s)
- Stefan A Fattinger
- Institute of Microbiology, Department of Biology, ETH Zurich, Zurich, Switzerland; Science for Life Laboratory, Department of Medical Biochemistry and Microbiology, Uppsala University, Uppsala, Sweden
| | - Mikael E Sellin
- Science for Life Laboratory, Department of Medical Biochemistry and Microbiology, Uppsala University, Uppsala, Sweden
| | - Wolf-Dietrich Hardt
- Institute of Microbiology, Department of Biology, ETH Zurich, Zurich, Switzerland.
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38
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Kreuzer M, Hardt WD. How Food Affects Colonization Resistance Against Enteropathogenic Bacteria. Annu Rev Microbiol 2020; 74:787-813. [DOI: 10.1146/annurev-micro-020420-013457] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Food has a major impact on all aspects of health. Recent data suggest that food composition can also affect susceptibility to infections by enteropathogenic bacteria. Here, we discuss how food may alter the microbiota as well as mucosal defenses and how this can affect infection. Salmonella Typhimurium diarrhea serves as a paradigm, and complementary evidence comes from other pathogens. We discuss the effects of food composition on colonization resistance, host defenses, and the infection process as well as the merits and limitations of mouse models and experimental foods, which are available to decipher the underlying mechanisms.
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Affiliation(s)
- Markus Kreuzer
- Institute of Microbiology, Department of Biology, ETH Zurich, CH-8093 Zurich, Switzerland
| | - Wolf-Dietrich Hardt
- Institute of Microbiology, Department of Biology, ETH Zurich, CH-8093 Zurich, Switzerland
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Transposon Insertion Site Sequencing of Providencia stuartii: Essential Genes, Fitness Factors for Catheter-Associated Urinary Tract Infection, and the Impact of Polymicrobial Infection on Fitness Requirements. mSphere 2020; 5:5/3/e00412-20. [PMID: 32461277 PMCID: PMC7253602 DOI: 10.1128/msphere.00412-20] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Providencia stuartii is a common cause of polymicrobial catheter-associated urinary tract infection (CAUTI), and yet literature describing the molecular mechanisms of its pathogenesis is limited. To identify factors important for colonization during single-species infection and during polymicrobial infection with a common cocolonizer, Proteus mirabilis, we created a saturating library of ∼50,000 transposon mutants and conducted transposon insertion site sequencing (Tn-Seq) in a murine model of CAUTI. P. stuartii strain BE2467 carries 4,398 genes, 521 of which were identified as essential for growth in laboratory medium and therefore could not be assessed for contribution to infection. Using an input/output fold change cutoff value of 20 and P values of <0.05, 340 genes were identified as important for establishing single-species infection only and 63 genes as uniquely important for polymicrobial infection with P. mirabilis, and 168 genes contributed to both single-species and coinfection. Seven mutants were constructed for experimental validation of the primary screen that corresponded to flagella (fliC mutant), twin arginine translocation (tatC), an ATP-dependent protease (clpP), d-alanine-d-alanine ligase (ddlA), type 3 secretion (yscI and sopB), and type VI secretion (impJ). Infection-specific phenotypes validated 6/7 (86%) mutants during direct cochallenge with wild-type P. stuartii and 3/5 (60%) mutants during coinfection with P. mirabilis, for a combined validation rate of 9/12 (75%). Tn-Seq therefore successfully identified genes that contribute to fitness of P. stuartii within the urinary tract, determined the impact of coinfection on fitness requirements, and added to the identification of a collection of genes that may contribute to fitness of multiple urinary tract pathogens.IMPORTANCE Providencia stuartii is a common cause of polymicrobial catheter-associated urinary tract infections (CAUTIs), particularly during long-term catheterization. However, little is known regarding the pathogenesis of this organism. Using transposon insertion site sequencing (Tn-Seq), we performed a global assessment of P. stuartii fitness factors for CAUTI while simultaneously determining how coinfection with another pathogen alters fitness requirements. This approach provides four important contributions to the field: (i) the first global estimation of P. stuartii genes essential for growth in laboratory medium, (ii) identification of novel fitness factors for P. stuartii colonization of the catheterized urinary tract, (iii) identification of core fitness factors for both single-species and polymicrobial CAUTI, and (iv) assessment of conservation of fitness factors between common uropathogens. Genomewide assessment of the fitness requirements for common uropathogens during single-species and polymicrobial CAUTI thus elucidates complex interactions that contribute to disease severity and will uncover conserved targets for therapeutic intervention.
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40
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Fattinger SA, Böck D, Di Martino ML, Deuring S, Samperio Ventayol P, Ek V, Furter M, Kreibich S, Bosia F, Müller-Hauser AA, Nguyen BD, Rohde M, Pilhofer M, Hardt WD, Sellin ME. Salmonella Typhimurium discreet-invasion of the murine gut absorptive epithelium. PLoS Pathog 2020; 16:e1008503. [PMID: 32365138 PMCID: PMC7224572 DOI: 10.1371/journal.ppat.1008503] [Citation(s) in RCA: 32] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2020] [Revised: 05/14/2020] [Accepted: 03/26/2020] [Indexed: 01/15/2023] Open
Abstract
Salmonella enterica serovar Typhimurium (S.Tm) infections of cultured cell lines have given rise to the ruffle model for epithelial cell invasion. According to this model, the Type-Three-Secretion-System-1 (TTSS-1) effectors SopB, SopE and SopE2 drive an explosive actin nucleation cascade, resulting in large lamellipodia- and filopodia-containing ruffles and cooperative S.Tm uptake. However, cell line experiments poorly recapitulate many of the cell and tissue features encountered in the host’s gut mucosa. Here, we employed bacterial genetics and multiple imaging modalities to compare S.Tm invasion of cultured epithelial cell lines and the gut absorptive epithelium in vivo in mice. In contrast to the prevailing ruffle-model, we find that absorptive epithelial cell entry in the mouse gut occurs through “discreet-invasion”. This distinct entry mode requires the conserved TTSS-1 effector SipA, involves modest elongation of local microvilli in the absence of expansive ruffles, and does not favor cooperative invasion. Discreet-invasion preferentially targets apicolateral hot spots at cell–cell junctions and shows strong dependence on local cell neighborhood. This proof-of-principle evidence challenges the current model for how S.Tm can enter gut absorptive epithelial cells in their intact in vivo context. Bacterial pathogens can use secreted effector molecules to drive entry into host cells. Studies of the intestinal pathogen S.Tm have been central to uncover the mechanistic basis for the entry process. More than two decades of research have resulted in a detailed model for how S.Tm invades gut epithelial cells through effector triggering of large Rho-GTPase-dependent actin ruffles. However, the evidence for this model comes predominantly from studies in cultured cell lines. These experimental systems lack many of the architectural and signaling features of the intact gut epithelium. Our study surprisingly reveals that in the intact mouse gut, S.Tm invades absorptive epithelial cells through a process that does not require the Rho-GTPase-activating effectors and can proceed in the absence of the prototypical ruffling response. Instead, S.Tm exploits another effector, SipA, to sneak in through discreet entry structures close to cell–cell junctions. Our results challenge the current model for S.Tm epithelial cell entry and emphasizes the need of taking a physiological host cell context into account when studying bacterium–host cell interactions.
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Affiliation(s)
- Stefan A. Fattinger
- Institute of Microbiology, Department of Biology, ETH Zürich, Zürich, Switzerland
- Science for Life Laboratory, Department of Medical Biochemistry and Microbiology, Uppsala University, Uppsala, Sweden
| | - Desirée Böck
- Institute of Molecular Biology & Biophysics, Department of Biology, ETH Zürich, Zürich, Switzerland
| | - Maria Letizia Di Martino
- Science for Life Laboratory, Department of Medical Biochemistry and Microbiology, Uppsala University, Uppsala, Sweden
| | - Sabrina Deuring
- Institute of Microbiology, Department of Biology, ETH Zürich, Zürich, Switzerland
| | - Pilar Samperio Ventayol
- Science for Life Laboratory, Department of Medical Biochemistry and Microbiology, Uppsala University, Uppsala, Sweden
| | - Viktor Ek
- Science for Life Laboratory, Department of Medical Biochemistry and Microbiology, Uppsala University, Uppsala, Sweden
| | - Markus Furter
- Institute of Microbiology, Department of Biology, ETH Zürich, Zürich, Switzerland
| | - Saskia Kreibich
- Institute of Microbiology, Department of Biology, ETH Zürich, Zürich, Switzerland
| | - Francesco Bosia
- Institute of Molecular Biology & Biophysics, Department of Biology, ETH Zürich, Zürich, Switzerland
| | | | - Bidong D. Nguyen
- Institute of Microbiology, Department of Biology, ETH Zürich, Zürich, Switzerland
| | - Manfred Rohde
- Central Facility for Microscopy, Helmholtz Centre for Infection Research, Braunschweig, Germany
| | - Martin Pilhofer
- Institute of Molecular Biology & Biophysics, Department of Biology, ETH Zürich, Zürich, Switzerland
- * E-mail: (MP); (WDH); (MES)
| | - Wolf-Dietrich Hardt
- Institute of Microbiology, Department of Biology, ETH Zürich, Zürich, Switzerland
- * E-mail: (MP); (WDH); (MES)
| | - Mikael E. Sellin
- Institute of Microbiology, Department of Biology, ETH Zürich, Zürich, Switzerland
- Science for Life Laboratory, Department of Medical Biochemistry and Microbiology, Uppsala University, Uppsala, Sweden
- * E-mail: (MP); (WDH); (MES)
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Pan X, Luo J, Li S. Bacteria-Catalyzed Arginine Glycosylation in Pathogens and Host. Front Cell Infect Microbiol 2020; 10:185. [PMID: 32411621 PMCID: PMC7199390 DOI: 10.3389/fcimb.2020.00185] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2020] [Accepted: 04/07/2020] [Indexed: 01/25/2023] Open
Abstract
In recent years, protein glycosylation in pathogenic bacteria has attracted more and more attention, and accumulating evidence indicated that this type of posttranslational modification is involved in many physiological processes. The NleB from several enteropathogenic bacteria species as well as SseK from Salmonella enterica are type III secretion system effectors, which have an atypical N-acetylglucosamine (N-GlcNAc) transferase activity that specifically modified a conserved arginine in TRADD, FADD, and RIPK1. NleB/SseKs GlcNAcylation of death domain proteins abrogates homotypic and heterotypic death receptors/adaptors interactions, thereby blocking an important antimicrobial host response. Interestingly, NleB/SseKs could also GlcNAcylate themselves, and self-GlcNAcylation of NleB, SseK1, and SseK3 are crucial for their biological activity during infection. In addition, EarP (EF-P specific arginine rhamnosyl transferase for Posttranslational activation) catalyzes arginine rhamnosylation of translation elongation factor P (EF-P). Importantly, this kind of N-linked protein glycosylation is not only important for EF-P dependent rescue of polyproline stalled ribosomes but also for pathogenicity in Pseudomonas aeruginosa and other clinically relevant bacteria. Glycosylation of arginine is unique because the guanidine group of arginine has a high acid dissociation constant value and representing an extremely poor nucleophile. Recently, the crystal structures of NleB, SseKs, EarP, arginine GlcNAcylated death domain-containing proteins, NleB/FADD-DD, and EarP/EF-P/dTDP-β-L-rhamnose were solved by our group and other groups, revealing the unique catalytic mechanisms. In this review, we provide detailed information about the currently known arginine glycosyltransferases and their potential catalytic mechanisms.
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Affiliation(s)
- Xing Pan
- Institute of Infection and Immunity, Taihe Hospital, Hubei University of Medicine, Shiyan, China.,College of Biomedicine and Health, Huazhong Agricultural University, Wuhan, China.,College of Life Science and Technology, Huazhong Agricultural University, Wuhan, China
| | - Jie Luo
- Institute of Infection and Immunity, Taihe Hospital, Hubei University of Medicine, Shiyan, China
| | - Shan Li
- Institute of Infection and Immunity, Taihe Hospital, Hubei University of Medicine, Shiyan, China.,College of Biomedicine and Health, Huazhong Agricultural University, Wuhan, China.,College of Life Science and Technology, Huazhong Agricultural University, Wuhan, China
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42
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Factors Required for Adhesion of Salmonella enterica Serovar Typhimurium to Corn Salad (Valerianella locusta). Appl Environ Microbiol 2020; 86:AEM.02757-19. [PMID: 32033951 DOI: 10.1128/aem.02757-19] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2019] [Accepted: 02/04/2020] [Indexed: 11/20/2022] Open
Abstract
Salmonella enterica is a foodborne pathogen often leading to gastroenteritis and is commonly acquired by consumption of contaminated food of animal origin. However, frequency of outbreaks linked to the consumption of fresh or minimally processed food of nonanimal origin is increasing. New infection routes of S. enterica by vegetables, fruits, nuts, and herbs have to be considered. This leads to special interest in S. enterica interactions with leafy products, e.g., salads, that are mainly consumed in a minimally processed form. The attachment of S. enterica to salad is a crucial step in contamination, but little is known about the bacterial factors required and mechanisms of adhesion. S. enterica possesses a complex set of adhesive structures whose functions are only partly understood. Potentially, S. enterica may deploy multiple adhesive strategies for adhering to various salad species and other vegetables. In this study, we systematically analyzed the contributions of the complete adhesiome, of lipopolysaccharide (LPS), and of flagellum-mediated motility of S. enterica serovar Typhimurium (STM) in adhesion to Valerianella locusta (corn salad). We deployed a reductionist, synthetic approach to identify factors involved in the surface binding of STM to leaves of corn salad, with particular regard to the expression of all known adhesive structures, using the Tet-on system. This work reveals the contribution of Saf fimbriae, type 1 secretion system-secreted BapA, an intact LPS, and flagellum-mediated motility of STM in adhesion to corn salad leaves.IMPORTANCE Transmission of gastrointestinal pathogens by contaminated fresh produce is of increasing relevance to human health. However, the mechanisms of contamination of, persistence on, and transmission by fresh produce are poorly understood. We investigated the contributions of the various adhesive structures of STM to the initial event in transmission, i.e., binding to the plant surface. A reductionist system was used that allowed experimentally controlled surface expression of individual adhesive structures and analyses of the contribution to binding to leave surfaces of corn salad under laboratory conditions. The model system allowed the determination of the relative contributions of fimbrial and nonfimbrial adhesins, the type 3 secretion systems, the O antigen of lipopolysaccharide, the flagella, and chemotaxis of STM to binding to corn salad leaves. Based on these data, future work could reveal the mechanism of binding and the relevance of interaction under agricultural conditions.
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43
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Wang M, Qazi IH, Wang L, Zhou G, Han H. Salmonella Virulence and Immune Escape. Microorganisms 2020; 8:microorganisms8030407. [PMID: 32183199 PMCID: PMC7143636 DOI: 10.3390/microorganisms8030407] [Citation(s) in RCA: 48] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2020] [Revised: 03/02/2020] [Accepted: 03/10/2020] [Indexed: 02/07/2023] Open
Abstract
Salmonella genus represents the most common foodborne pathogens causing morbidity, mortality, and burden of disease in all regions of the world. The introduction of antimicrobial agents and Salmonella-specific phages has been considered as an effective intervention strategy to reduce Salmonella contamination. However, data from the United States, European countries, and low- and middle-income countries indicate that Salmonella cases are still a commonly encountered cause of bacterial foodborne diseases globally. The control programs have not been successful and even led to the emergence of some multidrug-resistant Salmonella strains. It is known that the host immune system is able to effectively prevent microbial invasion and eliminate microorganisms. However, Salmonella has evolved mechanisms of resisting host physical barriers and inhibiting subsequent activation of immune response through their virulence factors. There has been a high interest in understanding how Salmonella interacts with the host. Therefore, in the present review, we characterize the functions of Salmonella virulence genes and particularly focus on the mechanisms of immune escape in light of evidence from the emerging mainstream literature.
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Affiliation(s)
- Mengyao Wang
- Beijing Key Laboratory for Animal Genetic Improvement, College of Animal Science and Technology, China Agricultural University, Beijing 100193, China; (M.W.); (L.W.)
- Key Laboratory of Animal Genetics and Breeding of the Ministry of Agriculture, College of Animal Science and Technology, China Agricultural University, Beijing 100193, China
| | - Izhar Hyder Qazi
- Farm Animal Genetic Resources Exploration and Innovation Key Laboratory of Sichuan Province, College of Animal Science and Technology, Sichuan Agricultural University, Chengdu 611130, China;
- Department of Veterinary Anatomy and Histology, Shaheed Benazir Bhutto University of Veterinary and Animal Sciences, Sakrand 67210, Pakistan
| | - Linli Wang
- Beijing Key Laboratory for Animal Genetic Improvement, College of Animal Science and Technology, China Agricultural University, Beijing 100193, China; (M.W.); (L.W.)
- Key Laboratory of Animal Genetics and Breeding of the Ministry of Agriculture, College of Animal Science and Technology, China Agricultural University, Beijing 100193, China
| | - Guangbin Zhou
- Farm Animal Genetic Resources Exploration and Innovation Key Laboratory of Sichuan Province, College of Animal Science and Technology, Sichuan Agricultural University, Chengdu 611130, China;
- Correspondence: (H.H.); (G.Z.)
| | - Hongbing Han
- Beijing Key Laboratory for Animal Genetic Improvement, College of Animal Science and Technology, China Agricultural University, Beijing 100193, China; (M.W.); (L.W.)
- Key Laboratory of Animal Genetics and Breeding of the Ministry of Agriculture, College of Animal Science and Technology, China Agricultural University, Beijing 100193, China
- Correspondence: (H.H.); (G.Z.)
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44
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Röder J, Hensel M. Presence of SopE and mode of infection result in increased
Salmonella
‐containing vacuole damage and cytosolic release during host cell infection by
Salmonella enterica. Cell Microbiol 2020; 22:e13155. [DOI: 10.1111/cmi.13155] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2019] [Revised: 12/15/2019] [Accepted: 12/16/2019] [Indexed: 12/21/2022]
Affiliation(s)
- Jennifer Röder
- Abteilung MikrobiologieUniversitat Osnabruck Osnabrück Germany
| | - Michael Hensel
- Abteilung MikrobiologieUniversitat Osnabruck Osnabrück Germany
- CellNanOs – Center for Cellular Nanoanalytics, Fachbereich Biologie/ChemieUniversität Osnabrück Osnabrück Germany
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45
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Karlinsey JE, Stepien TA, Mayho M, Singletary LA, Bingham-Ramos LK, Brehm MA, Greiner DL, Shultz LD, Gallagher LA, Bawn M, Kingsley RA, Libby SJ, Fang FC. Genome-wide Analysis of Salmonella enterica serovar Typhi in Humanized Mice Reveals Key Virulence Features. Cell Host Microbe 2019; 26:426-434.e6. [PMID: 31447308 DOI: 10.1016/j.chom.2019.08.001] [Citation(s) in RCA: 29] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2019] [Revised: 07/03/2019] [Accepted: 07/31/2019] [Indexed: 11/29/2022]
Abstract
Salmonella enterica serovar Typhi causes typhoid fever only in humans. Murine infection with S. Typhimurium is used as a typhoid model, but its relevance to human typhoid is limited. Non-obese diabetic-scid IL2rγnull mice engrafted with human hematopoietic stem cells (hu-SRC-SCID) are susceptible to lethal S. Typhi infection. In this study, we use a high-density S. Typhi transposon library in hu-SRC-SCID mice to identify virulence loci using transposon-directed insertion site sequencing (TraDIS). Vi capsule, lipopolysaccharide (LPS), and aromatic amino acid biosynthesis were essential for virulence, along with the siderophore salmochelin. However, in contrast to the murine S. Typhimurium model, neither the PhoPQ two-component system nor the SPI-2 pathogenicity island was required for lethal S. Typhi infection, nor was the CdtB typhoid toxin. These observations highlight major differences in the pathogenesis of typhoid and non-typhoidal Salmonella infections and demonstrate the utility of humanized mice for understanding the pathogenesis of a human-specific pathogen.
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Affiliation(s)
- Joyce E Karlinsey
- Department of Microbiology, University of Washington, Seattle, WA 98195, USA
| | - Taylor A Stepien
- Department of Global Health, University of Washington, Seattle, WA 98195, USA
| | | | | | | | - Michael A Brehm
- Program in Molecular Medicine and the Diabetes Center of Excellence, University of Massachusetts Medical School, Worcester, MA 01605, USA
| | - Dale L Greiner
- Program in Molecular Medicine and the Diabetes Center of Excellence, University of Massachusetts Medical School, Worcester, MA 01605, USA
| | | | - Larry A Gallagher
- Department of Genome Sciences, School of Medicine, University of Washington, Seattle, WA 98195, USA
| | - Matt Bawn
- Quadram Institute Bioscience, Norwich, UK; Earlham Institute, Norwich, UK
| | - Robert A Kingsley
- Quadram Institute Bioscience, Norwich, UK; School of Biological Science, University of East Anglia, Norwich, UK
| | - Stephen J Libby
- Department of Laboratory Medicine, University of Washington, Seattle, WA 98195, USA
| | - Ferric C Fang
- Department of Microbiology, University of Washington, Seattle, WA 98195, USA; Department of Global Health, University of Washington, Seattle, WA 98195, USA; Department of Laboratory Medicine, University of Washington, Seattle, WA 98195, USA.
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46
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Chong A, Starr T, Finn CE, Steele-Mortimer O. A role for the Salmonella Type III Secretion System 1 in bacterial adaptation to the cytosol of epithelial cells. Mol Microbiol 2019; 112:1270-1283. [PMID: 31370104 DOI: 10.1111/mmi.14361] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/29/2019] [Indexed: 12/15/2022]
Abstract
Salmonella enterica serovar Typhimurium is a facultative intracellular pathogen that invades the intestinal epithelium. Following invasion of epithelial cells, Salmonella survives and replicates within two distinct intracellular niches. While all of the bacteria are initially taken up into a membrane bound vacuole, the Salmonella-containing vacuole or SCV, a significant proportion of them promptly escape into the cytosol. Cytosolic Salmonella replicates more rapidly compared to the vacuolar population, although the reasons for this are not well understood. SipA, a multi-function effector protein, has been shown to affect intracellular replication and is secreted by cytosolic Salmonella via the invasion-associated Type III Secretion System 1 (T3SS1). Here, we have used a multipronged microscopy approach to show that SipA does not affect bacterial replication rates per se, but rather mediates intra-cytosolic survival and/or initiation of replication following bacterial egress from the SCV. Altogether, our findings reveal an important role for SipA in the early survival of cytosolic Salmonella.
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Affiliation(s)
- Audrey Chong
- Laboratory of Bacteriology, Rocky Mountain Laboratories, National Institutes of Allergy and Infectious Diseases, National Institutes of Health, Hamilton, MT, USA
| | - Tregei Starr
- Laboratory of Bacteriology, Rocky Mountain Laboratories, National Institutes of Allergy and Infectious Diseases, National Institutes of Health, Hamilton, MT, USA
| | - Ciaran E Finn
- Laboratory of Bacteriology, Rocky Mountain Laboratories, National Institutes of Allergy and Infectious Diseases, National Institutes of Health, Hamilton, MT, USA
| | - Olivia Steele-Mortimer
- Laboratory of Bacteriology, Rocky Mountain Laboratories, National Institutes of Allergy and Infectious Diseases, National Institutes of Health, Hamilton, MT, USA
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47
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Lou L, Zhang P, Piao R, Wang Y. Salmonella Pathogenicity Island 1 (SPI-1) and Its Complex Regulatory Network. Front Cell Infect Microbiol 2019; 9:270. [PMID: 31428589 PMCID: PMC6689963 DOI: 10.3389/fcimb.2019.00270] [Citation(s) in RCA: 153] [Impact Index Per Article: 30.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2019] [Accepted: 07/12/2019] [Indexed: 11/30/2022] Open
Abstract
Salmonella species can infect a diverse range of birds, reptiles, and mammals, including humans. The type III protein secretion system (T3SS) encoded by Salmonella pathogenicity island 1 (SPI-1) delivers effector proteins required for intestinal invasion and the production of enteritis. The T3SS is regarded as the most important virulence factor of Salmonella. SPI-1 encodes transcription factors that regulate the expression of some virulence factors of Salmonella, while other transcription factors encoded outside SPI-1 participate in the expression of SPI-1-encoded genes. SPI-1 genes are responsible for the invasion of host cells, regulation of the host immune response, e.g., the host inflammatory response, immune cell recruitment and apoptosis, and biofilm formation. The regulatory network of SPI-1 is very complex and crucial. Here, we review the function, effectors, and regulation of SPI-1 genes and their contribution to the pathogenicity of Salmonella.
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Affiliation(s)
- Lixin Lou
- Department of Infectious Diseases, First Hospital of Jilin University, Changchun, China
| | - Peng Zhang
- Department of Infectious Diseases, First Hospital of Jilin University, Changchun, China.,Department of Pediatrics, University of Oklahoma Health Sciences Center, Oklahoma City, OK, United States
| | - Rongli Piao
- Department of Pediatrics, University of Oklahoma Health Sciences Center, Oklahoma City, OK, United States.,Department of Gastroenterology, First Hospital of Jilin University, Changchun, China
| | - Yang Wang
- Department of Infectious Diseases, First Hospital of Jilin University, Changchun, China.,Department of Pediatrics, University of Oklahoma Health Sciences Center, Oklahoma City, OK, United States
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48
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Wemyss MA, Pearson JS. Host Cell Death Responses to Non-typhoidal Salmonella Infection. Front Immunol 2019; 10:1758. [PMID: 31402916 PMCID: PMC6676415 DOI: 10.3389/fimmu.2019.01758] [Citation(s) in RCA: 44] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2019] [Accepted: 07/11/2019] [Indexed: 12/20/2022] Open
Abstract
Salmonella enterica subsp. enterica serovar Typhimurium (S. Typhimurium) is a Gram-negative bacterium with a broad host range that causes non-typhoidal salmonellosis in humans. S. Typhimurium infects epithelial cells and macrophages in the small intestine where it replicates in a specialized intracellular niche called the Salmonella-containing vacuole (SCV) and promotes inflammation of the mucosa to induce typically self-limiting gastroenteritis. Virulence and spread of the bacterium is determined in part by the host individual's ability to limit the infection through innate immune responses at the gastrointestinal mucosa, including programmed cell death. S. Typhimurium however, has evolved a myriad of mechanisms to counteract or exploit host responses through the use of Type III Secretion Systems (T3SS), which allow the translocation of virulence (effector) proteins into the host cell for the benefit of optimal bacterial replication and dissemination. T3SS effectors have been found to interact with apoptotic, necroptotic, and pyroptotic cell death cascades, interfering with both efficient clearance of the bacteria and the recruitment of neutrophils or dendritic cells to the area of infection. The interplay of host inflammation, programmed cell death responses, and bacterial defenses in the context of non-typhoidal Salmonella (NTS) infection is a continuing area of interest within the field, and as such has been reviewed here.
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Affiliation(s)
- Madeleine A Wemyss
- Department of Molecular and Translational Research, Monash University, Clayton, VIC, Australia.,Department of Microbiology, Monash University, Clayton, VIC, Australia
| | - Jaclyn S Pearson
- Department of Molecular and Translational Research, Monash University, Clayton, VIC, Australia.,Department of Microbiology, Monash University, Clayton, VIC, Australia
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49
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Self-Labeling Enzyme Tags for Analyses of Translocation of Type III Secretion System Effector Proteins. mBio 2019; 10:mBio.00769-19. [PMID: 31239375 PMCID: PMC6593401 DOI: 10.1128/mbio.00769-19] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Type III secretion systems (T3SS) are molecular machines in Gram-negative pathogens that translocate effector proteins with central roles in virulence. The analyses of the translocation, subcellular localization, and mode of action of T3SS effector proteins are of central importance for the understanding of host-pathogen interaction and pathogenesis of bacterial infections. The analysis of translocation requires dedicated techniques to address the temporal and spatial dynamics of translocation. Here we describe a novel approach to deploy self-labeling enzymes (SLE) as universal tags for localization and tracking of translocated effector proteins. Effector-SLE fusion proteins allow live-cell imaging of translocation by T3SS, superresolution microscopy, and single-molecule tracking of effector motility in living host cells. We describe the application of the approach to T3SS effector proteins for invasion and intracellular lifestyle of Salmonella enterica serovar Typhimurium and to a T3SS effector of Yersinia enterocolitica The novel approach enables analyses of the role of T3SS in host-pathogen interaction at the highest temporal and spatial resolution, toward understanding the molecular mechanisms of their effector proteins.IMPORTANCE Type III secretion systems mediate translocation of effector proteins into mammalian cells. These proteins interfere with host cell functions, being main virulence factors of Gram-negative pathogens. Analyses of the process of translocation, the subcellular distribution, and the dynamics of effector proteins in host cells have been hampered by the lack of suitable tags and detection systems. Here we describe the use of self-labeling enzyme tags for generation of fusions with effector proteins that are translocated and functional in host cell manipulation. Self-labeling reactions with cell-permeable ligand dyes are possible prior to or after translocation. We applied the new approach to superresolution microscopy for effector protein translocation. For the first time, we show the dynamic properties of effector proteins in living host cells after translocation by intracellular bacteria. The new approach of self-labeling enzyme tags fusions will enable analyses of type III secretion system effector proteins with new dimensions of temporal and spatial resolution.
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50
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Alghoribi MF, Doumith M, Alrodayyan M, Al Zayer M, Köster WL, Muhanna A, Aljohani SM, Balkhy HH, Desin TS. S. Enteritidis and S. Typhimurium Harboring SPI-1 and SPI-2 Are the Predominant Serotypes Associated With Human Salmonellosis in Saudi Arabia. Front Cell Infect Microbiol 2019; 9:187. [PMID: 31214517 PMCID: PMC6554431 DOI: 10.3389/fcimb.2019.00187] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2019] [Accepted: 05/15/2019] [Indexed: 12/25/2022] Open
Abstract
Non-typhoidal Salmonella (NTS) strains are Gram negative bacterial pathogens that are associated with foodborne illness worldwide. During the process of infection, Salmonella uses two molecular injectisomes known as Type 3 Secretion Systems (T3SS) to secrete virulence factors that are encoded by Salmonella Pathogenicity Island-1 (SPI-1) and SPI-2 into host cells. These secretion systems play a major role in virulence, as shown in various animal models, but little is known about their role in human infections. In Saudi Arabia, NTS strains frequently cause human infections but data regarding these pathogenic strains is fairly limited. The aim of this study was to characterize Salmonella human clinical isolates in Riyadh, Saudi Arabia, by determining their serotype, testing for the presence of SPI-1 and SPI-2 genes and to determine the antibiotic resistance profiles of these strains. Using the rapid Check and Trace Salmonella™ (CTS) system our results demonstrate that S. Enteritidis and S. Typhimurium were the predominant serovars, followed by S. Livingstone, S. Kentucky and S. Poona among a list of 36 serovars reported for the first time in the country. In addition, SPI-1 genes were detected in 99% of the isolates, while the sifA gene (SPI-2) was not detected in 13.5% of the isolates. These results suggest that both the SPI-1 and SPI-2 virulence determinants are important for human infection. Moreover, we report the presence of a Multi-Drug (MDR) carbapenem resistant S. Kentucky isolate harboring the blaOXA−48 gene not reported previously in Saudi Arabia.
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Affiliation(s)
- Majed F Alghoribi
- King Saud Bin Abdulaziz University for Health Sciences, Riyadh, Saudi Arabia.,Infectious Diseases Research Department, King Abdullah International Medical Research Center, Riyadh, Saudi Arabia
| | - Michel Doumith
- King Saud Bin Abdulaziz University for Health Sciences, Riyadh, Saudi Arabia.,Infectious Diseases Research Department, King Abdullah International Medical Research Center, Riyadh, Saudi Arabia
| | - Maha Alrodayyan
- King Saud Bin Abdulaziz University for Health Sciences, Riyadh, Saudi Arabia.,Infectious Diseases Research Department, King Abdullah International Medical Research Center, Riyadh, Saudi Arabia
| | - Maha Al Zayer
- King Saud Bin Abdulaziz University for Health Sciences, Riyadh, Saudi Arabia.,Infectious Diseases Research Department, King Abdullah International Medical Research Center, Riyadh, Saudi Arabia
| | - Wolfgang L Köster
- Vaccine and Infectious Disease Organization-International Vaccine Center, University of Saskatchewan, Saskatoon, SK, Canada
| | - Abdulhai Muhanna
- John H. Stroger Junior Hospital of Cook County, Chicago, IL, United States
| | - Sameera M Aljohani
- King Saud Bin Abdulaziz University for Health Sciences, Riyadh, Saudi Arabia.,Infectious Diseases Research Department, King Abdullah International Medical Research Center, Riyadh, Saudi Arabia.,Ministry of National Guard-Health Affairs, Riyadh, Saudi Arabia
| | - Hanan H Balkhy
- King Saud Bin Abdulaziz University for Health Sciences, Riyadh, Saudi Arabia.,Infectious Diseases Research Department, King Abdullah International Medical Research Center, Riyadh, Saudi Arabia.,Ministry of National Guard-Health Affairs, Riyadh, Saudi Arabia
| | - Taseen S Desin
- King Saud Bin Abdulaziz University for Health Sciences, Riyadh, Saudi Arabia.,Infectious Diseases Research Department, King Abdullah International Medical Research Center, Riyadh, Saudi Arabia
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