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Ling J, Hryckowian AJ. Re-framing the importance of Group B Streptococcus as a gut-resident pathobiont. Infect Immun 2024; 92:e0047823. [PMID: 38436256 PMCID: PMC11392526 DOI: 10.1128/iai.00478-23] [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] [Indexed: 03/05/2024] Open
Abstract
Streptococcus agalactiae (Group B Streptococcus, GBS) is a Gram-positive bacterial species that causes disease in humans across the lifespan. While antibiotics are used to mitigate GBS infections, it is evident that antibiotics disrupt human microbiomes (which can predispose people to other diseases later in life), and antibiotic resistance in GBS is on the rise. Taken together, these unintended negative impacts of antibiotics highlight the need for precision approaches for minimizing GBS disease. One possible approach involves selectively depleting GBS in its commensal niches before it can cause disease at other body sites or be transmitted to at-risk individuals. One understudied commensal niche of GBS is the adult gastrointestinal (GI) tract, which may predispose colonization at other body sites in individuals at risk for GBS disease. However, a better understanding of the host-, microbiome-, and GBS-determined variables that dictate GBS GI carriage is needed before precise GI decolonization approaches can be developed. In this review, we synthesize current knowledge of the diverse body sites occupied by GBS as a pathogen and as a commensal. We summarize key molecular factors GBS utilizes to colonize different host-associated niches to inform future efforts to study GBS in the GI tract. We also discuss other GI commensals that are pathogenic in other body sites to emphasize the broader utility of precise de-colonization approaches for mitigating infections by GBS and other bacterial pathogens. Finally, we highlight how GBS treatments could be improved with a more holistic understanding of GBS enabled by continued GI-focused study.
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Affiliation(s)
- Joie Ling
- Department of Medicine, Division of Gastroenterology and Hepatology, University of Wisconsin School of Medicine and Public Health, Madison, Wisconsin, USA
- Department of Medical Microbiology and Immunology, University of Wisconsin School of Medicine and Public Healthon, Madison, Wisconsin, USA
- Microbiology Doctoral Training Program, University of Wisconsin-Madison, Madison, Wisconsin, USA
| | - Andrew J Hryckowian
- Department of Medicine, Division of Gastroenterology and Hepatology, University of Wisconsin School of Medicine and Public Health, Madison, Wisconsin, USA
- Department of Medical Microbiology and Immunology, University of Wisconsin School of Medicine and Public Healthon, Madison, Wisconsin, USA
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2
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Pellegrini A, Motta C, Bellan Menegussi E, Pierangelini A, Viglio S, Coppolino F, Beninati C, De Filippis V, Barbieri G, Pietrocola G. The serine-rich repeat glycoprotein Srr2 mediates Streptococcus agalactiae interaction with host fibronectin. BMC Microbiol 2024; 24:221. [PMID: 38909237 PMCID: PMC11193222 DOI: 10.1186/s12866-024-03374-6] [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: 02/29/2024] [Accepted: 06/17/2024] [Indexed: 06/24/2024] Open
Abstract
BACKGROUND Group B Streptococcus (GBS) is a commensal of healthy adults and an important pathogen in newborns, the elderly and immunocompromised individuals. GBS displays several virulence factors that promote colonisation and host infection, including the ST-17 strain-specific adhesin Srr2, previously characterised for its binding to fibrinogen. Another common target for bacterial adhesins and for host colonization is fibronectin, a multi-domain glycoprotein found ubiquitously in body fluids, in the extracellular matrix and on the surface of cells. RESULTS In this study, fibronectin was identified as a novel ligand for the Srr2 adhesin of GBS. A derivative of the ST-17 strain BM110 overexpressing the srr2 gene showed an increased ability to bind fibrinogen and fibronectin, compared to the isogenic wild-type strain. Conversely, the deletion of srr2 impaired bacterial adhesion to both ligands. ELISA assays and surface plasmon resonance studies using the recombinant binding region (BR) form of Srr2 confirmed a direct interaction with fibronectin with an estimated Kd of 92 nM. Srr2-BR variants defective in fibrinogen binding also exhibited no interaction with fibronectin, suggesting that Srr2 binds this ligand through the dock-lock-latch mechanism, previously described for fibrinogen binding. The fibronectin site responsible for recombinant Srr2-BR binding was identified and localised in the central cell-binding domain of the protein. Finally, in the presence of fibronectin, the ability of a Δsrr2 mutant to adhere to human cervico-vaginal epithelial cells was significantly lower than that of the wild-type strain. CONCLUSION By combining genetic and biochemical approaches, we demonstrate a new role for Srr2, namely interacting with fibronectin. We characterised the molecular mechanism of this interaction and demonstrated that it plays a role in promoting the adhesion of GBS to human cervico-vaginal epithelial cells, further substantiating the role of Srr2 as a factor responsible for the hypervirulence of GBS ST-17 strains. The discovery of the previously undescribed interaction between Srr2 and fibronectin establishes this adhesin as a key factor for GBS colonisation of host tissues.
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Affiliation(s)
| | - Chiara Motta
- Department of Molecular Medicine, University of Pavia, Pavia, Italy
| | | | - Andrea Pierangelini
- Department of Pharmaceutical and Pharmacological Sciences, University of Padua, Padua, Italy
| | - Simona Viglio
- Department of Molecular Medicine, University of Pavia, Pavia, Italy
| | - Francesco Coppolino
- Department of Human Pathology and Medicine, University of Messina, Messina, Italy
| | - Concetta Beninati
- Department of Human Pathology and Medicine, University of Messina, Messina, Italy
| | - Vincenzo De Filippis
- Department of Pharmaceutical and Pharmacological Sciences, University of Padua, Padua, Italy
| | - Giulia Barbieri
- Department of Biology and Biotechnology "Lazzaro Spallanzani", University of Pavia, Pavia, Italy.
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Liu Y, Ai H. Current research update on group B streptococcal infection related to obstetrics and gynecology. Front Pharmacol 2024; 15:1395673. [PMID: 38953105 PMCID: PMC11215423 DOI: 10.3389/fphar.2024.1395673] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2024] [Accepted: 05/31/2024] [Indexed: 07/03/2024] Open
Abstract
Group B streptococcal (GBS) is a Gram-positive bacterium that is commonly found in the gastrointestinal tract and urogenital tract. GBS infestation during pregnancy is a significant contributor to maternal and neonatal morbidity and mortality globally. This article aims to discuss the infectious diseases caused by GBS in the field of obstetrics and gynecology, as well as the challenges associated with the detection, treatment, and prevention of GBS.
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Affiliation(s)
| | - Hao Ai
- Liaoning Provincial Key Laboratory of Follicular Development and Reproductive Health, Jinzhou Medical University, Jinzhou, Liaoning, China
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Ma J, Wu H, Ma Z, Wu Z. Bacterial and host factors involved in zoonotic Streptococcal meningitis. Microbes Infect 2024:105335. [PMID: 38582147 DOI: 10.1016/j.micinf.2024.105335] [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: 02/01/2024] [Revised: 04/01/2024] [Accepted: 04/02/2024] [Indexed: 04/08/2024]
Abstract
Zoonotic streptococci cause several invasive diseases with high mortality rates, especially meningitis. Numerous studies elucidated the meningitis pathogenesis of zoonotic streptococci, some specific to certain bacterial species. In contrast, others are shared among different bacterial species, involving colonization and invasion of mucosal barriers, survival in the bloodstream, breaching the blood-brain and/or blood-cerebrospinal fluid barrier to access the central nervous system, and triggering inflammation of the meninges. This review focuses on the recent advancements in comprehending the molecular and cellular events of five major zoonotic streptococci responsible for causing meningitis in humans or animals, including Streptococcus agalactiae, Streptococcus equi subspecies zooepidemicus, Streptococcus suis, Streptococcus dysgalactiae, and Streptococcus iniae. The underlying mechanism was summarized into four themes, including 1) bacterial survival in blood, 2) brain microvascular endothelial cell adhesion and invasion, 3) penetration of the blood-brain barrier, and 4) activation of the immune system and inflammatory reaction within the brain. This review may contribute to developing therapeutics to prevent or mitigate injury of streptococcal meningitis and improve risk stratification.
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Affiliation(s)
- Jiale Ma
- MOE Joint International Research Laboratory of Animal Health and Food Safety, College of Veterinary Medicine, Nanjing Agricultural University, Nanjing 210014, China; Key Lab of Animal Bacteriology, Ministry of Agriculture, Nanjing 210014, China; WOAH Reference Lab for Swine Streptococcosis, Nanjing 210014, China
| | - Huizhen Wu
- MOE Joint International Research Laboratory of Animal Health and Food Safety, College of Veterinary Medicine, Nanjing Agricultural University, Nanjing 210014, China; Key Lab of Animal Bacteriology, Ministry of Agriculture, Nanjing 210014, China; WOAH Reference Lab for Swine Streptococcosis, Nanjing 210014, China
| | - Zhe Ma
- MOE Joint International Research Laboratory of Animal Health and Food Safety, College of Veterinary Medicine, Nanjing Agricultural University, Nanjing 210014, China; Key Lab of Animal Bacteriology, Ministry of Agriculture, Nanjing 210014, China; Jiangsu Co-innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou 225009, China.
| | - Zongfu Wu
- MOE Joint International Research Laboratory of Animal Health and Food Safety, College of Veterinary Medicine, Nanjing Agricultural University, Nanjing 210014, China; Key Lab of Animal Bacteriology, Ministry of Agriculture, Nanjing 210014, China; WOAH Reference Lab for Swine Streptococcosis, Nanjing 210014, China; Guangdong Provincial Key Laboratory of Research on the Technology of Pig-breeding and Pig-disease Prevention, Guangzhou 511400, China.
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5
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Vollmuth N, Sin J, Kim BJ. Host-microbe interactions at the blood-brain barrier through the lens of induced pluripotent stem cell-derived brain-like endothelial cells. mBio 2024; 15:e0286223. [PMID: 38193670 PMCID: PMC10865987 DOI: 10.1128/mbio.02862-23] [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] [Indexed: 01/10/2024] Open
Abstract
Microbe-induced meningoencephalitis/meningitis is a life-threatening infection of the central nervous system (CNS) that occurs when pathogens are able to cross the blood-brain barrier (BBB) and gain access to the CNS. The BBB consists of highly specialized brain endothelial cells that exhibit specific properties to allow tight regulation of CNS homeostasis and prevent pathogen crossing. However, during meningoencephalitis/meningitis, the BBB fails to protect the CNS. Modeling the BBB remains a challenge due to the specialized characteristics of these cells. In this review, we cover the induced pluripotent stem cell-derived, brain-like endothelial cell model during host-pathogen interaction, highlighting the strengths and recent work on various pathogens known to interact with the BBB. As stem cell technologies are becoming more prominent, the stem cell-derived, brain-like endothelial cell model has been able to reveal new insights in vitro, which remain challenging with other in vitro cell-based models consisting of primary human brain endothelial cells and immortalized human brain endothelial cell lines.
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Affiliation(s)
- Nadine Vollmuth
- Department of Biological Sciences, University of Alabama, Tuscaloosa, Alabama, USA
| | - Jon Sin
- Department of Biological Sciences, University of Alabama, Tuscaloosa, Alabama, USA
| | - Brandon J. Kim
- Department of Biological Sciences, University of Alabama, Tuscaloosa, Alabama, USA
- Department of Microbiology, Heersink School of Medicine, University of Alabama at Birmingham, Birmingham, Alabama, USA
- Center for Convergent Biosciences and Medicine, University of Alabama, Tuscaloosa, Alabama, USA
- Alabama Life Research Institute, University of Alabama, Tuscaloosa, Alabama, USA
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Badawi AH, Mohamad NA, Stanslas J, Kirby BP, Neela VK, Ramasamy R, Basri H. In Vitro Blood-Brain Barrier Models for Neuroinfectious Diseases: A Narrative Review. Curr Neuropharmacol 2024; 22:1344-1373. [PMID: 38073104 PMCID: PMC11092920 DOI: 10.2174/1570159x22666231207114346] [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: 09/12/2022] [Revised: 11/04/2022] [Accepted: 11/25/2022] [Indexed: 05/16/2024] Open
Abstract
The blood-brain barrier (BBB) is a complex, dynamic, and adaptable barrier between the peripheral blood system and the central nervous system. While this barrier protects the brain and spinal cord from inflammation and infection, it prevents most drugs from reaching the brain tissue. With the expanding interest in the pathophysiology of BBB, the development of in vitro BBB models has dramatically evolved. However, due to the lack of a standard model, a range of experimental protocols, BBB-phenotype markers, and permeability flux markers was utilized to construct in vitro BBB models. Several neuroinfectious diseases are associated with BBB dysfunction. To conduct neuroinfectious disease research effectively, there stems a need to design representative in vitro human BBB models that mimic the BBB's functional and molecular properties. The highest necessity is for an in vitro standardised BBB model that accurately represents all the complexities of an intact brain barrier. Thus, this in-depth review aims to describe the optimization and validation parameters for building BBB models and to discuss previous research on neuroinfectious diseases that have utilized in vitro BBB models. The findings in this review may serve as a basis for more efficient optimisation, validation, and maintenance of a structurally- and functionally intact BBB model, particularly for future studies on neuroinfectious diseases.
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Affiliation(s)
- Ahmad Hussein Badawi
- Department of Neurology, Faculty of Medicine and Health Sciences, Universiti Putra Malaysia, 43400, Serdang, Selangor, Malaysia
| | - Nur Afiqah Mohamad
- Department of Neurology, Faculty of Medicine and Health Sciences, Universiti Putra Malaysia, 43400, Serdang, Selangor, Malaysia
- Centre for Foundation Studies, Lincoln University College, 47301, Petaling Jaya, Selangor, Malaysia
| | - Johnson Stanslas
- Department of Medicine, Faculty of Medicine and Health Sciences, Universiti Putra Malaysia, 43400, Serdang, Selangor, Malaysia
| | - Brian Patrick Kirby
- School of Pharmacy and Biomolecular Sciences, RCSI University of Medicine and Health Sciences, Dublin, Ireland
| | - Vasantha Kumari Neela
- Department of Medical Microbiology and Parasitology, Faculty of Medicine and Health Sciences, Universiti Putra Malaysia, 43400, Serdang, Selangor, Malaysia
| | - Rajesh Ramasamy
- Department of Pathology, Faculty of Medicine and Health Sciences, Universiti Putra Malaysia, 43400, Serdang, Selangor, Malaysia
| | - Hamidon Basri
- Department of Neurology, Faculty of Medicine and Health Sciences, Universiti Putra Malaysia, 43400, Serdang, Selangor, Malaysia
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Guo Z, Ma Y, Jia Z, Wang L, Lu X, Chen Y, Wang Y, Hao H, Yu S, Wang Z. Crosstalk between integrin/FAK and Crk/Vps25 governs invasion of bovine mammary epithelial cells by S. agalactiae. iScience 2023; 26:107884. [PMID: 37766995 PMCID: PMC10520442 DOI: 10.1016/j.isci.2023.107884] [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: 02/20/2023] [Revised: 07/26/2023] [Accepted: 09/07/2023] [Indexed: 09/29/2023] Open
Abstract
Streptococcus agalactiae (S. agalactiae) is a contagious obligate parasite of the udder in dairy cows. Here, we examined S. agalactiae-host interactions in bovine mammary epithelial cells (BMECs) in vitro. We found that S. agalactiae infected BMECs through laminin β2 and integrin. Crk, Vps25, and RhoA were differentially expressed in S. agalactiae-infected cells. S. agalactiae infection activated FAK and Crk. FAK deficiency decreased the number of intracellular S. agalactiae and Crk activation. Knockdown of Crk or Vps25 increased the level of intracellular S. agalactiae, whereas its overexpression had the opposite effect. RhoA expression and actin cytoskeleton were altered in S. agalactiae-infected BMECs. Crk and Vps25 interact in cells, and invaded S. agalactiae also activates Crk, allowing it to cooperate with Vps25 to defend against intracellular infection by S. agalactiae. This study provides insights into the mechanism by which intracellular infection by S. agalactiae is regulated in BMECs.
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Affiliation(s)
- Zhixin Guo
- State Key Laboratory of Reproductive Regulation & Breeding of Grassland Livestock, School of Life Sciences, Inner Mongolia University, Hohhot 010021, China
- School of Fisheries and Life Science, Dalian Ocean University, Dalian 116023, China
| | - Yuze Ma
- State Key Laboratory of Reproductive Regulation & Breeding of Grassland Livestock, School of Life Sciences, Inner Mongolia University, Hohhot 010021, China
| | - Zhibo Jia
- State Key Laboratory of Reproductive Regulation & Breeding of Grassland Livestock, School of Life Sciences, Inner Mongolia University, Hohhot 010021, China
| | - Liping Wang
- State Key Laboratory of Reproductive Regulation & Breeding of Grassland Livestock, School of Life Sciences, Inner Mongolia University, Hohhot 010021, China
| | - Xinyue Lu
- State Key Laboratory of Reproductive Regulation & Breeding of Grassland Livestock, School of Life Sciences, Inner Mongolia University, Hohhot 010021, China
| | - Yuhao Chen
- State Key Laboratory of Reproductive Regulation & Breeding of Grassland Livestock, School of Life Sciences, Inner Mongolia University, Hohhot 010021, China
- School of Life Sciences, Jining Normal University, Jining 012000, China
| | - Yanfeng Wang
- State Key Laboratory of Reproductive Regulation & Breeding of Grassland Livestock, School of Life Sciences, Inner Mongolia University, Hohhot 010021, China
| | - Huifang Hao
- State Key Laboratory of Reproductive Regulation & Breeding of Grassland Livestock, School of Life Sciences, Inner Mongolia University, Hohhot 010021, China
| | - Shuixing Yu
- State Key Laboratory of Reproductive Regulation & Breeding of Grassland Livestock, School of Life Sciences, Inner Mongolia University, Hohhot 010021, China
| | - Zhigang Wang
- State Key Laboratory of Reproductive Regulation & Breeding of Grassland Livestock, School of Life Sciences, Inner Mongolia University, Hohhot 010021, China
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8
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Segklia K, Matsas R, Papastefanaki F. Brain Infection by Group B Streptococcus Induces Inflammation and Affects Neurogenesis in the Adult Mouse Hippocampus. Cells 2023; 12:1570. [PMID: 37371040 DOI: 10.3390/cells12121570] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2023] [Revised: 06/01/2023] [Accepted: 06/02/2023] [Indexed: 06/29/2023] Open
Abstract
Central nervous system infections caused by pathogens crossing the blood-brain barrier are extremely damaging and trigger cellular alterations and neuroinflammation. Bacterial brain infection, in particular, is a major cause of hippocampal neuronal degeneration. Hippocampal neurogenesis, a continuous multistep process occurring throughout life in the adult brain, could compensate for such neuronal loss. However, the high rates of cognitive and other sequelae from bacterial meningitis/encephalitis suggest that endogenous repair mechanisms might be severely affected. In the current study, we used Group B Streptococcus (GBS) strain NEM316, to establish an adult mouse model of brain infection and determine its impact on adult neurogenesis. Experimental encephalitis elicited neurological deficits and death, induced inflammation, and affected neurogenesis in the dentate gyrus of the adult hippocampus by suppressing the proliferation of progenitor cells and the generation of newborn neurons. These effects were specifically associated with hippocampal neurogenesis while subventricular zone neurogenesis was not affected. Overall, our data provide new insights regarding the effect of GBS infection on adult brain neurogenesis.
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Affiliation(s)
- Katerina Segklia
- Laboratory of Cellular and Molecular Neurobiology-Stem Cells, Neurobiology Department, Hellenic Pasteur Institute, 11521 Athens, Greece
| | - Rebecca Matsas
- Laboratory of Cellular and Molecular Neurobiology-Stem Cells, Neurobiology Department, Hellenic Pasteur Institute, 11521 Athens, Greece
| | - Florentia Papastefanaki
- Laboratory of Cellular and Molecular Neurobiology-Stem Cells, Neurobiology Department, Hellenic Pasteur Institute, 11521 Athens, Greece
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Derk J, Como CN, Jones HE, Joyce LR, Kim S, Spencer BL, Bonney S, O'Rourke R, Pawlikowski B, Doran KS, Siegenthaler JA. Formation and function of the meningeal arachnoid barrier around the developing mouse brain. Dev Cell 2023; 58:635-644.e4. [PMID: 36996816 PMCID: PMC10231667 DOI: 10.1016/j.devcel.2023.03.005] [Citation(s) in RCA: 15] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2022] [Revised: 12/13/2022] [Accepted: 03/08/2023] [Indexed: 03/31/2023]
Abstract
The arachnoid barrier, a component of the blood-cerebrospinal fluid barrier (B-CSFB) in the meninges, is composed of epithelial-like, tight-junction-expressing cells. Unlike other central nervous system (CNS) barriers, its' developmental mechanisms and timing are largely unknown. Here, we show that mouse arachnoid barrier cell specification requires the repression of Wnt-β-catenin signaling and that constitutively active β-catenin can prevent its formation. We also show that the arachnoid barrier is functional prenatally and, in its absence, a small molecular weight tracer and the bacterium group B Streptococcus can cross into the CNS following peripheral injection. Acquisition of barrier properties prenatally coincides with the junctional localization of Claudin 11, and increased E-cadherin and maturation continues after birth, where postnatal expansion is marked by proliferation and re-organization of junctional domains. This work identifies fundamental mechanisms that drive arachnoid barrier formation, highlights arachnoid barrier fetal functions, and provides novel tools for future studies on CNS barrier development.
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Affiliation(s)
- Julia Derk
- University of Colorado Anschutz Medical Campus, Department of Pediatrics, Section of Developmental Biology, Aurora, CO 80045, USA
| | - Christina N Como
- University of Colorado Anschutz Medical Campus, Department of Pediatrics, Section of Developmental Biology, Aurora, CO 80045, USA; University of Colorado Anschutz Medical Campus, Neuroscience Graduate Program, Aurora, CO 80045, USA
| | - Hannah E Jones
- University of Colorado Anschutz Medical Campus, Department of Pediatrics, Section of Developmental Biology, Aurora, CO 80045, USA; University of Colorado Anschutz Medical Campus, Cell Biology Stem Cells and Development Graduate Program, Aurora, CO 80045, USA
| | - Luke R Joyce
- Department of Immunology and Microbiology, University of Colorado Anschutz Medical Campus, Aurora, CO 80045, USA
| | - Sol Kim
- University of Colorado Anschutz Medical Campus, Department of Pediatrics, Section of Developmental Biology, Aurora, CO 80045, USA; University of Colorado Anschutz Medical Campus, Cell Biology Stem Cells and Development Graduate Program, Aurora, CO 80045, USA
| | - Brady L Spencer
- Department of Immunology and Microbiology, University of Colorado Anschutz Medical Campus, Aurora, CO 80045, USA
| | - Stephanie Bonney
- University of Colorado Anschutz Medical Campus, Department of Pediatrics, Section of Developmental Biology, Aurora, CO 80045, USA
| | - Rebecca O'Rourke
- University of Colorado Anschutz Medical Campus, Department of Pediatrics, Section of Developmental Biology, Aurora, CO 80045, USA
| | - Brad Pawlikowski
- University of Colorado Anschutz Medical Campus, Department of Pediatrics, Section of Developmental Biology, Aurora, CO 80045, USA
| | - Kelly S Doran
- Department of Immunology and Microbiology, University of Colorado Anschutz Medical Campus, Aurora, CO 80045, USA
| | - Julie A Siegenthaler
- University of Colorado Anschutz Medical Campus, Department of Pediatrics, Section of Developmental Biology, Aurora, CO 80045, USA; University of Colorado Anschutz Medical Campus, Neuroscience Graduate Program, Aurora, CO 80045, USA; University of Colorado Anschutz Medical Campus, Cell Biology Stem Cells and Development Graduate Program, Aurora, CO 80045, USA.
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Mamana J, Humber GM, Espinal ER, Seo S, Vollmuth N, Sin J, Kim BJ. Coxsackievirus B3 infects and disrupts human induced-pluripotent stem cell derived brain-like endothelial cells. Front Cell Infect Microbiol 2023; 13:1171275. [PMID: 37139492 PMCID: PMC10149843 DOI: 10.3389/fcimb.2023.1171275] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2023] [Accepted: 03/30/2023] [Indexed: 05/05/2023] Open
Abstract
Coxsackievirus B3 (CVB3) is a significant human pathogen that is commonly found worldwide. CVB3 among other enteroviruses, are the leading causes of aseptic meningo-encephalitis which can be fatal especially in young children. How the virus gains access to the brain is poorly-understood, and the host-virus interactions that occur at the blood-brain barrier (BBB) is even less-characterized. The BBB is a highly specialized biological barrier consisting primarily of brain endothelial cells which possess unique barrier properties and facilitate the passage of nutrients into the brain while restricting access to toxins and pathogens including viruses. To determine the effects of CVB3 infection on the BBB, we utilized a model of human induced-pluripotent stem cell-derived brain-like endothelial cells (iBECs) to ascertain if CVB3 infection may alter barrier cell function and overall survival. In this study, we determined that these iBECs indeed are susceptible to CVB3 infection and release high titers of extracellular virus. We also determined that infected iBECs maintain high transendothelial electrical resistance (TEER) during early infection despite possessing high viral load. TEER progressively declines at later stages of infection. Interestingly, despite the high viral burden and TEER disruptions at later timepoints, infected iBEC monolayers remain intact, indicating a low degree of late-stage virally-mediated cell death, which may contribute to prolonged viral shedding. We had previously reported that CVB3 infections rely on the activation of transient receptor vanilloid potential 1 (TRPV1) and found that inhibiting TRPV1 activity with SB-366791 significantly limited CVB3 infection of HeLa cervical cancer cells. Similarly in this study, we observed that treating iBECs with SB-366791 significantly reduced CVB3 infection, which suggests that not only can this drug potentially limit viral entry into the brain, but also demonstrates that this infection model could be a valuable platform for testing antiviral treatments of neurotropic viruses. In all, our findings elucidate the unique effects of CVB3 infection on the BBB and shed light on potential mechanisms by which the virus can initiate infections in the brain.
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Affiliation(s)
- Julia Mamana
- Department of Biological Sciences, University of Alabama, Tuscaloosa, AL, United States
| | - Gabrielle M. Humber
- Department of Biological Sciences, University of Alabama, Tuscaloosa, AL, United States
| | - Eric R. Espinal
- Department of Biological Sciences, University of Alabama, Tuscaloosa, AL, United States
| | - Soojung Seo
- Department of Biological Sciences, University of Alabama, Tuscaloosa, AL, United States
| | - Nadine Vollmuth
- Department of Biological Sciences, University of Alabama, Tuscaloosa, AL, United States
| | - Jon Sin
- Department of Biological Sciences, University of Alabama, Tuscaloosa, AL, United States
- *Correspondence: Jon Sin, ; Brandon J. Kim,
| | - Brandon J. Kim
- Department of Biological Sciences, University of Alabama, Tuscaloosa, AL, United States
- Department of Microbiology, Heersink School of Medicine, University of Alabama at Birmingham, Birmingham, AL, United States
- Center for Convergent Biosciences and Medicine, University of Alabama, Tuscaloosa, AL, United States
- Alabama Life Research Institute, University of Alabama, Tuscaloosa, AL, United States
- *Correspondence: Jon Sin, ; Brandon J. Kim,
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A Novel Conserved Protein in Streptococcus agalactiae, BvaP, Is Important for Vaginal Colonization and Biofilm Formation. mSphere 2022; 7:e0042122. [PMID: 36218343 PMCID: PMC9769775 DOI: 10.1128/msphere.00421-22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023] Open
Abstract
Streptococcus agalactiae (group B streptococcus [GBS]) infections in neonates are often fatal and strongly associated with maternal GBS vaginal colonization. Here, we investigated the role of an uncharacterized protein, BvaP, in GBS vaginal colonization. bvaP was previously identified as the most highly upregulated gene in the GBS A909 transcriptome when comparing vaginal colonization to growth in liquid culture. We found that the absence of BvaP affects the ability of GBS to adhere to extracellular matrix components and human vaginal epithelial cells, and the ability of a ΔbvaP mutant to colonize the murine vaginal tract was significantly decreased. Cellular morphological alterations such as changes in cell shape, chain length, and clumping were also observed in a knockout mutant strain. Given its high expression level in vivo, high degree of conservation among GBS strains, and role in vaginal colonization, BvaP may be an eligible target for GBS vaccination and/or drug therapy. IMPORTANCE Neonatal GBS disease is a major cause of morbidity and mortality, and maternal vaginal colonization is the leading risk factor for the disease. Colonization prevention would greatly impact the rates of disease transmission, but vaccine development has stalled as capsular polysaccharide vaccines have low immunogenicity in vivo. While these vaccines are still in development, the addition of a protein conjugate may prove fruitful in increasing immunogenicity and strain coverage across GBS serotypes. Previous research identified sak_1753 as a highly upregulated gene during murine vaginal colonization. This study reveals that Sak_1753 is required to maintain proper GBS cellular morphology and colonization phenotypes and is required for full in vivo vaginal colonization in a murine model. We have renamed Sak_1753 group B streptococcus vaginal adherence protein (BvaP). The findings of this study indicate that BvaP is important for GBS colonization of the vaginal tract and, given its high expression level in vivo and strain conservation, may be a candidate for vaccine development.
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Abstract
Neonatal bacterial meningitis is a devastating disease, associated with high mortality and neurological disability, in both developed and developing countries. Streptococcus agalactiae, commonly referred to as group B Streptococcus (GBS), remains the most common bacterial cause of meningitis among infants younger than 90 days. Maternal colonization with GBS in the gastrointestinal and/or genitourinary tracts is the primary risk factor for neonatal invasive disease. Despite prophylactic intrapartum antibiotic administration to colonized women and improved neonatal intensive care, the incidence and morbidity associated with GBS meningitis have not declined since the 1970s. Among meningitis survivors, a significant number suffer from complex neurological or neuropsychiatric sequelae, implying that the pathophysiology and pathogenic mechanisms leading to brain injury and devastating outcomes are not yet fully understood. It is imperative to develop new therapeutic and neuroprotective approaches aiming at protecting the developing brain. In this review, we provide updated clinical information regarding the understanding of neonatal GBS meningitis, including epidemiology, diagnosis, management, and human evidence of the disease's underlying mechanisms. Finally, we explore the experimental models used to study GBS meningitis and discuss their clinical and physiologic relevance to the complexities of human disease.
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Affiliation(s)
- Teresa Tavares
- Instituto de Ciências Biomédicas de Abel Salazar, Universidade do Porto, Porto, Portugal
| | - Liliana Pinho
- Centro Hospitalar Universitário do Porto, Centro Materno Infantil do Norte, Porto, Portugal
| | - Elva Bonifácio Andrade
- Instituto de Ciências Biomédicas de Abel Salazar, Universidade do Porto, Porto, Portugal
- Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Porto, Portugal
- Instituto de Biologia Molecular e Celular, Universidade do Porto, Porto, Portugal
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13
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Common Colonization Genes Profiling and BOX-PCR Based Genotyping of Streptococcus agalactiae from Pregnant Women in Tehran, Iran. Jundishapur J Microbiol 2022. [DOI: 10.5812/jjm-122008] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
Background: Streptococcus agalactiae or group B streptococcus (GBS) is a prominent cause of severe neonatal infections. GBS is a part of the intestinal and vaginal normal flora. Maternal colonization is recognized as the main path of GBS transmission. GBS is a pathobiont that changes from a non-symptomatic mucosal carriage state to a significant bacterial pathogen, causing major infections. Objectives: This study aimed to investigate the concomitant presence of major colonization genes, including ftsA, ftsB, lmb, and sfbA, and to determine the genetic relatedness of clinical GBS isolates. Methods: The GBS isolates were obtained from urinary and placental samples of pregnant women with a urinary tract infection, who were admitted to a hospital in Tehran, Iran. The presence of some major colonization factors was investigated via multiplex PCR assay. Genotyping of the isolates was performed using the BOX-PCR fingerprint technique with a BOX-A1R primer. Next, the data were analyzed using the UPGMA method and the coefficient of Jaccard in NTSYS software. Results: A total of 60 GBS isolates were examined in this study. The concomitant presence of target colonization genes was observed in all isolates. The BOX-PCR discriminated GBS isolates into six different genetic clusters at a 60% cutoff point. The majority of isolates (80%) from both clinical samples were clustered into genotypes 2, 6, and 4, while the rest (20%) were distributed equally into three different genotypes. Conclusions: Determining the colonization associated genes and genetic polymorphism in a different geographical area provides the epidemiological basis for the prevention of GBS infections in pregnant women and infants.
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Manzer HS, Villarreal RI, Doran KS. Targeting the BspC-vimentin interaction to develop anti-virulence therapies during Group B streptococcal meningitis. PLoS Pathog 2022; 18:e1010397. [PMID: 35316308 PMCID: PMC8939794 DOI: 10.1371/journal.ppat.1010397] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2021] [Accepted: 02/25/2022] [Indexed: 12/21/2022] Open
Abstract
Bacterial infections are a major cause of morbidity and mortality worldwide and the rise of antibiotic resistance necessitates development of alternative treatments. Pathogen adhesins that bind to host cells initiate disease pathogenesis and represent potential therapeutic targets. We have shown previously that the BspC adhesin in Group B Streptococcus (GBS), the leading cause of bacterial neonatal meningitis, interacts with host vimentin to promote attachment to brain endothelium and disease development. Here we determined that the BspC variable (V-) domain contains the vimentin binding site and promotes GBS adherence to brain endothelium. Site directed mutagenesis identified a binding pocket necessary for GBS host cell interaction and development of meningitis. Using a virtual structure-based drug screen we identified compounds that targeted the V-domain binding pocket, which blocked GBS adherence and entry into the brain in vivo. These data indicate the utility of targeting the pathogen-host interface to develop anti-virulence therapeutics.
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Affiliation(s)
- Haider S. Manzer
- University of Colorado Anschutz Medical Campus, Department of Immunology and Microbiology, Aurora, Colorado, United States of America
| | - Ricardo I. Villarreal
- University of Colorado Anschutz Medical Campus, Department of Immunology and Microbiology, Aurora, Colorado, United States of America
| | - Kelly S. Doran
- University of Colorado Anschutz Medical Campus, Department of Immunology and Microbiology, Aurora, Colorado, United States of America
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15
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Frelet-Barrand A. Lactococcus lactis, an Attractive Cell Factory for the Expression of Functional Membrane Proteins. Biomolecules 2022; 12:180. [PMID: 35204681 PMCID: PMC8961550 DOI: 10.3390/biom12020180] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2021] [Revised: 01/17/2022] [Accepted: 01/21/2022] [Indexed: 01/27/2023] Open
Abstract
Membrane proteins play key roles in most crucial cellular processes, ranging from cell-to-cell communication to signaling processes. Despite recent improvements, the expression of functionally folded membrane proteins in sufficient amounts for functional and structural characterization remains a challenge. Indeed, it is still difficult to predict whether a protein can be overproduced in a functional state in some expression system(s), though studies of high-throughput screens have been published in recent years. Prokaryotic expression systems present several advantages over eukaryotic ones. Among them, Lactococcus lactis (L. lactis) has emerged in the last two decades as a good alternative expression system to E. coli. The purpose of this chapter is to describe L. lactis and its tightly inducible system, NICE, for the effective expression of membrane proteins from both prokaryotic and eukaryotic origins.
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Affiliation(s)
- Annie Frelet-Barrand
- FEMTO-ST Institute, UMR 6174, CNRS, Université Bourgogne Franche-Comté, 15B Avenue des Montboucons, CEDEX, 25030 Besançon, France
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16
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Jin T, Guan N, Du Y, Zhang X, Li J, Xia X. Cronobacter sakazakii ATCC 29544 Translocated Human Brain Microvascular Endothelial Cells via Endocytosis, Apoptosis Induction, and Disruption of Tight Junction. Front Microbiol 2021; 12:675020. [PMID: 34163451 PMCID: PMC8215149 DOI: 10.3389/fmicb.2021.675020] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2021] [Accepted: 04/23/2021] [Indexed: 01/19/2023] Open
Abstract
Cronobacter sakazakii (C. sakazakii) is an emerging opportunistic foodborne pathogen that can cause neonatal necrotizing enterocolitis, meningitis, sepsis in neonates and infants with a relatively high mortality rate. Bacterial transcytosis across the human brain microvascular endothelial cells (HBMEC) is vital for C. sakazakii to induce neonatal meningitis. However, few studies focus on the mechanisms by which C. sakazakii translocates HBMEC. In this study, the translocation processes of C. sakazakii on HBMEC were explored. C. sakazakii strains could effectively adhere to, invade and intracellularly survive in HBMEC. The strain ATCC 29544 exhibited the highest translocation efficiency across HBMEC monolayer among four tested strains. Bacteria-contained intracellular endosomes were detected in C. sakazakii-infected HBMEC by a transmission electron microscope. Endocytosis-related proteins CD44, Rab5, Rab7, and LAMP2 were increased after infection, while the level of Cathepsin L did not change. C. sakazakii induced TLR4/NF-κB inflammatory signal pathway activation in HBMEC, with increased NO production and elevated mRNA levels of IL-8, IL-6, TNF-α, IL-1β, iNOS, and COX-2. C. sakazakii infection also caused LDH release, caspase-3 activation, and HBMEC apoptosis. Meanwhile, increased Dextran-FITC permeability and decreased trans epithelial electric resistance indicated that C. sakazakii disrupted tight junction of HBMEC monolayers, which was confirmed by the decreased levels of tight junction-related proteins ZO-1 and Occludin. These findings suggest that C. sakazakii induced intracellular bacterial endocytosis, stimulated inflammation and apoptosis, disrupted monolayer tight junction in HBMEC, which all together contribute to bacterial translocation.
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Affiliation(s)
- Tong Jin
- College of Food Science and Engineering, Northwest A&F University, Xianyang, China
| | - Ning Guan
- College of Food Science and Engineering, Northwest A&F University, Xianyang, China
| | - Yuhang Du
- College of Food Science and Engineering, Northwest A&F University, Xianyang, China
| | - Xinpeng Zhang
- College of Food Science and Engineering, Northwest A&F University, Xianyang, China
| | - Jiahui Li
- College of Food Science and Engineering, Northwest A&F University, Xianyang, China
| | - Xiaodong Xia
- College of Food Science and Engineering, Northwest A&F University, Xianyang, China
- National Engineering Research Center of Seafood, Collaborative Innovation Center of Seafood Deep Processing, Dalian Polytechnic University, Dalian, China
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17
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van Sorge NM, Bonsor DA, Deng L, Lindahl E, Schmitt V, Lyndin M, Schmidt A, Nilsson OR, Brizuela J, Boero E, Sundberg EJ, van Strijp JAG, Doran KS, Singer BB, Lindahl G, McCarthy AJ. Bacterial protein domains with a novel Ig-like fold target human CEACAM receptors. EMBO J 2021; 40:e106103. [PMID: 33522633 PMCID: PMC8013792 DOI: 10.15252/embj.2020106103] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2020] [Revised: 12/08/2020] [Accepted: 12/10/2020] [Indexed: 01/19/2023] Open
Abstract
Streptococcus agalactiae, also known as group B Streptococcus (GBS), is the major cause of neonatal sepsis in humans. A critical step to infection is adhesion of bacteria to epithelial surfaces. GBS adhesins have been identified to bind extracellular matrix components and cellular receptors. However, several putative adhesins have no host binding partner characterised. We report here that surface-expressed β protein of GBS binds to human CEACAM1 and CEACAM5 receptors. A crystal structure of the complex showed that an IgSF domain in β represents a novel Ig-fold subtype called IgI3, in which unique features allow binding to CEACAM1. Bioinformatic assessment revealed that this newly identified IgI3 fold is not exclusively present in GBS but is predicted to be present in adhesins from other clinically important human pathogens. In agreement with this prediction, we found that CEACAM1 binds to an IgI3 domain found in an adhesin from a different streptococcal species. Overall, our results indicate that the IgI3 fold could provide a broadly applied mechanism for bacteria to target CEACAMs.
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Affiliation(s)
- Nina M van Sorge
- Department of Medical MicrobiologyUniversity Medical Center UtrechtUtrecht UniversityUtrechtThe Netherlands
- Present address:
Department of Medical Microbiology,Infection Prevention and Netherlands Reference Laboratory for Bacterial MeningitisAmsterdam University Medical CenterUniversity of AmsterdamAmsterdamThe Netherlands
| | - Daniel A Bonsor
- Institute of Human VirologyUniversity of Maryland School of MedicineUniversity of MarylandBaltimoreMDUSA
| | - Liwen Deng
- Department of Immunology & MicrobiologyUniversity of Colorado Anschutz Medical CampusAuroraCOUSA
| | - Erik Lindahl
- Department of Biochemistry and BiophysicsScience for Life LaboratoryStockholm UniversityStockholmSweden
| | - Verena Schmitt
- Institute of AnatomyMedical Faculty, University Duisburg‐EssenEssenGermany
| | - Mykola Lyndin
- Institute of AnatomyMedical Faculty, University Duisburg‐EssenEssenGermany
- Department of PathologySumy State UniversitySumyUkraine
| | - Alexej Schmidt
- Department of Medical BiosciencesUmeå UniversityPathology, UmeåSweden
| | - Olof R Nilsson
- Department of Laboratory MedicineDivision of Medical MicrobiologyLund UniversityLundSweden
| | - Jaime Brizuela
- Department of Infectious Disease, MRC Centre for Molecular Bacteriology & InfectionImperial College LondonLondonUK
| | - Elena Boero
- Department of Medical MicrobiologyUniversity Medical Center UtrechtUtrecht UniversityUtrechtThe Netherlands
| | - Eric J Sundberg
- Institute of Human VirologyUniversity of Maryland School of MedicineUniversity of MarylandBaltimoreMDUSA
- Department of BiochemistryEmory University School of MedicineAtlantaGAUSA
| | - Jos A G van Strijp
- Department of Medical MicrobiologyUniversity Medical Center UtrechtUtrecht UniversityUtrechtThe Netherlands
| | - Kelly S Doran
- Department of Immunology & MicrobiologyUniversity of Colorado Anschutz Medical CampusAuroraCOUSA
| | - Bernhard B Singer
- Institute of AnatomyMedical Faculty, University Duisburg‐EssenEssenGermany
| | - Gunnar Lindahl
- Department of Laboratory MedicineDivision of Medical MicrobiologyLund UniversityLundSweden
- Department of ChemistryDivision of Applied MicrobiologyLund UniversityLundSweden
| | - Alex J McCarthy
- Department of Medical MicrobiologyUniversity Medical Center UtrechtUtrecht UniversityUtrechtThe Netherlands
- Department of Infectious Disease, MRC Centre for Molecular Bacteriology & InfectionImperial College LondonLondonUK
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Lannes-Costa PS, de Oliveira JSS, da Silva Santos G, Nagao PE. A current review of pathogenicity determinants of Streptococcus sp. J Appl Microbiol 2021; 131:1600-1620. [PMID: 33772968 DOI: 10.1111/jam.15090] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2020] [Revised: 03/16/2021] [Accepted: 03/24/2021] [Indexed: 12/16/2022]
Abstract
The genus Streptococcus comprises important pathogens, many of them are part of the human or animal microbiota. Advances in molecular genetics, taxonomic approaches and phylogenomic studies have led to the establishment of at least 100 species that have a severe impact on human health and are responsible for substantial economic losses to agriculture. The infectivity of the pathogens is linked to cell-surface components and/or secreted virulence factors. Bacteria have evolved sophisticated and multifaceted adaptation strategies to the host environment, including biofilm formation, survival within professional phagocytes, escape the host immune response, amongst others. This review focuses on virulence mechanism and zoonotic potential of Streptococcus species from pyogenic (S. agalactiae, S. pyogenes) and mitis groups (S. pneumoniae).
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Affiliation(s)
- P S Lannes-Costa
- Laboratory of Molecular Biology and Physiology of Streptococci, Institute of Biology Roberto Alcantara Gomes, Rio de Janeiro State University (UERJ), Rio de Janeiro, Rio de Janeiro, Brazil
| | - J S S de Oliveira
- Laboratory of Molecular Biology and Physiology of Streptococci, Institute of Biology Roberto Alcantara Gomes, Rio de Janeiro State University (UERJ), Rio de Janeiro, Rio de Janeiro, Brazil
| | - G da Silva Santos
- Laboratory of Molecular Biology and Physiology of Streptococci, Institute of Biology Roberto Alcantara Gomes, Rio de Janeiro State University (UERJ), Rio de Janeiro, Rio de Janeiro, Brazil
| | - P E Nagao
- Laboratory of Molecular Biology and Physiology of Streptococci, Institute of Biology Roberto Alcantara Gomes, Rio de Janeiro State University (UERJ), Rio de Janeiro, Rio de Janeiro, Brazil
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19
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Abstract
Group B Streptococcus (GBS) remains the leading cause of neonatal meningitis, a disease associated with high rates of adverse neurological sequelae. The in vivo relationship between GBS and brain tissues remains poorly characterized, partly because past studies had focused on microbial rather than host processes. Additionally, the field has not capitalized on systems-level technologies to probe the host-pathogen relationship. Here, we use multiplexed quantitative proteomics to investigate the effect of GBS infection in the murine brain at various levels of tissue complexity, beginning with the whole organ and moving to brain vascular substructures. Infected whole brains showed classical signatures associated with the acute-phase response. In isolated brain microvessels, classical blood-brain barrier proteins were unaltered, but interferon signaling and leukocyte recruitment proteins were upregulated. The choroid plexus showed increases in peripheral immune cell proteins. Proteins that increased in abundance in the vasculature during GBS invasion were associated with major histocompatibility complex (MHC) class I antigen processing and endoplasmic reticulum dysfunction, a finding which correlated with altered host protein glycosylation profiles. Globally, there was low concordance between the infection proteome of whole brains and isolated vascular tissues. This report underscores the utility of unbiased, systems-scale analyses of functional tissue substructures for understanding disease.IMPORTANCE Group B Streptococcus (GBS) meningitis remains a major cause of poor health outcomes very early in life. Both the host-pathogen relationship leading to disease and the massive host response to infection contributing to these poor outcomes are orchestrated at the tissue and cell type levels. GBS meningitis is thought to result when bacteria present in the blood circumvent the selectively permeable vascular barriers that feed the brain. Additionally, tissue damage subsequent to bacterial invasion is mediated by inflammation and by immune cells from the periphery crossing the blood-brain barrier. Indeed, the vasculature plays a central role in disease processes occurring during GBS infection of the brain. Here, we employed quantitative proteomic analysis of brain vascular substructures during invasive GBS disease. We used the generated data to map molecular alterations associated with tissue perturbation, finding widespread intracellular dysfunction and punctuating the importance of investigations relegated to tissue type over the whole organ.
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20
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Wu XM, Cao L, Hu YW, Chang MX. Transcriptomic characterization of adult zebrafish infected with Streptococcus agalactiae. FISH & SHELLFISH IMMUNOLOGY 2019; 94:355-372. [PMID: 31533079 DOI: 10.1016/j.fsi.2019.09.040] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/12/2019] [Revised: 09/12/2019] [Accepted: 09/15/2019] [Indexed: 06/10/2023]
Abstract
Streptococcus agalactiae is a major aquaculture pathogen infecting various saltwater and freshwater fish. To better understand the mechanism of the immune responses to S. agalactiae in wildtype zebrafish, the transcriptomic profiles of two organs containing mucosal-associated lymphoid tissues from S. agalactiae-infected and non-infected groups were obtained using RNA-seq techniques. In the intestines, 6735 and 12908 differently expressed genes (DEGs) were identified at 24 hpi and 48 hpi, respectively. Among 66 and 116 significantly enriched pathways, 15 and 21 pathways were involved in immune system or signal transduction at 24 hpi and 48 hpi, respectively. A number of genes involved in Toll-like receptor signaling pathway, RIG-I-like receptor signaling pathway, NOD-like receptor signaling pathway, T cell receptor signaling pathway, B cell receptor signaling pathway, Antigen processing and presentation, NF-kappa B signaling pathway and PI3K-Akt signaling pathway were significantly downregulated. In the skins, 3113 and 4467 DEGs were identified at 24 hpi and 48 hpi, respectively. Among 24 and 56 significantly enriched pathways, 4 and 13 pathways were involved in immune system or signal transduction at 24 hpi and 48 hpi, respectively. More immune-related signaling pathways including Leukocyte transendothelial migration, Cytokine-cytokine receptor interaction, PI3K-Akt signaling pathway, IL-17 signaling pathway, MAPK signaling pathway, TNF signaling pathway, Complement and coagulation cascades, Hematopoietic cell lineage and Jak-STAT signaling pathway were differently enriched for upregulated DEGs at 48 hpi, which were completely different from that in the intestines. Furthmore, comparative transcriptome analysis revealed that the downregulated 1618 genes and upregulated 1622 genes existed both at 24 hpi and 48 hpi for the intestine samples. In the skins, the downregulated 672 genes and upregulated 428 genes existed both at 24 hpi and 48 hpi. Three pathways related to immune processes were significantly enriched for downregulated DEGs both in the intestines and skins collected at 24 hpi and 48 hpi, which included Antigen processing and presentation, Intestinal immune network for IgA production and Hematopoietic cell lineage. Interaction network analysis of DEGs identified the main DEGs in the sub-network of complement and coagulation cascades both in the intestines and skins. Twenty of DEGs involved in complement and coagulation cascades were further validated by Real-time quantitative PCR. Altogether, the results obtained in this study will provide insight into the immune response of zebrafish against S. agalactiae XQ-1 infection in fatal conditions, and reveal the discrepant expression pattern of complement and coagulation cascades in the intestines and skins.
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Affiliation(s)
- Xiao Man Wu
- State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, Hubei Province, China; University of Chinese Academy of Sciences, Beijing, China
| | - Lu Cao
- State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, Hubei Province, China; University of Chinese Academy of Sciences, Beijing, China
| | - Yi Wei Hu
- State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, Hubei Province, China; University of Chinese Academy of Sciences, Beijing, China
| | - Ming Xian Chang
- State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, Hubei Province, China; Key Laboratory of Aquaculture Disease Control, Ministry of Agriculture, Wuhan, Hubei Province, China; The Innovative Academy of Seed Design, Chinese Academy of Sciences, Beijing, China; University of Chinese Academy of Sciences, Beijing, China.
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21
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Virulence Factors of Meningitis-Causing Bacteria: Enabling Brain Entry across the Blood-Brain Barrier. Int J Mol Sci 2019; 20:ijms20215393. [PMID: 31671896 PMCID: PMC6862235 DOI: 10.3390/ijms20215393] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2019] [Revised: 10/24/2019] [Accepted: 10/25/2019] [Indexed: 12/16/2022] Open
Abstract
Infections of the central nervous system (CNS) are still a major cause of morbidity and mortality worldwide. Traversal of the barriers protecting the brain by pathogens is a prerequisite for the development of meningitis. Bacteria have developed a variety of different strategies to cross these barriers and reach the CNS. To this end, they use a variety of different virulence factors that enable them to attach to and traverse these barriers. These virulence factors mediate adhesion to and invasion into host cells, intracellular survival, induction of host cell signaling and inflammatory response, and affect barrier function. While some of these mechanisms differ, others are shared by multiple pathogens. Further understanding of these processes, with special emphasis on the difference between the blood-brain barrier and the blood-cerebrospinal fluid barrier, as well as virulence factors used by the pathogens, is still needed.
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22
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Kim BJ, McDonagh MA, Deng L, Gastfriend BD, Schubert-Unkmeir A, Doran KS, Shusta EV. Streptococcus agalactiae disrupts P-glycoprotein function in brain endothelial cells. Fluids Barriers CNS 2019; 16:26. [PMID: 31434575 PMCID: PMC6704684 DOI: 10.1186/s12987-019-0146-5] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2019] [Accepted: 07/30/2019] [Indexed: 01/16/2023] Open
Abstract
Bacterial meningitis is a serious life threatening infection of the CNS. To cause meningitis, blood-borne bacteria need to interact with and penetrate brain endothelial cells (BECs) that comprise the blood-brain barrier. BECs help maintain brain homeostasis and they possess an array of efflux transporters, such as P-glycoprotein (P-gp), that function to efflux potentially harmful compounds from the CNS back into the circulation. Oftentimes, efflux also serves to limit the brain uptake of therapeutic drugs, representing a major hurdle for CNS drug delivery. During meningitis, BEC barrier integrity is compromised; however, little is known about efflux transport perturbations during infection. Thus, understanding the impact of bacterial infection on P-gp function would be important for potential routes of therapeutic intervention. To this end, the meningeal bacterial pathogen, Streptococcus agalactiae, was found to inhibit P-gp activity in human induced pluripotent stem cell-derived BECs, and live bacteria were required for the observed inhibition. This observation was correlated to decreased P-gp expression both in vitro and during infection in vivo using a mouse model of bacterial meningitis. Given the impact of bacterial interactions on P-gp function, it will be important to incorporate these findings into analyses of drug delivery paradigms for bacterial infections of the CNS.
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Affiliation(s)
- Brandon J. Kim
- Department of Chemical and Biological Engineering, University of Wisconsin, Madison, WI USA
- Department of Hygiene and Microbiology, University of Würzburg, Joseph Schneider Strasse 2/E1, 97080 Würzburg, Germany
| | - Maura A. McDonagh
- Department of Chemical and Biological Engineering, University of Wisconsin, Madison, WI USA
| | - Liwen Deng
- Department of Immunology and Microbiology, University of Colorado School of Medicine, Aurora, CO USA
| | - Benjamin D. Gastfriend
- Department of Chemical and Biological Engineering, University of Wisconsin, Madison, WI USA
| | - Alexandra Schubert-Unkmeir
- Department of Hygiene and Microbiology, University of Würzburg, Joseph Schneider Strasse 2/E1, 97080 Würzburg, Germany
| | - Kelly S. Doran
- Department of Immunology and Microbiology, University of Colorado School of Medicine, Aurora, CO USA
| | - Eric V. Shusta
- Department of Chemical and Biological Engineering, University of Wisconsin, Madison, WI USA
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Spencer BL, Deng L, Patras KA, Burcham ZM, Sanches GF, Nagao PE, Doran KS. Cas9 Contributes to Group B Streptococcal Colonization and Disease. Front Microbiol 2019; 10:1930. [PMID: 31497003 PMCID: PMC6712506 DOI: 10.3389/fmicb.2019.01930] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2019] [Accepted: 08/05/2019] [Indexed: 12/20/2022] Open
Abstract
Group B Streptococcus (GBS) is a major opportunistic pathogen in certain adult populations, including pregnant women, and remains a leading etiologic agent of newborn disease. During pregnancy, GBS asymptomatically colonizes the vaginal tract of 20-30% of healthy women, but can be transmitted to the neonate in utero or during birth resulting in neonatal pneumonia, sepsis, meningitis, and subsequently 10-15% mortality regardless of antibiotic treatment. While various GBS virulence factors have been implicated in vaginal colonization and invasive disease, the regulation of many of these factors remains unclear. Recently, CRISPR-associated protein-9 (Cas9), an endonuclease known for its role in CRISPR/Cas immunity, has also been observed to modulate virulence in a number of bacterial pathogens. However, the role of Cas9 in GBS colonization and disease pathogenesis has not been well-studied. We performed allelic replacement of cas9 in GBS human clinical isolates of the hypervirulent sequence-type 17 strain lineage to generate isogenic Δcas9 mutants. Compared to parental strains, Δcas9 mutants were attenuated in murine models of hematogenous meningitis and vaginal colonization and exhibited significantly decreased invasion of human brain endothelium and adherence to vaginal epithelium. To determine if Cas9 alters transcription in GBS, we performed RNA-Seq analysis and found that 353 genes (>17% of the GBS genome) were differentially expressed between the parental WT and Δcas9 mutant strain. Significantly dysregulated genes included those encoding predicted virulence factors, metabolic factors, two-component systems (TCS), and factors important for cell wall formation. These findings were confirmed by qRT-PCR and suggest that Cas9 may regulate a significant portion of the GBS genome. We studied one of the TCS regulators, CiaR, that was significantly downregulated in the Δcas9 mutant strain. RNA-Seq analysis of the WT and ΔciaR strains demonstrated that almost all CiaR-regulated genes were also significantly regulated by Cas9, suggesting that Cas9 may modulate GBS gene expression through other regulators. Further we show that CiaR contributes to GBS vaginal colonization and persistence. Altogether, these data highlight the potential complexity and importance of the non-canonical function of Cas9 in GBS colonization and disease.
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Affiliation(s)
- Brady L. Spencer
- Department of Immunology & Microbiology, University of Colorado Anschutz Medical Campus, Aurora, CO, United States
| | - Liwen Deng
- Department of Immunology & Microbiology, University of Colorado Anschutz Medical Campus, Aurora, CO, United States
- Department of Biology, San Diego State University, San Diego, CA, United States
| | - Kathryn A. Patras
- Department of Biology, San Diego State University, San Diego, CA, United States
| | - Zachary M. Burcham
- Department of Animal Sciences, Colorado State University, Fort Collins, CO, United States
| | - Glenda F. Sanches
- Department of Immunology & Microbiology, University of Colorado Anschutz Medical Campus, Aurora, CO, United States
- Roberto Alcântara Gomes Biology Institute, Rio de Janeiro State University, Rio de Janeiro, Brazil
| | - Prescilla E. Nagao
- Roberto Alcântara Gomes Biology Institute, Rio de Janeiro State University, Rio de Janeiro, Brazil
| | - Kelly S. Doran
- Department of Immunology & Microbiology, University of Colorado Anschutz Medical Campus, Aurora, CO, United States
- Department of Biology, San Diego State University, San Diego, CA, United States
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24
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Beninati C, Famà A, Teti G. How BspC from Streptococcus agalactiae Interacts with Host Vimentin during Meningitis. Trends Microbiol 2019; 27:727-728. [PMID: 31324435 DOI: 10.1016/j.tim.2019.07.001] [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: 07/01/2019] [Accepted: 07/02/2019] [Indexed: 10/26/2022]
Abstract
Streptococcus agalactiae meningitis is a frequent neonatal disease associated with high mortality and permanent neurological damage. Deng et al. (PLoS Pathog., 2019) now show that interactions between the bacterial protein BspC and host cell vimentin participate in the process of invasion of the meninges by this bacterial pathogen.
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Affiliation(s)
- Concetta Beninati
- Metchnikoff Laboratory, Department of Pathology, University of Messina, 98124 Messina, Italy
| | - Agata Famà
- Charybdis Vaccines S.r.l., 98124 Messina, Italy
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25
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Liu F, Li J, Yan K, Li H, Sun C, Zhang S, Yuan F, Wang X, Tan C, Chen H, Bei W. Binding of Fibronectin to SsPepO Facilitates the Development of Streptococcus suis Meningitis. J Infect Dis 2019; 217:973-982. [PMID: 29253192 DOI: 10.1093/infdis/jix523] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023] Open
Abstract
Background SsPepO is an important virulence in Streptococcus suis. Methods In this study, we showed that SsPepO contributes to the human fibronectin-mediated adherence ability of S. suis to human brain microvascular endothelial cells. Results The addition of an antifibronectin antibody or an arginine-glycine-aspartic acid peptide that blocks fibronectin binding to integrins significantly reduced adherence of the wild-type but not the SspepO mutant strain, indicating the importance of the SsPepO-fibronectin-integrin interaction for S. suis cellular adherence. Conclusions By analyzing Evans blue extravasation in vivo, we showed that the interaction between SsPepO and human fibronectin significantly increased permeability of the blood-brain barrier. Furthermore, the SspepO mutant caused lower bacterial loads in the brain than wild-type S. suis in models of meningitis. These data demonstrate that SsPepO is a fibronectin-binding protein, which plays a contributing role in the development of S. suis meningitis.
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Affiliation(s)
- Feng Liu
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, Hubei, China.,The Cooperative Innovation Center for Sustainable Pig Production, Huazhong Agricultural University, Wuhan, Hubei, China.,Key Laboratory of Development of Veterinary Diagnostic Products of Ministry of Agriculture, Huazhong Agricultural University, Wuhan, Hubei, China
| | - Jinquan Li
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, Hubei, China.,State Key Laboratory of Agricultural Microbiology, College of Food Science and Technology, Huazhong Agricultural University, Wuhan, Hubei, China
| | - Kang Yan
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, Hubei, China.,The Cooperative Innovation Center for Sustainable Pig Production, Huazhong Agricultural University, Wuhan, Hubei, China.,Key Laboratory of Development of Veterinary Diagnostic Products of Ministry of Agriculture, Huazhong Agricultural University, Wuhan, Hubei, China
| | - Huan Li
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, Hubei, China.,The Cooperative Innovation Center for Sustainable Pig Production, Huazhong Agricultural University, Wuhan, Hubei, China.,Key Laboratory of Development of Veterinary Diagnostic Products of Ministry of Agriculture, Huazhong Agricultural University, Wuhan, Hubei, China
| | - Chengfeng Sun
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, Hubei, China.,The Cooperative Innovation Center for Sustainable Pig Production, Huazhong Agricultural University, Wuhan, Hubei, China.,Key Laboratory of Development of Veterinary Diagnostic Products of Ministry of Agriculture, Huazhong Agricultural University, Wuhan, Hubei, China
| | - Shuo Zhang
- Hubei Key Laboratory of Animal Embryo and Molecular Breeding, Institute of Animal Husbandry and Veterinary Sciences, Hubei Academy of Agricultural Sciences, Wuhan, China
| | - Fangyan Yuan
- Hubei Key Laboratory of Animal Embryo and Molecular Breeding, Institute of Animal Husbandry and Veterinary Sciences, Hubei Academy of Agricultural Sciences, Wuhan, China
| | - Xiangru Wang
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, Hubei, China.,The Cooperative Innovation Center for Sustainable Pig Production, Huazhong Agricultural University, Wuhan, Hubei, China.,Key Laboratory of Development of Veterinary Diagnostic Products of Ministry of Agriculture, Huazhong Agricultural University, Wuhan, Hubei, China
| | - Chen Tan
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, Hubei, China.,The Cooperative Innovation Center for Sustainable Pig Production, Huazhong Agricultural University, Wuhan, Hubei, China.,Key Laboratory of Development of Veterinary Diagnostic Products of Ministry of Agriculture, Huazhong Agricultural University, Wuhan, Hubei, China
| | - Huanchun Chen
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, Hubei, China.,The Cooperative Innovation Center for Sustainable Pig Production, Huazhong Agricultural University, Wuhan, Hubei, China.,Key Laboratory of Development of Veterinary Diagnostic Products of Ministry of Agriculture, Huazhong Agricultural University, Wuhan, Hubei, China
| | - Weicheng Bei
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, Hubei, China.,The Cooperative Innovation Center for Sustainable Pig Production, Huazhong Agricultural University, Wuhan, Hubei, China.,Key Laboratory of Development of Veterinary Diagnostic Products of Ministry of Agriculture, Huazhong Agricultural University, Wuhan, Hubei, China
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26
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Tsai MH, Hsu JF, Lai MY, Lin LC, Chu SM, Huang HR, Chiang MC, Fu RH, Lu JJ. Molecular Characteristics and Antimicrobial Resistance of Group B Streptococcus Strains Causing Invasive Disease in Neonates and Adults. Front Microbiol 2019; 10:264. [PMID: 30833941 PMCID: PMC6387999 DOI: 10.3389/fmicb.2019.00264] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2018] [Accepted: 02/01/2019] [Indexed: 11/17/2022] Open
Abstract
We aimed to analyze the molecular characteristics, clonality and antimicrobial resistance profiles of group B streptococcus (GBS) isolates collected in Taiwan from invasive diseases and carriage. Multilocus sequence typing (MLST) was used to assess the genetic diversity of 225 GBS strains from neonates and adults with invasive GBS diseases. 100 GBS strains collected from colonized pregnant women during the same period were compared, and all strains were characterized for one of nine capsule genotypes. We also determined the susceptibilities of all GBS isolates to various antimicrobial agents. The most frequently identified serotypes that caused invasive disease in neonates were III (60.6%) and Ia (17.3%), whereas type VI (32.7%), Ib (19.4%), and V (19.4%) were the most common to cause invasive disease in adults. Serotype VI was the leading type that colonized pregnant women (35.0%). Twenty-six sequence types (STs) were identified, and 90.5% of GBS strains were represented by 6 STs. ST-17 and ST-1 were more prevalent in invasive diseases in neonates and adults, respectively. The majority of serotype III and VI isolates belonged to clonal complex (CC)-17 and CC-1, respectively. ST-17 strains were more likely to cause meningitis and late-onset disease than other strains. In addition, ST-12 and ST-17 GBS strains showed the highest rate of resistance to erythromycin and clindamycin (range: 75.8–100%). In conclusion, CC-17/type III and CC-1/type VI are the most important invasive pathogens in infants and non-pregnant adults in Taiwan, respectively. GBS genotypes vary between different age groups and geographical areas and should be considered during GBS vaccine development.
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Affiliation(s)
- Ming-Horng Tsai
- Division of Neonatology and Pediatric Hematology/Oncology, Department of Pediatrics, Chang Gung Memorial Hospital, Yunlin, Taiwan.,College of Medicine, Chang Gung University, Taoyuan, Taiwan
| | - Jen-Fu Hsu
- College of Medicine, Chang Gung University, Taoyuan, Taiwan.,Division of Pediatric Neonatology, Department of Pediatrics, Chang Gung Memorial Hospital, Taoyuan, Taiwan
| | - Mei-Yin Lai
- College of Medicine, Chang Gung University, Taoyuan, Taiwan.,Division of Pediatric Neonatology, Department of Pediatrics, Chang Gung Memorial Hospital, Taoyuan, Taiwan
| | - Lee-Chung Lin
- Department of Laboratory Medicine, Chang Gung Memorial Hospital at Linkou, Taoyuan, Taiwan
| | - Shih-Ming Chu
- College of Medicine, Chang Gung University, Taoyuan, Taiwan.,Division of Pediatric Neonatology, Department of Pediatrics, Chang Gung Memorial Hospital, Taoyuan, Taiwan
| | - Hsuan-Rong Huang
- College of Medicine, Chang Gung University, Taoyuan, Taiwan.,Division of Pediatric Neonatology, Department of Pediatrics, Chang Gung Memorial Hospital, Taoyuan, Taiwan
| | - Ming-Chou Chiang
- College of Medicine, Chang Gung University, Taoyuan, Taiwan.,Division of Pediatric Neonatology, Department of Pediatrics, Chang Gung Memorial Hospital, Taoyuan, Taiwan
| | - Ren-Huei Fu
- College of Medicine, Chang Gung University, Taoyuan, Taiwan.,Division of Pediatric Neonatology, Department of Pediatrics, Chang Gung Memorial Hospital, Taoyuan, Taiwan
| | - Jang-Jih Lu
- College of Medicine, Chang Gung University, Taoyuan, Taiwan.,Department of Laboratory Medicine, Chang Gung Memorial Hospital at Linkou, Taoyuan, Taiwan.,Department of Medical Biotechnology and Laboratory Science, Chang Gung University, Taoyuan, Taiwan
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27
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Armistead B, Oler E, Adams Waldorf K, Rajagopal L. The Double Life of Group B Streptococcus: Asymptomatic Colonizer and Potent Pathogen. J Mol Biol 2019; 431:2914-2931. [PMID: 30711542 DOI: 10.1016/j.jmb.2019.01.035] [Citation(s) in RCA: 69] [Impact Index Per Article: 13.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2018] [Revised: 01/22/2019] [Accepted: 01/23/2019] [Indexed: 12/22/2022]
Abstract
Group B streptococcus (GBS) is a β-hemolytic gram-positive bacterium that colonizes the lower genital tract of approximately 18% of women globally as an asymptomatic member of the gastrointestinal and/or vaginal flora. If established in other host niches, however, GBS is highly pathogenic. During pregnancy, ascending GBS infection from the vagina to the intrauterine space is associated with preterm birth, stillbirth, and fetal injury. In addition, vertical transmission of GBS during or after birth results in life-threatening neonatal infections, including pneumonia, sepsis, and meningitis. Although the mechanisms by which GBS traffics from the lower genital tract to vulnerable host niches are not well understood, recent advances have revealed that many of the same bacterial factors that promote asymptomatic vaginal carriage also facilitate dissemination and virulence. Furthermore, highly pathogenic GBS strains have acquired unique factors that enhance survival in invasive niches. Several host factors also exist that either subdue GBS upon vaginal colonization or alternatively permit invasive infection. This review summarizes the GBS and host factors involved in GBS's state as both an asymptomatic colonizer and an invasive pathogen. Gaining a better understanding of these mechanisms is key to overcoming the challenges associated with vaccine development and identification of novel strategies to mitigate GBS virulence.
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Affiliation(s)
- Blair Armistead
- Department of Global Health, University of Washington, Seattle 98195, WA, USA; Center for Global Infectious Disease Research, Seattle Children's Research Institute, Seattle 98101, WA, USA
| | - Elizabeth Oler
- Department of Obstetrics and Gynecology, University of Washington School of Medicine, Seattle 98195, WA, USA
| | - Kristina Adams Waldorf
- Department of Global Health, University of Washington, Seattle 98195, WA, USA; Department of Obstetrics and Gynecology, University of Washington School of Medicine, Seattle 98195, WA, USA; Center for Innate Immunity and Immune Disease, University of Washington, Seattle 98109, WA, USA; Sahlgrenska Academy, Gothenburg University, Gothenburg 413 90, Sweden
| | - Lakshmi Rajagopal
- Department of Global Health, University of Washington, Seattle 98195, WA, USA; Center for Global Infectious Disease Research, Seattle Children's Research Institute, Seattle 98101, WA, USA; Department of Pediatrics, University of Washington School of Medicine, Seattle 98195, WA, USA.
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28
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Crystal structure of GAPDH of Streptococcus agalactiae and characterization of its interaction with extracellular matrix molecules. Microb Pathog 2018; 127:359-367. [PMID: 30553015 DOI: 10.1016/j.micpath.2018.12.020] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2018] [Revised: 11/10/2018] [Indexed: 11/21/2022]
Abstract
GAPDH being a key enzyme in the glycolytic pathway is one of the surface adhesins of many Gram-positive bacteria including Streptococcus agalactiae. This anchorless adhesin is known to bind to host plasminogen (PLG) and fibrinogen (Fg), which enhances the virulence and modulates the host immune system. The crystal structure of the recombinant GAPDH from S. agalactiae (SagGAPDH) was determined at 2.6 Å resolution by molecular replacement. The structure was found to be highly conserved with a typical NAD binding domain and a catalytic domain. In this paper, using biolayer interferometry studies, we report that the multifunctional SagGAPDH enzyme binds to a variety of host molecules such as PLG, Fg, laminin, transferrin and mucin with a KD value of 4.4 × 10-7 M, 9.8 × 10-7 M, 1 × 10-5 M, 9.7 × 10-12 M and 1.4 × 10-7 M respectively. The ligand affinity blots reveal that SagGAPDH binds specifically to α and β subunits of Fg and the competitive binding ELISA assay reveals that the Fg and PLG binding sites on GAPDH does not overlap each other. The PLG binding motif of GAPDH varies with organisms, however positively charged residues in the hydrophobic surroundings is essential for PLG binding. The lysine analogue competitive binding assay and lysine succinylation experiments deciphered the role of SagGAPDH lysines in PLG binding. On structural comparison with S. pneumoniae GAPDH, K171 of SagGAPDH is being predicted to be involved in PLG binding. Further SagGAPDH exhibited enzymatic activity in the presence of Fg, PLG and transferrin. This suggests that these host molecules does not mask the active site and bind at some other region of GAPDH.
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29
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Rizvi SMD, Hussain T, Ahmed ABF, Alshammari TM, Moin A, Ahmed MQ, Barreto GE, Kamal MA, Ashraf GM. Gold nanoparticles: A plausible tool to combat neurological bacterial infections in humans. Biomed Pharmacother 2018; 107:7-18. [PMID: 30075371 DOI: 10.1016/j.biopha.2018.07.130] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2018] [Revised: 07/16/2018] [Accepted: 07/24/2018] [Indexed: 01/08/2023] Open
Abstract
Management of bacterial infections of central nervous system is a major challenge for the scientists all over the world. Despite the development of various potential drugs, the issue of central nervous system infections persists in the society. The main constraint is the delivery of drugs across the blood brain barrier and only a few drugs after meeting the stringent criteria could cross the blood brain barrier. On the other hand, certain bacterial pathogens could easily enter the brain by using several factors and mechanisms by crossing the blood brain barriers. Interestingly, in the recent past, gold nanoparticles have shown immense potential to overcome the issues associated with the treatment of central nervous system infections, especially due to their inherent ability to cross the blood brain barrier. Initially, the present review summarized the recent updates on the pathogenesis and factors involved in neurological bacterial infections, including the mechanism used by bacterial pathogens to cross the blood brain barriers. Thereafter, the emphasis of the review was on providing current information on gold nanoparticles pertinent to their applicability for the treatment of neurological infections. After discussing the background of neurological bacterial infections, the characteristic features, antibacterial properties, mechanisms of antibacterial action and ability to cross the blood brain barrier of gold nanoparticles have been summarized. Some of the features of gold nanoparticles that make them an ideal candidate for brain delivery are biocompatibity, stability, ability to get synthesized in different sizes with facile methods, surface affinity towards various functional groups, spontaneous crossing of blood brain barrier without applying any external field and most importantly, easy non-invasive tracing by CT imaging. The current updates on the development of gold nanoparticles based therapeutic strategies for the prevention and treatment of central nervous system infections have been discussed in the present study. However, further investigation would be required to translate these preclinical outcomes into clinical applications. Nevertheless, we could safely state that the information gathered and discussed in the present review would benefit the scientists working in the field of neuro-nanotechnology.
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Affiliation(s)
- Syed Mohd Danish Rizvi
- Department of Pharmacology and Toxicology, College of Pharmacy, University of Hail, Hail, Saudi Arabia.
| | - Talib Hussain
- Department of Pharmacology and Toxicology, College of Pharmacy, University of Hail, Hail, Saudi Arabia
| | - Abo Bakr Fathy Ahmed
- Department of Pharmaceutics, College of Pharmacy, University of Hail, Hail, Saudi Arabia
| | - Thamir M Alshammari
- Department of Clinical Pharmacy, College of Pharmacy, University of Hail, Hail, Saudi Arabia
| | - Afrasim Moin
- Department of Pharmaceutics, College of Pharmacy, University of Hail, Hail, Saudi Arabia
| | - Mohammed Qumani Ahmed
- Department of Pharmacology, College of Medicine,University of Hail, Hail, Saudi Arabia
| | - George E Barreto
- Departamento de Nutrición y Bioquímica, Facultad de Ciencias, Pontificia Universidad Javeriana, Bogotá D.C, Colombia; Instituto de Ciencias Biomédicas, Universidad Autónoma de Chile, Santiago, Chile
| | - Mohammad Ajmal Kamal
- Enzymoics, 7 Peterlee Place, Hebersham, NSW 2770, Sydney, Australia; Novel Global Community Educational Foundation, Australia; King Fahd Medical Research Center, King Abdulaziz University, Jeddah 21589, Saudi Arabia
| | - Ghulam Md Ashraf
- King Fahd Medical Research Center, King Abdulaziz University, Jeddah 21589, Saudi Arabia.
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30
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Vornhagen J, Armistead B, Santana-Ufret V, Gendrin C, Merillat S, Coleman M, Quach P, Boldenow E, Alishetti V, Leonhard-Melief C, Ngo LY, Whidbey C, Doran KS, Curtis C, Waldorf KMA, Nance E, Rajagopal L. Group B streptococcus exploits vaginal epithelial exfoliation for ascending infection. J Clin Invest 2018; 128:1985-1999. [PMID: 29629904 DOI: 10.1172/jci97043] [Citation(s) in RCA: 46] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2017] [Accepted: 02/27/2018] [Indexed: 12/11/2022] Open
Abstract
Thirteen percent of pregnancies result in preterm birth or stillbirth, accounting for fifteen million preterm births and three and a half million deaths annually. A significant cause of these adverse pregnancy outcomes is in utero infection by vaginal microorganisms. To establish an in utero infection, vaginal microbes enter the uterus by ascending infection; however, the mechanisms by which this occurs are unknown. Using both in vitro and murine models of vaginal colonization and ascending infection, we demonstrate how a vaginal microbe, group B streptococcus (GBS), which is frequently associated with adverse pregnancy outcomes, uses vaginal exfoliation for ascending infection. GBS induces vaginal epithelial exfoliation by activation of integrin and β-catenin signaling. However, exfoliation did not diminish GBS vaginal colonization as reported for other vaginal microbes. Rather, vaginal exfoliation increased bacterial dissemination and ascending GBS infection, and abrogation of exfoliation reduced ascending infection and improved pregnancy outcomes. Thus, for some vaginal bacteria, exfoliation promotes ascending infection rather than preventing colonization. Our study provides insight into mechanisms of ascending infection by vaginal microbes.
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Affiliation(s)
- Jay Vornhagen
- Department of Global Health, University of Washington, Seattle, Washington, USA.,Center for Global Infectious Disease Research, Seattle Children's Research Institute, Seattle, Washington, USA
| | - Blair Armistead
- Department of Global Health, University of Washington, Seattle, Washington, USA.,Center for Global Infectious Disease Research, Seattle Children's Research Institute, Seattle, Washington, USA
| | - Verónica Santana-Ufret
- Center for Global Infectious Disease Research, Seattle Children's Research Institute, Seattle, Washington, USA
| | - Claire Gendrin
- Center for Global Infectious Disease Research, Seattle Children's Research Institute, Seattle, Washington, USA
| | - Sean Merillat
- Center for Global Infectious Disease Research, Seattle Children's Research Institute, Seattle, Washington, USA
| | - Michelle Coleman
- Center for Global Infectious Disease Research, Seattle Children's Research Institute, Seattle, Washington, USA.,Department of Pediatrics, University of Washington, Seattle, Washington, USA
| | - Phoenicia Quach
- Center for Global Infectious Disease Research, Seattle Children's Research Institute, Seattle, Washington, USA
| | - Erica Boldenow
- Center for Global Infectious Disease Research, Seattle Children's Research Institute, Seattle, Washington, USA.,Department of Pediatrics, University of Washington, Seattle, Washington, USA
| | - Varchita Alishetti
- Center for Global Infectious Disease Research, Seattle Children's Research Institute, Seattle, Washington, USA
| | | | - Lisa Y Ngo
- Center for Global Infectious Disease Research, Seattle Children's Research Institute, Seattle, Washington, USA
| | - Christopher Whidbey
- Department of Global Health, University of Washington, Seattle, Washington, USA.,Center for Global Infectious Disease Research, Seattle Children's Research Institute, Seattle, Washington, USA
| | - Kelly S Doran
- Department of Microbiology and Immunology, University of Colorado Denver, Aurora, Colorado, USA
| | | | - Kristina M Adams Waldorf
- Department of Global Health, University of Washington, Seattle, Washington, USA.,Department of Obstetrics and Gynecology, and.,Center for Innate Immunity and Immune Disease, University of Washington, Seattle, Washington, USA.,Sahlgrenska Academy, Gothenburg University, Gothenburg, Sweden
| | | | - Lakshmi Rajagopal
- Department of Global Health, University of Washington, Seattle, Washington, USA.,Center for Global Infectious Disease Research, Seattle Children's Research Institute, Seattle, Washington, USA.,Department of Pediatrics, University of Washington, Seattle, Washington, USA.,Center for Innate Immunity and Immune Disease, University of Washington, Seattle, Washington, USA
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31
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Shabayek S, Spellerberg B. Group B Streptococcal Colonization, Molecular Characteristics, and Epidemiology. Front Microbiol 2018; 9:437. [PMID: 29593684 PMCID: PMC5861770 DOI: 10.3389/fmicb.2018.00437] [Citation(s) in RCA: 154] [Impact Index Per Article: 25.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2017] [Accepted: 02/26/2018] [Indexed: 11/13/2022] Open
Abstract
Streptococcus agalactiae or group B streptococcus (GBS) is a leading cause of serious neonatal infections. GBS is an opportunistic commensal constituting a part of the intestinal and vaginal physiologic flora and maternal colonization is the principal route of GBS transmission. GBS is a pathobiont that converts from the asymptomatic mucosal carriage state to a major bacterial pathogen causing severe invasive infections. At present, as many as 10 serotypes (Ia, Ib, and II–IX) are recognized. The aim of the current review is to shed new light on the latest epidemiological data and clonal distribution of GBS in addition to discussing the most important colonization determinants at a molecular level. The distribution and predominance of certain serotypes is susceptible to variations and can change over time. With the availability of multilocus sequence typing scheme (MLST) data, it became clear that GBS strains of certain clonal complexes possess a higher potential to cause invasive disease, while other harbor mainly colonizing strains. Colonization and persistence in different host niches is dependent on the adherence capacity of GBS to host cells and tissues. Bacterial biofilms represent well-known virulence factors with a vital role in persistence and chronic infections. In addition, GBS colonization, persistence, translocation, and invasion of host barriers are largely dependent on their adherence abilities to host cells and extracellular matrix proteins (ECM). Major adhesins mediating GBS interaction with host cells include the fibrinogen-binding proteins (Fbs), the laminin-binding protein (Lmb), the group B streptococcal C5a peptidase (ScpB), the streptococcal fibronectin binding protein A (SfbA), the GBS immunogenic bacterial adhesin (BibA), and the hypervirulent adhesin (HvgA). These adhesins facilitate persistent and intimate contacts between the bacterial cell and the host, while global virulence regulators play a major role in the transition to invasive infections. This review combines for first time epidemiological data with data on adherence and colonization for GBS. Investigating the epidemiology along with understanding the determinants of mucosal colonization and the development of invasive disease at a molecular level is therefore important for the development of strategies to prevent invasive GBS disease worldwide.
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Affiliation(s)
- Sarah Shabayek
- Department of Microbiology and Immunology, Faculty of Pharmacy, Suez Canal University, Ismailia, Egypt
| | - Barbara Spellerberg
- Institute of Medical Microbiology and Hygiene, University of Ulm, Ulm, Germany
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32
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Chen X, Harkness L, Jia Z, Prowse A, Monteiro MJ, Gray PP. Methods for Expansion of Three-Dimensional Cultures of Human Embryonic Stem Cells Using a Thermoresponsive Polymer. Tissue Eng Part C Methods 2017; 24:146-157. [PMID: 29239281 DOI: 10.1089/ten.tec.2017.0331] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023] Open
Abstract
Human pluripotent stem cells (hPSCs) are viewed as promising candidates for applications in regenerative medicine and therapy due to their proliferative and pluripotent properties. However, obtaining clinically significant numbers of hPSCs remains a limiting factor and impedes their use in therapeutic applications. Conventionally, hPSCs are cultured on two-dimensional surfaces coated with a suitable substrate, such as Matrigel™. This method, however, requires a large surface area to generate sufficient cell numbers to meet clinical needs and is therefore impractical as a manufacturing platform for cell expansion. In addition, the use of enzymes for cell detachment and small molecule inhibitors to increase plating efficiency may impact future cell behavior when used for routine subculturing. In this study, we describe a protocol to generate and maintain hPSC aggregates in a three-dimensional suspension culture by utilizing thermoresponsive nanobridges. The property of the polymer used in the nanobridges enables passaging and expansion through a temperature change in combination with mechanically applied shear to dissociate aggregates; thus, we eliminate the need of enzymes or small molecules for cell dissociation and viability, respectively. Utilizing this platform, maintenance of human embryonic stem cells for three continuous passages demonstrated high expression levels in key pluripotent markers.
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Affiliation(s)
- Xiaoli Chen
- 1 Australian Institute for Bioengineering and Nanotechnology (AIBN), University of Queensland , Brisbane, Australia
| | - Linda Harkness
- 1 Australian Institute for Bioengineering and Nanotechnology (AIBN), University of Queensland , Brisbane, Australia
| | - Zhongfan Jia
- 1 Australian Institute for Bioengineering and Nanotechnology (AIBN), University of Queensland , Brisbane, Australia
| | - Andrew Prowse
- 2 The Garvan Institute of Medical Research , Sydney, Australia
| | - Michael J Monteiro
- 1 Australian Institute for Bioengineering and Nanotechnology (AIBN), University of Queensland , Brisbane, Australia
| | - Peter P Gray
- 1 Australian Institute for Bioengineering and Nanotechnology (AIBN), University of Queensland , Brisbane, Australia
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Modeling Group B Streptococcus and Blood-Brain Barrier Interaction by Using Induced Pluripotent Stem Cell-Derived Brain Endothelial Cells. mSphere 2017; 2:mSphere00398-17. [PMID: 29104935 PMCID: PMC5663983 DOI: 10.1128/msphere.00398-17] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2017] [Accepted: 10/05/2017] [Indexed: 11/20/2022] Open
Abstract
Bacterial meningitis is a serious infection of the central nervous system (CNS) that occurs after bacteria interact with and penetrate the blood-brain barrier (BBB). The BBB is comprised of highly specialized brain microvascular endothelial cells (BMECs) that function to separate the circulation from the CNS and act as a formidable barrier for toxins and pathogens. Certain bacteria, such as Streptococcus agalactiae (group B Streptococcus [GBS]), possess the ability to interact with and penetrate the BBB to cause meningitis. Modeling bacterial interaction with the BBB in vitro has been limited to primary and immortalized BMEC culture. While useful, these cells often do not retain BBB-like properties, and human primary cells have limited availability. Recently, a human induced pluripotent stem cell (iPSC)-derived BMEC model has been established that is readily renewable and retains key BBB phenotypes. Here, we sought to evaluate whether the iPSC-derived BMECs were appropriate for modeling bacterial interaction with the BBB. Using GBS as a model meningeal pathogen, we demonstrate that wild-type GBS adhered to, invaded, and activated the iPSC-derived BMECs, while GBS mutants known to have diminished BBB interaction were attenuated in the iPSC-derived model. Furthermore, bacterial infection resulted in the disruption of tight junction components ZO-1, occludin, and claudin-5. Thus, we show for the first time that the iPSC-derived BBB model can be utilized to study BBB interaction with a bacterial CNS pathogen. IMPORTANCE Here for the first time, human iPSC-derived BMECs were used to model bacterial interaction with the BBB. Unlike models previously used to study these interactions, iPSC-derived BMECs possess robust BBB properties, such as the expression of complex tight junctions that are key components for the investigation of bacterial effects on the BBB. Here, we demonstrated that GBS interacts with the iPSC-derived BMECs and specifically disrupts these tight junctions. Thus, using this BBB model may allow researchers to uncover novel mechanisms of BBB disruption during meningitis that are inaccessible to immortalized or primary cell models that lack substantial tight junctions.
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Luo S, Cao Q, Ma K, Wang Z, Liu G, Lu C, Liu Y. Quantitative assessment of the blood-brain barrier opening caused by Streptococcus agalactiae hyaluronidase in a BALB/c mouse model. Sci Rep 2017; 7:13529. [PMID: 29051603 PMCID: PMC5648924 DOI: 10.1038/s41598-017-13234-1] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2017] [Accepted: 09/20/2017] [Indexed: 12/30/2022] Open
Abstract
Streptococcus agalactiae is a pathogen causing meningitis in animals and humans. However, little is known about the entry of S. agalactiae into brain tissue. In this study, we developed a BALB/c mouse model based on the intravenous injection of β-galactosidase-positive Escherichia coli M5 as an indicator of blood-brain barrier (BBB) opening. Under physiological conditions, the BBB is impermeable to E. coli M5. In pathological conditions caused by S. agalactiae, E. coli M5 is capable of penetrating the brain through a disrupted BBB. The level of BBB opening can be assessed by quantitative measurement of E. coli M5 loads per gram of brain tissue. Further, we used the model to evaluate the role of S. agalactiae hyaluronidase in BBB opening. The inactivation of hylB gene encoding a hyaluronidase, HylB, resulted in significantly decreased E. coli M5 colonization, and the intravenous injection of purified HylB protein induced BBB opening in a dose-dependent manner. This finding verified the direct role of HylB in BBB invasion and traversal, and further demonstrated the practicability of the in vivo mouse model established in this study. This model will help to understand the S. agalactiae-host interactions that are involved in this bacterial traversal of the BBB and to develop efficacious strategies to prevent central nervous system infections.
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Affiliation(s)
- Su Luo
- College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, 210095, China
| | - Qing Cao
- College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, 210095, China
| | - Ke Ma
- College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, 210095, China
| | - Zhaofei Wang
- College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, 210095, China
| | - Guangjin Liu
- College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, 210095, China
| | - Chengping Lu
- College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, 210095, China
| | - Yongjie Liu
- College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, 210095, China.
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Group B Streptococcus: developing a correlate of protection for a vaccine against neonatal infections. Curr Opin Infect Dis 2017; 29:262-7. [PMID: 26926474 DOI: 10.1097/qco.0000000000000266] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
PURPOSE OF REVIEW Maternal vaccination to prevent invasive Group B Streptococcus (GBS) disease in infants is an important alternative strategy to intrapartum antibiotic prophylaxis. Licensure of GBS vaccines could be expedited using immunological correlates of protection. RECENT FINDINGS Between 2014 and 2015, we identified two studies that demonstrated an inverse association between invasive GBS disease and maternal serotype III capsular antibody levels greater than 1 μg/ml and greater than 3 μg/ml, and higher maternal antibody levels were associated with protection against serotype Ia disease. Furthermore, serotype Ia and III antibody levels greater than 3 μg/ml were associated with a reduced risk of GBS colonization in pregnant women.Experimental studies have investigated the use of GBS surface proteins as vaccine candidates. Although the immunogenic potential of pilus island and other surface proteins has been shown in animal-model studies, no association between maternal pilus island antibody levels and invasive GBS disease was demonstrated in infants. Additionally, several novel innate immune mediators that prevent GBS infection have been described in human and experimental studies. SUMMARY Recent studies suggest that maternal capsular antibody thresholds may be used as immunological correlates of protection for vaccine licensure. Surface proteins, as candidate vaccines or conjugates to the polysaccharide-protein vaccine, may broaden protection against invasive GBS disease.
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Gendrin C, Shubin NJ, Boldenow E, Merillat S, Clauson M, Power D, Doran KS, Abrink M, Pejler G, Rajagopal L, Piliponsky AM. Mast cell chymase decreases the severity of group B Streptococcus infections. J Allergy Clin Immunol 2017; 142:120-129.e6. [PMID: 28916188 DOI: 10.1016/j.jaci.2017.07.042] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2017] [Revised: 07/06/2017] [Accepted: 07/24/2017] [Indexed: 12/13/2022]
Abstract
BACKGROUND Group B Streptococcus (GBS) or Streptococcus agalactiae are β-hemolytic gram-positive bacteria that colonize the lower genital tracts of women and are frequently associated with infections during pregnancy. Innate immune defenses are critical for controlling GBS dissemination and systemic infection. Mast cells are resident sentinel cells that come into contact with pathogens early during colonization and infection. OBJECTIVE We aimed to investigate the contribution of chymase to systemic GBS infection and rates of preterm birth. METHODS Pharmacologic and genetic approaches using mice deficient in mast cell protease (MCPT) 4, the mouse functional homologue of human chymase, were used. RESULTS Our studies show that mast cells release a protease with chymotrypsin-like cleavage specificity in response to GBS. Additionally, increased GBS systemic infection and preterm births were observed in MCPT4-deficient mice versus MCPT4-sufficient mice. Furthermore, we observed that proteolytic cleavage of the host extracellular matrix protein fibronectin by peritoneal cell-derived mast cell lysates diminished GBS adherence. Consistent with this observation, the increase in GBS dissemination and preterm births observed in MCPT4-deficient mice was abolished when GBS was deficient in expression of the fibronectin-binding protein SfbA. CONCLUSIONS Taken together, our results suggest that the protective effect of MCPT4 against GBS dissemination and preterm labor can be attributed in part to MCPT4-mediated proteolysis of fibronectin. Our studies reveal a novel role of mast cells in defense against bacterial infections.
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Affiliation(s)
- Claire Gendrin
- Department of Pediatric Infectious Diseases, University of Washington, Seattle, Wash; Seattle Children's Research Institute, Seattle, Wash
| | | | | | - Sean Merillat
- Seattle Children's Research Institute, Seattle, Wash
| | | | - Danial Power
- Seattle Children's Research Institute, Seattle, Wash
| | - Kelly S Doran
- Department of Biology and Center for Microbial Sciences, San Diego State University, San Diego, Calif; Department of Pediatrics, University of California San Diego School of Medicine, La Jolla, Calif
| | - Magnus Abrink
- Department of Biomedical Sciences and Veterinary Public Health, Swedish University for Agricultural Sciences, Uppsala, Sweden
| | - Gunnar Pejler
- Department of Medical Biochemistry and Microbiology, Uppsala University, Uppsala, Sweden; Department of Anatomy, Physiology and Biochemistry, the Swedish University of Agricultural Sciences, Uppsala, Sweden
| | - Lakshmi Rajagopal
- Department of Pediatric Infectious Diseases, University of Washington, Seattle, Wash; Seattle Children's Research Institute, Seattle, Wash; Department of Global Health, University of Washington, Seattle, Wash.
| | - Adrian M Piliponsky
- Department of Pediatric Infectious Diseases, University of Washington, Seattle, Wash; Seattle Children's Research Institute, Seattle, Wash.
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Lazzarin M, Mu R, Fabbrini M, Ghezzo C, Rinaudo CD, Doran KS, Margarit I. Contribution of pilus type 2b to invasive disease caused by a Streptococcus agalactiae ST-17 strain. BMC Microbiol 2017; 17:148. [PMID: 28673237 PMCID: PMC5496222 DOI: 10.1186/s12866-017-1057-8] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2016] [Accepted: 06/23/2017] [Indexed: 12/02/2022] Open
Abstract
Background Group B Streptococcus (GBS) is a major cause of invasive disease especially in neonates. In GBS three structurally distinct pilus polymers have been identified as important virulence factors and promising vaccine candidates. The vast majority of Group B Streptococci belonging to the hypervirulent serotype III ST-17 lineage bear pilus types 1 and 2b. The purpose of this study was to investigate the relative contribution of these two pilus types to the pathogenesis of a ST-17 strain. Results We performed in vivo and in vitro analysis of isogenic knockout mutants derived from the GBS COH1 ST-17 strain deprived of either pilus type 1 or 2b. We compared the two pilus mutants with the wild type strain in a mouse model of invasive disease, in vitro survival in macrophages, and adherence/invasion assays using human brain endothelial and lung epithelial cell lines. Significantly less of the pilus 2b mutant was recovered from the blood, lungs and brain tissue of infected mice compared to the wild-type and pilus 1 mutant strains. Further, while the pilus 2b mutant survived similarly in murine macrophages, it exhibited a lower capacity to adhere and invade human brain epithelial and lung endothelial cell lines. Conclusions The data suggest an important role of pilus 2b in mediating GBS infection and host cell interaction of strains belonging to the hypervirulent GBS ST-17 lineage.
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Affiliation(s)
| | - Rong Mu
- Department of Biology and Center for Microbial Sciences, San Diego State University, 5500 Campanile Dr., NLS 317, San Diego, CA, 92182, USA
| | | | | | | | - Kelly S Doran
- Department of Biology and Center for Microbial Sciences, San Diego State University, 5500 Campanile Dr., NLS 317, San Diego, CA, 92182, USA.,Department of Pediatrics, University of California San Diego School of Medicine, La Jolla, CA, 92093, USA
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A journey into the brain: insight into how bacterial pathogens cross blood-brain barriers. Nat Rev Microbiol 2017; 15:149-159. [PMID: 28090076 DOI: 10.1038/nrmicro.2016.178] [Citation(s) in RCA: 164] [Impact Index Per Article: 23.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
The blood-brain barrier, which is one of the tightest barriers in the body, protects the brain from insults, such as infections. Indeed, only a few of the numerous blood-borne bacteria can cross the blood-brain barrier to cause meningitis. In this Review, we focus on invasive extracellular pathogens, such as Neisseria meningitidis, Streptococcus pneumoniae, group B Streptococcus and Escherichia coli, to review the obstacles that bacteria have to overcome in order to invade the meninges from the bloodstream, and the specific skills they have developed to bypass the blood-brain barrier. The medical importance of understanding how these barriers can be circumvented is underlined by the fact that we need to improve drug delivery into the brain.
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Buscetta M, Firon A, Pietrocola G, Biondo C, Mancuso G, Midiri A, Romeo L, Galbo R, Venza M, Venza I, Kaminski PA, Gominet M, Teti G, Speziale P, Trieu-Cuot P, Beninati C. PbsP, a cell wall-anchored protein that binds plasminogen to promote hematogenous dissemination of group B Streptococcus. Mol Microbiol 2016; 101:27-41. [PMID: 26888569 DOI: 10.1111/mmi.13357] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 02/15/2016] [Indexed: 02/04/2023]
Abstract
Streptococcus agalactiae (Group B Streptococcus or GBS) is a leading cause of invasive infections in neonates whose virulence is dependent on its ability to interact with cells and host components. We here characterized a surface protein with a critical function in GBS pathophysiology. This adhesin, designated PbsP, possesses two Streptococcal Surface Repeat domains, a methionine and lysine-rich region, and a LPXTG cell wall-anchoring motif. PbsP mediates plasminogen (Plg) binding both in vitro and in vivo and we showed that cell surface-bound Plg can be activated into plasmin by tissue plasminogen activator to increase the bacterial extracellular proteolytic activity. Absence of PbsP results in a decreased bacterial transmigration across brain endothelial cells and impaired virulence in a murine model of infection. PbsP is conserved among the main GBS lineages and is a major plasminogen adhesin in non-CC17 GBS strains. Importantly, immunization of mice with recombinant PbsP confers protective immunity. Our results indicate that GBS have evolved different strategies to recruit Plg which indicates that the ability to acquire cell surface proteolytic activity is essential for the invasiveness of this bacterium.
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Affiliation(s)
- Marco Buscetta
- Metchnikoff Laboratory, Departments of Human Pathology and Medicine, University of Messina, Messina, Italy.,Institut Pasteur, Unité de Biologie des Bactéries Pathogènes à Gram Positif, CNRS ERL3526, 75015, Paris, France
| | - Arnaud Firon
- Institut Pasteur, Unité de Biologie des Bactéries Pathogènes à Gram Positif, CNRS ERL3526, 75015, Paris, France
| | - Giampiero Pietrocola
- Department of Molecular Medicine, Unit of Biochemistry, University of Pavia, Pavia, Italy
| | - Carmelo Biondo
- Metchnikoff Laboratory, Departments of Human Pathology and Medicine, University of Messina, Messina, Italy
| | - Giuseppe Mancuso
- Metchnikoff Laboratory, Departments of Human Pathology and Medicine, University of Messina, Messina, Italy
| | - Angelina Midiri
- Metchnikoff Laboratory, Departments of Human Pathology and Medicine, University of Messina, Messina, Italy
| | - Letizia Romeo
- Metchnikoff Laboratory, Departments of Human Pathology and Medicine, University of Messina, Messina, Italy
| | - Roberta Galbo
- Metchnikoff Laboratory, Departments of Human Pathology and Medicine, University of Messina, Messina, Italy
| | - Mario Venza
- Metchnikoff Laboratory, Departments of Human Pathology and Medicine, University of Messina, Messina, Italy
| | - Isabella Venza
- Metchnikoff Laboratory, Departments of Human Pathology and Medicine, University of Messina, Messina, Italy
| | - Pierre-Alexandre Kaminski
- Institut Pasteur, Unité de Biologie des Bactéries Pathogènes à Gram Positif, CNRS ERL3526, 75015, Paris, France
| | - Myriam Gominet
- Institut Pasteur, Unité de Biologie des Bactéries Pathogènes à Gram Positif, CNRS ERL3526, 75015, Paris, France
| | - Giuseppe Teti
- Metchnikoff Laboratory, Departments of Human Pathology and Medicine, University of Messina, Messina, Italy
| | - Pietro Speziale
- Department of Molecular Medicine, Unit of Biochemistry, University of Pavia, Pavia, Italy
| | - Patrick Trieu-Cuot
- Institut Pasteur, Unité de Biologie des Bactéries Pathogènes à Gram Positif, CNRS ERL3526, 75015, Paris, France
| | - Concetta Beninati
- Metchnikoff Laboratory, Departments of Human Pathology and Medicine, University of Messina, Messina, Italy.,Scylla Biotech Srl, Messina, Italy
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Mu R, Cutting AS, Del Rosario Y, Villarino N, Stewart L, Weston TA, Patras KA, Doran KS. Identification of CiaR Regulated Genes That Promote Group B Streptococcal Virulence and Interaction with Brain Endothelial Cells. PLoS One 2016; 11:e0153891. [PMID: 27100296 PMCID: PMC4839699 DOI: 10.1371/journal.pone.0153891] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2015] [Accepted: 04/05/2016] [Indexed: 11/18/2022] Open
Abstract
Group B Streptococcus (GBS) is a major causative agent of neonatal meningitis due to its ability to efficiently cross the blood-brain barrier (BBB) and enter the central nervous system (CNS). It has been demonstrated that GBS can invade human brain microvascular endothelial cells (hBMEC), a primary component of the BBB; however, the mechanism of intracellular survival and trafficking is unclear. We previously identified a two component regulatory system, CiaR/H, which promotes GBS intracellular survival in hBMEC. Here we show that a GBS strain deficient in the response regulator, CiaR, localized more frequently with Rab5, Rab7 and LAMP1 positive vesicles. Further, lysosomes isolated from hBMEC contained fewer viable bacteria following initial infection with the ΔciaR mutant compared to the WT strain. To characterize the contribution of CiaR-regulated genes, we constructed isogenic mutant strains lacking the two most down-regulated genes in the CiaR-deficient mutant, SAN_2180 and SAN_0039. These genes contributed to bacterial uptake and intracellular survival. Furthermore, competition experiments in mice showed that WT GBS had a significant survival advantage over the Δ2180 and Δ0039 mutants in the bloodstream and brain.
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Affiliation(s)
- Rong Mu
- Department of Biology and Center for Microbial Sciences, San Diego State University, San Diego, California, 92182, United States of America
| | - Andrew S. Cutting
- Department of Biology and Center for Microbial Sciences, San Diego State University, San Diego, California, 92182, United States of America
| | - Yvette Del Rosario
- Department of Biology and Center for Microbial Sciences, San Diego State University, San Diego, California, 92182, United States of America
| | - Nicholas Villarino
- Department of Biology and Center for Microbial Sciences, San Diego State University, San Diego, California, 92182, United States of America
| | - Lara Stewart
- Department of Biology and Center for Microbial Sciences, San Diego State University, San Diego, California, 92182, United States of America
| | - Thomas A. Weston
- Department of Biology and Center for Microbial Sciences, San Diego State University, San Diego, California, 92182, United States of America
| | - Kathryn A. Patras
- Department of Biology and Center for Microbial Sciences, San Diego State University, San Diego, California, 92182, United States of America
| | - Kelly S. Doran
- Department of Biology and Center for Microbial Sciences, San Diego State University, San Diego, California, 92182, United States of America
- Department of Pediatrics, University of California San Diego School of Medicine, La Jolla, California, 92093, United States of America
- * E-mail:
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Dehbashi S, Pourmand MR, Mashhadi R. Characterization of Afb, a novel bifunctional protein in Streptococcus agalactiae. IRANIAN JOURNAL OF MICROBIOLOGY 2016; 8:73-9. [PMID: 27092228 PMCID: PMC4833744] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/02/2022]
Abstract
BACKGROUND AND OBJECTIVES Streptococcus agalactiae is the leading cause of bacterial sepsis and meningitis in newborns and results in pneumonia and bacteremia in adults. A number of S. agalactiae components are involved in colonization of target cells. Destruction of peptidoglycan and division of covalently linked daughter cells is mediated by autolysins. In this study, autolytic activity and plasma binding ability of AFb novel recombinant protein of S. agalactiae was investigated. MATERIALS AND METHODS The gbs1805 gene was cloned and expressed. E. coli strains DH5α and BL21 were used as cloning and expression hosts, respectively. After purification, antigenicity and binding ability to plasma proteins of the recombinant protein was evaluated. RESULTS AFb, the 18KDa protein was purified successfully. The insoluble mature protein revealed the ability to bind to fibrinogen and fibronectin. This insoluble mature protein revealed that it has the ability to bind to fibrinogen and fibronectin plasma proteins. Furthermore, in silico analysis demonstrated the AFb has an autolytic activity. CONCLUSIONS AFb is a novel protein capable of binding to fibrinogen and fibronectin. This findings lay a ground work for further investigation of the role of the bacteria in adhesion and colonization to the host.
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Affiliation(s)
- Sanaz Dehbashi
- Department of Pathobiology, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran
| | - Mohammad Reza Pourmand
- Urology Research Center, Tehran University of Medical Sciences, Tehran, Iran,Corresponding author: Mohammad Reza Pourmand Address: Department of Pathobiology, School of Public Health and Biotechnology Research Center, Tehran University of Medical Sciences, Tehran, Iran. Tel: +98-21- 88954910, E-mail:
| | - Rahil Mashhadi
- Urology Research Center, Tehran University of Medical Sciences, Tehran, Iran
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Doran KS, Fulde M, Gratz N, Kim BJ, Nau R, Prasadarao N, Schubert-Unkmeir A, Tuomanen EI, Valentin-Weigand P. Host-pathogen interactions in bacterial meningitis. Acta Neuropathol 2016; 131:185-209. [PMID: 26744349 PMCID: PMC4713723 DOI: 10.1007/s00401-015-1531-z] [Citation(s) in RCA: 112] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2015] [Revised: 12/21/2015] [Accepted: 12/22/2015] [Indexed: 12/26/2022]
Abstract
Bacterial meningitis is a devastating disease occurring worldwide with up to half of the survivors left with permanent neurological sequelae. Due to intrinsic properties of the meningeal pathogens and the host responses they induce, infection can cause relatively specific lesions and clinical syndromes that result from interference with the function of the affected nervous system tissue. Pathogenesis is based on complex host–pathogen interactions, some of which are specific for certain bacteria, whereas others are shared among different pathogens. In this review, we summarize the recent progress made in understanding the molecular and cellular events involved in these interactions. We focus on selected major pathogens, Streptococcus pneumonia, S. agalactiae (Group B Streptococcus), Neisseria meningitidis, and Escherichia coli K1, and also include a neglected zoonotic pathogen, Streptococcus suis. These neuroinvasive pathogens represent common themes of host–pathogen interactions, such as colonization and invasion of mucosal barriers, survival in the blood stream, entry into the central nervous system by translocation of the blood–brain and blood–cerebrospinal fluid barrier, and induction of meningeal inflammation, affecting pia mater, the arachnoid and subarachnoid spaces.
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The fibronectin-binding protein Fnm contributes to adherence to extracellular matrix components and virulence of Enterococcus faecium. Infect Immun 2015; 83:4653-61. [PMID: 26371130 DOI: 10.1128/iai.00885-15] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2015] [Accepted: 09/10/2015] [Indexed: 12/29/2022] Open
Abstract
The interaction between bacteria and fibronectin is believed to play an important role in the pathogenicity of clinically important Gram-positive cocci. In the present study, we identified a gene encoding a predicted fibronectin-binding protein of Enterococcus faecium (fnm), a homologue of Streptococcus pneumoniae pavA, in the genomes of E. faecium strain TX82 and all other sequenced E. faecium isolates. Full-length recombinant Fnm from strain TX82 bound to immobilized fibronectin in a concentration-dependent manner and also appeared to bind collagen type V and laminin, but not other proteins, such as transferrin, heparin, bovine serum albumin, mucin, or collagen IV. We demonstrated that the N-terminal fragment of Fnm is required for full fibronectin binding, since truncation of this region caused a 2.4-fold decrease (P < 0.05) in the adhesion of E. faecium TX82 to fibronectin. Deletion of fnm resulted in a significant reduction (P < 0.001) in the ability of the mutant, TX6128, to bind fibronectin relative to that of the wild-type strain; in situ reconstitution of fnm in the deletion mutant strain restored adherence. In addition, the Δfnm mutant was highly attenuated relative to TX82 (P ≤ 0.0001) in a mixed-inoculum rat endocarditis model. Taken together, these results demonstrate that Fnm affects the adherence of E. faecium to fibronectin and is important in the pathogenesis of experimental endocarditis.
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The fibronectin-binding protein EfbA contributes to pathogenesis and protects against infective endocarditis caused by Enterococcus faecalis. Infect Immun 2015; 83:4487-94. [PMID: 26351286 DOI: 10.1128/iai.00884-15] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2015] [Accepted: 09/01/2015] [Indexed: 12/24/2022] Open
Abstract
EfbA is a PavA-like fibronectin adhesin of Enterococcus faecalis previously shown to be important in experimental urinary tract infection. Here, we expressed and purified the E. faecalis OG1RF EfbA and confirmed that this protein binds with high affinity to immobilized fibronectin, collagen I, and collagen V. We constructed an efbA deletion mutant and demonstrated that its virulence was significantly attenuated (P < 0.0006) versus the wild type in a mixed inoculum rat endocarditis model. Furthermore, efbA deletion resulted in diminished ability to bind fibronectin (P < 0.0001) and reduced biofilm (P < 0.001). Reintroduction of efbA into the original chromosomal location restored virulence, adherence to fibronectin, and biofilm formation to wild-type levels. Finally, vaccination of rats with purified recombinant EfbA protein protected against OG1RF endocarditis (P = 0.008 versus control). Taken together, our results demonstrate that EfbA is an important factor involved in E. faecalis endocarditis and that rEfbA immunization is effective in preventing such infection, likely by interfering with bacterial adherence.
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Generic determinants of Streptococcus colonization and infection. INFECTION GENETICS AND EVOLUTION 2015; 33:361-70. [DOI: 10.1016/j.meegid.2014.09.018] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/22/2014] [Revised: 09/10/2014] [Accepted: 09/14/2014] [Indexed: 11/20/2022]
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Stoner TD, Weston TA, Trejo J, Doran KS. Group B streptococcal infection and activation of human astrocytes. PLoS One 2015; 10:e0128431. [PMID: 26030618 PMCID: PMC4452173 DOI: 10.1371/journal.pone.0128431] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2014] [Accepted: 04/27/2015] [Indexed: 01/08/2023] Open
Abstract
Background Streptococcus agalactiae (Group B Streptococcus, GBS) is the leading cause of life-threatening meningitis in human newborns in industrialized countries. Meningitis results from neonatal infection that occurs when GBS leaves the bloodstream (bacteremia), crosses the blood-brain barrier (BBB), and enters the central nervous system (CNS), where the bacteria contact the meninges. Although GBS is known to invade the BBB, subsequent interaction with astrocytes that physically associate with brain endothelium has not been well studied. Methodology/Principal Findings We hypothesize that human astrocytes play a unique role in GBS infection and contribute to the development of meningitis. To address this, we used a well- characterized human fetal astrocyte cell line, SVG-A, and examined GBS infection in vitro. We observed that all GBS strains of representative clinically dominant serotypes (Ia, Ib, III, and V) were able to adhere to and invade astrocytes. Cellular invasion was dependent on host actin cytoskeleton rearrangements, and was specific to GBS as Streptococcus gordonii failed to enter astrocytes. Analysis of isogenic mutant GBS strains deficient in various cell surface organelles showed that anchored LTA, serine-rich repeat protein (Srr1) and fibronectin binding (SfbA) proteins all contribute to host cell internalization. Wild-type GBS also displayed an ability to persist and survive within an intracellular compartment for at least 12 h following invasion. Moreover, GBS infection resulted in increased astrocyte transcription of interleukin (IL)-1β, IL-6 and VEGF. Conclusions/Significance This study has further characterized the interaction of GBS with human astrocytes, and has identified the importance of specific virulence factors in these interactions. Understanding the role of astrocytes during GBS infection will provide important information regarding BBB disruption and the development of neonatal meningitis.
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Affiliation(s)
- Terri D. Stoner
- Department of Biology, Center for Microbial Sciences, San Diego State University, San Diego, CA, United States of America
- Department of Pharmacology, School of Medicine, University of California San Diego, La Jolla, CA, United States of America
| | - Thomas A. Weston
- Department of Biology, Center for Microbial Sciences, San Diego State University, San Diego, CA, United States of America
| | - JoAnn Trejo
- Department of Pharmacology, School of Medicine, University of California San Diego, La Jolla, CA, United States of America
| | - Kelly S. Doran
- Department of Biology, Center for Microbial Sciences, San Diego State University, San Diego, CA, United States of America
- Departmant of Pediatrics, School of Medicine, University of California San Diego, La Jolla, CA, United States of America
- * E-mail:
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Rosinski-Chupin I, Sauvage E, Sismeiro O, Villain A, Da Cunha V, Caliot ME, Dillies MA, Trieu-Cuot P, Bouloc P, Lartigue MF, Glaser P. Single nucleotide resolution RNA-seq uncovers new regulatory mechanisms in the opportunistic pathogen Streptococcus agalactiae. BMC Genomics 2015; 16:419. [PMID: 26024923 PMCID: PMC4448216 DOI: 10.1186/s12864-015-1583-4] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2015] [Accepted: 04/27/2015] [Indexed: 11/15/2022] Open
Abstract
Background Streptococcus agalactiae, or Group B Streptococcus, is a leading cause of neonatal infections and an increasing cause of infections in adults with underlying diseases. In an effort to reconstruct the transcriptional networks involved in S. agalactiae physiology and pathogenesis, we performed an extensive and robust characterization of its transcriptome through a combination of differential RNA-sequencing in eight different growth conditions or genetic backgrounds and strand-specific RNA-sequencing. Results Our study identified 1,210 transcription start sites (TSSs) and 655 transcript ends as well as 39 riboswitches and cis-regulatory regions, 39 cis-antisense non-coding RNAs and 47 small RNAs potentially acting in trans. Among these putative regulatory RNAs, ten were differentially expressed in response to an acid stress and two riboswitches sensed directly or indirectly the pH modification. Strikingly, 15% of the TSSs identified were associated with the incorporation of pseudo-templated nucleotides, showing that reiterative transcription is a pervasive process in S. agalactiae. In particular, 40% of the TSSs upstream genes involved in nucleotide metabolism show reiterative transcription potentially regulating gene expression, as exemplified for pyrG and thyA encoding the CTP synthase and the thymidylate synthase respectively. Conclusions This comprehensive map of the transcriptome at the single nucleotide resolution led to the discovery of new regulatory mechanisms in S. agalactiae. It also provides the basis for in depth analyses of transcriptional networks in S. agalactiae and of the regulatory role of reiterative transcription following variations of intra-cellular nucleotide pools. Electronic supplementary material The online version of this article (doi:10.1186/s12864-015-1583-4) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Isabelle Rosinski-Chupin
- Institut Pasteur, Unité de Biologie des Bactéries Pathogènes à Gram Positif, 28 rue du Docteur Roux, 75724,, Paris Cedex 15, France. .,CNRS UMR 3525, Paris, France.
| | - Elisabeth Sauvage
- Institut Pasteur, Unité de Biologie des Bactéries Pathogènes à Gram Positif, 28 rue du Docteur Roux, 75724,, Paris Cedex 15, France. .,CNRS UMR 3525, Paris, France.
| | - Odile Sismeiro
- Institut Pasteur, Transcriptome and Epigenome Platform, 28 rue du Docteur Roux, 75724,, Paris Cedex 15, France.
| | - Adrien Villain
- Institut Pasteur, Unité de Biologie des Bactéries Pathogènes à Gram Positif, 28 rue du Docteur Roux, 75724,, Paris Cedex 15, France. .,CNRS UMR 3525, Paris, France.
| | - Violette Da Cunha
- Institut Pasteur, Unité de Biologie des Bactéries Pathogènes à Gram Positif, 28 rue du Docteur Roux, 75724,, Paris Cedex 15, France. .,CNRS UMR 3525, Paris, France.
| | - Marie-Elise Caliot
- Institut Pasteur, Unité de Biologie des Bactéries Pathogènes à Gram Positif, 28 rue du Docteur Roux, 75724,, Paris Cedex 15, France.
| | - Marie-Agnès Dillies
- Institut Pasteur, Transcriptome and Epigenome Platform, 28 rue du Docteur Roux, 75724,, Paris Cedex 15, France.
| | - Patrick Trieu-Cuot
- Institut Pasteur, Unité de Biologie des Bactéries Pathogènes à Gram Positif, 28 rue du Docteur Roux, 75724,, Paris Cedex 15, France.
| | - Philippe Bouloc
- Institute for Integrative Biology of the Cell (I2BC), CEA, CNRS, Université Paris-Sud, bâtiment 400, 91405, Orsay, France.
| | - Marie-Frédérique Lartigue
- Institute for Integrative Biology of the Cell (I2BC), CEA, CNRS, Université Paris-Sud, bâtiment 400, 91405, Orsay, France. .,Université de Tours, UMR1282 Infectiologie et Santé Publique, F-37000, Tours, France. .,CHRU de Tours, F-37044, Tours, France. .,INRA, UMR1282 Infectiologie et Santé Publique, F-37380, Nouzilly, France.
| | - Philippe Glaser
- Institut Pasteur, Unité de Biologie des Bactéries Pathogènes à Gram Positif, 28 rue du Docteur Roux, 75724,, Paris Cedex 15, France. .,CNRS UMR 3525, Paris, France.
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Dover RS, Bitler A, Shimoni E, Trieu-Cuot P, Shai Y. Multiparametric AFM reveals turgor-responsive net-like peptidoglycan architecture in live streptococci. Nat Commun 2015; 6:7193. [PMID: 26018339 PMCID: PMC4458890 DOI: 10.1038/ncomms8193] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2015] [Accepted: 04/16/2015] [Indexed: 12/13/2022] Open
Abstract
Cell-wall peptidoglycan (PG) of Gram-positive bacteria is a strong and elastic multi-layer designed to resist turgor pressure and determine the cell shape and growth. Despite its crucial role, its architecture remains largely unknown. Here using high-resolution multiparametric atomic force microscopy (AFM), we studied how the structure and elasticity of PG change when subjected to increasing turgor pressure in live Group B Streptococcus. We show a new net-like arrangement of PG, which stretches and stiffens following osmotic challenge. The same structure also exists in isogenic mutants lacking surface appendages. Cell aging does not alter the elasticity of the cell wall, yet destroys the net architecture and exposes single segmented strands with the same circumferential orientation as predicted for intact glycans. Together, we show a new functional PG architecture in live Gram-positive bacteria. The peptidoglycan (PG) layer of the Gram-positive bacteria cell wall resists turgor pressure, but the architecture of this layer is largely unknown. Here the authors use high resolution atomic force microscopy to image the PG layer from live Streptococcus to reveal a net-like arrangement that resists osmotic challenge by stretching and stiffening.
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Affiliation(s)
- Ron Saar Dover
- Department of Biological Chemistry, 8 Ulman Building, The Weizmann Institute of Science, Rehovot 76100, Israel
| | - Arkady Bitler
- Department of Chemical Research Support, Surface Analysis Unit, Goldwurm Building, The Weizmann Institute of Science, Rehovot 76100, Israel
| | - Eyal Shimoni
- Department of Chemical Research Support, Electron Microscopy Unit, Issac Wolfson Building, The Weizmann Institute of Science, Rehovot 76100, Israel
| | - Patrick Trieu-Cuot
- Department of Microbiology, Institut Pasteur, Unité de Biologie des Bactéries Pathogènes à Gram-Positif, CNRS ERL3526, Paris 75015, France
| | - Yechiel Shai
- Department of Biological Chemistry, 8 Ulman Building, The Weizmann Institute of Science, Rehovot 76100, Israel
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Raymond BBA, Djordjevic S. Exploitation of plasmin(ogen) by bacterial pathogens of veterinary significance. Vet Microbiol 2015; 178:1-13. [PMID: 25937317 DOI: 10.1016/j.vetmic.2015.04.008] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2015] [Revised: 04/07/2015] [Accepted: 04/09/2015] [Indexed: 01/31/2023]
Abstract
The plasminogen (Plg) system plays an important homeostatic role in the degradation of fibrin clots, extracellular matrices and tissue barriers important for cellular migration, as well as the promotion of neurotransmitter release. Plg circulates in plasma at physiologically high concentrations (150-200μg ml(-1)) as an inactive proenzyme. Proteins enriched in lysine and other positively charged residues (histidine and arginine) as well as glycosaminoglycans and gangliosides bind Plg. The binding interaction initiates a structural adjustment to the bound Plg that facilitates cleavage by proteases (plasminogen activators tPA and uPA) that activate Plg to the active serine protease plasmin. Both pathogenic and commensal bacteria capture Plg onto their cell surface and promote its conversion to plasmin. Many microbial Plg-binding proteins have been described underpinning the importance this process plays in how bacteria interact with their hosts. Bacteria exploit the proteolytic capabilities of plasmin by (i) targeting the mammalian fibrinolytic system and degrading fibrin clots, (ii) remodeling the extracellular matrix and generating bioactive cleavage fragments of the ECM that influence signaling pathways, (iii) activating matrix metalloproteinases that assist in the destruction of tissue barriers and promote microbial metastasis and (iv) destroying immune effector molecules. There has been little focus on the exploitation of the fibrinolytic system by veterinary pathogens. Here we describe several pathogens of veterinary significance that possess adhesins that bind plasmin(ogen) onto their cell surface and promote its activation to plasmin. Cumulative data suggests that these attributes provide pathogenic and commensal bacteria with a means to colonize and persist within the host environment.
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Affiliation(s)
- Benjamin B A Raymond
- The ithree Institute, University of Technology, Sydney, PO Box 123, Broadway, NSW 2007, Australia
| | - Steven Djordjevic
- The ithree Institute, University of Technology, Sydney, PO Box 123, Broadway, NSW 2007, Australia.
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50
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Streptococcus agalactiae infection in zebrafish larvae. Microb Pathog 2015; 79:57-60. [PMID: 25617657 DOI: 10.1016/j.micpath.2015.01.007] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2014] [Revised: 01/14/2015] [Accepted: 01/20/2015] [Indexed: 11/23/2022]
Abstract
Streptococcus agalactiae (Group B Streptococcus, GBS) is an encapsulated, Gram-positive bacterium that is a leading cause of neonatal pneumonia, sepsis and meningitis, and an emerging aquaculture pathogen. The zebrafish (Danio rerio) is a genetically tractable model vertebrate that has been used to analyze the pathogenesis of both aquatic and human bacterial pathogens. We have developed a larval zebrafish model of GBS infection to study bacterial and host factors that contribute to disease progression. GBS infection resulted in dose dependent larval death, and GBS serotype III, ST-17 strain was observed as the most virulent. Virulence was dependent on the presence of the GBS capsule, surface anchored lipoteichoic acid (LTA) and toxin production, as infection with GBS mutants lacking these factors resulted in little to no mortality. Additionally, interleukin-1β (il1b) and CXCL-8 (cxcl8a) were significantly induced following GBS infection compared to controls. We also visualized GBS outside the brain vasculature, suggesting GBS penetration into the brain during the course of infection. Our data demonstrate that zebrafish larvae are a valuable model organism to study GBS pathogenesis.
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