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Goh KGK, Desai D, Thapa R, Prince D, Acharya D, Sullivan MJ, Ulett GC. An opportunistic pathogen under stress: how Group B Streptococcus responds to cytotoxic reactive species and conditions of metal ion imbalance to survive. FEMS Microbiol Rev 2024; 48:fuae009. [PMID: 38678005 PMCID: PMC11098048 DOI: 10.1093/femsre/fuae009] [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: 08/31/2023] [Revised: 03/26/2024] [Accepted: 04/16/2024] [Indexed: 04/29/2024] Open
Abstract
Group B Streptococcus (GBS; also known as Streptococcus agalactiae) is an opportunistic bacterial pathogen that causes sepsis, meningitis, pneumonia, and skin and soft tissue infections in neonates and healthy or immunocompromised adults. GBS is well-adapted to survive in humans due to a plethora of virulence mechanisms that afford responses to support bacterial survival in dynamic host environments. These mechanisms and responses include counteraction of cell death from exposure to excess metal ions that can cause mismetallation and cytotoxicity, and strategies to combat molecules such as reactive oxygen and nitrogen species that are generated as part of innate host defence. Cytotoxicity from reactive molecules can stem from damage to proteins, DNA, and membrane lipids, potentially leading to bacterial cell death inside phagocytic cells or within extracellular spaces within the host. Deciphering the ways in which GBS responds to the stress of cytotoxic reactive molecules within the host will benefit the development of novel therapeutic and preventative strategies to manage the burden of GBS disease. This review summarizes knowledge of GBS carriage in humans and the mechanisms used by the bacteria to circumvent killing by these important elements of host immune defence: oxidative stress, nitrosative stress, and stress from metal ion intoxication/mismetallation.
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Affiliation(s)
- Kelvin G K Goh
- School of Pharmacy and Medical Sciences, and Menzies Health Institute Queensland, Griffith University, Parklands Drive, Southport, Gold Coast Campus, QLD 4222, Australia
| | - Devika Desai
- School of Pharmacy and Medical Sciences, and Menzies Health Institute Queensland, Griffith University, Parklands Drive, Southport, Gold Coast Campus, QLD 4222, Australia
| | - Ruby Thapa
- School of Pharmacy and Medical Sciences, and Menzies Health Institute Queensland, Griffith University, Parklands Drive, Southport, Gold Coast Campus, QLD 4222, Australia
| | - Darren Prince
- School of Pharmacy and Medical Sciences, and Menzies Health Institute Queensland, Griffith University, Parklands Drive, Southport, Gold Coast Campus, QLD 4222, Australia
| | - Dhruba Acharya
- School of Pharmacy and Medical Sciences, and Menzies Health Institute Queensland, Griffith University, Parklands Drive, Southport, Gold Coast Campus, QLD 4222, Australia
| | - Matthew J Sullivan
- School of Pharmacy and Medical Sciences, and Menzies Health Institute Queensland, Griffith University, Parklands Drive, Southport, Gold Coast Campus, QLD 4222, Australia
- School of Biological Sciences, University of East Anglia, Norwich Research Park, Norwich, NR4 7TJ, United Kingdom
| | - Glen C Ulett
- School of Pharmacy and Medical Sciences, and Menzies Health Institute Queensland, Griffith University, Parklands Drive, Southport, Gold Coast Campus, QLD 4222, Australia
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2
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Sun WS, Lassinantti L, Järvå M, Schmitt A, ter Beek J, Berntsson RPA. Structural foundation for the role of enterococcal PrgB in conjugation, biofilm formation, and virulence. eLife 2023; 12:RP84427. [PMID: 37860966 PMCID: PMC10588982 DOI: 10.7554/elife.84427] [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: 10/21/2023] Open
Abstract
Type 4 Secretion Systems are a main driver for the spread of antibiotic resistance genes and virulence factors in bacteria. In Gram-positives, these secretion systems often rely on surface adhesins to enhance cellular aggregation and mating-pair formation. One of the best studied adhesins is PrgB from the conjugative plasmid pCF10 of Enterococcus faecalis, which has been shown to play major roles in conjugation, biofilm formation, and importantly also in bacterial virulence. Since prgB orthologs exist on a large number of conjugative plasmids in various different species, this makes PrgB a model protein for this widespread virulence factor. After characterizing the polymer adhesin domain of PrgB previously, we here report the structure for almost the entire remainder of PrgB, which reveals that PrgB contains four immunoglobulin (Ig)-like domains. Based on this new insight, we re-evaluate previously studied variants and present new in vivo data where specific domains or conserved residues have been removed. For the first time, we can show a decoupling of cellular aggregation from biofilm formation and conjugation in prgB mutant phenotypes. Based on the presented data, we propose a new functional model to explain how PrgB mediates its different functions. We hypothesize that the Ig-like domains act as a rigid stalk that presents the polymer adhesin domain at the right distance from the cell wall.
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Affiliation(s)
- Wei-Sheng Sun
- Department of Medical Biochemistry and Biophysics, Umeå UniversityUmeåSweden
- Wallenberg Centre for Molecular Medicine, Umeå UniversityUmeåSweden
| | - Lena Lassinantti
- Department of Medical Biochemistry and Biophysics, Umeå UniversityUmeåSweden
| | - Michael Järvå
- Department of Medical Biochemistry and Biophysics, Umeå UniversityUmeåSweden
| | - Andreas Schmitt
- Department of Medical Biochemistry and Biophysics, Umeå UniversityUmeåSweden
| | - Josy ter Beek
- Department of Medical Biochemistry and Biophysics, Umeå UniversityUmeåSweden
- Wallenberg Centre for Molecular Medicine, Umeå UniversityUmeåSweden
| | - Ronnie P-A Berntsson
- Department of Medical Biochemistry and Biophysics, Umeå UniversityUmeåSweden
- Wallenberg Centre for Molecular Medicine, Umeå UniversityUmeåSweden
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3
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Popovic A, Cao EY, Han J, Nursimulu N, Alves-Ferreira EVC, Burrows K, Kennard A, Alsmadi N, Grigg ME, Mortha A, Parkinson J. The commensal protist Tritrichomonas musculus exhibits a dynamic life cycle that induces extensive remodeling of the gut microbiota. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.03.06.528774. [PMID: 37090671 PMCID: PMC10120700 DOI: 10.1101/2023.03.06.528774] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/03/2023]
Abstract
Commensal protists and gut bacterial communities exhibit complex relationships, mediated at least in part through host immunity. To improve our understanding of this tripartite interplay, we investigated community and functional dynamics between the murine protist Tritrichomonas musculus ( T. mu ) and intestinal bacteria in healthy and B cell-deficient mice. We identified dramatic, protist-driven remodeling of resident microbiome growth and activities, in parallel with T. mu functional changes, accelerated in the absence of B cells. Metatranscriptomic data revealed nutrient-based competition between bacteria and the protist. Single cell transcriptomics identified distinct T. mu life stages, providing new evidence for trichomonad sexual replication and the formation of pseudocysts. Unique cell states were validated in situ through microscopy and flow cytometry. Our results reveal complex microbial dynamics during the establishment of a commensal protist in the gut, and provide valuable datasets to drive future mechanistic studies.
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Mejia ME, Robertson CM, Patras KA. Interspecies Interactions within the Host: the Social Network of Group B Streptococcus. Infect Immun 2023; 91:e0044022. [PMID: 36975791 PMCID: PMC10112235 DOI: 10.1128/iai.00440-22] [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: 03/29/2023] Open
Abstract
Group B Streptococcus (GBS) is a pervasive neonatal pathogen accounting for a combined half a million deaths and stillbirths annually. The most common source of fetal or neonatal GBS exposure is the maternal microbiota. GBS asymptomatically colonizes the gastrointestinal and vaginal mucosa of 1 in 5 individuals globally, although its precise role in these niches is not well understood. To prevent vertical transmission, broad-spectrum antibiotics are administered to GBS-positive mothers during labor in many countries. Although antibiotics have significantly reduced GBS early-onset neonatal disease, there are several unintended consequences, including an altered neonatal microbiota and increased risk for other microbial infections. Additionally, the incidence of late-onset GBS neonatal disease remains unaffected and has sparked an emerging hypothesis that GBS-microbe interactions in developing neonatal gut microbiota may be directly involved in this disease process. This review summarizes our current understanding of GBS interactions with other resident microbes at the mucosal surface from multiple angles, including clinical association studies, agriculture and aquaculture observations, and experimental animal model systems. We also include a comprehensive review of in vitro findings of GBS interactions with other bacterial and fungal microbes, both commensal and pathogenic, along with newly established animal models of GBS vaginal colonization and in utero or neonatal infection. Finally, we provide a perspective on emerging areas of research and current strategies to design microbe-targeting prebiotic or probiotic therapeutic intervention strategies to prevent GBS disease in vulnerable populations.
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Affiliation(s)
- Marlyd E. Mejia
- Department of Molecular Virology and Microbiology, Baylor College of Medicine, Houston, Texas, USA
| | - Clare M. Robertson
- Department of Molecular Virology and Microbiology, Baylor College of Medicine, Houston, Texas, USA
| | - Kathryn A. Patras
- Department of Molecular Virology and Microbiology, Baylor College of Medicine, Houston, Texas, USA
- Alkek Center for Metagenomics and Microbiome Research, Baylor College of Medicine, Houston, Texas, USA
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The Group B Streptococcal Adhesin BspC Interacts with Host Cytokeratin 19 To Promote Colonization of the Female Reproductive Tract. mBio 2022; 13:e0178122. [PMID: 36069447 PMCID: PMC9600255 DOI: 10.1128/mbio.01781-22] [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] [Indexed: 02/02/2023] Open
Abstract
Streptococcus agalactiae, otherwise known as Group B Streptococcus (GBS), is an opportunistic pathogen that vaginally colonizes approximately one third of healthy women. During pregnancy, this can lead to in utero infection, resulting in premature rupture of membranes, chorioamnionitis, and stillbirths. Furthermore, GBS causes serious infection in newborns, including sepsis, pneumonia, and meningitis. Previous studies have indicated that GBS antigen (Ag) I/II family proteins promote interaction with vaginal epithelial cells; thus, we hypothesized that the Ag I/II Group B streptococcal surface protein C (BspC) contributes to GBS colonization of the female reproductive tract (FRT). Here, we show that a ΔbspC mutant has decreased bacterial adherence to vaginal, ecto-, and endocervical cells, as well as decreased auto-aggregation and biofilm-like formation on cell monolayers. Using a murine model of vaginal colonization, we observed that the ΔbspC mutant strain exhibited a significant fitness defect compared to wild-type (WT) GBS and was less able to ascend to the cervix and uterus in vivo, resulting in reduced neutrophil chemokine signaling. Furthermore, we determined that BspC interacts directly with the host intermediate filament protein cytokeratin 19 (K19). Surface localization of K19 was increased during GBS infection, and interaction was mediated by the BspC variable (V) domain. Finally, mice treated with a drug that targets the BspC V-domain exhibited reduced bacterial loads in the vaginal lumen and reproductive tissues. These results demonstrate the importance of BspC in promoting GBS colonization of the FRT and that it may be targeted therapeutically to reduce GBS vaginal persistence and ascending infection. IMPORTANCE Group B Streptococcus (GBS) asymptomatically colonizes the female reproductive tract (FRT) of up to one third of women, but GBS carriage can lead to adverse pregnancy outcomes, including premature rupture of membranes, preterm labor, and chorioamnionitis. GBS colonization during pregnancy is also the largest predisposing factor for neonatal GBS disease, including pneumonia, sepsis, and meningitis. The molecular interactions between bacterial surface proteins and the host cell receptors that promote GBS colonization are vastly understudied, and a better understanding would facilitate development of novel therapeutics to prevent GBS colonization and disease. Here, we characterize the role of the GBS surface protein BspC in colonization of the FRT. We show for the first time that GBS infection induces cytokeratin 19 (K19) surface localization on vaginal epithelial cells; GBS then uses the BspC V-domain to interact with K19 to promote colonization and ascending infection. Furthermore, this interaction can be targeted therapeutically to reduce GBS carriage.
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6
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Li H, Miao MX, Jia CL, Cao YB, Yan TH, Jiang YY, Yang F. Interactions between Candida albicans and the resident microbiota. Front Microbiol 2022; 13:930495. [PMID: 36204612 PMCID: PMC9531752 DOI: 10.3389/fmicb.2022.930495] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2022] [Accepted: 08/31/2022] [Indexed: 01/09/2023] Open
Abstract
Candida albicans is a prevalent, opportunistic human fungal pathogen. It usually dwells in the human body as a commensal, however, once in its pathogenic state, it causes diseases ranging from debilitating superficial to life-threatening systemic infections. The switch from harmless colonizer to virulent pathogen is, in most cases, due to perturbation of the fungus-host-microbiota interplay. In this review, we focused on the interactions between C. albicans and the host microbiota in the mouth, gut, blood, and vagina. We also highlighted important future research directions. We expect that the evaluation of these interplays will help better our understanding of the etiology of fungal infections and shed new light on the therapeutic approaches.
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Affiliation(s)
- Hao Li
- Department of Pharmacy, Shanghai Tenth People’s Hospital, Tongji University School of Medicine, Shanghai, China,Department of Physiology and Pharmacology, School of Basic Medicine and Clinical Pharmacy, China Pharmaceutical University, Nanjing, China
| | - Ming-xing Miao
- Department of Physiology and Pharmacology, School of Basic Medicine and Clinical Pharmacy, China Pharmaceutical University, Nanjing, China
| | - Cheng-lin Jia
- Institute of Vascular Disease, Shanghai TCM-Integrated Hospital, Shanghai University of Traditional Chinese Medicine, Shanghai, China
| | - Yong-bing Cao
- Institute of Vascular Disease, Shanghai TCM-Integrated Hospital, Shanghai University of Traditional Chinese Medicine, Shanghai, China
| | - Tian-hua Yan
- Department of Physiology and Pharmacology, School of Basic Medicine and Clinical Pharmacy, China Pharmaceutical University, Nanjing, China,*Correspondence: Tian-hua Yan,
| | - Yuan-ying Jiang
- Department of Pharmacy, Shanghai Tenth People’s Hospital, Tongji University School of Medicine, Shanghai, China,Yuan-ying Jiang,
| | - Feng Yang
- Department of Pharmacy, Shanghai Tenth People’s Hospital, Tongji University School of Medicine, Shanghai, China,Feng Yang,
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Abril AG, Quintela-Baluja M, Villa TG, Calo-Mata P, Barros-Velázquez J, Carrera M. Proteomic Characterization of Virulence Factors and Related Proteins in Enterococcus Strains from Dairy and Fermented Food Products. Int J Mol Sci 2022; 23:ijms231810971. [PMID: 36142880 PMCID: PMC9503237 DOI: 10.3390/ijms231810971] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2022] [Revised: 09/08/2022] [Accepted: 09/16/2022] [Indexed: 01/23/2023] Open
Abstract
Enterococcus species are Gram-positive bacteria that are normal gastrointestinal tract inhabitants that play a beneficial role in the dairy and meat industry. However, Enterococcus species are also the causative agents of health care-associated infections that can be found in dairy and fermented food products. Enterococcal infections are led by strains of Enterococcus faecalis and Enterococcus faecium, which are often resistant to antibiotics and biofilm formation. Enterococci virulence factors attach to host cells and are also involved in immune evasion. LC-MS/MS-based methods offer several advantages compared with other approaches because one can directly identify microbial peptides without the necessity of inferring conclusions based on other approaches such as genomics tools. The present study describes the use of liquid chromatography−electrospray ionization tandem mass spectrometry (LC−ESI−MS/MS) to perform a global shotgun proteomics characterization for opportunistic pathogenic Enterococcus from different dairy and fermented food products. This method allowed the identification of a total of 1403 nonredundant peptides, representing 1327 proteins. Furthermore, 310 of those peptides corresponded to proteins playing a direct role as virulence factors for Enterococcus pathogenicity. Virulence factors, antibiotic sensitivity, and proper identification of the enterococcal strain are required to propose an effective therapy. Data are available via ProteomeXchange with identifier PXD036435. Label-free quantification (LFQ) demonstrated that the majority of the high-abundance proteins corresponded to E. faecalis species. Therefore, the global proteomic repository obtained here can be the basis for further research into pathogenic Enterococcus species, thus facilitating the development of novel therapeutics.
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Affiliation(s)
- Ana G. Abril
- Department of Microbiology and Parasitology, Faculty of Pharmacy, University of Santiago de Compostela, 15898 Santiago de Compostela, Spain
- Department of Food Technology, Spanish National Research Council (CSIC), Marine Research Institute (IIM), 36208 Vigo, Spain
| | - Marcos Quintela-Baluja
- Department of Analytical Chemistry, Nutrition and Food Science, Food Technology Division, School of Veterinary Sciences, University of Santiago de Compostela, Campus Lugo, 27002 Lugo, Spain
| | - Tomás G. Villa
- Department of Microbiology and Parasitology, Faculty of Pharmacy, University of Santiago de Compostela, 15898 Santiago de Compostela, Spain
| | - Pilar Calo-Mata
- Department of Analytical Chemistry, Nutrition and Food Science, Food Technology Division, School of Veterinary Sciences, University of Santiago de Compostela, Campus Lugo, 27002 Lugo, Spain
| | - Jorge Barros-Velázquez
- Department of Analytical Chemistry, Nutrition and Food Science, Food Technology Division, School of Veterinary Sciences, University of Santiago de Compostela, Campus Lugo, 27002 Lugo, Spain
| | - Mónica Carrera
- Department of Food Technology, Spanish National Research Council (CSIC), Marine Research Institute (IIM), 36208 Vigo, Spain
- Correspondence:
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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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9
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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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10
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Brokaw A, Furuta A, Dacanay M, Rajagopal L, Adams Waldorf KM. Bacterial and Host Determinants of Group B Streptococcal Vaginal Colonization and Ascending Infection in Pregnancy. Front Cell Infect Microbiol 2021; 11:720789. [PMID: 34540718 PMCID: PMC8446444 DOI: 10.3389/fcimb.2021.720789] [Citation(s) in RCA: 30] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2021] [Accepted: 08/09/2021] [Indexed: 12/17/2022] Open
Abstract
Group B streptococcus (GBS) is a gram-positive bacteria that asymptomatically colonizes the vaginal tract. However, during pregnancy maternal GBS colonization greatly predisposes the mother and baby to a wide range of adverse outcomes, including preterm birth (PTB), stillbirth, and neonatal infection. Although many mechanisms involved in GBS pathogenesis are partially elucidated, there is currently no approved GBS vaccine. The development of a safe and effective vaccine that can be administered during or prior to pregnancy remains a principal objective in the field, because current antibiotic-based therapeutic strategies do not eliminate all cases of invasive GBS infections. Herein, we review our understanding of GBS disease pathogenesis at the maternal-fetal interface with a focus on the bacterial virulence factors and host defenses that modulate the outcome of infection. We follow GBS along its path from an asymptomatic colonizer of the vagina to an invasive pathogen at the maternal-fetal interface, noting factors critical for vaginal colonization, ascending infection, and vertical transmission to the fetus. Finally, at each stage of infection we emphasize important host-pathogen interactions, which, if targeted therapeutically, may help to reduce the global burden of GBS.
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Affiliation(s)
- Alyssa Brokaw
- Center for Global Infectious Disease Research, Seattle Children's Research Institute, Seattle, WA, United States.,Department of Global Health, University of Washington, Seattle, WA, United States
| | - Anna Furuta
- Center for Global Infectious Disease Research, Seattle Children's Research Institute, Seattle, WA, United States.,Department of Global Health, University of Washington, Seattle, WA, United States
| | - Matthew Dacanay
- Department of Obstetrics & Gynecology, University of Washington, Seattle, WA, United States
| | - Lakshmi Rajagopal
- Center for Global Infectious Disease Research, Seattle Children's Research Institute, Seattle, WA, United States.,Department of Global Health, University of Washington, Seattle, WA, United States.,Department of Pediatrics, University of Washington, Seattle, WA, United States
| | - Kristina M Adams Waldorf
- Department of Global Health, University of Washington, Seattle, WA, United States.,Department of Obstetrics & Gynecology, University of Washington, Seattle, WA, United States.,Department of Obstetrics and Gynecology, University of Washington and Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
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11
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Molecular Characteristics of IS 1216 Carrying Multidrug Resistance Gene Cluster in Serotype III/Sequence Type 19 Group B Streptococcus. mSphere 2021; 6:e0054321. [PMID: 34319128 PMCID: PMC8386385 DOI: 10.1128/msphere.00543-21] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Streptococcus agalactiae is the leading cause of meningitis in newborns and a significant cause of invasive diseases in pregnant women and adults with underlying diseases. Antibiotic resistance against erythromycin and clindamycin in group B streptococcus (GBS) isolates has been increasing worldwide. GBS expresses the Srr1 and Srr2 proteins, which have important roles in bacterial infection. They have been investigated as novel vaccine candidates against GBS infection, with promising results. But a recent study detected non-srr1/2-expressing clinical isolates belonging to serotype III. Thus, we aimed to analyze the genotypes of non-srr1/2 GBS clinical isolates collected between 2013 and 2016 in South Korea. Forty-one (13.4%) of the 305 serotype III isolates were identified as non-srr1/2 strains, including sequence type 19 (ST19) (n = 16) and ST27 (n = 18) strains. The results of the comparative genomic analysis of the ST19/serotype III/non-srr1/2 strains further revealed four unique gene clusters. Site 4 in the srr1 gene locus was replaced by an lsa(E)-lnu(B)-aadK-aac-aph-aadE-carrying multidrug-resistant gene cluster flanked by two IS1216 transposases with 99% homology to the enterococcal plasmid pKUB3007-1. Despite the Srr1 and Srr2 deficiencies, which resulted in reduced fibrinogen binding, the adherence of non-srr1/2 strains to endothelial and epithelial cells was comparable to that of Srr1- or Srr2-expressing strains. Moreover, their virulence in mouse models of meningitis was not significantly affected. Furthermore, additional adhesin-encoding genes, including a gene encoding a BspA-like protein, which may contribute to colonization by non-srr1/2 strains, were identified via whole-genome analysis. Thus, our study provides important findings that can aid in the development of vaccines and antibiotics against GBS. IMPORTANCE Most previously isolated group B streptococcus (GBS) strains express either the Srr1 or Srr2 glycoprotein, which plays an important role in bacterial colonization and invasion. These glycoproteins are potential protein vaccine candidates. In this study, we first report GBS clinical isolates in which the srr1/2 gene was deleted or replaced with foreign genes. Despite Srr1/2 deficiency, in vitro adherence to mammalian cells and in vivo virulence in murine models were not affected, suggesting that the isolates might have another adherence mechanism that enhanced their virulence aside from Srr1/2-fibrinogen-mediated adherence. In addition, several non-srr1/2 isolates replaced the srr1/2 gene with the lnu(B) and lsa(E) antibiotic resistance genes flanked by IS1216, effectively causing multidrug resistance. Collectively, we believe that our study identifies the underlying genes responsible for the pathogenesis of new GBS serotype III. Furthermore, our study emphasizes the need for alternative antibiotics for patients who are allergic to β-lactams and for those who are pregnant.
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12
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Chilambi GS, Nordstrom HR, Evans DR, Kowalski RP, Dhaliwal DK, Jhanji V, Shanks RMQ, Van Tyne D. Genomic and phenotypic diversity of Enterococcus faecalis isolated from endophthalmitis. PLoS One 2021; 16:e0250084. [PMID: 33852628 PMCID: PMC8046195 DOI: 10.1371/journal.pone.0250084] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2020] [Accepted: 03/30/2021] [Indexed: 11/30/2022] Open
Abstract
Enterococcus faecalis are hospital-associated opportunistic pathogens and also causative agents of post-operative endophthalmitis. Patients with enterococcal endophthalmitis often have poor visual outcomes, despite appropriate antibiotic therapy. Here we investigated the genomic and phenotypic characteristics of E. faecalis isolates collected from 13 patients treated at the University of Pittsburgh Medical Center Eye Center over 19 years. Comparative genomic analysis indicated that patients were infected with E. faecalis belonging to diverse multi-locus sequence types (STs) and resembled E. faecalis sampled from clinical, commensal, and environmental sources. We identified known E. faecalis virulence factors and antibiotic resistance genes in each genome, including genes conferring resistance to aminoglycosides, erythromycin, and tetracyclines. We assessed all isolates for their cytolysin production, biofilm formation, and antibiotic susceptibility, and observed phenotypic differences between isolates. Fluoroquinolone and cephalosporin susceptibilities were particularly variable between isolates, as were biofilm formation and cytolysin production. In addition, we found evidence of E. faecalis adaptation during recurrent endophthalmitis by identifying genetic variants that arose in sequential isolates sampled over eight months from the same patient. We identified a mutation in the DNA mismatch repair gene mutS that was associated with an increased rate of spontaneous mutation in the final isolate from the patient. Overall this study documents the genomic and phenotypic variability among E. faecalis causing endophthalmitis, as well as possible adaptive mechanisms underlying bacterial persistence during recurrent ocular infection.
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Affiliation(s)
- Gayatri Shankar Chilambi
- Division of Infectious Diseases, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, United States of America
| | - Hayley R. Nordstrom
- Division of Infectious Diseases, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, United States of America
| | - Daniel R. Evans
- Division of Infectious Diseases, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, United States of America
| | - Regis P. Kowalski
- The Charles T. Campbell Ophthalmic Microbiology Laboratory, UPMC Eye Center, Ophthalmology and Visual Sciences Research Center, The Eye and Ear Institute, Department of Ophthalmology, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, United States of America
| | - Deepinder K. Dhaliwal
- The Charles T. Campbell Ophthalmic Microbiology Laboratory, UPMC Eye Center, Ophthalmology and Visual Sciences Research Center, The Eye and Ear Institute, Department of Ophthalmology, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, United States of America
| | - Vishal Jhanji
- The Charles T. Campbell Ophthalmic Microbiology Laboratory, UPMC Eye Center, Ophthalmology and Visual Sciences Research Center, The Eye and Ear Institute, Department of Ophthalmology, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, United States of America
| | - Robert M. Q. Shanks
- The Charles T. Campbell Ophthalmic Microbiology Laboratory, UPMC Eye Center, Ophthalmology and Visual Sciences Research Center, The Eye and Ear Institute, Department of Ophthalmology, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, United States of America
| | - Daria Van Tyne
- Division of Infectious Diseases, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, United States of America
- * E-mail:
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13
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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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14
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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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15
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Potential role of the gut microbiota in neuromyelitis optica spectrum disorder: Implication for intervention. J Clin Neurosci 2020; 82:193-199. [PMID: 33257156 DOI: 10.1016/j.jocn.2020.11.011] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2020] [Revised: 10/22/2020] [Accepted: 11/01/2020] [Indexed: 12/19/2022]
Abstract
The gut microbiota plays an important role in the occurrence and development of neuroimmunological diseases. Neuromyelitis optica spectrum disorder (NMOSD) is an autoimmune disease of the central nervous system that is characterized by the peripheral production of the disease-specific serum autoantibody aquaporin-4 (AQP4)-IgG. Recently, accumulating evidence has provided insights into the associations of gut microbiota dysbiosis and intestinal mucosal barrier destruction with NMOSD, but the underlying pathogenesis remains unclear. Thus, a microbiota intervention might be a potential therapeutic strategy for NMOSD by regulating the gut microbiota, repairing the intestinal mucosal barrier, and modulating intestinal immunity and peripheral immunity.
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16
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Manzer HS, Nobbs AH, Doran KS. The Multifaceted Nature of Streptococcal Antigen I/II Proteins in Colonization and Disease Pathogenesis. Front Microbiol 2020; 11:602305. [PMID: 33329493 PMCID: PMC7732690 DOI: 10.3389/fmicb.2020.602305] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2020] [Accepted: 10/29/2020] [Indexed: 12/22/2022] Open
Abstract
Streptococci are Gram-positive bacteria that belong to the natural microbiota of humans and animals. Certain streptococcal species are known as opportunistic pathogens with the potential to cause severe invasive disease. Antigen I/II (AgI/II) family proteins are sortase anchored cell surface adhesins that are nearly ubiquitous across streptococci and contribute to many streptococcal diseases, including dental caries, respiratory tract infections, and meningitis. They appear to be multifunctional adhesins with affinities to various host substrata, acting to mediate attachment to host surfaces and stimulate immune responses from the colonized host. Here we will review the literature including recent work that has demonstrated the multifaceted nature of AgI/II family proteins, focusing on their overlapping and distinct functions and their important contribution to streptococcal colonization and disease.
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Affiliation(s)
- Haider S. Manzer
- Department of Immunology and Microbiology, University of Colorado Anschutz Medical Campus, Aurora, CO, United States
| | - Angela H. Nobbs
- Bristol Dental School, University of Bristol, Bristol, United Kingdom
| | - Kelly S. Doran
- Department of Immunology and Microbiology, University of Colorado Anschutz Medical Campus, Aurora, CO, United States
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17
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Palang I, Hirono I, Senapin S, Sirimanapong W, Withyachumnarnkul B, Vanichviriyakit R. Cytotoxicity of Streptococcus agalactiae secretory protein on tilapia cultured cells. JOURNAL OF FISH DISEASES 2020; 43:1229-1236. [PMID: 32974952 DOI: 10.1111/jfd.13230] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/05/2020] [Revised: 07/10/2020] [Accepted: 07/13/2020] [Indexed: 06/11/2023]
Abstract
Streptococcus agalactiae secrete virulence factors believed to be able of killing host tissues, especially under elevated water temperature. A direct effect of S. agalactiae secretory products on tilapia cells was tested on the tilapia kidney (TK-1) cell culture. The bacteria were cultured under four different temperature levels: 22, 29, 32 and 37°C; the cell-free portion was processed through SDS-PAGE; and distinct bands were identified by LC-MS/MS. At least, three virulence factors were identified, Bsp, PcsB and CAMP factor, with increasing levels as the cultured temperature rose. Expressions of bsp, pcsB and cfb were also up-regulated with the rising of the temperature in S. agalactiae culture. The supernatant from the bacteria cultured under specified temperatures was added into TK-1 cell-cultured wells. Morphological damage and mortality of the cultured cells, as determined by MTT method, were increased progressively from the supernatant treatment according to the rise of temperature in S. agalactiae culture. This study suggests that the production of the three virulence factors of S. agalactiae reported herein is temperature-dependent, and it is likely that CAMP factor directly kills the TK-1 cells since the other two types of protein are involved in S. agalactiae cell division and the bacterial adherence to host tissues.
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Affiliation(s)
- Iyapa Palang
- Center of Excellence for Shrimp Molecular Biology and Biotechnology (Centex Shrimp), Faculty of Science, Mahidol University, Bangkok, Thailand
- Department of Anatomy, Faculty of Science, Mahidol University, Bangkok, Thailand
| | - Ikuo Hirono
- Laboratory of Genome Science, Graduate School of Marine Science and Technology, Tokyo University of Marine Science and Technology, Tokyo, Japan
| | - Saengchan Senapin
- Center of Excellence for Shrimp Molecular Biology and Biotechnology (Centex Shrimp), Faculty of Science, Mahidol University, Bangkok, Thailand
- National Center for Genetic Engineering and Biotechnology, National Science and Technology Development Agency, Pathumthani, Thailand
| | - Wanna Sirimanapong
- Veterinary Aquatic Animal Research Health Care Unit, Department of Clinical Sciences and Public Health, Faculty of Veterinary Science, Mahidol University, Bangkok, Thailand
| | - Boonsirm Withyachumnarnkul
- Faculty of Science and Industrial Technology, Prince of Songkla University, Surat Thani, Thailand
- AquaAcademy Farm, Surat Thani, Thailand
| | - Rapeepun Vanichviriyakit
- Center of Excellence for Shrimp Molecular Biology and Biotechnology (Centex Shrimp), Faculty of Science, Mahidol University, Bangkok, Thailand
- Department of Anatomy, Faculty of Science, Mahidol University, Bangkok, Thailand
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18
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Ma Y, Hao L, Liang Z, Ma J, Ke H, Kang H, Yang H, Wu J, Feng G, Liu Z. Characterization of novel antigenic vaccine candidates for nile tilapia (Oreochromis niloticus) against Streptococcus agalactiae infection. FISH & SHELLFISH IMMUNOLOGY 2020; 105:405-414. [PMID: 32712231 DOI: 10.1016/j.fsi.2020.07.024] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/17/2020] [Revised: 06/23/2020] [Accepted: 07/13/2020] [Indexed: 06/11/2023]
Abstract
Streptococcus agalactiae is one of the important pathogens responsible for high mortality and economic losses of the tilapia industry worldwide. Based on ten serovars of S. agalactiae infection, subunit vaccine with conserved antigens is promising strategy corresponding stimulated long-term immunity and provides protection for animals against different serotypes of S. agalactiae. In the present study, eight proteins (AP, AL, LivK, ESAT6, essA, essB, essC and esaA) were selected from the S. agalactiae serotype Ia genome as immunogenic antigens with bioinformation and immune experiment assays. These recombinant proteins were successfully obtained through expression in Escherichia coli and the immunogenicity was assessed in tilapia challenge model. The results showed that the recombinant proteins caused high-level-specific antibodies production and high lysozyme activities, suggesting that the recombinant proteins induced specific humoral immune response and innate immune response of tilapia. The signficant increase were observed in the cytokines levels of TNF-α, IL-1β, IFN-γ, cc1, cc2 and immune-related genes levels of CD8α and MHC factors in the spleen and head kidney tissues, suggesting that the recombinant proteins induced immune response of tilapia through cytokines signal pathway and activated high cytotoxic T-lymphocyte (CTL) activity of tilapia. Furthermore, vaccinated tilapia conferred high levels of protection against challenge with a lethal dose of highly virulent serovar Ⅰa (highest RPS was 91.60% in AL and essC protein groups). Our results indicated that the eight recombinant proteins induced high level of immune responses and offered protection against S. agalactiae infection, could be potential subunit vaccine candidates.
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Affiliation(s)
- Yanping Ma
- Institute of Animal Health, Guangdong Academy of Agricultural Sciences; Key Laboratory of Livestock Disease Prevention of Guangdong Province; Scientific Observation and Experiment Station of Veterinary Drugs and Diagnostic Techniques of Guangdong Province, Ministry of Agriculture and Rural Affairs, PRC, Guangzhou, China
| | - Le Hao
- Institute of Animal Health, Guangdong Academy of Agricultural Sciences; Key Laboratory of Livestock Disease Prevention of Guangdong Province; Scientific Observation and Experiment Station of Veterinary Drugs and Diagnostic Techniques of Guangdong Province, Ministry of Agriculture and Rural Affairs, PRC, Guangzhou, China
| | - Zhiling Liang
- Institute of Animal Health, Guangdong Academy of Agricultural Sciences; Key Laboratory of Livestock Disease Prevention of Guangdong Province; Scientific Observation and Experiment Station of Veterinary Drugs and Diagnostic Techniques of Guangdong Province, Ministry of Agriculture and Rural Affairs, PRC, Guangzhou, China
| | - Jiangyao Ma
- Institute of Animal Health, Guangdong Academy of Agricultural Sciences; Key Laboratory of Livestock Disease Prevention of Guangdong Province; Scientific Observation and Experiment Station of Veterinary Drugs and Diagnostic Techniques of Guangdong Province, Ministry of Agriculture and Rural Affairs, PRC, Guangzhou, China
| | - Hao Ke
- Institute of Animal Health, Guangdong Academy of Agricultural Sciences; Key Laboratory of Livestock Disease Prevention of Guangdong Province; Scientific Observation and Experiment Station of Veterinary Drugs and Diagnostic Techniques of Guangdong Province, Ministry of Agriculture and Rural Affairs, PRC, Guangzhou, China
| | - Huahua Kang
- Institute of Animal Health, Guangdong Academy of Agricultural Sciences; Key Laboratory of Livestock Disease Prevention of Guangdong Province; Scientific Observation and Experiment Station of Veterinary Drugs and Diagnostic Techniques of Guangdong Province, Ministry of Agriculture and Rural Affairs, PRC, Guangzhou, China; Zhaoqing Branch, Guangdong Laboratory for Lingnan Modern Agriculture, Zhaoqing, China
| | - Hongwei Yang
- College of Animal Science and Technology, Zhongkai University of Agriculture and Engineering, Guangzhou, China
| | - Jing Wu
- College of Veterinary Medicine, South China Agricultural University, Guangzhou, China
| | - Guoqing Feng
- Institute of Animal Health, Guangdong Academy of Agricultural Sciences; Key Laboratory of Livestock Disease Prevention of Guangdong Province; Scientific Observation and Experiment Station of Veterinary Drugs and Diagnostic Techniques of Guangdong Province, Ministry of Agriculture and Rural Affairs, PRC, Guangzhou, China
| | - Zhenxing Liu
- Institute of Animal Health, Guangdong Academy of Agricultural Sciences; Key Laboratory of Livestock Disease Prevention of Guangdong Province; Scientific Observation and Experiment Station of Veterinary Drugs and Diagnostic Techniques of Guangdong Province, Ministry of Agriculture and Rural Affairs, PRC, Guangzhou, China.
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19
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Back CR, Higman VA, Le Vay K, Patel VV, Parnell AE, Frankel D, Jenkinson HF, Burston SG, Crump MP, Nobbs AH, Race PR. The streptococcal multidomain fibrillar adhesin CshA has an elongated polymeric architecture. J Biol Chem 2020; 295:6689-6699. [PMID: 32229583 PMCID: PMC7212634 DOI: 10.1074/jbc.ra119.011719] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2019] [Revised: 03/26/2020] [Indexed: 11/06/2022] Open
Abstract
The cell surfaces of many bacteria carry filamentous polypeptides termed adhesins that enable binding to both biotic and abiotic surfaces. Surface adherence is facilitated by the exquisite selectivity of the adhesins for their cognate ligands or receptors and is a key step in niche or host colonization and pathogenicity. Streptococcus gordonii is a primary colonizer of the human oral cavity and an opportunistic pathogen, as well as a leading cause of infective endocarditis in humans. The fibrillar adhesin CshA is an important determinant of S. gordonii adherence, forming peritrichous fibrils on its surface that bind host cells and other microorganisms. CshA possesses a distinctive multidomain architecture comprising an N-terminal target-binding region fused to 17 repeat domains (RDs) that are each ∼100 amino acids long. Here, using structural and biophysical methods, we demonstrate that the intact CshA repeat region (CshA_RD1-17, domains 1-17) forms an extended polymeric monomer in solution. We recombinantly produced a subset of CshA RDs and found that they differ in stability and unfolding behavior. The NMR structure of CshA_RD13 revealed a hitherto unreported all β-fold, flanked by disordered interdomain linkers. These findings, in tandem with complementary hydrodynamic studies of CshA_RD1-17, indicate that this polypeptide possesses a highly unusual dynamic transitory structure characterized by alternating regions of order and disorder. This architecture provides flexibility for the adhesive tip of the CshA fibril to maintain bacterial attachment that withstands shear forces within the human host. It may also help mitigate deleterious folding events between neighboring RDs that share significant structural identity without compromising mechanical stability.
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Affiliation(s)
- Catherine R Back
- Bristol Dental School, University of Bristol, Bristol BS1 2LY, United Kingdom
- School of Biochemistry, University of Bristol, Bristol BS8 1TD, United Kingdom
- BrisSynBio Synthetic Biology Research Centre, University of Bristol, Bristol BS8 1TQ, United Kingdom
| | - Victoria A Higman
- School of Chemistry, University of Bristol, Bristol BS8 1TS, United Kingdom
| | - Kristian Le Vay
- School of Biochemistry, University of Bristol, Bristol BS8 1TD, United Kingdom
- Bristol Centre for Functional Nanomaterials, H. H. Wills Physics Laboratory, University of Bristol, Bristol BS8 1TL, United Kingdom
| | - Viren V Patel
- School of Biochemistry, University of Bristol, Bristol BS8 1TD, United Kingdom
| | - Alice E Parnell
- School of Biochemistry, University of Bristol, Bristol BS8 1TD, United Kingdom
- BrisSynBio Synthetic Biology Research Centre, University of Bristol, Bristol BS8 1TQ, United Kingdom
| | - Daniel Frankel
- School of Engineering, Newcastle University, Newcastle-upon-Tyne NE1 7RU, United Kingdom
| | - Howard F Jenkinson
- Bristol Dental School, University of Bristol, Bristol BS1 2LY, United Kingdom
| | - Steven G Burston
- School of Biochemistry, University of Bristol, Bristol BS8 1TD, United Kingdom
- BrisSynBio Synthetic Biology Research Centre, University of Bristol, Bristol BS8 1TQ, United Kingdom
| | - Matthew P Crump
- BrisSynBio Synthetic Biology Research Centre, University of Bristol, Bristol BS8 1TQ, United Kingdom
- School of Chemistry, University of Bristol, Bristol BS8 1TS, United Kingdom
| | - Angela H Nobbs
- Bristol Dental School, University of Bristol, Bristol BS1 2LY, United Kingdom
| | - Paul R Race
- School of Biochemistry, University of Bristol, Bristol BS8 1TD, United Kingdom
- BrisSynBio Synthetic Biology Research Centre, University of Bristol, Bristol BS8 1TQ, United Kingdom
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20
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Shing SR, Ramos AR, Patras KA, Riestra AM, McCabe S, Nizet V, Coady A. The Fungal Pathogen Candida albicans Promotes Bladder Colonization of Group B Streptococcus. Front Cell Infect Microbiol 2020; 9:437. [PMID: 31998657 PMCID: PMC6966239 DOI: 10.3389/fcimb.2019.00437] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2019] [Accepted: 12/05/2019] [Indexed: 12/16/2022] Open
Abstract
Group B Streptococcus (GBS) is a common cause of bacterial urinary tract infections (UTI) in susceptible populations, including pregnant women and the elderly. However, the factors that govern GBS persistence and disease severity in this niche are not fully understood. Here, we report that the presence of the fungus Candida albicans, a common urogenital colonizer, can promote GBS UTI. Co-inoculation of GBS with C. albicans increased bacterial adherence to bladder epithelium and promoted GBS colonization in vivo in a C. albicans adhesin-dependent manner. This study demonstrates that fungal colonization of the urogenital tract may be an important determinant of bacterial pathogenesis during UTI.
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Affiliation(s)
- Samuel R Shing
- Collaborative to Halt Antibiotic-Resistant Microbes, Department of Pediatrics, University of California, San Diego, La Jolla, CA, United States
| | - Anissa R Ramos
- Collaborative to Halt Antibiotic-Resistant Microbes, Department of Pediatrics, University of California, San Diego, La Jolla, CA, United States
| | - Kathryn A Patras
- Collaborative to Halt Antibiotic-Resistant Microbes, Department of Pediatrics, University of California, San Diego, La Jolla, CA, United States
| | - Angelica M Riestra
- Collaborative to Halt Antibiotic-Resistant Microbes, Department of Pediatrics, University of California, San Diego, La Jolla, CA, United States
| | - Sinead McCabe
- Collaborative to Halt Antibiotic-Resistant Microbes, Department of Pediatrics, University of California, San Diego, La Jolla, CA, United States
| | - Victor Nizet
- Collaborative to Halt Antibiotic-Resistant Microbes, Department of Pediatrics, University of California, San Diego, La Jolla, CA, United States.,Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California, San Diego, La Jolla, CA, United States
| | - Alison Coady
- Collaborative to Halt Antibiotic-Resistant Microbes, Department of Pediatrics, University of California, San Diego, La Jolla, CA, United States
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21
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The Group B Streptococcal surface antigen I/II protein, BspC, interacts with host vimentin to promote adherence to brain endothelium and inflammation during the pathogenesis of meningitis. PLoS Pathog 2019; 15:e1007848. [PMID: 31181121 PMCID: PMC6586375 DOI: 10.1371/journal.ppat.1007848] [Citation(s) in RCA: 44] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2019] [Revised: 06/20/2019] [Accepted: 05/16/2019] [Indexed: 12/29/2022] Open
Abstract
Streptococcus agalactiae (Group B Streptococcus, GBS) normally colonizes healthy adults but can cause invasive disease, such as meningitis, in the newborn. To gain access to the central nervous system, GBS must interact with and penetrate brain or meningeal blood vessels; however, the exact mechanisms are still being elucidated. Here, we investigate the contribution of BspC, an antigen I/II family adhesin, to the pathogenesis of GBS meningitis. Disruption of the bspC gene reduced GBS adherence to human cerebral microvascular endothelial cells (hCMEC), while heterologous expression of BspC in non-adherent Lactococcus lactis conferred bacterial attachment. In a murine model of hematogenous meningitis, mice infected with ΔbspC mutants exhibited lower mortality as well as decreased brain bacterial counts and inflammatory infiltrate compared to mice infected with WT GBS strains. Further, BspC was both necessary and sufficient to induce neutrophil chemokine expression. We determined that BspC interacts with the host cytoskeleton component vimentin and confirmed this interaction using a bacterial two-hybrid assay, microscale thermophoresis, immunofluorescent staining, and imaging flow cytometry. Vimentin null mice were protected from WT GBS infection and also exhibited less inflammatory cytokine production in brain tissue. These results suggest that BspC and the vimentin interaction is critical for the pathogenesis of GBS meningitis. Group B Streptococcus (GBS) typically colonizes healthy adults but can cause severe disease in immune-compromised individuals, including newborns. Despite wide-spread intrapartum antibiotic prophylaxis given to pregnant women, GBS remains a leading cause of neonatal meningitis. To cause meningitis, GBS must interact with and penetrate the blood-brain barrier (BBB), which separates bacteria and immune cells in the blood from the brain. In order to develop targeted therapies to treat GBS meningitis, it is important to understand the mechanisms of BBB crossing. Here, we describe the role of the GBS surface factor, BspC, in promoting meningitis and discover the host ligand for BspC, vimentin, which is an intermediate filament protein that is constitutively expressed by endothelial cells. We determined that BspC interacts with the C-terminal domain of cell-surface vimentin to promote bacterial attachment to brain endothelial cells and that purified BspC protein can induce immune signaling pathways. In a mouse model of hematogenous meningitis, we observed that a GBS mutant lacking BspC was less virulent compared to WT GBS and resulted in less inflammatory disease. We also observed that mice lacking vimentin were protected from GBS infection. These results reveal the importance of the BspC-vimentin interaction in the progression of GBS meningitis disease.
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22
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Guillén N. The interaction betweenEntamoeba histolyticaand enterobacteria shed light on an ancient antibacterial response. Cell Microbiol 2019; 21:e13039. [DOI: 10.1111/cmi.13039] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2019] [Revised: 04/17/2019] [Accepted: 04/30/2019] [Indexed: 01/27/2023]
Affiliation(s)
- Nancy Guillén
- Institut Pasteur Paris France
- INSBCentre National de la Recherche Scientifique, CNRS‐ERL9195 Paris France
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23
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Giussani S, Pietrocola G, Donnarumma D, Norais N, Speziale P, Fabbrini M, Margarit I. The Streptococcus agalactiae complement interfering protein combines multiple complement-inhibitory mechanisms by interacting with both C4 and C3 ligands. FASEB J 2018; 33:4448-4457. [PMID: 30566365 PMCID: PMC6404586 DOI: 10.1096/fj.201801991r] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Abstract
Group B Streptococcus (GBS) colonizes the human lower intestinal and genital tracts and constitutes a major threat to neonates from pregnant carrier mothers and to adults with underlying morbidity. The pathogen expresses cell-surface virulence factors that enable cell adhesion and penetration and that counteract innate and adaptive immune responses. Among these, the complement interfering protein (CIP) was recently described for its capacity to interact with the human C4b ligand and to interfere with the classical- and lectin-complement pathways. In the present study, we provide evidence that CIP can also interact with C3, C3b, and C3d. Immunoassay-based competition experiments showed that binding of CIP to C3d interferes with the interaction between C3d and the complement receptor 2/cluster of differentiation 21 (CR2/CD21) receptor on B cells. By B-cell intracellular signaling assays, CIP was confirmed to down-regulate CR2/CD21-dependent B-cell activation. The CIP domain involved in C3d binding was mapped via hydrogen deuterium exchange–mass spectrometry. The data obtained reveal a new role for this GBS polypeptide at the interface between the innate and adaptive immune responses, adding a new member to the growing list of virulence factors secreted by gram-positive pathogens that incorporate multiple immunomodulatory functions.—Giussani, S., Pietrocola, G., Donnarumma, D., Norais, N., Speziale, P., Fabbrini, M., Margarit, I. The Streptococcus agalactiae complement interfering protein combines multiple complement-inhibitory mechanisms by interacting with both C4 and C3 ligands.
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Affiliation(s)
- Stefania Giussani
- GlaxoSmithKline (GSK), Siena, Italy; and.,Unit of Biochemistry, Molecular Medicine Department, University of Pavia, Pavia, Italy
| | - Giampiero Pietrocola
- Unit of Biochemistry, Molecular Medicine Department, University of Pavia, Pavia, Italy
| | | | | | - Pietro Speziale
- Unit of Biochemistry, Molecular Medicine Department, University of Pavia, Pavia, Italy
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24
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Kohler V, Keller W, Grohmann E. Enterococcus adhesin PrgB facilitates type IV secretion by condensation of extracellular DNA. Mol Microbiol 2018; 109:263-267. [PMID: 29873122 DOI: 10.1111/mmi.13994] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/24/2018] [Indexed: 12/15/2022]
Abstract
Conjugative type IV secretion systems (T4SSs) are multi-protein complexes in Gram-negative and Gram-positive (G+) bacteria, responsible for spreading antibiotic resistances and virulence factors among different species. Compared to Gram-negative bacteria, which establish close contacts for conjugative transfer via sex pili, G+ T4SSs are suggested to employ surface adhesins instead. One example is pCF10, an enterococcal conjugative sex-pheromone responsive plasmid with a narrow host range, thus disseminating genetic information only among closely related species. This MicroCommentary is dedicated to the crystal structure of the pCF10-encoded adhesion domain of PrgB presented by Schmitt et al. The authors show in their work that this adhesion domain is responsible for biofilm formation, tight binding and condensation of extracellular DNA (eDNA) and conjugative transfer of pCF10. A sophisticated two-step mechanism for highly efficient conjugative transfer is postulated, including the formation of PrgB-mediated long-range intercellular contacts by binding and establishment of shorter-range contacts via condensation of eDNA. PrgB binding to lipoteichoic acid on the recipient cell surface stabilizes junctions between the mating partners. The major findings by Schmitt et al. will be brought into a broader context and potential medical applications targeting eDNA as essential component in biofilm formation and conjugation will be discussed.
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Affiliation(s)
- Verena Kohler
- Institute of Molecular Biosciences, BioTechMed, University of Graz, Graz, Austria
| | - Walter Keller
- Institute of Molecular Biosciences, BioTechMed, University of Graz, Graz, Austria
| | - Elisabeth Grohmann
- Life Sciences and Technology, Beuth University of Applied Sciences, Berlin, Germany
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25
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Varet H, Shaulov Y, Sismeiro O, Trebicz-Geffen M, Legendre R, Coppée JY, Ankri S, Guillen N. Enteric bacteria boost defences against oxidative stress in Entamoeba histolytica. Sci Rep 2018; 8:9042. [PMID: 29899530 PMCID: PMC5998147 DOI: 10.1038/s41598-018-27086-w] [Citation(s) in RCA: 34] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2018] [Accepted: 05/30/2018] [Indexed: 12/18/2022] Open
Abstract
Oxidative stress is one of the strongest toxic factors in nature: it can harm or even kill cells. Cellular means of subverting the toxicity of oxidative stress are important for the success of infectious diseases. Many types of bacterium inhabit the intestine, where they can encounter pathogens. During oxidative stress, we analyzed the interplay between an intestinal parasite (the pathogenic amoeba Entamoeba histolytica - the agent of amoebiasis) and enteric bacteria (microbiome residents, pathogens and probiotics). We found that live enteric bacteria protected E. histolytica against oxidative stress. By high-throughput RNA sequencing, two amoebic regulatory modes were observed with enteric bacteria but not with probiotics. The first controls essential elements of homeostasis, and the second the levels of factors required for amoeba survival. Characteristic genes of both modes have been acquired by the amoebic genome through lateral transfer from the bacterial kingdom (e.g. glycolytic enzymes and leucine-rich proteins). Members of the leucine-rich are homologous to proteins from anti-bacterial innate immune such as Toll-like receptors. The factors identified here suggest that despite its old age in evolutionary terms, the protozoan E. histolytica displays key characteristics of higher eukaryotes' innate immune systems indicating that components of innate immunity existed in the common ancestor of plants and animals.
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Affiliation(s)
- Hugo Varet
- Institut Pasteur, Plate-forme Transcriptome et Epigenome, Biomics, Centre d'Innovation et Recherche Technologique (Citech), Paris, France
- Institut Pasteur, Hub Bioinformatique et Biostatistique, Centre de Bioinformatique, Biostatistique et Biologie Intégrative (C3BI, USR 3756 IP CNRS), Paris, France
| | - Yana Shaulov
- Technion Institute, Department of Molecular Microbiology, Ruth and Bruce Rappaport Faculty of Medicine, Haifa, Israel
| | - Odile Sismeiro
- Institut Pasteur, Plate-forme Transcriptome et Epigenome, Biomics, Centre d'Innovation et Recherche Technologique (Citech), Paris, France
| | - Meirav Trebicz-Geffen
- Technion Institute, Department of Molecular Microbiology, Ruth and Bruce Rappaport Faculty of Medicine, Haifa, Israel
| | - Rachel Legendre
- Institut Pasteur, Plate-forme Transcriptome et Epigenome, Biomics, Centre d'Innovation et Recherche Technologique (Citech), Paris, France
- Institut Pasteur, Hub Bioinformatique et Biostatistique, Centre de Bioinformatique, Biostatistique et Biologie Intégrative (C3BI, USR 3756 IP CNRS), Paris, France
| | - Jean-Yves Coppée
- Institut Pasteur, Plate-forme Transcriptome et Epigenome, Biomics, Centre d'Innovation et Recherche Technologique (Citech), Paris, France
| | - Serge Ankri
- Technion Institute, Department of Molecular Microbiology, Ruth and Bruce Rappaport Faculty of Medicine, Haifa, Israel.
| | - Nancy Guillen
- Centre National de la Recherche Scientifique, CNRS-ERL9195, Paris, France.
- Institut Pasteur, Paris, France.
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26
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Pietrocola G, Arciola CR, Rindi S, Montanaro L, Speziale P. Streptococcus agalactiae Non-Pilus, Cell Wall-Anchored Proteins: Involvement in Colonization and Pathogenesis and Potential as Vaccine Candidates. Front Immunol 2018; 9:602. [PMID: 29686667 PMCID: PMC5900788 DOI: 10.3389/fimmu.2018.00602] [Citation(s) in RCA: 30] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2017] [Accepted: 03/09/2018] [Indexed: 11/13/2022] Open
Abstract
Group B Streptococcus (GBS) remains an important etiological agent of several infectious diseases including neonatal septicemia, pneumonia, meningitis, and orthopedic device infections. This pathogenicity is due to a variety of virulence factors expressed by Streptococcus agalactiae. Single virulence factors are not sufficient to provoke a streptococcal infection, which is instead promoted by the coordinated activity of several pathogenicity factors. Such determinants, mostly cell wall-associated and secreted proteins, include adhesins that mediate binding of the pathogen to host extracellular matrix/plasma ligands and cell surfaces, proteins that cooperate in the invasion of and survival within host cells and factors that neutralize phagocytosis and/or modulate the immune response. The genome-based approaches and bioinformatics tools and the extensive use of biophysical and biochemical methods and animal model studies have provided a great wealth of information on the molecular structure and function of these virulence factors. In fact, a number of new GBS surface-exposed or secreted proteins have been identified (GBS immunogenic bacterial adhesion protein, leucine-rich repeat of GBS, serine-rich repeat proteins), the three-dimensional structures of known streptococcal proteins (αC protein, C5a peptidase) have been solved and an understanding of the pathogenetic role of "old" and new determinants has been better defined in recent years. Herein, we provide an update of our current understanding of the major surface cell wall-anchored proteins from GBS, with emphasis on their biochemical and structural properties and the pathogenetic roles they may have in the onset and progression of host infection. We also focus on the antigenic profile of these compounds and discuss them as targets for therapeutic intervention.
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Affiliation(s)
- Giampiero Pietrocola
- Unit of Biochemistry, Department of Molecular Medicine, University of Pavia, Pavia, Italy
| | - Carla Renata Arciola
- Research Unit on Implant Infections, Rizzoli Orthopaedic Institute, Bologna, Italy.,Department of Experimental, Diagnostic, and Specialty Medicine, University of Bologna, Bologna, Italy
| | - Simonetta Rindi
- Unit of Biochemistry, Department of Molecular Medicine, University of Pavia, Pavia, Italy
| | - Lucio Montanaro
- Research Unit on Implant Infections, Rizzoli Orthopaedic Institute, Bologna, Italy.,Department of Experimental, Diagnostic, and Specialty Medicine, University of Bologna, Bologna, Italy
| | - Pietro Speziale
- Unit of Biochemistry, Department of Molecular Medicine, University of Pavia, Pavia, Italy.,Department of Industrial and Information Engineering, University of Pavia, Pavia, Italy
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27
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McNitt DH, Choi SJ, Keene DR, Van De Water L, Squeglia F, Berisio R, Lukomski S. Surface-exposed loops and an acidic patch in the Scl1 protein of group A Streptococcus enable Scl1 binding to wound-associated fibronectin. J Biol Chem 2018; 293:7796-7810. [PMID: 29615492 DOI: 10.1074/jbc.ra118.002250] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2018] [Revised: 03/29/2018] [Indexed: 12/22/2022] Open
Abstract
Keratinized epidermis constitutes a powerful barrier of the mucosa and skin, effectively preventing bacterial invasion, unless it is wounded and no longer protective. Wound healing involves deposition of distinct extracellular matrix (ECM) proteins enriched in cellular fibronectin (cFn) isoforms containing extra domain A (EDA). The streptococcal collagen-like protein 1 (Scl1) is a surface adhesin of group A Streptococcus (GAS), which contains an N-terminal variable (V) domain and a C-terminally located collagen-like domain. During wound infection, Scl1 selectively binds EDA/cFn isoforms and laminin, as well as low-density lipoprotein (LDL), through its V domain. The trimeric V domain has a six-helical bundle fold composed of three pairs of anti-parallel α-helices interconnected by hypervariable loops, but the roles of these structures in EDA/cFn binding are unclear. Here, using recombinant Scl (rScl) constructs to investigate structure-function determinants of the Scl1-EDA/cFn interaction, we found that full-length rScl1, containing both the globular V and the collagen domains, is necessary for EDA/cFn binding. We established that the surface-exposed loops, interconnecting conserved α-helices, guide recognition and binding of Scl1-V to EDA and binding to laminin and LDL. Moreover, electrostatic surface potential models of the Scl1-V domains pointed to a conserved, negatively charged pocket, surrounded by positively charged and neutral regions, as a determining factor for the binding. In light of these findings, we propose an updated model of EDA/cFn recognition by the Scl1 adhesin from GAS, representing a significant step in understanding the Scl1-ECM interactions within the wound microenvironment that underlie GAS pathogenesis.
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Affiliation(s)
- Dudley H McNitt
- From the Department of Microbiology, Immunology, and Cell Biology, West Virginia University School of Medicine, Morgantown, West Virginia 26506
| | - Soo Jeon Choi
- From the Department of Microbiology, Immunology, and Cell Biology, West Virginia University School of Medicine, Morgantown, West Virginia 26506
| | - Douglas R Keene
- the Micro-imaging Center, Shriners Hospital for Children, Portland, Oregon 97239
| | - Livingston Van De Water
- the Departments of Surgery and Regenerative and Cancer Cell Biology, Albany Medical College, Albany, New York 12208, and
| | - Flavia Squeglia
- the Institute of Biostructures and Bioimaging, Italian National Research Council, Via Mezzocannone 16, I-80134 Naples, Italy
| | - Rita Berisio
- the Institute of Biostructures and Bioimaging, Italian National Research Council, Via Mezzocannone 16, I-80134 Naples, Italy
| | - Slawomir Lukomski
- From the Department of Microbiology, Immunology, and Cell Biology, West Virginia University School of Medicine, Morgantown, West Virginia 26506,
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28
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Coassociation between Group B Streptococcus and Candida albicans Promotes Interactions with Vaginal Epithelium. Infect Immun 2018; 86:IAI.00669-17. [PMID: 29339458 DOI: 10.1128/iai.00669-17] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2017] [Accepted: 12/26/2017] [Indexed: 12/13/2022] Open
Abstract
Group B Streptococcus (GBS) is a leading cause of neonatal sepsis, pneumonia, and meningitis worldwide. In the majority of cases, GBS is transmitted vertically from mother to neonate, making maternal vaginal colonization a key risk factor for neonatal disease. The fungus Candida albicans is an opportunistic pathogen of the female genitourinary tract and the causative agent of vaginal thrush. Carriage of C. albicans has been shown to be an independent risk factor for vaginal colonization by GBS. However, the nature of interactions between these two microbes is poorly understood. This study provides evidence of a reciprocal, synergistic interplay between GBS and C. albicans that may serve to promote their cocolonization of the vaginal mucosa. GBS strains NEM316 (serotype III) and 515 (serotype Ia) are shown to physically interact with C. albicans, with the bacteria exhibiting tropism for candidal hyphal filaments. This interaction enhances association levels of both microbes with the vaginal epithelial cell line VK2/E6E7. The ability of GBS to coassociate with C. albicans is dependent upon expression of the hypha-specific adhesin Als3. In turn, expression of GBS antigen I/II family adhesins (Bsp polypeptides) facilitates this coassociation and confers upon surrogate Lactococcus lactis the capacity to exhibit enhanced interactions with C. albicans on vaginal epithelium. As genitourinary tract colonization is an essential first step in the pathogenesis of GBS and C. albicans, the coassociation mechanism reported here may have important implications for the risk of disease involving both of these pathogens.
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29
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Surface proteins involved in the adhesion of Streptococcus salivarius to human intestinal epithelial cells. Appl Microbiol Biotechnol 2018; 102:2851-2865. [PMID: 29442170 PMCID: PMC5847202 DOI: 10.1007/s00253-018-8794-y] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2017] [Revised: 01/10/2018] [Accepted: 01/14/2018] [Indexed: 01/08/2023]
Abstract
The adhesion properties of 14 Streptococcus salivarius strains to mucus (HT29-MTX) and non-mucus secreting (Caco-2/TC7) human intestinal epithelial cells were investigated. Ability to adhere to these two eukaryotic cell lines greatly differs between strains. The presence of mucus played a major factor in adhesion, likely due to high adhesiveness to mucins present in the native human mucus layer covering the whole cell surface. Only one S. salivarius strain (F6-1), isolated from the feces of a healthy baby, was found to strongly adhere to HT-29 MTX cells at a level comparable to that of Lactobacillus rhamnosus GG, a probiotic strain considered to be highly adherent. By sequencing the genome of F6-1, we were able to identify 36 genes encoding putative surface proteins. Deletion mutants were constructed for six of them and their adhesion abilities on HT-29 MTX cells were checked. Our study confirmed that four of these genes encode adhesins involved in the adhesion of S. salivarius to host cells. Such adhesins were also identified in other S. salivarius strains.
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30
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Patras KA, Nizet V. Group B Streptococcal Maternal Colonization and Neonatal Disease: Molecular Mechanisms and Preventative Approaches. Front Pediatr 2018; 6:27. [PMID: 29520354 PMCID: PMC5827363 DOI: 10.3389/fped.2018.00027] [Citation(s) in RCA: 90] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Group B Streptococcus (GBS) colonizes the gastrointestinal and vaginal epithelium of a significant percentage of healthy women, with potential for ascending intrauterine infection or transmission during parturition, creating a risk of serious disease in the vulnerable newborn. This review highlights new insights on the bacterial virulence determinants, host immune responses, and microbiome interactions that underpin GBS vaginal colonization, the proximal step in newborn infectious disease pathogenesis. From the pathogen perspective, the function GBS adhesins and biofilms, β-hemolysin/cytolysin toxin, immune resistance factors, sialic acid mimicry, and two-component transcriptional regulatory systems are reviewed. From the host standpoint, pathogen recognition, cytokine responses, and the vaginal mucosal and placental immunity to the pathogen are detailed. Finally, the rationale, efficacy, and potential unintended consequences of current universal recommended intrapartum antibiotic prophylaxis are considered, with updates on new developments toward a GBS vaccine or alternative approaches to reducing vaginal colonization.
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Affiliation(s)
- Kathryn A Patras
- Division of Host-Microbe Systems & Therapeutics, Department of Pediatrics, University of California, San Diego, La Jolla, CA, United States
| | - Victor Nizet
- Division of Host-Microbe Systems & Therapeutics, Department of Pediatrics, University of California, San Diego, La Jolla, CA, United States.,Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California, San Diego, La Jolla, CA, United States
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31
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de Ruyck J, Roos G, Krammer EM, Prévost M, Lensink MF, Bouckaert J. Molecular Mechanisms of Drug Action: X-ray Crystallography at the Basis of Structure-based and Ligand-based Drug Design. BIOPHYSICAL TECHNIQUES IN DRUG DISCOVERY 2017. [DOI: 10.1039/9781788010016-00067] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
Biological systems are recognized for their complexity and diversity and yet we sometimes manage to cure disease via the administration of small chemical drug molecules. At first, active ingredients were found accidentally and at that time there did not seem a need to understand the molecular mechanism of drug functioning. However, the urge to develop new drugs, the discovery of multipurpose characteristics of some drugs, and the necessity to remove unwanted secondary drug effects, incited the pharmaceutical sector to rationalize drug design. This did not deliver success in the years directly following its conception, but it drove the evolution of biochemical and biophysical techniques to enable the characterization of molecular mechanisms of drug action. Functional and structural data generated by biochemists and structural biologists became a valuable input for computational biologists, chemists and bioinformaticians who could extrapolate in silico, based on variations in the structural aspects of the drug molecules and their target. This opened up new avenues with much improved predictive power because of a clearer perception of the role and impact of structural elements in the intrinsic affinity and specificity of the drug for its target. In this chapter, we review how crystal structures can initiate structure-based drug design in general.
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Affiliation(s)
- J. de Ruyck
- Unité de Glycobiologie Structurale et Fonctionnelle, UMR 8576 of the Centre National de la Recherche Scientifique and the University of Lille 50 Avenue de Halley 59658 Villeneuve d'Ascq France
| | - G. Roos
- Unité de Glycobiologie Structurale et Fonctionnelle, UMR 8576 of the Centre National de la Recherche Scientifique and the University of Lille 50 Avenue de Halley 59658 Villeneuve d'Ascq France
- Université Libre de Bruxelles (ULB), Structure and Function of Biological Membranes CP 206/2, Boulevard du Triomphe, 1050 Brussels Belgium
| | - E.-M. Krammer
- Unité de Glycobiologie Structurale et Fonctionnelle, UMR 8576 of the Centre National de la Recherche Scientifique and the University of Lille 50 Avenue de Halley 59658 Villeneuve d'Ascq France
- Université Libre de Bruxelles (ULB), Structure and Function of Biological Membranes CP 206/2, Boulevard du Triomphe, 1050 Brussels Belgium
| | - M. Prévost
- Université Libre de Bruxelles (ULB), Structure and Function of Biological Membranes CP 206/2, Boulevard du Triomphe, 1050 Brussels Belgium
| | - M. F. Lensink
- Unité de Glycobiologie Structurale et Fonctionnelle, UMR 8576 of the Centre National de la Recherche Scientifique and the University of Lille 50 Avenue de Halley 59658 Villeneuve d'Ascq France
| | - J. Bouckaert
- Unité de Glycobiologie Structurale et Fonctionnelle, UMR 8576 of the Centre National de la Recherche Scientifique and the University of Lille 50 Avenue de Halley 59658 Villeneuve d'Ascq France
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32
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Back CR, Sztukowska MN, Till M, Lamont RJ, Jenkinson HF, Nobbs AH, Race PR. The Streptococcus gordonii Adhesin CshA Protein Binds Host Fibronectin via a Catch-Clamp Mechanism. J Biol Chem 2017; 292:1538-1549. [PMID: 27920201 PMCID: PMC5290933 DOI: 10.1074/jbc.m116.760975] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2016] [Revised: 12/01/2016] [Indexed: 11/06/2022] Open
Abstract
Adherence of bacteria to biotic or abiotic surfaces is a prerequisite for host colonization and represents an important step in microbial pathogenicity. This attachment is facilitated by bacterial adhesins at the cell surface. Because of their size and often elaborate multidomain architectures, these polypeptides represent challenging targets for detailed structural and functional characterization. The multifunctional fibrillar adhesin CshA, which mediates binding to both host molecules and other microorganisms, is an important determinant of colonization by Streptococcus gordonii, an oral commensal and opportunistic pathogen of animals and humans. CshA binds the high-molecular-weight glycoprotein fibronectin (Fn) via an N-terminal non-repetitive region, and this protein-protein interaction has been proposed to promote S. gordonii colonization at multiple sites within the host. However, the molecular details of how these two proteins interact have yet to be established. Here we present a structural description of the Fn binding N-terminal region of CshA, derived from a combination of X-ray crystallography, small angle X-ray scattering, and complementary biophysical methods. In vitro binding studies support a previously unreported two-state "catch-clamp" mechanism of Fn binding by CshA, in which the disordered N-terminal domain of CshA acts to "catch" Fn, via formation of a rapidly assembled but also readily dissociable pre-complex, enabling its neighboring ligand binding domain to tightly clamp the two polypeptides together. This study presents a new paradigm for target binding by a bacterial adhesin, the identification of which will inform future efforts toward the development of anti-adhesive agents that target S. gordonii and related streptococci.
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Affiliation(s)
- Catherine R Back
- From the School of Oral and Dental Sciences, University of Bristol, Lower Maudlin Street, Bristol BS1 2LY, United Kingdom
| | - Maryta N Sztukowska
- the Department of Oral Immunology and Infectious Diseases, University of Louisville, Louisville, Kentucky 40202; the Department of Dentistry, University of Information Technology and Management, 35-225 Rzeszow, Poland
| | - Marisa Till
- the School of Biochemistry, University of Bristol, University Walk, Bristol BS8 1TD, United Kingdom; the BrisSynBio Synthetic Biology Research Centre, University of Bristol, Life Sciences Building, Tyndall Avenue, Bristol, BS8 1TQ, United Kingdom
| | - Richard J Lamont
- the Department of Oral Immunology and Infectious Diseases, University of Louisville, Louisville, Kentucky 40202
| | - Howard F Jenkinson
- From the School of Oral and Dental Sciences, University of Bristol, Lower Maudlin Street, Bristol BS1 2LY, United Kingdom
| | - Angela H Nobbs
- From the School of Oral and Dental Sciences, University of Bristol, Lower Maudlin Street, Bristol BS1 2LY, United Kingdom.
| | - Paul R Race
- the School of Biochemistry, University of Bristol, University Walk, Bristol BS8 1TD, United Kingdom; the BrisSynBio Synthetic Biology Research Centre, University of Bristol, Life Sciences Building, Tyndall Avenue, Bristol, BS8 1TQ, United Kingdom.
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