51
|
Modeling Group B Streptococcus and Blood-Brain Barrier Interaction by Using Induced Pluripotent Stem Cell-Derived Brain Endothelial Cells. mSphere 2017; 2:mSphere00398-17. [PMID: 29104935 PMCID: PMC5663983 DOI: 10.1128/msphere.00398-17] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2017] [Accepted: 10/05/2017] [Indexed: 11/20/2022] Open
Abstract
Bacterial meningitis is a serious infection of the central nervous system (CNS) that occurs after bacteria interact with and penetrate the blood-brain barrier (BBB). The BBB is comprised of highly specialized brain microvascular endothelial cells (BMECs) that function to separate the circulation from the CNS and act as a formidable barrier for toxins and pathogens. Certain bacteria, such as Streptococcus agalactiae (group B Streptococcus [GBS]), possess the ability to interact with and penetrate the BBB to cause meningitis. Modeling bacterial interaction with the BBB in vitro has been limited to primary and immortalized BMEC culture. While useful, these cells often do not retain BBB-like properties, and human primary cells have limited availability. Recently, a human induced pluripotent stem cell (iPSC)-derived BMEC model has been established that is readily renewable and retains key BBB phenotypes. Here, we sought to evaluate whether the iPSC-derived BMECs were appropriate for modeling bacterial interaction with the BBB. Using GBS as a model meningeal pathogen, we demonstrate that wild-type GBS adhered to, invaded, and activated the iPSC-derived BMECs, while GBS mutants known to have diminished BBB interaction were attenuated in the iPSC-derived model. Furthermore, bacterial infection resulted in the disruption of tight junction components ZO-1, occludin, and claudin-5. Thus, we show for the first time that the iPSC-derived BBB model can be utilized to study BBB interaction with a bacterial CNS pathogen. IMPORTANCE Here for the first time, human iPSC-derived BMECs were used to model bacterial interaction with the BBB. Unlike models previously used to study these interactions, iPSC-derived BMECs possess robust BBB properties, such as the expression of complex tight junctions that are key components for the investigation of bacterial effects on the BBB. Here, we demonstrated that GBS interacts with the iPSC-derived BMECs and specifically disrupts these tight junctions. Thus, using this BBB model may allow researchers to uncover novel mechanisms of BBB disruption during meningitis that are inaccessible to immortalized or primary cell models that lack substantial tight junctions.
Collapse
|
52
|
Uribe-Querol E, Rosales C. Control of Phagocytosis by Microbial Pathogens. Front Immunol 2017; 8:1368. [PMID: 29114249 PMCID: PMC5660709 DOI: 10.3389/fimmu.2017.01368] [Citation(s) in RCA: 141] [Impact Index Per Article: 20.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2017] [Accepted: 10/05/2017] [Indexed: 12/17/2022] Open
Abstract
Phagocytosis is a fundamental process of cells to capture and ingest foreign particles. Small unicellular organisms such as free-living amoeba use this process to acquire food. In pluricellular organisms, phagocytosis is a universal phenomenon that all cells are able to perform (including epithelial, endothelial, fibroblasts, etc.), but some specialized cells (such as neutrophils and macrophages) perform this very efficiently and were therefore named professional phagocytes by Rabinovitch. Cells use phagocytosis to capture and clear all particles larger than 0.5 µm, including pathogenic microorganisms and cellular debris. Phagocytosis involves a series of steps from recognition of the target particle, ingestion of it in a phagosome (phagocytic vacuole), maturation of this phagosome into a phagolysosome, to the final destruction of the ingested particle in the robust antimicrobial environment of the phagolysosome. For the most part, phagocytosis is an efficient process that eliminates invading pathogens and helps maintaining homeostasis. However, several pathogens have also evolved different strategies to prevent phagocytosis from proceeding in a normal way. These pathogens have a clear advantage to perpetuate the infection and continue their replication. Here, we present an overview of the phagocytic process with emphasis on the antimicrobial elements professional phagocytes use. We also summarize the current knowledge on the microbial strategies different pathogens use to prevent phagocytosis either at the level of ingestion, phagosome formation, and maturation, and even complete escape from phagosomes.
Collapse
Affiliation(s)
- Eileen Uribe-Querol
- División de Estudios de Posgrado e Investigación, Facultad de Odontología, Universidad Nacional Autónoma de México, Mexico City, Mexico
| | - Carlos Rosales
- Departamento de Inmunología, Instituto de Investigaciones Biomédicas, Universidad Nacional Autónoma de México, Mexico City, Mexico
| |
Collapse
|
53
|
Luo S, Cao Q, Ma K, Wang Z, Liu G, Lu C, Liu Y. Quantitative assessment of the blood-brain barrier opening caused by Streptococcus agalactiae hyaluronidase in a BALB/c mouse model. Sci Rep 2017; 7:13529. [PMID: 29051603 PMCID: PMC5648924 DOI: 10.1038/s41598-017-13234-1] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2017] [Accepted: 09/20/2017] [Indexed: 12/30/2022] Open
Abstract
Streptococcus agalactiae is a pathogen causing meningitis in animals and humans. However, little is known about the entry of S. agalactiae into brain tissue. In this study, we developed a BALB/c mouse model based on the intravenous injection of β-galactosidase-positive Escherichia coli M5 as an indicator of blood-brain barrier (BBB) opening. Under physiological conditions, the BBB is impermeable to E. coli M5. In pathological conditions caused by S. agalactiae, E. coli M5 is capable of penetrating the brain through a disrupted BBB. The level of BBB opening can be assessed by quantitative measurement of E. coli M5 loads per gram of brain tissue. Further, we used the model to evaluate the role of S. agalactiae hyaluronidase in BBB opening. The inactivation of hylB gene encoding a hyaluronidase, HylB, resulted in significantly decreased E. coli M5 colonization, and the intravenous injection of purified HylB protein induced BBB opening in a dose-dependent manner. This finding verified the direct role of HylB in BBB invasion and traversal, and further demonstrated the practicability of the in vivo mouse model established in this study. This model will help to understand the S. agalactiae-host interactions that are involved in this bacterial traversal of the BBB and to develop efficacious strategies to prevent central nervous system infections.
Collapse
Affiliation(s)
- Su Luo
- College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, 210095, China
| | - Qing Cao
- College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, 210095, China
| | - Ke Ma
- College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, 210095, China
| | - Zhaofei Wang
- College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, 210095, China
| | - Guangjin Liu
- College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, 210095, China
| | - Chengping Lu
- College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, 210095, China
| | - Yongjie Liu
- College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, 210095, China.
| |
Collapse
|
54
|
Shabayek S, Spellerberg B. Acid Stress Response Mechanisms of Group B Streptococci. Front Cell Infect Microbiol 2017; 7:395. [PMID: 28936424 PMCID: PMC5594096 DOI: 10.3389/fcimb.2017.00395] [Citation(s) in RCA: 43] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2017] [Accepted: 08/23/2017] [Indexed: 12/20/2022] Open
Abstract
Group B streptococcus (GBS) is a leading cause of neonatal mortality and morbidity in the United States and Europe. It is part of the vaginal microbiota in up to 30% of pregnant women and can be passed on to the newborn through perinatal transmission. GBS has the ability to survive in multiple different host niches. The pathophysiology of this bacterium reveals an outstanding ability to withstand varying pH fluctuations of the surrounding environments inside the human host. GBS host pathogen interations include colonization of the acidic vaginal mucosa, invasion of the neutral human blood or amniotic fluid, breaching of the blood brain barrier as well as survival within the acidic phagolysosomal compartment of macrophages. However, investigations on GBS responses to acid stress are limited. Technologies, such as whole genome sequencing, genome-wide transcription and proteome mapping facilitate large scale identification of genes and proteins. Mechanisms enabling GBS to cope with acid stress have mainly been studied through these techniques and are summarized in the current review
Collapse
Affiliation(s)
- Sarah Shabayek
- Institute of Medical Microbiology and Hygiene, University of UlmUlm, Germany.,Department of Microbiology and Immunology, Faculty of Pharmacy, Suez Canal UniversityIsmailia, Egypt
| | - Barbara Spellerberg
- Institute of Medical Microbiology and Hygiene, University of UlmUlm, Germany
| |
Collapse
|
55
|
Khalil MR, Uldbjerg N, Thorsen PB, Henriksen B, Møller JK. Risk-based screening combined with a PCR-based test for group B streptococci diminishes the use of antibiotics in laboring women. Eur J Obstet Gynecol Reprod Biol 2017. [DOI: 10.1016/j.ejogrb.2017.06.019] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
|
56
|
Gram-Positive Uropathogens, Polymicrobial Urinary Tract Infection, and the Emerging Microbiota of the Urinary Tract. Microbiol Spectr 2017; 4. [PMID: 27227294 DOI: 10.1128/microbiolspec.uti-0012-2012] [Citation(s) in RCA: 200] [Impact Index Per Article: 28.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Abstract
Gram-positive bacteria are a common cause of urinary-tract infection (UTI), particularly among individuals who are elderly, pregnant, or who have other risk factors for UTI. Here we review the epidemiology, virulence mechanisms, and host response to the most frequently isolated Gram-positive uropathogens: Staphylococcus saprophyticus, Enterococcus faecalis, and Streptococcus agalactiae. We also review several emerging, rare, misclassified, and otherwise underreported Gram-positive pathogens of the urinary tract including Aerococcus, Corynebacterium, Actinobaculum, and Gardnerella. The literature strongly suggests that urologic diseases involving Gram-positive bacteria may be easily overlooked due to limited culture-based assays typically utilized for urine in hospital microbiology laboratories. Some UTIs are polymicrobial in nature, often involving one or more Gram-positive bacteria. We herein review the risk factors and recent evidence for mechanisms of bacterial synergy in experimental models of polymicrobial UTI. Recent experimental data has demonstrated that, despite being cleared quickly from the bladder, some Gram-positive bacteria can impact pathogenic outcomes of co-infecting organisms. When taken together, the available evidence argues that Gram-positive bacteria are important uropathogens in their own right, but that some can be easily overlooked because they are missed by routine diagnostic methods. Finally, a growing body of evidence demonstrates that a surprising variety of fastidious Gram-positive bacteria may either reside in or be regularly exposed to the urinary tract and further suggests that their presence is widespread among women, as well as men. Experimental studies in this area are needed; however, there is a growing appreciation that the composition of bacteria found in the bladder could be a potentially important determinant in urologic disease, including susceptibility to UTI.
Collapse
|
57
|
Lemire P, Galbas T, Thibodeau J, Segura M. Natural Killer Cell Functions during the Innate Immune Response to Pathogenic Streptococci. Front Microbiol 2017; 8:1196. [PMID: 28706510 PMCID: PMC5489694 DOI: 10.3389/fmicb.2017.01196] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2017] [Accepted: 06/12/2017] [Indexed: 01/21/2023] Open
Abstract
Dendritic cells (DCs) and NK cells play a crucial role in the first phase of host defense against infections. Group B Streptococcus (GBS) and Streptococcus suis are encapsulated streptococci causing severe systemic inflammation, leading to septicemia and meningitis. Yet, the involvement of NK cells in the innate immune response to encapsulated bacterial infection is poorly characterized. Here, it was observed that these two streptococcal species rapidly induce the release of IFN-γ and that NK cells are the major cell type responsible for this production during the acute phase of the infection. Albeit S. suis capacity to activate NK cells was lower than that of GBS, these cells partially contribute to S. suis systemic infection; mainly through amplification of the inflammatory loop. In contrast, such a role was not observed during GBS systemic infection. IFN-γ release by NK cells required the presence of DCs, which in turn had a synergistic effect on DC cytokine production. These responses were mainly mediated by direct DC-NK cell contact and partially dependent on soluble factors. Though IL-12 and LFA-1 were shown to be critical in S. suis-mediated activation of the DC-NK cell crosstalk, different or redundant molecular pathways modulate DC-NK interactions during GBS infection. The bacterial capsular polysaccharides also differently modulated NK cell activation. Together, these results demonstrated a role of NK cells in the innate immune response against encapsulated streptococcal infections; yet the molecular pathways governing NK activation seem to differ upon the pathogen and should not be generalized when studying bacterial infections.
Collapse
Affiliation(s)
- Paul Lemire
- Laboratory of Immunology of the Swine and Poultry Infectious Diseases Research Centre, Faculty of Veterinary Medicine, University of MontrealSt-Hyacinthe, QC, Canada
| | - Tristan Galbas
- Laboratory of Molecular Immunology, Faculty of Medicine, University of MontrealMontreal, QC, Canada
| | - Jacques Thibodeau
- Laboratory of Molecular Immunology, Faculty of Medicine, University of MontrealMontreal, QC, Canada
| | - Mariela Segura
- Laboratory of Immunology of the Swine and Poultry Infectious Diseases Research Centre, Faculty of Veterinary Medicine, University of MontrealSt-Hyacinthe, QC, Canada
| |
Collapse
|
58
|
Cools P, Melin P. Group B Streptococcus and perinatal mortality. Res Microbiol 2017; 168:793-801. [PMID: 28435137 DOI: 10.1016/j.resmic.2017.04.002] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2017] [Accepted: 04/03/2017] [Indexed: 12/12/2022]
Abstract
The World Health Organization estimates that every year, one million neonatal deaths occur because of neonatal infection. Furthermore, an equal number of stillbirths are thought to be caused by infections. Here we discuss the role of Streptococcus agalactiae (group B Streptococcus, GBS) in neonatal disease and stillbirth.
Collapse
Affiliation(s)
- Piet Cools
- Laboratory Bacteriology Research, Department of Microbiology, Immunology and Clinical Chemistry, Faculty of Medicine and Health Sciences, Ghent University, Ghent, Belgium.
| | - Pierrette Melin
- Clinical Microbiology, National Reference Centre for Streptococcus agalactiae, University Hospital of Liège, Faculty of Medicine, Liege University, Liège, Belgium
| |
Collapse
|
59
|
The role of lactic acid production by probiotic Lactobacillus species in vaginal health. Res Microbiol 2017; 168:782-792. [PMID: 28435139 DOI: 10.1016/j.resmic.2017.04.001] [Citation(s) in RCA: 287] [Impact Index Per Article: 41.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2016] [Revised: 04/03/2017] [Accepted: 04/03/2017] [Indexed: 12/12/2022]
Abstract
Vaginal eubiosis is characterised by beneficial lactobacillus-dominated microbiota. In contrast, vaginal dysbiosis (e.g. bacterial vaginosis, BV), characterised by an overgrowth of multiple anaerobes, is associated with an increased risk of adverse urogenital and reproductive health outcomes. A major distinguishing feature between the vaginal environment in states of eubiosis and dysbiosis is a high concentration of lactic acid, produced by lactobacilli, that acidifies the vagina in eubiosis versus a sharp drop in lactic acid and an increase in pH in dysbiosis. Here we review the antimicrobial, antiviral and immunomodulatory properties of lactic acid and the use of lactic acid and lactobacilli probiotics in preventing or treating BV.
Collapse
|
60
|
A journey into the brain: insight into how bacterial pathogens cross blood-brain barriers. Nat Rev Microbiol 2017; 15:149-159. [PMID: 28090076 DOI: 10.1038/nrmicro.2016.178] [Citation(s) in RCA: 164] [Impact Index Per Article: 23.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
The blood-brain barrier, which is one of the tightest barriers in the body, protects the brain from insults, such as infections. Indeed, only a few of the numerous blood-borne bacteria can cross the blood-brain barrier to cause meningitis. In this Review, we focus on invasive extracellular pathogens, such as Neisseria meningitidis, Streptococcus pneumoniae, group B Streptococcus and Escherichia coli, to review the obstacles that bacteria have to overcome in order to invade the meninges from the bloodstream, and the specific skills they have developed to bypass the blood-brain barrier. The medical importance of understanding how these barriers can be circumvented is underlined by the fact that we need to improve drug delivery into the brain.
Collapse
|
61
|
Efstratiou A, Lamagni T, Turner CE. Streptococci and Enterococci. Infect Dis (Lond) 2017. [DOI: 10.1016/b978-0-7020-6285-8.00177-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/21/2022] Open
|
62
|
Hancock BM, Doran KS. Importance of strain lineages for Group B streptococcal survival. Virulence 2016; 8:646-648. [PMID: 28033037 DOI: 10.1080/21505594.2016.1271860] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022] Open
Affiliation(s)
- Bryan M Hancock
- a Department of Biology and Center for Microbial Sciences , San Diego State University , San Diego , CA , USA
| | - Kelly S Doran
- a Department of Biology and Center for Microbial Sciences , San Diego State University , San Diego , CA , USA
| |
Collapse
|
63
|
Abstract
Streptococcus agalactiae (group B Streptococcus, GBS), is a Gram-positive, asymptomatic colonizer of the human gastrointestinal tract and vaginal tract of 10 - 30% of adults. In immune-compromised individuals, including neonates, pregnant women, and the elderly, GBS may switch to an invasive pathogen causing sepsis, arthritis, pneumonia, and meningitis. Because GBS is a leading bacterial pathogen of neonates, current prophylaxis is comprised of late gestation screening for GBS vaginal colonization and subsequent peripartum antibiotic treatment of GBS-positive mothers. Heavy GBS vaginal burden is a risk factor for both neonatal disease and colonization. Unfortunately, little is known about the host and bacterial factors that promote or permit GBS vaginal colonization. This protocol describes a technique for establishing persistent GBS vaginal colonization using a single β-estradiol pre-treatment and daily sampling to determine bacterial load. It further details methods to administer additional therapies or reagents of interest and to collect vaginal lavage fluid and reproductive tract tissues. This mouse model will further the understanding of the GBS-host interaction within the vaginal environment, which will lead to potential therapeutic targets to control maternal vaginal colonization during pregnancy and to prevent transmission to the vulnerable newborn. It will also be of interest to increase our understanding of general bacterial-host interactions in the female vaginal tract.
Collapse
Affiliation(s)
- Kathryn A Patras
- Department of Pediatrics, Division of Host-Microbe Systems & Therapeutics, University of California San Diego School of Medicine
| | - Kelly S Doran
- Department of Pediatrics, Division of Host-Microbe Systems & Therapeutics, University of California San Diego School of Medicine; Department of Biology and Center for Microbial Sciences, San Diego State University;
| |
Collapse
|
64
|
Barato P, Martins E, Vasquez G, Ramirez M, Melo-Cristino J, Martínez N, Iregui C. Capsule impairs efficient adherence of Streptococcus agalactiae to intestinal epithelium in tilapias Oreochromis sp. Microb Pathog 2016; 100:30-36. [DOI: 10.1016/j.micpath.2016.08.040] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2015] [Revised: 05/30/2016] [Accepted: 08/31/2016] [Indexed: 10/21/2022]
|
65
|
Kobayashi M, Vekemans J, Baker CJ, Ratner AJ, Le Doare K, Schrag SJ. Group B Streptococcus vaccine development: present status and future considerations, with emphasis on perspectives for low and middle income countries. F1000Res 2016; 5:2355. [PMID: 27803803 PMCID: PMC5070600 DOI: 10.12688/f1000research.9363.1] [Citation(s) in RCA: 55] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 09/08/2016] [Indexed: 01/07/2023] Open
Abstract
Globally, group B Streptococcus (GBS) remains the leading cause of sepsis and meningitis in young infants, with its greatest burden in the first 90 days of life. Intrapartum antibiotic prophylaxis (IAP) for women at risk of transmitting GBS to their newborns has been effective in reducing, but not eliminating, the young infant GBS disease burden in many high income countries. However, identification of women at risk and administration of IAP is very difficult in many low and middle income country (LMIC) settings, and is not possible for home deliveries. Immunization of pregnant women with a GBS vaccine represents an alternate pathway to protecting newborns from GBS disease, through the transplacental antibody transfer to the fetus in utero. This approach to prevent GBS disease in young infants is currently under development, and is approaching late stage clinical evaluation. This manuscript includes a review of the natural history of the disease, global disease burden estimates, diagnosis and existing control options in different settings, the biological rationale for a vaccine including previous supportive studies, analysis of current candidates in development, possible correlates of protection and current status of immunogenicity assays. Future potential vaccine development pathways to licensure and use in LMICs, trial design and implementation options are discussed, with the objective to provide a basis for reflection, rather than recommendations.
Collapse
Affiliation(s)
- Miwako Kobayashi
- National Center for Immunization and Respiratory Diseases, Division of Bacterial Diseases, Centers for Disease Control and Prevention, Atlanta, USA
- Epidemic Intelligence Service, Centers for Disease Control and Prevention, Atlanta, USA
| | - Johan Vekemans
- Initiative for Vaccine Research, World Health Organization, Geneva, Switzerland
| | - Carol J. Baker
- Department of Pediatrics, Baylor College of Medicine, Houston, USA
- Department of Molecular Virology and Microbiology, Baylor College of Medicine, Houston, USA
- Center for Vaccine Awareness and Research, Texas Children's Hospital, Houston, USA
| | - Adam J. Ratner
- Departments of Pediatrics and Microbiology, New York University School of Medicine, New York, USA
| | - Kirsty Le Doare
- Centre for International Child Health, Imperial College, London, UK
| | - Stephanie J. Schrag
- National Center for Immunization and Respiratory Diseases, Division of Bacterial Diseases, Centers for Disease Control and Prevention, Atlanta, USA
| |
Collapse
|
66
|
Willenborg J, Goethe R. Metabolic traits of pathogenic streptococci. FEBS Lett 2016; 590:3905-3919. [PMID: 27442496 DOI: 10.1002/1873-3468.12317] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2016] [Revised: 07/12/2016] [Accepted: 07/18/2016] [Indexed: 12/13/2022]
Abstract
Invasive and noninvasive diseases caused by facultative pathogenic streptococci depend on their equipment with virulence factors and on their ability to sense and adapt to changing nutrients in different host environments. The knowledge of the principal metabolic mechanisms which allow these bacteria to recognize and utilize nutrients in host habitats is a prerequisite for our understanding of streptococcal pathogenicity and the development of novel control strategies. This review aims to summarize and compare the central carbohydrate metabolic and amino acid biosynthetic pathways of a selected group of streptococcal species, all belonging to the naso-oropharyngeal microbiome in humans and/or animals. We also discuss the urgent need of comprehensive metabolomics approaches for a better understanding of the streptococcal metabolism during host-pathogen interaction.
Collapse
Affiliation(s)
- Jörg Willenborg
- Institute for Microbiology, University of Veterinary Medicine Hannover, Germany
| | - Ralph Goethe
- Institute for Microbiology, University of Veterinary Medicine Hannover, Germany
| |
Collapse
|
67
|
Zorgani MA, Quentin R, Lartigue MF. Regulatory RNAs in the Less Studied Streptococcal Species: From Nomenclature to Identification. Front Microbiol 2016; 7:1161. [PMID: 27507970 PMCID: PMC4960207 DOI: 10.3389/fmicb.2016.01161] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2016] [Accepted: 07/12/2016] [Indexed: 12/23/2022] Open
Abstract
Streptococcal species are Gram-positive bacteria involved in severe and invasive diseases in humans and animals. Although, this group includes different pathogenic species involved in life-threatening infections for humans, it also includes beneficial species, such as Streptococcus thermophilus, which is used in yogurt production. In bacteria virulence factors are controlled by various regulatory networks including regulatory RNAs. For clearness and to develop logical thinking, we start this review with a revision of regulatory RNAs nomenclature. Previous reviews are mostly dealing with Streptococcus pyogenes and Streptococcus pneumoniae regulatory RNAs. We especially focused our analysis on regulatory RNAs in Streptococcus agalactiae, Streptococcus mutans, Streptococcus thermophilus and other less studied Streptococcus species. Although, S. agalactiae RNome remains largely unknown, sRNAs (small RNAs) are supposed to mediate regulation during environmental adaptation and host infection. In the case of S. mutans, sRNAs are suggested to be involved in competence regulation, carbohydrate metabolism, and Toxin–Antitoxin systems. A new category of miRNA-size small RNAs (msRNAs) was also identified for the first time in this species. The analysis of S. thermophilus sRNome shows that many sRNAs are associated to the bacterial immune system known as CRISPR-Cas system. Only few of the other different Streptococcus species have been the subject of studies pointed toward the characterization of regulatory RNAs. Finally, understanding bacterial sRNome can constitute one step forward to the elaboration of new strategies in therapy such as substitution of antibiotics in the management of S. agalactiae neonatal infections, prevention of S. mutans dental caries or use of S. thermophilus CRISPR-Cas system in genome editing applications.
Collapse
Affiliation(s)
- Mohamed A Zorgani
- ISP, INRA, Equipe 5 "Bactéries et Risque Materno-foetal", Faculté de Médecine, UMR 1282, Université François Rabelais de Tours, Tours France
| | - Roland Quentin
- ISP, INRA, Equipe 5 "Bactéries et Risque Materno-foetal", Faculté de Médecine, UMR 1282, Université François Rabelais de Tours, ToursFrance; Service de Bactériologie Virologie et Hygiène Hospitalière, Centre Hospitalier Régional Universitaire de Tours, ToursFrance
| | - Marie-Frédérique Lartigue
- ISP, INRA, Equipe 5 "Bactéries et Risque Materno-foetal", Faculté de Médecine, UMR 1282, Université François Rabelais de Tours, ToursFrance; Service de Bactériologie Virologie et Hygiène Hospitalière, Centre Hospitalier Régional Universitaire de Tours, ToursFrance
| |
Collapse
|
68
|
Franza T, Delavenne E, Derré-Bobillot A, Juillard V, Boulay M, Demey E, Vinh J, Lamberet G, Gaudu P. A partial metabolic pathway enables group b streptococcus to overcome quinone deficiency in a host bacterial community. Mol Microbiol 2016; 102:81-91. [PMID: 27328751 DOI: 10.1111/mmi.13447] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/20/2016] [Indexed: 11/28/2022]
Abstract
Aerobic respiration metabolism in Group B Streptococcus (GBS) is activated by exogenous heme and menaquinone. This capacity enhances resistance of GBS to acid and oxidative stress and improves its survival. In this work, we discovered that GBS is able to respire in the presence of heme and 1,4-dihydroxy-2-naphthoic acid (DHNA). DHNA is a biosynthetic precursor of demethylmenaquinone (DMK) in many bacterial species. A GBS gene (gbs1789) encodes a homolog of the MenA 1,4-dihydroxy-2-naphthoate prenyltransferase enzyme, involved in the synthesis of demethylmenaquinone. In this study, we showed that gbs1789 is involved in the biosynthesis of long-chain demethylmenaquinones (DMK-10). The Δgbs1789 mutant cannot respire in the presence of heme and DHNA, indicating that endogenously synthesized DMKs are cofactors of the GBS respiratory chain. We also found that isoprenoid side chains from GBS DMKs are produced by the protein encoded by the gbs1783 gene, since this gene can complement an Escherichia coli ispB mutant defective for isoprenoids chain synthesis. In the gut or vaginal microbiote, where interspecies metabolite exchanges occur, this partial DMK biosynthetic pathway can be important for GBS respiration and survival in different niches.
Collapse
Affiliation(s)
- Thierry Franza
- Micalis Institute, INRA, AgroParisTech, Université Paris-Saclay, Jouy-en-Josas, 78350, France.
| | - Emilie Delavenne
- Micalis Institute, INRA, AgroParisTech, Université Paris-Saclay, Jouy-en-Josas, 78350, France
| | - Aurélie Derré-Bobillot
- Micalis Institute, INRA, AgroParisTech, Université Paris-Saclay, Jouy-en-Josas, 78350, France
| | - Vincent Juillard
- Micalis Institute, INRA, AgroParisTech, Université Paris-Saclay, Jouy-en-Josas, 78350, France
| | - Mylène Boulay
- Micalis Institute, INRA, AgroParisTech, Université Paris-Saclay, Jouy-en-Josas, 78350, France
| | | | - Joelle Vinh
- ESPCI Paris, SMBP USR3149 CNRS, Paris, F-75005, France
| | - Gilles Lamberet
- Micalis Institute, INRA, AgroParisTech, Université Paris-Saclay, Jouy-en-Josas, 78350, France
| | - Philippe Gaudu
- Micalis Institute, INRA, AgroParisTech, Université Paris-Saclay, Jouy-en-Josas, 78350, France
| |
Collapse
|
69
|
Wang B, Gan Z, Cai S, Wang Z, Yu D, Lin Z, Lu Y, Wu Z, Jian J. Comprehensive identification and profiling of Nile tilapia (Oreochromis niloticus) microRNAs response to Streptococcus agalactiae infection through high-throughput sequencing. FISH & SHELLFISH IMMUNOLOGY 2016; 54:93-106. [PMID: 27050313 DOI: 10.1016/j.fsi.2016.03.159] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/25/2015] [Revised: 03/22/2016] [Accepted: 03/26/2016] [Indexed: 06/05/2023]
Abstract
MicroRNAs are a kind of small non-coding RNAs that participate in various biological processes. Deregulated microRNA expression is associated with several types of diseases. Tilapia (Oreochromis niloticus) is an important commercial fish species in China. To identify miRNAs and investigate immune-related miRNAs of O. niloticus, we applied high-throughput sequencing technology to identify and analyze miRNAs from tilapia infected with Streptococcus agalactiae at a timescale of 72 h divided into six different time points. The results showed that a total of 3009 tilapia miRNAs were identified, including in 1121 miRNAs which have homologues in the currently available databases and 1878 novel miRNAs. The expression levels of 218 tilapia miRNAs were significantly altered at 6 h-72 h post-bacterial infection (pi), and these miRNAs were therefore classified as differentially expressed tilapia miRNAs. For the 1121 differentially expressed tilapia miRNAs target 41961 genes. GO and KEGG enrichment analysis revealed that some target genes of tilapia miRNAs were grouped mainly into the categories of apoptotic process, signal pathway, and immune response. This is the first report of comprehensive identification of O. niloticus miRNAs being differentially regulated in spleen in normal conditions relating to S. agalactiae infection. This work provides an opportunity for further understanding of the molecular mechanisms of miRNA regulation in O. niloticus host-pathogen interactions.
Collapse
Affiliation(s)
- Bei Wang
- College of Fishery, Guangdong Ocean University, Guangdong Provincial Key Laboratory of Pathogenic Biology and Epidemiology for Aquatic Economic Animala, Key Laboratory of Control for Disease of Aquatic Animals of Guangdong Higher Education Insititutes, Zhanjiang, 524025, China
| | - Zhen Gan
- College of Fishery, Guangdong Ocean University, Guangdong Provincial Key Laboratory of Pathogenic Biology and Epidemiology for Aquatic Economic Animala, Key Laboratory of Control for Disease of Aquatic Animals of Guangdong Higher Education Insititutes, Zhanjiang, 524025, China; State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, 430072, China
| | - Shuanghu Cai
- College of Fishery, Guangdong Ocean University, Guangdong Provincial Key Laboratory of Pathogenic Biology and Epidemiology for Aquatic Economic Animala, Key Laboratory of Control for Disease of Aquatic Animals of Guangdong Higher Education Insititutes, Zhanjiang, 524025, China
| | - Zhongliang Wang
- College of Fishery, Guangdong Ocean University, Guangdong Provincial Key Laboratory of Pathogenic Biology and Epidemiology for Aquatic Economic Animala, Key Laboratory of Control for Disease of Aquatic Animals of Guangdong Higher Education Insititutes, Zhanjiang, 524025, China
| | - Dapeng Yu
- College of Fishery, Guangdong Ocean University, Guangdong Provincial Key Laboratory of Pathogenic Biology and Epidemiology for Aquatic Economic Animala, Key Laboratory of Control for Disease of Aquatic Animals of Guangdong Higher Education Insititutes, Zhanjiang, 524025, China
| | - Ziwei Lin
- College of Fishery, Guangdong Ocean University, Guangdong Provincial Key Laboratory of Pathogenic Biology and Epidemiology for Aquatic Economic Animala, Key Laboratory of Control for Disease of Aquatic Animals of Guangdong Higher Education Insititutes, Zhanjiang, 524025, China
| | - Yishan Lu
- College of Fishery, Guangdong Ocean University, Guangdong Provincial Key Laboratory of Pathogenic Biology and Epidemiology for Aquatic Economic Animala, Key Laboratory of Control for Disease of Aquatic Animals of Guangdong Higher Education Insititutes, Zhanjiang, 524025, China
| | - Zaohe Wu
- College of Fishery, Guangdong Ocean University, Guangdong Provincial Key Laboratory of Pathogenic Biology and Epidemiology for Aquatic Economic Animala, Key Laboratory of Control for Disease of Aquatic Animals of Guangdong Higher Education Insititutes, Zhanjiang, 524025, China
| | - Jichang Jian
- College of Fishery, Guangdong Ocean University, Guangdong Provincial Key Laboratory of Pathogenic Biology and Epidemiology for Aquatic Economic Animala, Key Laboratory of Control for Disease of Aquatic Animals of Guangdong Higher Education Insititutes, Zhanjiang, 524025, China.
| |
Collapse
|
70
|
Mu R, Cutting AS, Del Rosario Y, Villarino N, Stewart L, Weston TA, Patras KA, Doran KS. Identification of CiaR Regulated Genes That Promote Group B Streptococcal Virulence and Interaction with Brain Endothelial Cells. PLoS One 2016; 11:e0153891. [PMID: 27100296 PMCID: PMC4839699 DOI: 10.1371/journal.pone.0153891] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2015] [Accepted: 04/05/2016] [Indexed: 11/18/2022] Open
Abstract
Group B Streptococcus (GBS) is a major causative agent of neonatal meningitis due to its ability to efficiently cross the blood-brain barrier (BBB) and enter the central nervous system (CNS). It has been demonstrated that GBS can invade human brain microvascular endothelial cells (hBMEC), a primary component of the BBB; however, the mechanism of intracellular survival and trafficking is unclear. We previously identified a two component regulatory system, CiaR/H, which promotes GBS intracellular survival in hBMEC. Here we show that a GBS strain deficient in the response regulator, CiaR, localized more frequently with Rab5, Rab7 and LAMP1 positive vesicles. Further, lysosomes isolated from hBMEC contained fewer viable bacteria following initial infection with the ΔciaR mutant compared to the WT strain. To characterize the contribution of CiaR-regulated genes, we constructed isogenic mutant strains lacking the two most down-regulated genes in the CiaR-deficient mutant, SAN_2180 and SAN_0039. These genes contributed to bacterial uptake and intracellular survival. Furthermore, competition experiments in mice showed that WT GBS had a significant survival advantage over the Δ2180 and Δ0039 mutants in the bloodstream and brain.
Collapse
Affiliation(s)
- Rong Mu
- Department of Biology and Center for Microbial Sciences, San Diego State University, San Diego, California, 92182, United States of America
| | - Andrew S. Cutting
- Department of Biology and Center for Microbial Sciences, San Diego State University, San Diego, California, 92182, United States of America
| | - Yvette Del Rosario
- Department of Biology and Center for Microbial Sciences, San Diego State University, San Diego, California, 92182, United States of America
| | - Nicholas Villarino
- Department of Biology and Center for Microbial Sciences, San Diego State University, San Diego, California, 92182, United States of America
| | - Lara Stewart
- Department of Biology and Center for Microbial Sciences, San Diego State University, San Diego, California, 92182, United States of America
| | - Thomas A. Weston
- Department of Biology and Center for Microbial Sciences, San Diego State University, San Diego, California, 92182, United States of America
| | - Kathryn A. Patras
- Department of Biology and Center for Microbial Sciences, San Diego State University, San Diego, California, 92182, United States of America
| | - Kelly S. Doran
- Department of Biology and Center for Microbial Sciences, San Diego State University, San Diego, California, 92182, United States of America
- Department of Pediatrics, University of California San Diego School of Medicine, La Jolla, California, 92093, United States of America
- * E-mail:
| |
Collapse
|
71
|
Stouch AN, McCoy AM, Greer RM, Lakhdari O, Yull FE, Blackwell TS, Hoffman HM, Prince LS. IL-1β and Inflammasome Activity Link Inflammation to Abnormal Fetal Airway Development. THE JOURNAL OF IMMUNOLOGY 2016; 196:3411-20. [PMID: 26951798 DOI: 10.4049/jimmunol.1500906] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Subscribe] [Scholar Register] [Received: 04/17/2015] [Accepted: 02/16/2016] [Indexed: 12/13/2022]
Abstract
Inflammation in the developing preterm lung leads to disrupted airway morphogenesis and chronic lung disease in human neonates. However, the molecular mechanisms linking inflammation and the pathways controlling airway morphogenesis remain unclear. In this article, we show that IL-1β released by activated fetal lung macrophages is the key inflammatory mediator that disrupts airway morphogenesis. In mouse lung explants, blocking IL-1β expression, posttranslational processing, and signaling protected the formation of new airways from the inhibitory effects ofEscherichia coliLPS. Consistent with a critical role for IL-1β, mice expressing a gain-of-functionNlrp3allele and subsequent overactive inflammasome activity displayed abnormal saccular-stage lung morphogenesis and died soon after birth. Although the early-stage fetal lung appeared capable of mounting an NF-κB-mediated immune response, airway formation became more sensitive to inflammation later in development. This period of susceptibility coincided with higher expression of multiple inflammasome components that could increase the ability to release bioactive IL-1β. Macrophages fromNlrp3gain-of-function mice also expressed higher levels of more mature cell surface markers, additionally linking inflammasome activation with macrophage maturation. These data identify developmental expression of the inflammasome and IL-1β release by fetal lung macrophages as key mechanisms and potential therapeutic targets for neonatal lung disease.
Collapse
Affiliation(s)
- Ashley N Stouch
- Department of Pediatrics, University of California, San Diego and Rady Children's Hospital, San Diego, La Jolla, CA 92093
| | - Alyssa M McCoy
- Department of Pediatrics, University of California, San Diego and Rady Children's Hospital, San Diego, La Jolla, CA 92093
| | - Rachel M Greer
- Department of Pediatrics, University of California, San Diego and Rady Children's Hospital, San Diego, La Jolla, CA 92093
| | - Omar Lakhdari
- Department of Pediatrics, University of California, San Diego and Rady Children's Hospital, San Diego, La Jolla, CA 92093
| | - Fiona E Yull
- Department of Cancer Biology, Vanderbilt University School of Medicine, Nashville, TN 37232
| | - Timothy S Blackwell
- Department of Cancer Biology, Vanderbilt University School of Medicine, Nashville, TN 37232; Department of Medicine, Vanderbilt University School of Medicine, Nashville, TN 37232; and Department of Cell and Developmental Biology, Vanderbilt University School of Medicine, Nashville, TN 37232
| | - Hal M Hoffman
- Department of Pediatrics, University of California, San Diego and Rady Children's Hospital, San Diego, La Jolla, CA 92093
| | - Lawrence S Prince
- Department of Pediatrics, University of California, San Diego and Rady Children's Hospital, San Diego, La Jolla, CA 92093;
| |
Collapse
|
72
|
Group B Streptococcus Induces a Robust IFN-γ Response by CD4(+) T Cells in an In Vitro and In Vivo Model. J Immunol Res 2016; 2016:5290604. [PMID: 26989699 PMCID: PMC4771917 DOI: 10.1155/2016/5290604] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2015] [Accepted: 01/06/2016] [Indexed: 11/17/2022] Open
Abstract
Group B Streptococcus (GBS) serotype III causes life-threatening infections. Cytokines have emerged as important players for the control of disease, particularly IFN-γ. Although potential sources of this cytokine have been proposed, no specific cell line has ever been described as a leading contributor. In this study, CD4+ T cell activation profiles in response to GBS were evaluated through in vivo, ex vivo, and in vitro approaches. Total splenocytes readily produce a type 1 proinflammatory response by releasing IFN-γ, TNF-α, and IL-6 and actively recruit T cells via chemokines like CXCL9, CXCL10, and CCL3. Responding CD4+ T cells differentiate into Th1 cells producing large amounts of IFN-γ, TNF-α, and IL-2. In vitro studies using dendritic cell and CD4+ T cell cocultures infected with wild-type GBS or a nonencapsulated mutant suggested that GBS capsular polysaccharide, one of the major bacterial virulence factors, differentially modulates surface expression of CD69 and IFN-γ production. Overall, CD4+ T cells are important producers of IFN-γ and might thus influence the course of GBS infection through the expression balance of this cytokine.
Collapse
|
73
|
Doran KS, Fulde M, Gratz N, Kim BJ, Nau R, Prasadarao N, Schubert-Unkmeir A, Tuomanen EI, Valentin-Weigand P. Host-pathogen interactions in bacterial meningitis. Acta Neuropathol 2016; 131:185-209. [PMID: 26744349 PMCID: PMC4713723 DOI: 10.1007/s00401-015-1531-z] [Citation(s) in RCA: 112] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2015] [Revised: 12/21/2015] [Accepted: 12/22/2015] [Indexed: 12/26/2022]
Abstract
Bacterial meningitis is a devastating disease occurring worldwide with up to half of the survivors left with permanent neurological sequelae. Due to intrinsic properties of the meningeal pathogens and the host responses they induce, infection can cause relatively specific lesions and clinical syndromes that result from interference with the function of the affected nervous system tissue. Pathogenesis is based on complex host–pathogen interactions, some of which are specific for certain bacteria, whereas others are shared among different pathogens. In this review, we summarize the recent progress made in understanding the molecular and cellular events involved in these interactions. We focus on selected major pathogens, Streptococcus pneumonia, S. agalactiae (Group B Streptococcus), Neisseria meningitidis, and Escherichia coli K1, and also include a neglected zoonotic pathogen, Streptococcus suis. These neuroinvasive pathogens represent common themes of host–pathogen interactions, such as colonization and invasion of mucosal barriers, survival in the blood stream, entry into the central nervous system by translocation of the blood–brain and blood–cerebrospinal fluid barrier, and induction of meningeal inflammation, affecting pia mater, the arachnoid and subarachnoid spaces.
Collapse
|
74
|
Ipe DS, Ben Zakour NL, Sullivan MJ, Beatson SA, Ulett KB, Benjamin WH, Davies MR, Dando SJ, King NP, Cripps AW, Schembri MA, Dougan G, Ulett GC. Discovery and Characterization of Human-Urine Utilization by Asymptomatic-Bacteriuria-Causing Streptococcus agalactiae. Infect Immun 2016; 84:307-19. [PMID: 26553467 PMCID: PMC4694007 DOI: 10.1128/iai.00938-15] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2015] [Accepted: 11/01/2015] [Indexed: 12/27/2022] Open
Abstract
Streptococcus agalactiae causes both symptomatic cystitis and asymptomatic bacteriuria (ABU); however, growth characteristics of S. agalactiae in human urine have not previously been reported. Here, we describe a phenotype of robust growth in human urine observed in ABU-causing S. agalactiae (ABSA) that was not seen among uropathogenic S. agalactiae (UPSA) strains isolated from patients with acute cystitis. In direct competition assays using pooled human urine inoculated with equal numbers of a prototype ABSA strain, designated ABSA 1014, and any one of several UPSA strains, measurement of the percentage of each strain recovered over time showed a markedly superior fitness of ABSA 1014 for urine growth. Comparative phenotype profiling of ABSA 1014 and UPSA strain 807, isolated from a patient with acute cystitis, using metabolic arrays of >2,500 substrates and conditions revealed unique and specific l-malic acid catabolism in ABSA 1014 that was absent in UPSA 807. Whole-genome sequencing also revealed divergence in malic enzyme-encoding genes between the strains predicted to impact the activity of the malate metabolic pathway. Comparative growth assays in urine comparing wild-type ABSA and gene-deficient mutants that were functionally inactivated for the malic enzyme metabolic pathway by targeted disruption of the maeE or maeK gene in ABSA demonstrated attenuated growth of the mutants in normal human urine as well as synthetic human urine containing malic acid. We conclude that some S. agalactiae strains can grow in human urine, and this relates in part to malic acid metabolism, which may affect the persistence or progression of S. agalactiae ABU.
Collapse
Affiliation(s)
- Deepak S Ipe
- School of Medical Sciences, Menzies Health Institute Queensland, Griffith University, Gold Coast Campus, QLD, Australia
| | - Nouri L Ben Zakour
- School of Chemistry and Molecular Biosciences, The University of Queensland, Brisbane, QLD, Australia
| | - Matthew J Sullivan
- School of Medical Sciences, Menzies Health Institute Queensland, Griffith University, Gold Coast Campus, QLD, Australia
| | - Scott A Beatson
- School of Chemistry and Molecular Biosciences, The University of Queensland, Brisbane, QLD, Australia
| | - Kimberly B Ulett
- Department of Medicine, University of Alabama at Birmingham, Birmingham, Alabama, USA
| | - William H Benjamin
- Department of Microbiology, University of Alabama at Birmingham, Birmingham, Alabama, USA Department of Pathology, University of Alabama at Birmingham, Birmingham, Alabama, USA
| | - Mark R Davies
- School of Chemistry and Molecular Biosciences, The University of Queensland, Brisbane, QLD, Australia Wellcome Trust Sanger Institute, Hinxton, Cambridge, United Kingdom
| | - Samantha J Dando
- Institute for Glycomics, Griffith University, Gold Coast Campus, QLD, Australia
| | - Nathan P King
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, QLD, Australia
| | - Allan W Cripps
- School of Medical Sciences, Menzies Health Institute Queensland, Griffith University, Gold Coast Campus, QLD, Australia
| | - Mark A Schembri
- School of Chemistry and Molecular Biosciences, The University of Queensland, Brisbane, QLD, Australia
| | - Gordon Dougan
- Wellcome Trust Sanger Institute, Hinxton, Cambridge, United Kingdom
| | - Glen C Ulett
- School of Medical Sciences, Menzies Health Institute Queensland, Griffith University, Gold Coast Campus, QLD, Australia Department of Microbiology, University of Alabama at Birmingham, Birmingham, Alabama, USA
| |
Collapse
|
75
|
Saralahti A, Rämet M. Zebrafish and Streptococcal Infections. Scand J Immunol 2015; 82:174-83. [PMID: 26095827 DOI: 10.1111/sji.12320] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2015] [Accepted: 04/28/2015] [Indexed: 12/11/2022]
Abstract
Streptococcal bacteria are a versatile group of gram-positive bacteria capable of infecting several host organisms, including humans and fish. Streptococcal species are common colonizers of the human respiratory and gastrointestinal tract, but they also cause some of the most common life-threatening, invasive infections in humans and aquaculture. With its unique characteristics and efficient tools for genetic and imaging applications, the zebrafish (Danio rerio) has emerged as a powerful vertebrate model for infectious diseases. Several zebrafish models introduced so far have shown that zebrafish are suitable models for both zoonotic and human-specific infections. Recently, several zebrafish models mimicking human streptococcal infections have also been developed. These models show great potential in providing novel information about the pathogenic mechanisms and host responses associated with human streptococcal infections. Here, we review the zebrafish infection models for the most relevant streptococcal species: the human-specific Streptococcus pneumoniae and Streptococcus pyogenes, and the zoonotic Streptococcus iniae and Streptococcus agalactiae. The recent success and the future potential of these models for the study of host-pathogen interactions in streptococcal infections are also discussed.
Collapse
Affiliation(s)
- A Saralahti
- BioMediTech, University of Tampere, Tampere, Finland
| | - M Rämet
- BioMediTech, University of Tampere, Tampere, Finland.,Department of Pediatrics, Tampere University Hospital, Tampere, Finland.,Department of Children and Adolescents, Oulu University Hospital, Oulu, Finland.,PEDEGO Research Center, Medical Research Center Oulu, University of Oulu, Oulu, Finland
| |
Collapse
|
76
|
De Gregorio PR, Juárez Tomás MS, Nader-Macías MEF. Immunomodulation of Lactobacillus reuteri CRL1324 on Group B Streptococcus Vaginal Colonization in a Murine Experimental Model. Am J Reprod Immunol 2015; 75:23-35. [PMID: 26547516 DOI: 10.1111/aji.12445] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2015] [Accepted: 10/06/2015] [Indexed: 12/26/2022] Open
Abstract
PROBLEM Maternal Group B Streptococcus (GBS) colonization is a risk factor for infectious disease in newborns. One promising strategy is the modulation of vaginal defense to increase the host's ability to combat infection. METHOD OF STUDY The effect of intravaginal (i.va.) Lactobacillus reuteri CRL1324 inoculation on different immune cell populations, cytokines, and immunoglobulin isotypes in a murine model of GBS vaginal colonization was evaluated. RESULTS Seven i.va. inoculations of L. reuteri CRL1324 previous to GBS challenge showed an immunomodulatory effect on the cells and mediators of innate immunity, decreasing the number of neutrophils induced by the pathogen and increasing the activated macrophage population. Moreover, increases in B lymphocytes and IgA and IgG subclasses were observed in mice inoculated with L. reuteri CRL1324 and then challenged with GBS. CONCLUSION Lactobacillus reuteri CRL1324 shows a protective effect against GBS colonization that could be mediated by the modulation of the immune response.
Collapse
|
77
|
Rosinski-Chupin I, Sauvage E, Sismeiro O, Villain A, Da Cunha V, Caliot ME, Dillies MA, Trieu-Cuot P, Bouloc P, Lartigue MF, Glaser P. Single nucleotide resolution RNA-seq uncovers new regulatory mechanisms in the opportunistic pathogen Streptococcus agalactiae. BMC Genomics 2015; 16:419. [PMID: 26024923 PMCID: PMC4448216 DOI: 10.1186/s12864-015-1583-4] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2015] [Accepted: 04/27/2015] [Indexed: 11/15/2022] Open
Abstract
Background Streptococcus agalactiae, or Group B Streptococcus, is a leading cause of neonatal infections and an increasing cause of infections in adults with underlying diseases. In an effort to reconstruct the transcriptional networks involved in S. agalactiae physiology and pathogenesis, we performed an extensive and robust characterization of its transcriptome through a combination of differential RNA-sequencing in eight different growth conditions or genetic backgrounds and strand-specific RNA-sequencing. Results Our study identified 1,210 transcription start sites (TSSs) and 655 transcript ends as well as 39 riboswitches and cis-regulatory regions, 39 cis-antisense non-coding RNAs and 47 small RNAs potentially acting in trans. Among these putative regulatory RNAs, ten were differentially expressed in response to an acid stress and two riboswitches sensed directly or indirectly the pH modification. Strikingly, 15% of the TSSs identified were associated with the incorporation of pseudo-templated nucleotides, showing that reiterative transcription is a pervasive process in S. agalactiae. In particular, 40% of the TSSs upstream genes involved in nucleotide metabolism show reiterative transcription potentially regulating gene expression, as exemplified for pyrG and thyA encoding the CTP synthase and the thymidylate synthase respectively. Conclusions This comprehensive map of the transcriptome at the single nucleotide resolution led to the discovery of new regulatory mechanisms in S. agalactiae. It also provides the basis for in depth analyses of transcriptional networks in S. agalactiae and of the regulatory role of reiterative transcription following variations of intra-cellular nucleotide pools. Electronic supplementary material The online version of this article (doi:10.1186/s12864-015-1583-4) contains supplementary material, which is available to authorized users.
Collapse
Affiliation(s)
- Isabelle Rosinski-Chupin
- Institut Pasteur, Unité de Biologie des Bactéries Pathogènes à Gram Positif, 28 rue du Docteur Roux, 75724,, Paris Cedex 15, France. .,CNRS UMR 3525, Paris, France.
| | - Elisabeth Sauvage
- Institut Pasteur, Unité de Biologie des Bactéries Pathogènes à Gram Positif, 28 rue du Docteur Roux, 75724,, Paris Cedex 15, France. .,CNRS UMR 3525, Paris, France.
| | - Odile Sismeiro
- Institut Pasteur, Transcriptome and Epigenome Platform, 28 rue du Docteur Roux, 75724,, Paris Cedex 15, France.
| | - Adrien Villain
- Institut Pasteur, Unité de Biologie des Bactéries Pathogènes à Gram Positif, 28 rue du Docteur Roux, 75724,, Paris Cedex 15, France. .,CNRS UMR 3525, Paris, France.
| | - Violette Da Cunha
- Institut Pasteur, Unité de Biologie des Bactéries Pathogènes à Gram Positif, 28 rue du Docteur Roux, 75724,, Paris Cedex 15, France. .,CNRS UMR 3525, Paris, France.
| | - Marie-Elise Caliot
- Institut Pasteur, Unité de Biologie des Bactéries Pathogènes à Gram Positif, 28 rue du Docteur Roux, 75724,, Paris Cedex 15, France.
| | - Marie-Agnès Dillies
- Institut Pasteur, Transcriptome and Epigenome Platform, 28 rue du Docteur Roux, 75724,, Paris Cedex 15, France.
| | - Patrick Trieu-Cuot
- Institut Pasteur, Unité de Biologie des Bactéries Pathogènes à Gram Positif, 28 rue du Docteur Roux, 75724,, Paris Cedex 15, France.
| | - Philippe Bouloc
- Institute for Integrative Biology of the Cell (I2BC), CEA, CNRS, Université Paris-Sud, bâtiment 400, 91405, Orsay, France.
| | - Marie-Frédérique Lartigue
- Institute for Integrative Biology of the Cell (I2BC), CEA, CNRS, Université Paris-Sud, bâtiment 400, 91405, Orsay, France. .,Université de Tours, UMR1282 Infectiologie et Santé Publique, F-37000, Tours, France. .,CHRU de Tours, F-37044, Tours, France. .,INRA, UMR1282 Infectiologie et Santé Publique, F-37380, Nouzilly, France.
| | - Philippe Glaser
- Institut Pasteur, Unité de Biologie des Bactéries Pathogènes à Gram Positif, 28 rue du Docteur Roux, 75724,, Paris Cedex 15, France. .,CNRS UMR 3525, Paris, France.
| |
Collapse
|
78
|
Ernst W, Kusi E, Fill Malfertheiner S, Reuschel E, Deml L, Seelbach-Göbel B. The effect of Indomethacin and Betamethasone on the cytokine response of human neonatal mononuclear cells to gram-positive bacteria. Cytokine 2015; 73:91-100. [PMID: 25743243 DOI: 10.1016/j.cyto.2015.01.023] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2014] [Revised: 10/14/2014] [Accepted: 01/23/2015] [Indexed: 11/29/2022]
Abstract
Intrauterine infections with gram-positive bacteria pose a serious threat to neonates since they can result in neonatal sepsis, induce a fetal inflammatory response and also cause preterm birth. Despite intensive care, prematurity remains a leading cause of neonatal death, and is often accompanied by a number of morbidities. In order to prevent premature birth, tocolytic agents like Indomethacin are administered. Betamethasone is used to promote lung maturation and prevent respiratory distress syndrome. A combination of both drugs is assumed to prevent premature delivery while simultaneously facilitating lung maturation. This study investigates the effect of Betamethasone, Indomethacin and a combination of both on the cytokine production of neonatal cord blood mononuclear cells (CBMC) after stimulation with lysates of the gram-positive pathogens Streptococcus agalactiae and Enterococcus faecalis. The aim of the study is to determine the impact of these drugs on the function of the neonatal immune system which should aid clinicians in choosing the optimal therapy in case of preterm birth associated with intrauterine infection. Betamethasone reduced the production of the pro-inflammatory cytokines IL-6, IL-12p40, MIP-1α and TNF and increased the expression of the anti-inflammatory cytokine IL-10, depending on the pathogen used for stimulation. In contrast to Betamethasone, Indomethacin almost exclusively increased IL-10 production. The combination of both drugs decreased the expression of IL-6, IL-12p40, MIP-1α and TNF while increasing IL-10 production, depending on the concentration of Indomethacin and the pathogen used for stimulation. Based on our results, the combination therapy with Indomethacin and Betamethasone has a similar effect on cytokine production as Betamethasone alone, which is generally administered in case of impending preterm birth. However, the combination therapy has the advantage of promoting lung maturation while simultaneously blocking preterm labor effectively.
Collapse
Affiliation(s)
- Wolfgang Ernst
- Clinic of Gynecology and Obstetrics St. Hedwig, University of Regensburg, Regensburg, Germany.
| | - Evelyn Kusi
- Clinic of Gynecology and Obstetrics St. Hedwig, University of Regensburg, Regensburg, Germany
| | - Sara Fill Malfertheiner
- Clinic of Gynecology and Obstetrics St. Hedwig, University of Regensburg, Regensburg, Germany
| | - Edith Reuschel
- Clinic of Gynecology and Obstetrics St. Hedwig, University of Regensburg, Regensburg, Germany
| | - Ludwig Deml
- Institute of Medical Microbiology, University of Regensburg, Regensburg, Germany; Lophius Biosciences GmbH, Josef-Engert Straße 13, 93053 Regensburg, Germany
| | - Birgit Seelbach-Göbel
- Clinic of Gynecology and Obstetrics St. Hedwig, University of Regensburg, Regensburg, Germany
| |
Collapse
|
79
|
De Gregorio PR, Juárez Tomás MS, Leccese Terraf MC, Nader-Macías MEF. Preventive effect of Lactobacillus reuteri CRL1324 on Group B Streptococcus vaginal colonization in an experimental mouse model. J Appl Microbiol 2015; 118:1034-47. [PMID: 25786121 DOI: 10.1111/jam.12739] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2014] [Revised: 12/01/2014] [Accepted: 12/18/2014] [Indexed: 11/28/2022]
Abstract
AIMS To assess the preventive effect of different intravaginal (i.va.) doses of Lactobacillus reuteri CRL1324 against vaginal colonization by Group B Streptococcus (GBS) in a murine experimental model. METHODS AND RESULTS The major virulence factors of four vaginal GBS clinical isolates were determined to select the most virulent strain and set up a murine model of streptococcal vaginal colonization. Later, the effect of four and seven doses of 10(8) viable cells of Lact. reuteri CRL1324 i.va. administered, prior to the GBS challenge was studied. Seven doses of lactobacilli were able to significantly reduce the number of viable GBS cells, while four doses showed no preventive effect. Both doses reduced the leucocyte influx induced by GBS. Seven doses caused a slight increase in the Lact. reuteri CRL1324 vaginal colonization compared with four doses and reduced murine vaginal pH compared to control mice. CONCLUSIONS Lactobacillus reuteri CRL1324 evidenced a preventive effect on GBS vaginal colonization in an experimental mouse model. SIGNIFICANCE AND IMPACTS OF THE STUDY Maternal GBS colonization is one of the most important risk factors for developing disease in newborns. Lactobacillus reuteri CRL1324 could be considered as a new biological agent to reduce infections caused by this micro-organism.
Collapse
Affiliation(s)
- P R De Gregorio
- Centro de Referencia para Lactobacilos (CERELA)-CONICET, San Miguel de Tucumán, Tucumán, Argentina
| | | | | | | |
Collapse
|
80
|
Streptococcus agalactiae infection in zebrafish larvae. Microb Pathog 2015; 79:57-60. [PMID: 25617657 DOI: 10.1016/j.micpath.2015.01.007] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2014] [Revised: 01/14/2015] [Accepted: 01/20/2015] [Indexed: 11/23/2022]
Abstract
Streptococcus agalactiae (Group B Streptococcus, GBS) is an encapsulated, Gram-positive bacterium that is a leading cause of neonatal pneumonia, sepsis and meningitis, and an emerging aquaculture pathogen. The zebrafish (Danio rerio) is a genetically tractable model vertebrate that has been used to analyze the pathogenesis of both aquatic and human bacterial pathogens. We have developed a larval zebrafish model of GBS infection to study bacterial and host factors that contribute to disease progression. GBS infection resulted in dose dependent larval death, and GBS serotype III, ST-17 strain was observed as the most virulent. Virulence was dependent on the presence of the GBS capsule, surface anchored lipoteichoic acid (LTA) and toxin production, as infection with GBS mutants lacking these factors resulted in little to no mortality. Additionally, interleukin-1β (il1b) and CXCL-8 (cxcl8a) were significantly induced following GBS infection compared to controls. We also visualized GBS outside the brain vasculature, suggesting GBS penetration into the brain during the course of infection. Our data demonstrate that zebrafish larvae are a valuable model organism to study GBS pathogenesis.
Collapse
|
81
|
Cutting AS, Del Rosario Y, Mu R, Rodriguez A, Till A, Subramani S, Gottlieb RA, Doran KS. The role of autophagy during group B Streptococcus infection of blood-brain barrier endothelium. J Biol Chem 2014; 289:35711-23. [PMID: 25371213 DOI: 10.1074/jbc.m114.588657] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Bacterial meningitis occurs when bloodborne pathogens invade and penetrate the blood-brain barrier (BBB), provoking inflammation and disease. Group B Streptococcus (GBS), the leading cause of neonatal meningitis, can enter human brain microvascular endothelial cells (hBMECs), but the host response to intracellular GBS has not been characterized. Here we sought to determine whether antibacterial autophagy, which involves selective recognition of intracellular organisms and their targeting to autophagosomes for degradation, is activated in BBB endothelium during bacterial infection. GBS infection resulted in increased punctate distribution of GFP-microtubule-associated protein 1 light chain 3 (LC3) and increased levels of endogenous LC3-II and p62 turnover, two hallmark indicators of active autophagic flux. Infection with GBS mutants revealed that bacterial invasion and the GBS pore-forming β-hemolysin/cytolysin (β-h/c) trigger autophagic activation. Cell-free bacterial extracts containing β-h/c activity induced LC3-II conversion, identifying this toxin as a principal provocative factor for autophagy activation. These results were confirmed in vivo using a mouse model of GBS meningitis as infection with WT GBS induced autophagy in brain tissue more frequently than a β-h/c-deficient mutant. Elimination of autophagy using Atg5-deficient fibroblasts or siRNA-mediated impairment of autophagy in hBMECs led to increased recovery of intracellular GBS. However, electron microscopy revealed that GBS was rarely found within double membrane autophagic structures even though we observed GBS-LC3 co-localization. These results suggest that although autophagy may act as a BBB cellular defense mechanism in response to invading and toxin-producing bacteria, GBS may actively thwart the autophagic pathway.
Collapse
Affiliation(s)
| | | | - Rong Mu
- From the Department of Biology and
| | | | - Andreas Till
- Division of Biological Sciences and San Diego Center for Systems Biology, University of California, San Diego, La Jolla, California 92093-0322, Stem Cell Pathologies Group, Life and Brain Center, University of Bonn, D-53127 Bonn, Germany, and
| | - Suresh Subramani
- Division of Biological Sciences and San Diego Center for Systems Biology, University of California, San Diego, La Jolla, California 92093-0322
| | - Roberta A Gottlieb
- Donald P. Shiley BioScience Center, San Diego State University, San Diego, California 92182
| | - Kelly S Doran
- From the Department of Biology and Department of Pediatrics, University of California San Diego School of Medicine, La Jolla, California 92093
| |
Collapse
|
82
|
Moon AF, Gaudu P, Pedersen LC. Structural characterization of the virulence factor nuclease A from Streptococcus agalactiae. ACTA CRYSTALLOGRAPHICA. SECTION D, BIOLOGICAL CRYSTALLOGRAPHY 2014; 70:2937-49. [PMID: 25372684 PMCID: PMC4220975 DOI: 10.1107/s1399004714019725] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/27/2014] [Accepted: 09/01/2014] [Indexed: 12/28/2022]
Abstract
The group B pathogen Streptococcus agalactiae commonly populates the human gut and urogenital tract, and is a major cause of infection-based mortality in neonatal infants and in elderly or immunocompromised adults. Nuclease A (GBS_NucA), a secreted DNA/RNA nuclease, serves as a virulence factor for S. agalactiae, facilitating bacterial evasion of the human innate immune response. GBS_NucA efficiently degrades the DNA matrix component of neutrophil extracellular traps (NETs), which attempt to kill and clear invading bacteria during the early stages of infection. In order to better understand the mechanisms of DNA substrate binding and catalysis of GBS_NucA, the high-resolution structure of a catalytically inactive mutant (H148G) was solved by X-ray crystallography. Several mutants on the surface of GBS_NucA which might influence DNA substrate binding and catalysis were generated and evaluated using an imidazole chemical rescue technique. While several of these mutants severely inhibited nuclease activity, two mutants (K146R and Q183A) exhibited significantly increased activity. These structural and biochemical studies have greatly increased our understanding of the mechanism of action of GBS_NucA in bacterial virulence and may serve as a foundation for the structure-based drug design of antibacterial compounds targeted to S. agalactiae.
Collapse
Affiliation(s)
- Andrea F. Moon
- Laboratory of Structural Biology, National Institute of Environmental Health Sciences, National Institutes of Health, Research Triangle Park, NC 27709, USA
| | - Philippe Gaudu
- INRA, UMR1319 Micalis, Domaine de Vilvert, Jouy-en-Josas, France; AgroParisTech, UMR Micalis, Jouy-en-Josas, France
| | - Lars C. Pedersen
- Laboratory of Structural Biology, National Institute of Environmental Health Sciences, National Institutes of Health, Research Triangle Park, NC 27709, USA
| |
Collapse
|
83
|
Fettucciari K, Ponsini P, Palumbo C, Rosati E, Mannucci R, Bianchini R, Modesti A, Marconi P. Macrophage induced gelsolin in response to Group BStreptococcus(GBS) infection. Cell Microbiol 2014; 17:79-104. [DOI: 10.1111/cmi.12338] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2013] [Revised: 07/04/2014] [Accepted: 07/31/2014] [Indexed: 12/20/2022]
Affiliation(s)
- Katia Fettucciari
- Department of Experimental Medicine; Perugia University; Perugia Italy
| | - Pamela Ponsini
- Department of Experimental Medicine; Perugia University; Perugia Italy
| | - Camilla Palumbo
- Department of Clinical Sciences and Translational Medicine; Tor Vergata University; Rome Italy
| | - Emanuela Rosati
- Department of Experimental Medicine; Perugia University; Perugia Italy
| | - Roberta Mannucci
- Department of Medicine, Laboratory of Image Analysis; Perugia University; Perugia Italy
| | - Rodolfo Bianchini
- Research Program for Receptor Biochemistry and Tumor Metabolism; Laura Bassi Centre of Expertise Therapep; Salzburg University Clinic; Salzburg Austria
- Department of Pediatrics; Paracelsus Medical University; Muellner Hauptstrasse Salzburg Austria
| | - Andrea Modesti
- Department of Clinical Sciences and Translational Medicine; Tor Vergata University; Rome Italy
| | | |
Collapse
|
84
|
Rosa-Fraile M, Dramsi S, Spellerberg B. Group B streptococcal haemolysin and pigment, a tale of twins. FEMS Microbiol Rev 2014; 38:932-46. [PMID: 24617549 PMCID: PMC4315905 DOI: 10.1111/1574-6976.12071] [Citation(s) in RCA: 56] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2013] [Revised: 02/18/2014] [Accepted: 03/03/2014] [Indexed: 12/11/2022] Open
Abstract
Group B streptococcus [(GBS or Streptococcus agalactiae)] is a leading cause of neonatal meningitis and septicaemia. Most clinical isolates express simultaneously a β-haemolysin/cytolysin and a red polyenic pigment, two phenotypic traits important for GBS identification in medical microbiology. The genetic determinants encoding the GBS haemolysin and pigment have been elucidated and the molecular structure of the pigment has been determined. The cyl operon involved in haemolysin and pigment production is regulated by the major two-component system CovS/R, which coordinates the expression of multiple virulence factors of GBS. Genetic analyses indicated strongly that the haemolysin activity was due to a cytolytic toxin encoded by cylE. However, the biochemical nature of the GBS haemolysin has remained elusive for almost a century because of its instability during purification procedures. Recently, it has been suggested that the haemolytic and cytolytic activity of GBS is due to the ornithine rhamnopolyenic pigment and not to the CylE protein. Here we review and summarize our current knowledge of the genetics, regulation and biochemistry of these twin GBS phenotypic traits, including their functions as GBS virulence factors.
Collapse
Affiliation(s)
| | - Shaynoor Dramsi
- Unité de Biologie des Bactéries Pathogènes à Gram positif, Institut PasteurParis, France
- CNRS ERL 3526Paris, France
| | - Barbara Spellerberg
- Institute of Medical Microbiology and Hygiene, University Hospital UlmUlm, Germany
| |
Collapse
|
85
|
Association and virulence gene expression vary among serotype III group B streptococcus isolates following exposure to decidual and lung epithelial cells. Infect Immun 2014; 82:4587-95. [PMID: 25135682 DOI: 10.1128/iai.02181-14] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Group B Streptococcus (GBS) causes severe disease in neonates, the elderly, and immunocompromised individuals. GBS species are highly diverse and can be classified by serotype and multilocus sequence typing. Sequence type 17 (ST-17) strains cause invasive neonatal disease more frequently than strains of other STs. Attachment and invasion of host cells are key steps in GBS pathogenesis. We investigated whether four serotype III strains representing ST-17 (two strains), ST-19, and ST-23 differ in their abilities to attach to and invade both decidual cells and lung epithelial cells. Virulence gene expression following host cell association and exposure to amnion cells was also tested. The ST-17 strains differed in their abilities to attach to and invade decidual cells, whereas there were no differences with lung epithelial cells. The ST-19 and ST-23 strains, however, attached to and invaded decidual cells less than both ST-17 strains. Although the ST-23 strain attached to lung epithelial cells better than ST-17 and -19 strains, none of the strains effectively invaded the lung epithelial cells. Notably, the association with host cells resulted in the differential expression of several virulence genes relative to basal expression levels. Similar expression patterns of some genes were observed regardless of cell type used. Collectively, these results show that GBS strains differ in their abilities to attach to distinct host cell types and express key virulence genes that are relevant to the disease process. Enhancing our understanding of pathogenic mechanisms could aid in the identification of novel therapeutic targets or vaccine candidates that could potentially decrease morbidity and mortality associated with neonatal infections.
Collapse
|
86
|
Nagarajan R, Ponnuraj K. Cloning, expression, purification, crystallization and preliminary X-ray diffraction analysis of glyceraldehyde-3-phosphate dehydrogenase from Streptococcus agalactiae NEM316. Acta Crystallogr F Struct Biol Commun 2014; 70:938-41. [PMID: 25005093 PMCID: PMC4089536 DOI: 10.1107/s2053230x14011418] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2014] [Accepted: 05/17/2014] [Indexed: 11/10/2022] Open
Abstract
Glyceraldehyde-3-phosphate dehydrogenase (GAPDH) is an essential enzyme involved in glycolysis. Despite lacking the secretory signal sequence, this cytosolic enzyme has been found localized at the surface of several bacteria and fungi. As a surface protein, GAPDH exhibits various adhesive functions, thereby facilitating colonization and invasion of host tissues. Streptococcus agalactiae, also known as group B streptococcus (GBS), binds onto the host using its surface adhesins and causes sepsis and pneumonia in neonates. GAPDH is one of the surface adhesins of GBS binding to human plasminogen and is a virulent factor associated with host colonization. Although the surface-associated GAPDH has been shown to bind to a variety of host extracellular matrix (ECM) molecules in various bacteria, the molecular mechanism underlying their interaction is not fully understood. To investigate this, structural studies on GAPDH of S. agalactiae were initiated. The gapC gene of S. agalactiae NEM316 encoding GAPDH protein was cloned into pET-28a vector, overexpressed in Escherichia coli BL21(DE3) cells and purified to homogeneity. The purified protein was crystallized using the hanging-drop vapour-diffusion method. The GAPDH crystals obtained in two different crystallization conditions diffracted to 2.8 and 2.6 Å resolution, belonging to two different space groups P2₁ and P2₁2₁2₁, respectively. The structure was solved by molecular replacement and structure refinement is now in progress.
Collapse
Affiliation(s)
- Revathi Nagarajan
- Centre of Advanced Study in Crystallography and Biophysics, University of Madras, Guindy Campus, Chennai 600 025, India
| | - Karthe Ponnuraj
- Centre of Advanced Study in Crystallography and Biophysics, University of Madras, Guindy Campus, Chennai 600 025, India
| |
Collapse
|
87
|
Dutra VG, Alves VMN, Olendzki AN, Dias CAG, de Bastos AFA, Santos GO, de Amorin ELT, Sousa MÂB, Santos R, Ribeiro PCS, Fontes CF, Andrey M, Magalhães K, Araujo AA, Paffadore LF, Marconi C, Murta EFC, Fernandes PC, Raddi MSG, Marinho PS, Bornia RBG, Palmeiro JK, Dalla-Costa LM, Pinto TCA, Botelho ACN, Teixeira LM, Fracalanzza SEL. Streptococcus agalactiae in Brazil: serotype distribution, virulence determinants and antimicrobial susceptibility. BMC Infect Dis 2014; 14:323. [PMID: 24919844 PMCID: PMC4061772 DOI: 10.1186/1471-2334-14-323] [Citation(s) in RCA: 68] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2013] [Accepted: 06/06/2014] [Indexed: 01/11/2023] Open
Abstract
Background Group B Streptococcus (GBS) remains a major cause of neonatal sepsis and is also associated with invasive and noninvasive infections in pregnant women and non-pregnant adults, elderly and patients with underlying medical conditions. Ten capsular serotypes have been recognized, and determination of their distribution within a specific population or geographical region is important as they are major targets for the development of vaccine strategies. We have evaluated the characteristics of GBS isolates recovered from individuals with infections or colonization by this microorganism, living in different geographic regions of Brazil. Methods A total of 434 isolates were identified and serotyped by conventional phenotypic tests. The determination of antimicrobial susceptibility was performed by the disk diffusion method. Genes associated with resistance to erythromycin (ermA, ermB, mefA) and tetracycline (tetK, tetL, tetM, tetO) as well as virulence-associated genes (bac, bca, lmb, scpB) were investigated using PCR. Pulsed-field gel electrophoresis (PFGE) was used to examine the genetic diversity of macrolide-resistant and of a number of selected macrolide-susceptible isolates. Results Overall, serotypes Ia (27.6%), II (19.1%), Ib (18.7%) and V (13.6%) were the most predominant, followed by serotypes IV (8.1%) and III (6.7%). All the isolates were susceptible to the beta-lactam antimicrobials tested and 97% were resistant to tetracycline. Resistance to erythromycin and clindamycin were found in 4.1% and 3% of the isolates, respectively. Among the resistance genes investigated, tetM (99.3%) and tetO (1.8%) were detected among tetracycline-resistant isolates and ermA (39%) and ermB (27.6%) were found among macrolide-resistant isolates. The lmb and scpB virulence genes were detected in all isolates, while bac and bca were detected in 57 (13.1%) and 237 (54.6%) isolates, respectively. Molecular typing by PFGE showed that resistance to erythromycin was associated with a variety of clones. Conclusion These findings indicate that GBS isolates circulating in Brazil have a variety of phenotypic and genotypic characteristics, and suggest that macrolide-resistant isolates may arise by both clonal spread and independent acquisition of resistance genes.
Collapse
Affiliation(s)
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | - Sérgio Eduardo L Fracalanzza
- Departamento de Microbiologia Médica, Instituto de Microbiologia Paulo de Góes, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil.
| |
Collapse
|
88
|
Analysis of two-component systems in group B Streptococcus shows that RgfAC and the novel FspSR modulate virulence and bacterial fitness. mBio 2014; 5:e00870-14. [PMID: 24846378 PMCID: PMC4030450 DOI: 10.1128/mbio.00870-14] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
Group B Streptococcus (GBS), in the transition from commensal organisms to pathogens, will encounter diverse host environments and, thus, require coordinated control of the transcriptional responses to these changes. This work was aimed at better understanding the role of two-component signal transduction systems (TCS) in GBS pathophysiology through a systematic screening procedure. We first performed a complete inventory and sensory mechanism classification of all putative GBS TCS by genomic analysis. Five TCS were further investigated by the generation of knockout strains, and in vitro transcriptome analysis identified genes regulated by these systems, ranging from 0.1% to 3% of the genome. Interestingly, two sugar phosphotransferase systems appeared to be differentially regulated in the TCS-16 knockout strain (TCS loci were numbered in order of their appearance on the chromosome), suggesting an involvement in monitoring carbon source availability. High-throughput analysis of bacterial growth on different carbon sources showed that TCS-16 was necessary for the growth of GBS on fructose-6-phosphate. Additional transcriptional analysis provided further evidence for a stimulus-response circuit where extracellular fructose-6-phosphate leads to autoinduction of TCS-16, with concomitant dramatic upregulation of the adjacent operon, which encodes a phosphotransferase system. The TCS-16-deficient strain exhibited decreased persistence in a model of vaginal colonization. All mutant strains were also characterized in a murine model of systemic infection, and inactivation of TCS-17 (also known as RgfAC) resulted in hypervirulence. Our data suggest a role for the previously unknown TCS-16, here named FspSR, in bacterial fitness and carbon metabolism during host colonization, and the data also provide experimental evidence for TCS-17/RgfAC involvement in virulence. Two-component systems have been evolved by bacteria to detect environmental changes, and they play key roles in pathogenicity. A comprehensive analysis of TCS in GBS has not been performed previously. In this work, we classify 21 TCS and present evidence for the involvement of two specific TCS in GBS virulence and colonization in vivo. Although pinpointing specific TCS stimuli is notoriously difficult, we used a combination of techniques to identify two systems with different effects on GBS pathogenesis. For one of the systems, we propose that fructose-6-phosphate, a metabolite in glycolysis, is sufficient to induce a regulatory response involving a sugar transport system. Our catalogue and classification of TCS may guide further studies into the role of TCS in GBS pathogenicity and biology.
Collapse
|
89
|
Six A, Joubrel C, Tazi A, Poyart C. [Maternal and perinatal infections to Streptococcus agalactiae]. Presse Med 2014; 43:706-14. [PMID: 24855049 DOI: 10.1016/j.lpm.2014.04.008] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/25/2022] Open
Abstract
Streptococcus agalactiae (Group B Streptococcus, GBS) is a Gram-positive encapsulated bacterium, found in the digestive and vaginal tracts of 20-30% healthy individuals. It is the leading cause of neonatal invasive infections (septicaemia and meningitis). Two GBS-associated syndromes have been recognized in neonates, the early-onset disease (EOD) and the late-onset disease (LOD), which occur in the first week of life (age 0-6 days) and after (age 7 days-3 months), respectively. Since the establishment of early antibiotic prophylaxis there has been a decrease in the incidence of EOD. However, LOD incidence remains stable. Epidemiological studies revealed a strong association between LOD and a single capsular serotype III ST-17 clone. This ST-17 clone, referred to as the "hypervirulent" clone, possesses specific virulence factors that could account for its increased virulence and neonatal tropism. Conjugate vaccines directed against several capsular serotypes are being developed to prevent invasive disease. However, hypervirulent strains having made a switch to a capsular serotype not covered by such vaccines are emerging, reinforcing the need to identify new candidate vaccines.
Collapse
Affiliation(s)
- Anne Six
- Inserm U 1016, institut Cochin, unité FRM « Barrières et pathogènes », 75014 Paris, France; CNRS UMR 8104, 75014 Paris, France; Université Paris Descartes, Sorbonne Paris Cité, 75014 Paris, France
| | - Caroline Joubrel
- Centre national de référence des streptocoques, 75014 Paris, France; Assistance publique-Hôpitaux de Paris, hôpitaux universitaires Paris Centre Site Cochin, service de bactériologie, 75014 Paris, France
| | - Asmaa Tazi
- Inserm U 1016, institut Cochin, unité FRM « Barrières et pathogènes », 75014 Paris, France; CNRS UMR 8104, 75014 Paris, France; Université Paris Descartes, Sorbonne Paris Cité, 75014 Paris, France; Centre national de référence des streptocoques, 75014 Paris, France; Assistance publique-Hôpitaux de Paris, hôpitaux universitaires Paris Centre Site Cochin, service de bactériologie, 75014 Paris, France
| | - Claire Poyart
- Inserm U 1016, institut Cochin, unité FRM « Barrières et pathogènes », 75014 Paris, France; CNRS UMR 8104, 75014 Paris, France; Université Paris Descartes, Sorbonne Paris Cité, 75014 Paris, France; Institut Pasteur, unité de biologie des bactéries pathogènes à Gram positif, 74016 Paris, France; CNRS 2172, 75015 Paris, France; Centre national de référence des streptocoques, 75014 Paris, France; Assistance publique-Hôpitaux de Paris, hôpitaux universitaires Paris Centre Site Cochin, service de bactériologie, 75014 Paris, France.
| |
Collapse
|
90
|
Lupo A, Ruppen C, Hemphill A, Spellerberg B, Sendi P. Phenotypic and molecular characterization of hyperpigmented group B Streptococci. Int J Med Microbiol 2014; 304:717-24. [PMID: 24933304 DOI: 10.1016/j.ijmm.2014.05.003] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2013] [Revised: 05/05/2014] [Accepted: 05/11/2014] [Indexed: 10/25/2022] Open
Abstract
Group B Streptococcus (GBS) causes invasive infections in neonates, older adults and patients with comorbidities. β-hemolysin/cytolysin is an important GBS virulence factor. It is encoded by the cyl operon and confers GBS hemolytic activity. Isolates displaying hyperpigmentation are typically hyperhemolytic. Comparison of clonally identical isolates displaying different levels of pigmentation has shown transcriptional dysregulation due to mutations in components of the control of the virulence S/R (CovS/R) regulatory system. In addition, hyperpigmented isolates show decreased CAMP factor and decreased capsule thickness. In analogy to findings in group A Streptococcus, a pivotal role of CovS/R has been proposed in the host-pathogen interaction of invasive GBS infection. However, corresponding investigations on multiple clinical GBS isolates have not been performed. We prospectively collected hyperpigmented isolates found in a diagnostic laboratory and performed phenotypic, molecular and transcriptional analyses. In the period from 2008 to 2012, we found 10 isolates obtained from 10 patients. The isolates reflected both invasive pathogens and colonizers. In three cases, clonally identical but phenotypically different variants were also found. Hence, the analyses included 13 isolates. No capsular serotype was found to be significantly more frequent. Bacterial pigments were analyzed via spectrophotometry and for their hemolytic activity. Data obtained for typical absorbance spectra peaks correlated significantly with hemolytic activity. Molecular analysis of the cyl operon showed that it was conserved in all isolates. The covR sequence displayed mutations in five isolates; in one isolate, the CovR binding site to cylX was abrogated. Our results on clinical isolates support previous findings on CovR-deficient isogenic mutants, but suggest that - at least in some clinical isolates - for β-hemolysin/cytolysin and CAMP factor production, other molecular pathways may be involved.
Collapse
Affiliation(s)
- Agnese Lupo
- Institute for Infectious Diseases, University of Bern, Bern, Switzerland
| | - Corinne Ruppen
- Institute for Infectious Diseases, University of Bern, Bern, Switzerland
| | - Andrew Hemphill
- Institute of Parasitology, University of Bern, Bern, Switzerland
| | - Barbara Spellerberg
- Institute of Medical Microbiology and Hygiene, University Hospital Ulm, Ulm, Germany
| | - Parham Sendi
- Institute for Infectious Diseases, University of Bern, Bern, Switzerland; Department of Infectious Diseases, Bern University Hospital, Bern, Switzerland.
| |
Collapse
|
91
|
Identification of a group B streptococcal fibronectin binding protein, SfbA, that contributes to invasion of brain endothelium and development of meningitis. Infect Immun 2014; 82:2276-86. [PMID: 24643538 DOI: 10.1128/iai.01559-13] [Citation(s) in RCA: 47] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Group B Streptococcus (GBS) is currently the leading cause of neonatal meningitis. This is due to its ability to survive and multiply in the bloodstream and interact with specialized human brain microvascular endothelial cells (hBMEC), which constitute the blood-brain barrier (BBB). The exact mechanism(s) of GBS-BBB penetration is still largely unknown. We and others have shown that GBS interacts with components of the extracellular matrix. In this study, we demonstrate that GBS of representative serotypes binds immobilized and cell surface fibronectin and identify a putative fibronectin binding protein, streptococcal fibronectin binding protein A (SfbA). Allelic replacement of sfbA in the GBS chromosome resulted in a significant decrease in ability to bind fibronection and invade hBMEC compared with the wild-type (WT) parental strain. Expression of SfbA in the noninvasive strain Lactococcus lactis was sufficient to promote fibronectin binding and hBMEC invasion. Furthermore, the addition of an antifibronectin antibody or an RGD peptide that blocks fibronectin binding to integrins significantly reduced invasion of the WT but not the sfbA-deficient mutant strain, demonstrating the importance of an SfbA-fibronectin-integrin interaction for GBS cellular invasion. Using a murine model of GBS meningitis, we also observed that WT GBS penetrated the brain and established meningitis more frequently than did the ΔsfbA mutant strain. Our data suggest that GBS SfbA plays an important role in bacterial interaction with BBB endothelium and the pathogenesis of streptococcal meningitis.
Collapse
|
92
|
De Gregorio PR, Tomás MSJ, Terraf MCL, Nader-Macías MEF. In vitro and in vivo effects of beneficial vaginal lactobacilli on pathogens responsible for urogenital tract infections. J Med Microbiol 2014; 63:685-696. [PMID: 24523160 DOI: 10.1099/jmm.0.069401-0] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
The aim of this work was to evaluate the effects of beneficial human vaginal lactobacilli (Lb) on urogenital pathogens through in vitro and in vivo experiments. Co-aggregative and antimicrobial properties between five vaginal Lb strains and urogenital pathogens or potential pathogens (Streptococcus agalactiae, Staphylococcus aureus and Candida albicans strains) were assayed. Also, associative cultures of Lb strains and S. agalactiae were performed and bacterial growth, pH, lactic acid and hydrogen peroxide (H2O2) were determined at different times. Based on the results obtained, the in vivo studies were assayed in mice with Lactobacillus gasseri CRL 1509 or Lactobacillus salivarius CRL 1328 inoculated intravaginally (i.v.) and then challenged i.v. with S. agalactiae. Results were analysed by ANOVA (repeated measures and general linear models). Most of the Lb strains increased the percentage of aggregation of S. agalactiae strains. Only one strain (Lactobacillus reuteri CRL 1324) positively affected the aggregation of S. aureus and none increased the aggregation of C. albicans. The inhibition of the growth of S. agalactiae strains by production of organic acids by lactobacilli was evidenced. The Lb-S. agalactiae co-cultures showed a significant inhibition of the pathogen after 4 h and 8 h of incubation. Parallel increases in lactic acid and H2O2 levels were observed. However, in the experimental murine model, no significant differences were obtained in the number of streptococci recovered from the vaginal tract of control mice and those inoculated with Lb. In conclusion, vaginal Lb exhibited in vitro co-aggregative and antimicrobial effects on S. agalactiae strains, suggesting that they could be promising candidates for protection against S. agalactiae challenge. However, as these effects were not evidenced in the murine model used, further animal studies under different experimental conditions should be conducted to evaluate the preventive effect of Lb against challenge with S. agalactiae.
Collapse
Affiliation(s)
- Priscilla Romina De Gregorio
- Centro de Referencia para Lactobacilos (CERELA)-CONICET, Chacabuco 145, 4000 San Miguel de Tucumán, Tucumán, Argentina
| | - María Silvina Juárez Tomás
- Centro de Referencia para Lactobacilos (CERELA)-CONICET, Chacabuco 145, 4000 San Miguel de Tucumán, Tucumán, Argentina
| | - María Cecilia Leccese Terraf
- Centro de Referencia para Lactobacilos (CERELA)-CONICET, Chacabuco 145, 4000 San Miguel de Tucumán, Tucumán, Argentina
| | | |
Collapse
|
93
|
Randis TM, Gelber SE, Hooven TA, Abellar RG, Akabas LH, Lewis EL, Walker LB, Byland LM, Nizet V, Ratner AJ. Group B Streptococcus β-hemolysin/cytolysin breaches maternal-fetal barriers to cause preterm birth and intrauterine fetal demise in vivo. J Infect Dis 2014; 210:265-73. [PMID: 24474814 DOI: 10.1093/infdis/jiu067] [Citation(s) in RCA: 86] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
BACKGROUND Maternal vaginal colonization with Streptococcus agalactiae (Group B Streptococcus [GBS]) is a precursor to chorioamnionitis, fetal infection, and neonatal sepsis, but the understanding of specific factors in the pathogenesis of ascending infection remains limited. METHODS We used a new murine model to evaluate the contribution of the pore-forming GBS β-hemolysin/cytolysin (βH/C) to vaginal colonization, ascension, and fetal infection. RESULTS Competition assays demonstrated a marked advantage to βH/C-expressing GBS during colonization. Intrauterine fetal demise and/or preterm birth were observed in 54% of pregnant mice colonized with wild-type (WT) GBS and 0% of those colonized with the toxin-deficient cylE knockout strain, despite efficient colonization and ascension by both strains. Robust placental inflammation, disruption of maternal-fetal barriers, and fetal infection were more frequent in animals colonized with WT bacteria. Histopathologic examination revealed bacterial tropism for fetal lung and liver. CONCLUSIONS Preterm birth and fetal demise are likely the direct result of toxin-induced damage and inflammation rather than differences in efficiency of ascension into the upper genital tract. These data demonstrate a distinct contribution of βH/C to GBS chorioamnionitis and subsequent fetal infection in vivo and showcase a model for this most proximal step in GBS pathogenesis.
Collapse
Affiliation(s)
- Tara M Randis
- Department of Pediatrics, Columbia University, New York, New York
| | - Shari E Gelber
- Department of Obstetrics and Gynecology, Weill-Cornell Medical Center, New York, New York
| | - Thomas A Hooven
- Department of Pediatrics, Columbia University, New York, New York
| | - Rosanna G Abellar
- Department of Pathology and Cell Biology, Columbia University, New York, New York
| | - Leor H Akabas
- Department of Pediatrics, Columbia University, New York, New York
| | - Emma L Lewis
- Department of Pediatrics, Columbia University, New York, New York
| | - Lindsay B Walker
- Department of Pediatrics, Columbia University, New York, New York
| | - Leah M Byland
- Department of Pediatrics, Columbia University, New York, New York
| | - Victor Nizet
- Department of Pediatrics and Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California, San Diego, La Jolla, California
| | - Adam J Ratner
- Department of Pediatrics, Columbia University, New York, New York
| |
Collapse
|
94
|
Cohen M, Varki A. Modulation of glycan recognition by clustered saccharide patches. INTERNATIONAL REVIEW OF CELL AND MOLECULAR BIOLOGY 2014; 308:75-125. [PMID: 24411170 DOI: 10.1016/b978-0-12-800097-7.00003-8] [Citation(s) in RCA: 57] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
All cells in nature are covered with a dense and complex array of glycan chains. Specific recognition and binding of glycans is a critical aspect of cellular interactions, both within and between species. Glycan-protein interactions tend to be of low affinity but high specificity, typically utilizing multivalency to generate the affinity required for biologically relevant binding. This review focuses on a higher level of glycan organization, the formation of clustered saccharide patches (CSPs), which can constitute unique ligands for highly specific interactions. Due to technical challenges, this aspect of glycan recognition remains poorly understood. We present a wealth of evidence for CSPs-mediated interactions, and discuss recent advances in experimental tools that are beginning to provide new insights into the composition and organization of CSPs. The examples presented here are likely the tip of the iceberg, and much further work is needed to elucidate fully this higher level of glycan organization.
Collapse
Affiliation(s)
- Miriam Cohen
- Department Cellular and Molecular Medicine, Glycobiology Research and Training Center, University of California, San Diego, California, USA.
| | - Ajit Varki
- Department of Medicine, University of California, San Diego, California, USA; Department Cellular and Molecular Medicine, Glycobiology Research and Training Center, University of California, San Diego, California, USA.
| |
Collapse
|
95
|
Olson AB, Kent H, Sibley CD, Grinwis ME, Mabon P, Ouellette C, Tyson S, Graham M, Tyler SD, Van Domselaar G, Surette MG, Corbett CR. Phylogenetic relationship and virulence inference of Streptococcus Anginosus Group: curated annotation and whole-genome comparative analysis support distinct species designation. BMC Genomics 2013; 14:895. [PMID: 24341328 PMCID: PMC3897883 DOI: 10.1186/1471-2164-14-895] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2013] [Accepted: 12/09/2013] [Indexed: 12/30/2022] Open
Abstract
Background The Streptococcus Anginosus Group (SAG) represents three closely related species of the viridans group streptococci recognized as commensal bacteria of the oral, gastrointestinal and urogenital tracts. The SAG also cause severe invasive infections, and are pathogens during cystic fibrosis (CF) pulmonary exacerbation. Little genomic information or description of virulence mechanisms is currently available for SAG. We conducted intra and inter species whole-genome comparative analyses with 59 publically available Streptococcus genomes and seven in-house closed high quality finished SAG genomes; S. constellatus (3), S. intermedius (2), and S. anginosus (2). For each SAG species, we sequenced at least one numerically dominant strain from CF airways recovered during acute exacerbation and an invasive, non-lung isolate. We also evaluated microevolution that occurred within two isolates that were cultured from one individual one year apart. Results The SAG genomes were most closely related to S. gordonii and S. sanguinis, based on shared orthologs and harbor a similar number of proteins within each COG category as other Streptococcus species. Numerous characterized streptococcus virulence factor homologs were identified within the SAG genomes including; adherence, invasion, spreading factors, LPxTG cell wall proteins, and two component histidine kinases known to be involved in virulence gene regulation. Mobile elements, primarily integrative conjugative elements and bacteriophage, account for greater than 10% of the SAG genomes. S. anginosus was the most variable species sequenced in this study, yielding both the smallest and the largest SAG genomes containing multiple genomic rearrangements, insertions and deletions. In contrast, within the S. constellatus and S. intermedius species, there was extensive continuous synteny, with only slight differences in genome size between strains. Within S. constellatus we were able to determine important SNPs and changes in VNTR numbers that occurred over the course of one year. Conclusions The comparative genomic analysis of the SAG clarifies the phylogenetics of these bacteria and supports the distinct species classification. Numerous potential virulence determinants were identified and provide a foundation for further studies into SAG pathogenesis. Furthermore, the data may be used to enable the development of rapid diagnostic assays and therapeutics for these pathogens.
Collapse
Affiliation(s)
| | | | | | | | | | | | | | | | | | | | - Michael G Surette
- National Microbiology Laboratory, Public Health Agency of Canada, Winnipeg, MB, Canada.
| | | |
Collapse
|
96
|
Cavaco CK, Patras KA, Zlamal JE, Thoman ML, Morgan EL, Sanderson SD, Doran KS. A novel C5a-derived immunobiotic peptide reduces Streptococcus agalactiae colonization through targeted bacterial killing. Antimicrob Agents Chemother 2013; 57:5492-9. [PMID: 23979760 PMCID: PMC3811312 DOI: 10.1128/aac.01590-13] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2013] [Accepted: 08/23/2013] [Indexed: 01/14/2023] Open
Abstract
Streptococcus agalactiae (group B Streptococcus [GBS]) is a Gram-positive bacterium that colonizes the cervicovaginal tract in approximately 25% of healthy women. Although colonization is asymptomatic, GBS can be vertically transmitted to newborns peripartum, causing severe disease such as pneumonia and meningitis. Current prophylaxis, consisting of late gestation screening and intrapartum antibiotics, has failed to completely prevent transmission, and GBS remains a leading cause of neonatal sepsis and meningitis in the United States. Lack of an effective vaccine and emerging antibiotic resistance necessitate exploring novel therapeutic strategies. We have employed a host-directed immunomodulatory therapy using a novel peptide, known as EP67, derived from the C-terminal region of human complement component C5a. Previously, we have demonstrated in vivo that EP67 engagement of the C5a receptor (CD88) effectively limits staphylococcal infection by promoting cytokine release and neutrophil infiltration. Here, using our established mouse model of GBS vaginal colonization, we observed that EP67 treatment results in rapid clearance of GBS from the murine vagina. However, this was not dependent on functional neutrophil recruitment or CD88 signaling, as EP67 treatment reduced the vaginal bacterial load in mice lacking CD88 or the major neutrophil receptor CXCr2. Interestingly, we found that EP67 inhibits GBS growth in vitro and in vivo and that antibacterial activity was specific to Streptococcus species. Our work establishes that EP67-mediated clearance of GBS is likely due to direct bacterial killing rather than to enhanced immune stimulation. We conclude that EP67 may have potential as a therapeutic to control GBS vaginal colonization.
Collapse
Affiliation(s)
- Courtney K. Cavaco
- Department of Biology and Center for Microbial Sciences, San Diego State University, San Diego, California, USA
| | - Kathryn A. Patras
- Department of Biology and Center for Microbial Sciences, San Diego State University, San Diego, California, USA
| | - Jaime E. Zlamal
- Department of Biology and Center for Microbial Sciences, San Diego State University, San Diego, California, USA
| | - Marilyn L. Thoman
- BioScience Center, San Diego State University, San Diego, California, USA
| | - Edward L. Morgan
- BioScience Center, San Diego State University, San Diego, California, USA
| | - Sam D. Sanderson
- Department of Pharmaceutical Sciences, College of Pharmacy, University of Nebraska Medical Center, Omaha, Nebraska, USA
| | - Kelly S. Doran
- Department of Biology and Center for Microbial Sciences, San Diego State University, San Diego, California, USA
- Department of Pediatrics, University of California San Diego School of Medicine, La Jolla, California, USA
| |
Collapse
|
97
|
Bassat Q. Maternal immunization: an intelligent solution to reduce the hidden burden of group B streptococcus perinatal disease. J Trop Pediatr 2013; 59:333-7. [PMID: 24092698 DOI: 10.1093/tropej/fmt084] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Affiliation(s)
- Quique Bassat
- Barcelona Centre for International Health Research (CRESIB, Hospital Clínic-Universitat de Barcelona), Barcelona, Spain and Centro de Investigação em Saúde de Manhiça (CISM), Maputo, Mozambique
| |
Collapse
|
98
|
Zhang R, Zhang LL, Ye X, Tian YY, Sun CF, Lu MX, Bai JJ. Transcriptome profiling and digital gene expression analysis of Nile tilapia (Oreochromis niloticus) infected by Streptococcus agalactiae. Mol Biol Rep 2013; 40:5657-68. [DOI: 10.1007/s11033-013-2667-3] [Citation(s) in RCA: 57] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2013] [Accepted: 09/14/2013] [Indexed: 01/01/2023]
|
99
|
Godoy D, Carvalho-Castro G, Leal C, Pereira U, Leite R, Figueiredo H. Genetic diversity and new genotyping scheme for fish pathogenic Streptococcus agalactiae. Lett Appl Microbiol 2013; 57:476-83. [DOI: 10.1111/lam.12138] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2013] [Revised: 07/05/2013] [Accepted: 07/17/2013] [Indexed: 12/01/2022]
Affiliation(s)
- D.T. Godoy
- AQUAVET - Laboratory of Aquatic Animal Diseases, Veterinary School; Federal University of Minas Gerais; Belo Horizonte Brazil
| | - G.A. Carvalho-Castro
- AQUAVET - Laboratory of Aquatic Animal Diseases, Veterinary School; Federal University of Minas Gerais; Belo Horizonte Brazil
| | - C.A.G. Leal
- AQUAVET - Laboratory of Aquatic Animal Diseases, Veterinary School; Federal University of Minas Gerais; Belo Horizonte Brazil
| | - U.P. Pereira
- AQUAVET - Laboratory of Aquatic Animal Diseases, Veterinary School; Federal University of Minas Gerais; Belo Horizonte Brazil
| | - R.C. Leite
- AQUAVET - Laboratory of Aquatic Animal Diseases, Veterinary School; Federal University of Minas Gerais; Belo Horizonte Brazil
| | - H.C.P. Figueiredo
- AQUAVET - Laboratory of Aquatic Animal Diseases, Veterinary School; Federal University of Minas Gerais; Belo Horizonte Brazil
| |
Collapse
|
100
|
Macchioni L, Fettucciari K, Davidescu M, Vitale R, Ponsini P, Rosati E, Corcelli A, Marconi P, Corazzi L. Impairment of brain mitochondrial functions by β-hemolytic Group B Streptococcus. Effect of cardiolipin and phosphatidylcholine. J Bioenerg Biomembr 2013; 45:519-29. [PMID: 23979483 DOI: 10.1007/s10863-013-9525-9] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2013] [Accepted: 08/15/2013] [Indexed: 01/02/2023]
Abstract
Group B Streptococcus (GBS) causes severe infection in the central nervous system. In this study, brain mitochondrial function was investigated by simulating infection of isolated mitochondria with GBS, which resulted in loss of mitochondrial activity. The β-hemolysin expressing strains GBS-III-NEM316 and GBS-III-COH31, but not the gGBS-III-COH31 that does not express β-hemolysin, caused dissipation of preformed mitochondrial membrane potential (Δψm). This indicates that β-hemolysin is responsible for decreasing of the reducing power of mitochondria. GBS-III-COH31 interacted with mitochondria causing increase of oxygen consumption, due to uncoupling of respiration, blocking of ATP synthesis, and cytochrome c release outside mitochondria. Moreover, the mitochondrial systems contributing to the control of cellular Ca(2+) uptake were lost. In spite of these alterations, mitochondrial phospholipid content and composition did not change significantly, as evaluated by MALDI-TOF mass spectrometry. However, exogenous cardiolipin (CL) and dipalmitoylphosphatidylcholine (DPPC) attenuated the uncoupling effect of GBS-III-COH31, although with different mechanisms. CL was effective only when fused to the inner mitochondrial membrane, probably reducing the extent of GBS-induced proton leakage. DPPC, which is not able to fuse with mitochondrial membranes, exerted its effect outside mitochondria, likely by shielding mitochondria against GBS β-hemolysin attack.
Collapse
Affiliation(s)
- Lara Macchioni
- Department of Internal Medicine, Section of Biochemistry, University of Perugia, Via Gambuli, 1, 06156, Perugia, Italy
| | | | | | | | | | | | | | | | | |
Collapse
|