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Ortiz Flores RM, Cáceres CS, Cortiñas TI, Gomez Mejiba SE, Sasso CV, Ramirez DC, Mattar Domínguez MA. Exotoxins secreted by Clostridium septicum induce macrophage death: Implications for bacterial immune evasion mechanisms at infection sites. Toxicon 2024; 249:108070. [PMID: 39127083 DOI: 10.1016/j.toxicon.2024.108070] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2023] [Revised: 07/25/2024] [Accepted: 08/07/2024] [Indexed: 08/12/2024]
Abstract
The induction of macrophage death is considered a potential mechanism by which components secreted by Clostridium septicum are used to evade the innate immune response and cause tissue damage. This study aimed to determine the effects of partially purified fractions of extracellular proteins secreted by C. septicum on the death of mouse peritoneal macrophages. Elicited mouse peritoneal macrophages were incubated with partially purified fractions of proteins secreted by C. septicum into the culture medium. After incubation, the protein fraction with a molecular weight ≥100 kDa caused significant cell death in macrophages, altered cell morphology, increased the expression of markers of apoptosis and autophagy, and increased the expression (protein and mRNA) of IL-10 and TNFα. Our data suggest that the proteins secreted by C. septicum (MW, ≥100 kDa) induce cell death in macrophages by promoting autophagy-triggered apoptosis. This study may contribute to our understanding of the molecular mechanism of immune evasion by C. septicum at the infection site.
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Affiliation(s)
- R M Ortiz Flores
- Department of Human Physiology, School of Medicine, CAMPUS TEATINOS C/Boulevard Luis Pasteur, University of Malaga, 29010, Malaga, Malaga, Spain.
| | - C S Cáceres
- Laboratory of Microbiology, School of Chemistry Biochemistry and Pharmacy, National University of San Luis, 5700, San Luis, San Luis, Argentina.
| | - T I Cortiñas
- Laboratory of Microbiology, School of Chemistry Biochemistry and Pharmacy, National University of San Luis, 5700, San Luis, San Luis, Argentina.
| | - S E Gomez Mejiba
- Laboratory of Experimental Therapeutics and Nutrition, IMIBIO-SL, CCT-San Luis, CONICET-National University of San Luis, 5700, San Luis, San Luis, Argentina.
| | - C V Sasso
- Department of Medicine and Dermatology, School of Medicine, CAMPUS TEATINOS, C/Boulevard Luis Pasteur, University of Malaga, 29010, Malaga, Malaga, Spain.
| | - D C Ramirez
- Laboratory of Experimental and Translational Medicine, IMIBIO-SL, CCT-San Luis, CONICET-National University of San Luis, 5700, San Luis, San Luis, Argentina.
| | - M A Mattar Domínguez
- Laboratory of Microbiology, School of Chemistry Biochemistry and Pharmacy, National University of San Luis, 5700, San Luis, San Luis, Argentina.
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2
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Caliot E, Firon A, Solgadi A, Trieu-Cuot P, Dramsi S. Lipid lysination by MprF contributes to hemolytic pigment retention in group B Streptococcus. Res Microbiol 2024:104231. [PMID: 39197696 DOI: 10.1016/j.resmic.2024.104231] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2024] [Revised: 07/17/2024] [Accepted: 08/20/2024] [Indexed: 09/01/2024]
Abstract
Group B Streptococcus (GBS) is the leading cause of neonatal sepsis and meningitis. A major virulence factor is a pigmented beta-haemolytic/cyto-lysin (β-h/c) toxin with an ornithine rhamnolipid structure. We initially observed that absence of MprF enzyme altered pigmentation and haemolytic activity in GBS. Next, we showed that MprF-dependent lipid lysination contributes to the retention of the ornithine rhamnolipid within GBS membrane. Furthermore, cationic lipidation by MprF altered membrane properties contributing to resistance to the cyclic lipopeptide daptomycin and to acidic pH. This study highlights the importance of cationic lipids in cell envelope homeostasis and in modulating β-h/c activity.
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Affiliation(s)
- Elise Caliot
- Institut Pasteur, Université Paris Cité, CNRS UMR6047, Biology of Gram-positive Pathogens Unit, F-75015 Paris, France
| | - Arnaud Firon
- Institut Pasteur, Université Paris Cité, CNRS UMR6047, Biology of Gram-positive Pathogens Unit, F-75015 Paris, France
| | - Audrey Solgadi
- UMS-IPSIT SAMM Facility, Université Paris-Saclay, Inserm, CNRS, Ingénierie et Plateformes au Service de l'Innovation Thérapeutique, F-91400 Orsay, France
| | - Patrick Trieu-Cuot
- Institut Pasteur, Université Paris Cité, CNRS UMR6047, Biology of Gram-positive Pathogens Unit, F-75015 Paris, France.
| | - Shaynoor Dramsi
- Institut Pasteur, Université Paris Cité, CNRS UMR6047, Biology of Gram-positive Pathogens Unit, F-75015 Paris, France.
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3
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Akbari MS, Joyce LR, Spencer BL, McIver KS, Doran KS. Identification of Glyoxalase A in Group B Streptococcus and its contribution to methylglyoxal tolerance and virulence. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.07.30.605887. [PMID: 39131367 PMCID: PMC11312555 DOI: 10.1101/2024.07.30.605887] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Indexed: 08/13/2024]
Abstract
Group B Streptococcus (GBS) is a Gram-positive pathobiont that commonly colonizes the gastrointestinal and lower female genital tracts but can cause sepsis and pneumonia in newborns and is a leading cause of neonatal meningitis. Despite the resulting disease severity, the pathogenesis of GBS is not completely understood, especially during the early phases of infection. To investigate GBS factors necessary for blood stream survival, we performed a transposon (Tn) mutant screen in our bacteremia infection model using a GBS mariner transposon mutant library previously developed by our group. We identified significantly underrepresented mutations in 628 genes that contribute to survival in the blood, including those encoding known virulence factors such as capsule, the β-hemolysin, and inorganic metal ion transport systems. Most of the underrepresented genes have not been previously characterized or studied in GBS, including gloA and gloB, which are homologs for genes involved in methylglyoxal (MG) detoxification. MG is a byproduct of glycolysis and a highly reactive toxic aldehyde that is elevated in immune cells during infection. Here, we observed MG sensitivity across multiple GBS isolates and confirm that gloA contributes to MG tolerance and invasive GBS infection. We show specifically that gloA contributes to GBS survival in the presence of neutrophils and depleting neutrophils in mice abrogates the decreased survival and infection of the gloA mutant. The requirement of the glyoxalase pathway during GBS infection suggests that MG detoxification is important for bacterial survival during host-pathogen interactions.
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Affiliation(s)
- Madeline S. Akbari
- Department of Immunology and Microbiology, School of Medicine, University of Colorado Anschutz Medical Campus, Aurora, Colorado USA
| | - Luke R. Joyce
- Department of Immunology and Microbiology, School of Medicine, University of Colorado Anschutz Medical Campus, Aurora, Colorado USA
| | - Brady L. Spencer
- Department of Immunology and Microbiology, School of Medicine, University of Colorado Anschutz Medical Campus, Aurora, Colorado USA
| | - Kevin S. McIver
- Cell Biology and Molecular Genetics, Maryland Pathogen Research Institute, University of Maryland, College Park, Maryland, USA
| | - Kelly S. Doran
- Department of Immunology and Microbiology, School of Medicine, University of Colorado Anschutz Medical Campus, Aurora, Colorado USA
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4
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Li H, Cao J, Han Q, Li Z, Zhuang J, Wang C, Wang H, Luo Z, Wang B, Li A. Protease SfpB plays an important role in cell membrane stability and immune system evasion in Streptococcus agalactiae. Microb Pathog 2024; 192:106683. [PMID: 38735447 DOI: 10.1016/j.micpath.2024.106683] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2024] [Revised: 05/08/2024] [Accepted: 05/09/2024] [Indexed: 05/14/2024]
Abstract
Bacteria possess the ability to develop diverse and ingenious strategies to outwit the host immune system, and proteases are one of the many weapons employed by bacteria. This study sought to identify S. agalactiae additional serine protease and determine its role in virulence. The S. agalactiae THN0901 genome features one S8 family serine peptidase B (SfpB), acting as a secreted and externally exposed entity. A S8 family serine peptidase mutant strain (ΔsfpB) and complement strain (CΔsfpB) were generated through homologous recombination. Compared to the wild-type strain THN0901, the absorption of EtBr dyes was significantly reduced (P < 0.01) in ΔsfpB, implying an altered cell membrane permeability. In addition, the ΔsfpB strain had a significantly lower survival rate in macrophages (P < 0.01) and a 61.85 % lower adhesion ability to the EPC cells (P < 0.01) compared to THN0901. In the in vivo colonization experiment using tilapia as a model, 210 fish were selected and injected with different bacterial strains at a concentration of 3 × 106 CFU/tail. At 6, 12, 24, 48, 72 and 96 h post-injection, three fish were randomly selected from each group and their brain, liver, spleen, and kidney tissues were isolated. Subsequently, it was demonstrated that the ΔsfpB strain exhibited a markedly diminished capacity for colonization in tilapia. Additionally, the cumulative mortality of ΔsfpB in fish after intraperitoneal injection was reduced by 19.92-23.85 %. In conclusion, the findings in this study have demonstrated that the SfpB plays a significant role in S. agalactiae cell membrane stability and immune evasion. The immune evasion is fundamental for the development and transmission of invasive diseases, the serine protease SfpB may be a promising candidate for the development of antimicrobial agents to reduce the transmission of S. agalactiae.
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Affiliation(s)
- Han Li
- State Key Laboratory of Biocontrol/Guangdong Provincial Key Laboratory of Improved Variety Reproduction in Aquatic Economic Animals and Institute of Aquatic Economic Animals, School of Life Sciences, Sun Yat-Sen University, Guangzhou, 510275, PR China
| | - Jizhen Cao
- State Key Laboratory of Biocontrol/Guangdong Provincial Key Laboratory of Improved Variety Reproduction in Aquatic Economic Animals and Institute of Aquatic Economic Animals, School of Life Sciences, Sun Yat-Sen University, Guangzhou, 510275, PR China
| | - Qing Han
- State Key Laboratory of Biocontrol/Guangdong Provincial Key Laboratory of Improved Variety Reproduction in Aquatic Economic Animals and Institute of Aquatic Economic Animals, School of Life Sciences, Sun Yat-Sen University, Guangzhou, 510275, PR China
| | - Zhicheng Li
- State Key Laboratory of Biocontrol/Guangdong Provincial Key Laboratory of Improved Variety Reproduction in Aquatic Economic Animals and Institute of Aquatic Economic Animals, School of Life Sciences, Sun Yat-Sen University, Guangzhou, 510275, PR China
| | - Jingyu Zhuang
- State Key Laboratory of Biocontrol/Guangdong Provincial Key Laboratory of Improved Variety Reproduction in Aquatic Economic Animals and Institute of Aquatic Economic Animals, School of Life Sciences, Sun Yat-Sen University, Guangzhou, 510275, PR China
| | - Chenxi Wang
- State Key Laboratory of Biocontrol/Guangdong Provincial Key Laboratory of Improved Variety Reproduction in Aquatic Economic Animals and Institute of Aquatic Economic Animals, School of Life Sciences, Sun Yat-Sen University, Guangzhou, 510275, PR China
| | - Hebing Wang
- State Key Laboratory of Biocontrol/Guangdong Provincial Key Laboratory of Improved Variety Reproduction in Aquatic Economic Animals and Institute of Aquatic Economic Animals, School of Life Sciences, Sun Yat-Sen University, Guangzhou, 510275, PR China
| | - Zhi Luo
- State Key Laboratory of Biocontrol/Guangdong Provincial Key Laboratory of Improved Variety Reproduction in Aquatic Economic Animals and Institute of Aquatic Economic Animals, School of Life Sciences, Sun Yat-Sen University, Guangzhou, 510275, PR China
| | - Baotun Wang
- State Key Laboratory of Biocontrol/Guangdong Provincial Key Laboratory of Improved Variety Reproduction in Aquatic Economic Animals and Institute of Aquatic Economic Animals, School of Life Sciences, Sun Yat-Sen University, Guangzhou, 510275, PR China
| | - Anxing Li
- State Key Laboratory of Biocontrol/Guangdong Provincial Key Laboratory of Improved Variety Reproduction in Aquatic Economic Animals and Institute of Aquatic Economic Animals, School of Life Sciences, Sun Yat-Sen University, Guangzhou, 510275, PR China.
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5
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Rajack F, Medford S, Ramadan A, Naab T. Emerging infection: streptococcal toxic shock-like syndrome caused by group B Streptococcus (GBS), Streptococcus agalactiae. Autops Case Rep 2024; 14:e2024497. [PMID: 39021470 PMCID: PMC11253910 DOI: 10.4322/acr.2024.497] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2023] [Accepted: 04/25/2024] [Indexed: 07/20/2024]
Abstract
Streptococcus agalactiae or Group B Streptococcus (GBS) infections are commonly associated with infections in neonates and pregnant women. However, there has been a rising incidence in nonpregnant adults. The risk of GBS infection in nonpregnant adults is increased for patients of advanced age and those with underlying medical conditions such as diabetes mellitus and cancer. We present a 77-year-old female with type-2 diabetes mellitus, hypertension, and bilateral foot ulcers that presented in probable septic shock with necrotic foot ulcers and necrotizing fasciitis and underwent bilateral lower limb amputations. The patient fulfilled the Streptococcal Toxic Shock Syndrome (STSS) criteria as defined by The Working Group on Severe Streptococcal Infections. These criteria were created for group A Streptococcus (Streptococcus pyogenes). Our patient fulfilled the Working Group's criteria, except that the blood culture was positive for group B Streptococcus (Streptococcus agalactiae). Numerous studies demonstrate the importance of early detection and antibiotic treatment for GBS infections in general and early surgical management for necrotizing soft tissue infections (NSTIs) such as necrotizing fasciitis.
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Affiliation(s)
- Fareed Rajack
- Howard University Hospital, Department of Pathology and Laboratory Medicine, Washington, D.C., United States of America
| | - Shawn Medford
- Howard University College of Medicine, Washington, D.C., United States of America
| | - Ali Ramadan
- Howard University Hospital, Department of Pathology and Laboratory Medicine, Washington, D.C., United States of America
| | - Tammey Naab
- Howard University Hospital, Department of Pathology and Laboratory Medicine, Washington, D.C., United States of America
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6
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Yang L, Wu Z, Ma TY, Zeng H, Chen M, Zhang YA, Zhou Y. Identification of ClpB, a molecular chaperone involved in the stress tolerance and virulence of Streptococcus agalactiae. Vet Res 2024; 55:60. [PMID: 38750480 PMCID: PMC11094935 DOI: 10.1186/s13567-024-01318-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2024] [Accepted: 03/06/2024] [Indexed: 05/19/2024] Open
Abstract
Bacterial ClpB is an ATP-dependent disaggregate that belongs to the Hsp100/Clp family and facilitates bacterial survival under hostile environmental conditions. Streptococcus agalactiae, which is regarded as the major bacterial pathogen of farmed Nile tilapia (Oreochromis niloticus), is known to cause high mortality and large economic losses. Here, we report a ClpB homologue of S. agalactiae and explore its functionality. S. agalactiae with a clpB deletion mutant (∆clpB) exhibited defective tolerance against heat and acidic stress, without affecting growth or morphology under optimal conditions. Moreover, the ΔclpB mutant exhibited reduced intracellular survival in RAW264.7 cells, diminished adherence to the brain cells of tilapia, increased sensitivity to leukocytes from the head kidney of tilapia and whole blood killing, and reduced mortality and bacterial loads in a tilapia infection assay. Furthermore, the reduced virulence of the ∆clpB mutant was investigated by transcriptome analysis, which revealed that deletion of clpB altered the expression levels of multiple genes that contribute to the stress response as well as certain metabolic pathways. Collectively, our findings demonstrated that ClpB, a molecular chaperone, plays critical roles in heat and acid stress resistance and virulence in S. agalactiae. This finding provides an enhanced understanding of the functionality of this ClpB homologue in gram-positive bacteria and the survival strategy of S. agalactiae against immune clearance during infection.
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Affiliation(s)
- Lan Yang
- National Key Laboratory of Agricultural Microbiology; Hubei Hongshan Laboratory; Engineering Research Center of Green Development for Conventional Aquatic Biological Industry in the Yangtze River Economic Belt, Ministry of Education; Shenzhen Institute of Nutrition and Health, College of Fisheries, Huazhong Agricultural University, Wuhan, 430000, China
| | - Zhihao Wu
- National Key Laboratory of Agricultural Microbiology; Hubei Hongshan Laboratory; Engineering Research Center of Green Development for Conventional Aquatic Biological Industry in the Yangtze River Economic Belt, Ministry of Education; Shenzhen Institute of Nutrition and Health, College of Fisheries, Huazhong Agricultural University, Wuhan, 430000, China
| | - Tian-Yu Ma
- National Key Laboratory of Agricultural Microbiology; Hubei Hongshan Laboratory; Engineering Research Center of Green Development for Conventional Aquatic Biological Industry in the Yangtze River Economic Belt, Ministry of Education; Shenzhen Institute of Nutrition and Health, College of Fisheries, Huazhong Agricultural University, Wuhan, 430000, China
| | - Hui Zeng
- National Key Laboratory of Agricultural Microbiology; Hubei Hongshan Laboratory; Engineering Research Center of Green Development for Conventional Aquatic Biological Industry in the Yangtze River Economic Belt, Ministry of Education; Shenzhen Institute of Nutrition and Health, College of Fisheries, Huazhong Agricultural University, Wuhan, 430000, China
| | - Ming Chen
- National Key Laboratory of Agricultural Microbiology; Hubei Hongshan Laboratory; Engineering Research Center of Green Development for Conventional Aquatic Biological Industry in the Yangtze River Economic Belt, Ministry of Education; Shenzhen Institute of Nutrition and Health, College of Fisheries, Huazhong Agricultural University, Wuhan, 430000, China
| | - Yong-An Zhang
- National Key Laboratory of Agricultural Microbiology; Hubei Hongshan Laboratory; Engineering Research Center of Green Development for Conventional Aquatic Biological Industry in the Yangtze River Economic Belt, Ministry of Education; Shenzhen Institute of Nutrition and Health, College of Fisheries, Huazhong Agricultural University, Wuhan, 430000, China.
- Guangdong Laboratory for Lingnan Modern Agriculture, Guangzhou, 510000, China.
| | - Yang Zhou
- National Key Laboratory of Agricultural Microbiology; Hubei Hongshan Laboratory; Engineering Research Center of Green Development for Conventional Aquatic Biological Industry in the Yangtze River Economic Belt, Ministry of Education; Shenzhen Institute of Nutrition and Health, College of Fisheries, Huazhong Agricultural University, Wuhan, 430000, China.
- Guangdong Laboratory for Lingnan Modern Agriculture, Guangzhou, 510000, China.
- Shenzhen Branch, Guangdong Laboratory for Lingnan Modern Agriculture, Genome Analysis Laboratory of the Ministry of Agriculture,, Agricultural Genomics Institute at Shenzhen, Chinese Academy of Agricultural Sciences, Shenzhen, 518000, China.
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7
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Goh KGK, Desai D, Thapa R, Prince D, Acharya D, Sullivan MJ, Ulett GC. An opportunistic pathogen under stress: how Group B Streptococcus responds to cytotoxic reactive species and conditions of metal ion imbalance to survive. FEMS Microbiol Rev 2024; 48:fuae009. [PMID: 38678005 PMCID: PMC11098048 DOI: 10.1093/femsre/fuae009] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2023] [Revised: 03/26/2024] [Accepted: 04/16/2024] [Indexed: 04/29/2024] Open
Abstract
Group B Streptococcus (GBS; also known as Streptococcus agalactiae) is an opportunistic bacterial pathogen that causes sepsis, meningitis, pneumonia, and skin and soft tissue infections in neonates and healthy or immunocompromised adults. GBS is well-adapted to survive in humans due to a plethora of virulence mechanisms that afford responses to support bacterial survival in dynamic host environments. These mechanisms and responses include counteraction of cell death from exposure to excess metal ions that can cause mismetallation and cytotoxicity, and strategies to combat molecules such as reactive oxygen and nitrogen species that are generated as part of innate host defence. Cytotoxicity from reactive molecules can stem from damage to proteins, DNA, and membrane lipids, potentially leading to bacterial cell death inside phagocytic cells or within extracellular spaces within the host. Deciphering the ways in which GBS responds to the stress of cytotoxic reactive molecules within the host will benefit the development of novel therapeutic and preventative strategies to manage the burden of GBS disease. This review summarizes knowledge of GBS carriage in humans and the mechanisms used by the bacteria to circumvent killing by these important elements of host immune defence: oxidative stress, nitrosative stress, and stress from metal ion intoxication/mismetallation.
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Affiliation(s)
- Kelvin G K Goh
- School of Pharmacy and Medical Sciences, and Menzies Health Institute Queensland, Griffith University, Parklands Drive, Southport, Gold Coast Campus, QLD 4222, Australia
| | - Devika Desai
- School of Pharmacy and Medical Sciences, and Menzies Health Institute Queensland, Griffith University, Parklands Drive, Southport, Gold Coast Campus, QLD 4222, Australia
| | - Ruby Thapa
- School of Pharmacy and Medical Sciences, and Menzies Health Institute Queensland, Griffith University, Parklands Drive, Southport, Gold Coast Campus, QLD 4222, Australia
| | - Darren Prince
- School of Pharmacy and Medical Sciences, and Menzies Health Institute Queensland, Griffith University, Parklands Drive, Southport, Gold Coast Campus, QLD 4222, Australia
| | - Dhruba Acharya
- School of Pharmacy and Medical Sciences, and Menzies Health Institute Queensland, Griffith University, Parklands Drive, Southport, Gold Coast Campus, QLD 4222, Australia
| | - Matthew J Sullivan
- School of Pharmacy and Medical Sciences, and Menzies Health Institute Queensland, Griffith University, Parklands Drive, Southport, Gold Coast Campus, QLD 4222, Australia
- School of Biological Sciences, University of East Anglia, Norwich Research Park, Norwich, NR4 7TJ, United Kingdom
| | - Glen C Ulett
- School of Pharmacy and Medical Sciences, and Menzies Health Institute Queensland, Griffith University, Parklands Drive, Southport, Gold Coast Campus, QLD 4222, Australia
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8
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Salas-Orozco MF, Lorenzo-Leal AC, de Alba Montero I, Marín NP, Santana MAC, Bach H. Mechanism of escape from the antibacterial activity of metal-based nanoparticles in clinically relevant bacteria: A systematic review. NANOMEDICINE : NANOTECHNOLOGY, BIOLOGY, AND MEDICINE 2024; 55:102715. [PMID: 37907198 DOI: 10.1016/j.nano.2023.102715] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/12/2023] [Revised: 08/05/2023] [Accepted: 10/05/2023] [Indexed: 11/02/2023]
Abstract
The emergency of antibiotic-resistant bacteria in severe infections is increasing, especially in nosocomial environments. The ESKAPE group is of special importance in the groups of multi-resistant bacteria due to its high capacity to generate resistance to antibiotics and bactericides. Therefore, metal-based nanomaterials are an attractive alternative to combat them because they have been demonstrated to damage biomolecules in the bacterial cells. However, there is a concern about bacteria developing resistance to NPs and their harmful effects due to environmental accumulation. Therefore, this systematic review aims to report the clinically relevant bacteria that have developed resistance to the NPs. According to the results of this systematic review, various mechanisms to counteract the antimicrobial activity of various NP types have been proposed. These mechanisms can be grouped into the following categories: production of extracellular compounds, metal efflux pumps, ROS response, genetic changes, DNA repair, adaptative morphogenesis, and changes in the plasma membrane.
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Affiliation(s)
- Marco Felipe Salas-Orozco
- Facultad de Estomatología, Doctorado en Ciencias Odontológicas, Universidad Autónoma de San Luis Potosí, San Luis Potosí, Mexico.
| | - Ana Cecilia Lorenzo-Leal
- Division of Infectious Diseases, Department of Medicine, University of British Columbia, Vancouver, BC, Canada
| | | | - Nuria Patiño Marín
- Facultad de Estomatología, Laboratorio de Investigación Clinica, Universidad Autónoma de San Luis Potosí, San Luis Potosí, Mexico
| | - Miguel Angel Casillas Santana
- Maestría en Estomatología con Opcion Terminal en Ortodoncia, Facultad de Estomatología, Benemérita Universidad Autónoma de Puebla, Puebla, Mexico
| | - Horacio Bach
- Division of Infectious Diseases, Department of Medicine, University of British Columbia, Vancouver, BC, Canada.
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9
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Bhavana VH, Hillebrand GH, Gopalakrishna KP, Rapp RA, Ratner AJ, Tettelin H, Hooven TA. A group B Streptococcus indexed transposon mutant library to accelerate genetic research on an important perinatal pathogen. Microbiol Spectr 2023; 11:e0204623. [PMID: 37933989 PMCID: PMC10714824 DOI: 10.1128/spectrum.02046-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2023] [Accepted: 09/29/2023] [Indexed: 11/08/2023] Open
Abstract
IMPORTANCE Group B Streptococcus (GBS) is a significant global cause of serious infections, most of which affect pregnant women, newborns, and infants. Studying GBS genetic mutant strains is a valuable approach for learning more about how these infections are caused and is a key step toward developing more effective preventative and treatment strategies. In this resource report, we describe a newly created library of defined GBS genetic mutants, containing over 1,900 genetic variants, each with a unique disruption to its chromosome. An indexed library of this scale is unprecedented in the GBS field; it includes strains with mutations in hundreds of genes whose potential functions in human disease remain unknown. We have made this resource freely available to the broader research community through deposition in a publicly funded bacterial maintenance and distribution repository.
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Affiliation(s)
- Venkata H. Bhavana
- Department of Pediatrics, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, USA
| | - Gideon H. Hillebrand
- University of Pittsburgh, Graduate Program in Microbiology and Immunology, Pittsburgh, Pennsylvania, USA
| | | | - Rebekah A. Rapp
- Department of Pediatrics, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, USA
- The Ellis School, Pittsburgh, Pennsylvania, USA
| | - Adam J. Ratner
- Department of Pediatrics, New York University, New York, New York, USA
- Department of Microbiology, New York University, New York, New York, USA
| | - Hervé Tettelin
- Department of Microbiology and Immunology, Institute for Genome Sciences, University of Maryland School of Medicine, Baltimore, Maryland, USA
| | - Thomas A. Hooven
- Department of Pediatrics, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, USA
- University of Pittsburgh, Graduate Program in Microbiology and Immunology, Pittsburgh, Pennsylvania, USA
- Richard King Mellon Institute for Pediatric Research, University of Pittsburgh Medical School, Pittsburgh, Pennsylvania, USA
- UPMC Children’s Hospital of Pittsburgh, Pittsburgh, Pennsylvania, USA
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10
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Jusuf S, Dong PT. Chromophore-Targeting Precision Antimicrobial Phototherapy. Cells 2023; 12:2664. [PMID: 37998399 PMCID: PMC10670386 DOI: 10.3390/cells12222664] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2023] [Revised: 11/11/2023] [Accepted: 11/18/2023] [Indexed: 11/25/2023] Open
Abstract
Phototherapy, encompassing the utilization of both natural and artificial light, has emerged as a dependable and non-invasive strategy for addressing a diverse range of illnesses, diseases, and infections. This therapeutic approach, primarily known for its efficacy in treating skin infections, such as herpes and acne lesions, involves the synergistic use of specific light wavelengths and photosensitizers, like methylene blue. Photodynamic therapy, as it is termed, relies on the generation of antimicrobial reactive oxygen species (ROS) through the interaction between light and externally applied photosensitizers. Recent research, however, has highlighted the intrinsic antimicrobial properties of light itself, marking a paradigm shift in focus from exogenous agents to the inherent photosensitivity of molecules found naturally within pathogens. Chemical analyses have identified specific organic molecular structures and systems, including protoporphyrins and conjugated C=C bonds, as pivotal components in molecular photosensitivity. Given the prevalence of these systems in organic life forms, there is an urgent need to investigate the potential impact of phototherapy on individual molecules expressed within pathogens and discern their contributions to the antimicrobial effects of light. This review delves into the recently unveiled key molecular targets of phototherapy, offering insights into their potential downstream implications and therapeutic applications. By shedding light on these fundamental molecular mechanisms, we aim to advance our understanding of phototherapy's broader therapeutic potential and contribute to the development of innovative treatments for a wide array of microbial infections and diseases.
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Affiliation(s)
- Sebastian Jusuf
- Division of Infectious Diseases, Massachusetts General Hospital, Harvard Medical School, Boston, MA 02114, USA;
| | - Pu-Ting Dong
- Department of Microbiology, The Forsyth Institute, Boston, MA 02142, USA
- Department of Oral Medicine, Infection and Immunity, Harvard School of Dental Medicine, Boston, MA 02115, USA
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11
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De-Leon-Lopez YS, Thompson ME, Kean JJ, Flaherty RA. The PI3K-Akt pathway is a multifaceted regulator of the macrophage response to diverse group B Streptococcus isolates. Front Cell Infect Microbiol 2023; 13:1258275. [PMID: 37928185 PMCID: PMC10622663 DOI: 10.3389/fcimb.2023.1258275] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2023] [Accepted: 09/25/2023] [Indexed: 11/07/2023] Open
Abstract
Group B Streptococcus (GBS), also known as Streptococcus agalactiae, is a common member of the microbial flora in healthy individuals. However, problems may arise when GBS-colonized mothers become pregnant. GBS may be transferred from a colonized mother to her newborn or developing fetus, which may result in complications such as miscarriage, pre-term birth, meningitis, pneumonia, or sepsis. Macrophages play an especially important role in the fetal and newborn response to GBS due to the limited development of the adaptive immune system early in life. The goal of this study was to expand what is currently known about how GBS manipulates macrophage cell signaling to evade the immune system and cause disease. To this end, we investigated whether the PI3K-Akt pathway was involved in several key aspects of the macrophage response to GBS. We explored whether certain GBS strains, such as sequence type (ST)-17 strains, rely on this pathway for the more rapid macrophage uptake they induce compared to other GBS strains. Our findings suggest that this pathway is, indeed, important for macrophage uptake of GBS. Consistent with these findings, we used immunofluorescence microscopy to demonstrate that more virulent strains of GBS induce more actin projections in macrophages than less virulent strains. Additionally, we explored whether PI3K-Akt signaling impacted the ability of GBS to survive within macrophages after phagocytosis and whether this pathway influenced the survival rate of macrophages themselves following GBS infection. The PI3K-Akt pathway was found to promote the survival of both macrophages and intracellular GBS following infection. We also observed that inhibition of the PI3K-Akt pathway significantly reduced GBS-mediated activation of NFκB, which is a key regulator of cell survival and inflammatory responses. Overall, these insights into strain-dependent GBS-mediated manipulation of the PI3K-Akt pathway and its downstream targets in infected macrophages may provide new insights for the development of diagnostic and therapeutic tools to combat severe GBS disease.
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Affiliation(s)
| | | | | | - Rebecca A. Flaherty
- Department of Biology and Health Science, Aquinas College, Grand Rapids, MI, United States
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12
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Furuta A, Coleman M, Casares R, Seepersaud R, Orvis A, Brokaw A, Quach P, Nguyen S, Sweeney E, Sharma K, Wallen G, Sanghavi R, Mateos-Gil J, Cuerva JM, Millán A, Rajagopal L. CD1 and iNKT cells mediate immune responses against the GBS hemolytic lipid toxin induced by a non-toxic analog. PLoS Pathog 2023; 19:e1011490. [PMID: 37384812 DOI: 10.1371/journal.ppat.1011490] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2022] [Accepted: 06/14/2023] [Indexed: 07/01/2023] Open
Abstract
Although hemolytic lipids have been discovered from many human pathogens including Group B Streptococcus (GBS), strategies that neutralize their function are lacking. GBS is a leading cause of pregnancy-associated neonatal infections, and adult GBS infections are on the rise. The GBS hemolytic lipid toxin or granadaene, is cytotoxic to many immune cells including T and B cells. We previously showed that mice immunized with a synthetic nontoxic analog of granadaene known as R-P4 had reduced bacterial dissemination during systemic infection. However, mechanisms important for R-P4 mediated immune protection was not understood. Here, we show that immune serum from R-P4-immunized mice facilitate GBS opsonophagocytic killing and protect naïve mice from GBS infection. Further, CD4+ T cells isolated from R-P4-immunized mice proliferated in response to R-P4 stimulation in a CD1d- and iNKT cell-dependent manner. Consistent with these observations, R-P4 immunized mice lacking CD1d or CD1d-restricted iNKT cells exhibit elevated bacterial burden. Additionally, adoptive transfer of iNKT cells from R-P4 vaccinated mice significantly reduced GBS dissemination compared to adjuvant controls. Finally, maternal R-P4 vaccination provided protection against ascending GBS infection during pregnancy. These findings are relevant in the development of therapeutic strategies targeting lipid cytotoxins.
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Affiliation(s)
- Anna Furuta
- Center for Global Infectious Disease Research, Seattle Children's Research Institute, Seattle, Washington, United States of America
- Department of Global Health, University of Washington, Seattle, Washington, United States of America
| | - Michelle Coleman
- Center for Global Infectious Disease Research, Seattle Children's Research Institute, Seattle, Washington, United States of America
| | - Raquel Casares
- Department of Organic Chemistry, University of Granada, Granada, Spain
| | - Ravin Seepersaud
- Center for Global Infectious Disease Research, Seattle Children's Research Institute, Seattle, Washington, United States of America
| | - Austyn Orvis
- Center for Global Infectious Disease Research, Seattle Children's Research Institute, Seattle, Washington, United States of America
| | - Alyssa Brokaw
- Center for Global Infectious Disease Research, Seattle Children's Research Institute, Seattle, Washington, United States of America
- Department of Global Health, University of Washington, Seattle, Washington, United States of America
| | - Phoenicia Quach
- Center for Global Infectious Disease Research, Seattle Children's Research Institute, Seattle, Washington, United States of America
| | - Shayla Nguyen
- Center for Global Infectious Disease Research, Seattle Children's Research Institute, Seattle, Washington, United States of America
| | - Erin Sweeney
- Center for Global Infectious Disease Research, Seattle Children's Research Institute, Seattle, Washington, United States of America
| | - Kavita Sharma
- Center for Global Infectious Disease Research, Seattle Children's Research Institute, Seattle, Washington, United States of America
| | - Grace Wallen
- Center for Global Infectious Disease Research, Seattle Children's Research Institute, Seattle, Washington, United States of America
| | - Rhea Sanghavi
- Center for Global Infectious Disease Research, Seattle Children's Research Institute, Seattle, Washington, United States of America
- Department of Global Health, University of Washington, Seattle, Washington, United States of America
| | - Jaime Mateos-Gil
- Department of Organic Chemistry, University of Granada, Granada, Spain
| | | | - Alba Millán
- Department of Organic Chemistry, University of Granada, Granada, Spain
| | - Lakshmi Rajagopal
- Center for Global Infectious Disease Research, Seattle Children's Research Institute, Seattle, Washington, United States of America
- Department of Global Health, University of Washington, Seattle, Washington, United States of America
- Department of Pediatrics, University of Washington, Seattle, Washington, United States of America
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13
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Gopalakrishna KP, Hillebrand GH, Bhavana VH, Elder JL, D'Mello A, Tettelin H, Hooven TA. Group B Streptococcus Cas9 variants provide insight into programmable gene repression and CRISPR-Cas transcriptional effects. Commun Biol 2023; 6:620. [PMID: 37296208 PMCID: PMC10256743 DOI: 10.1038/s42003-023-04994-w] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2023] [Accepted: 05/30/2023] [Indexed: 06/12/2023] Open
Abstract
Group B Streptococcus (GBS; S. agalactiae) causes chorioamnionitis, neonatal sepsis, and can also cause disease in healthy or immunocompromised adults. GBS possesses a type II-A CRISPR-Cas9 system, which defends against foreign DNA within the bacterial cell. Several recent publications have shown that GBS Cas9 influences genome-wide transcription through a mechanism uncoupled from its function as a specific, RNA-programmable endonuclease. We examine GBS Cas9 effects on genome-wide transcription through generation of several isogenic variants with specific functional defects. We compare whole-genome RNA-seq from Δcas9 GBS with a full-length Cas9 gene deletion; dcas9 defective in its ability to cleave DNA but still able to bind to frequently occurring protospacer adjacent motifs; and scas9 that retains its catalytic domains but is unable to bind protospacer adjacent motifs. Comparing scas9 GBS to the other variants, we identify nonspecific protospacer adjacent motif binding as a driver of genome-wide, Cas9 transcriptional effects in GBS. We also show that Cas9 transcriptional effects from nonspecific scanning tend to influence genes involved in bacterial defense and nucleotide or carbohydrate transport and metabolism. While genome-wide transcription effects are detectable by analysis of next-generation sequencing, they do not result in virulence changes in a mouse model of sepsis. We also demonstrate that catalytically inactive dCas9 expressed from the GBS chromosome can be used with a straightforward, plasmid-based, single guide RNA expression system to suppress transcription of specific GBS genes without potentially confounding off-target effects. We anticipate that this system will be useful for study of nonessential and essential gene roles in GBS physiology and pathogenesis.
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Affiliation(s)
| | - Gideon H Hillebrand
- University of Pittsburgh School of Medicine, Program in Microbiology and Immunology, Pittsburgh, PA, USA
| | - Venkata H Bhavana
- University of Pittsburgh School of Medicine, Department of Pediatrics, Pittsburgh, PA, USA
| | - Jordan L Elder
- The Cleveland Clinic, Clinical Laboratory Services, Cleveland, OH, USA
| | - Adonis D'Mello
- Institute for Genome Sciences, University of Maryland School of Medicine, Baltimore, MD, USA
| | - Hervé Tettelin
- Institute for Genome Sciences, University of Maryland School of Medicine, Baltimore, MD, USA
| | - Thomas A Hooven
- University of Pittsburgh School of Medicine, Department of Pediatrics, Pittsburgh, PA, USA.
- Richard King Mellon Institute for Pediatric Research, University of Pittsburgh Medical Center, Pittsburgh, PA, USA.
- UPMC Children's Hospital of Pittsburgh, Pittsburgh, PA, USA.
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14
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Gopalakrishna KP, Hillebrand GH, Bhavana VH, Elder JL, D'Mello A, Tettelin H, Hooven TA. Group B Streptococcus Cas9 variants provide insight into programmable gene repression and CRISPR-Cas transcriptional effects. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.05.24.542094. [PMID: 37292749 PMCID: PMC10245859 DOI: 10.1101/2023.05.24.542094] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Group B Streptococcus (GBS; S. agalactiae ) causes chorioamnionitis, neonatal sepsis, and can also cause disease in healthy or immunocompromised adults. GBS possesses a type II-A CRISPR-Cas9 system, which defends against foreign DNA within the bacterial cell. Several recent publications have shown that GBS Cas9 influences genome-wide transcription through a mechanism uncoupled from its function as a specific, RNA-programmable endonuclease. We examine GBS Cas9 effects on genome-wide transcription through generation of several isogenic variants with specific functional defects. We compare whole-genome RNA-seq from Δ cas9 GBS with a full-length Cas9 gene deletion; dcas9 defective in its ability to cleave DNA but still able to bind to frequently occurring protospacer adjacent motifs; and scas9 that retains its catalytic domains but is unable to bind protospacer adjacent motifs. Comparing scas9 GBS to the other variants, we identify nonspecific protospacer adjacent motif binding as a driver of genome-wide, Cas9 transcriptional effects in GBS. We also show that Cas9 transcriptional effects from nonspecific scanning tend to influence genes involved in bacterial defense and nucleotide or carbohydrate transport and metabolism. While genome-wide transcription effects are detectable by analysis of next-generation sequencing, they do not result in virulence changes in a mouse model of sepsis. We also demonstrate that catalytically inactive dCas9 expressed from the GBS chromosome can be used with a straightforward, plasmid-based, single guide RNA expression system to suppress transcription of specific GBS genes without potentially confounding off-target effects. We anticipate that this system will be useful for study of nonessential and essential gene roles in GBS physiology and pathogenesis.
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15
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Kuperwaser F, Avital G, Vaz MJ, Noble KN, Dammann AN, Randis TM, Aronoff DM, Ratner AJ, Yanai I. Host inflammatory dynamics reveal placental immune modulation by Group B Streptococcus during pregnancy. Mol Syst Biol 2023; 19:e11021. [PMID: 36744393 PMCID: PMC9996236 DOI: 10.15252/msb.202211021] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2022] [Revised: 01/06/2023] [Accepted: 01/10/2023] [Indexed: 02/07/2023] Open
Abstract
Group B Streptococcus (GBS) is a pathobiont that can ascend to the placenta and cause adverse pregnancy outcomes, in part through production of the toxin β-hemolysin/cytolysin (β-h/c). Innate immune cells have been implicated in the response to GBS infection, but the impact of β-h/c on their response is poorly defined. We show that GBS modulates innate immune cell states by subversion of host inflammation through β-h/c, allowing worse outcomes. We used an ascending mouse model of GBS infection to measure placental cell state changes over time following infection with a β-h/c-deficient and isogenic wild type GBS strain. Transcriptomic analysis suggests that β-h/c-producing GBS elicit a worse phenotype through suppression of host inflammatory signaling in placental macrophages and neutrophils, and comparison of human placental macrophages infected with the same strains recapitulates these results. Our findings have implications for identification of new targets in GBS disease to support host defense against pathogenic challenge.
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Affiliation(s)
- Felicia Kuperwaser
- Institute for Computational MedicineNYU Grossman School of MedicineNew YorkNYUSA
| | - Gal Avital
- Institute for Computational MedicineNYU Grossman School of MedicineNew YorkNYUSA
| | - Michelle J Vaz
- Department of PediatricsNYU Grossman School of MedicineNew YorkNYUSA
| | - Kristen N Noble
- Division of Neonatology, Department of PediatricsVanderbilt University Medical CenterNashvilleTNUSA
| | - Allison N Dammann
- Renaissance School of Medicine at Stony Brook UniversityStony BrookNYUSA
| | - Tara M Randis
- Departments of Pediatrics and Molecular Medicine, Morsani School of MedicineUniversity of South FloridaFLTampaUSA
| | | | - Adam J Ratner
- Department of PediatricsNYU Grossman School of MedicineNew YorkNYUSA
- Department of MicrobiologyNYU Grossman School of MedicineNew YorkNYUSA
| | - Itai Yanai
- Institute for Computational MedicineNYU Grossman School of MedicineNew YorkNYUSA
- Department of Biochemistry and Molecular PharmacologyNYU Grossman School of MedicineNew YorkNYUSA
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16
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Affiliation(s)
- Rebecca A. Keogh
- Department of Immunology and Microbiology, University of Colorado Anschutz, Aurora, Colorado, United States of America
| | - Kelly S. Doran
- Department of Immunology and Microbiology, University of Colorado Anschutz, Aurora, Colorado, United States of America
- * E-mail:
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17
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Roux AE, Robert S, Bastat M, Rosinski-Chupin I, Rong V, Holbert S, Mereghetti L, Camiade E. The Role of Regulator Catabolite Control Protein A (CcpA) in Streptococcus agalactiae Physiology and Stress Response. Microbiol Spectr 2022; 10:e0208022. [PMID: 36264242 PMCID: PMC9784791 DOI: 10.1128/spectrum.02080-22] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2022] [Accepted: 09/21/2022] [Indexed: 01/06/2023] Open
Abstract
Streptococcus agalactiae is a leading cause of infections in neonates. This opportunistic pathogen colonizes the vagina, where it has to cope with acidic pH and hydrogen peroxide produced by lactobacilli. Thus, in the host, this bacterium possesses numerous adaptation mechanisms in which the pleiotropic regulators play a major role. The transcriptional regulator CcpA (catabolite control protein A) has previously been shown to be the major regulator involved in carbon catabolite repression in Gram-positive bacteria but is also involved in other functions. By transcriptomic analysis, we characterized the CcpA-dependent gene regulation in S. agalactiae. Approximately 13.5% of the genome of S. agalactiae depends on CcpA for regulation and comprises genes involved in sugar uptake and fermentation, confirming the role of CcpA in carbon metabolism. We confirmed by electrophoretic mobility shift assays (EMSAs) that the DNA binding site called cis-acting catabolite responsive element (cre) determined for other streptococci was effective in S. agalactiae. We also showed that CcpA is of capital importance for survival under acidic and oxidative stresses and is implicated in macrophage survival by regulating several genes putatively or already described as involved in stress response. Among them, we focused our study on SAK_1689, which codes a putative UspA protein. We demonstrated that SAK_1689, highly downregulated by CcpA, is overexpressed under oxidative stress conditions, this overexpression being harmful for the bacterium in a ΔccpA mutant. IMPORTANCE Streptococcus agalactiae is a major cause of disease burden leading to morbidity and mortality in neonates worldwide. Deciphering its adaptation mechanisms is essential to understand how this bacterium manages to colonize its host. Here, we determined the regulon of the pleiotropic regulator CcpA in S. agalactiae. Our findings reveal that CcpA is not only involved in carbon catabolite repression, but is also important for acidic and oxidative stress resistance and survival in macrophages.
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Affiliation(s)
| | | | | | - Isabelle Rosinski-Chupin
- Unité Écologie et Évolution de la Résistance aux Antibiotiques, CNRS UMR3525, Institut Pasteur, Paris, France
| | | | | | - Laurent Mereghetti
- ISP, Université de Tours, INRAE, Tours, France
- CHRU Tours, Service de Bactériologie-Virologie-Hygiène, Tours, France
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18
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Streptococcus agalactiae npx Is Required for Survival in Human Placental Macrophages and Full Virulence in a Model of Ascending Vaginal Infection during Pregnancy. mBio 2022; 13:e0287022. [PMID: 36409087 PMCID: PMC9765263 DOI: 10.1128/mbio.02870-22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
Streptococcus agalactiae, also known as group B Streptococcus (GBS), is a Gram-positive encapsulated bacterium that colonizes the gastrointestinal tract of 30 to 50% of humans. GBS causes invasive infection during pregnancy that can lead to chorioamnionitis, funisitis, preterm prelabor rupture of membranes (PPROM), preterm birth, neonatal sepsis, and maternal and fetal demise. Upon infecting the host, GBS encounters sentinel innate immune cells, such as macrophages, within reproductive tissues. Once phagocytosed by macrophages, GBS upregulates the expression of the gene npx, which encodes an NADH peroxidase. GBS mutants with an npx deletion (Δnpx) are exquisitely sensitive to reactive oxygen stress. Furthermore, we have shown that npx is required for GBS survival in both THP-1 and placental macrophages. In an in vivo murine model of ascending GBS vaginal infection during pregnancy, npx is required for invading reproductive tissues and is critical for inducing disease progression, including PPROM and preterm birth. Reproductive tissue cytokine production was also significantly diminished in Δnpx mutant-infected animals compared to that in animals infected with wild-type (WT) GBS. Complementation in trans reversed this phenotype, indicating that npx is critical for GBS survival and the initiation of proinflammatory signaling in the gravid host. IMPORTANCE This study sheds new light on the way that group B Streptococcus (GBS) defends itself against oxidative stress in the infected host. The enzyme encoded by the GBS gene npx is an NADH peroxidase that, our study reveals, provides defense against macrophage-derived reactive oxygen stress and facilitates infections of the uterus during pregnancy. This enzyme could represent a tractable target for future treatment strategies against invasive GBS infections.
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19
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Group B Streptococcus: Virulence Factors and Pathogenic Mechanism. Microorganisms 2022; 10:microorganisms10122483. [PMID: 36557736 PMCID: PMC9784991 DOI: 10.3390/microorganisms10122483] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2022] [Revised: 12/10/2022] [Accepted: 12/13/2022] [Indexed: 12/23/2022] Open
Abstract
Group B Streptococcus (GBS) or Streptococcus agalactiae is a major cause of neonatal mortality. When colonizing the lower genital tract of pregnant women, GBS may cause premature birth and stillbirth. If transmitted to the newborn, it may result in life-threatening illnesses, including sepsis, meningitis, and pneumonia. Moreover, through continuous evolution, GBS can use its original structure and unique factors to greatly improve its survival rate in the human body. This review discusses the key virulence factors that facilitate GBS invasion and colonization and their action mechanisms. A comprehensive understanding of the role of virulence factors in GBS infection is crucial to develop better treatment options and screen potential candidate molecules for the development of the vaccine.
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20
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Keogh RA, Haeberle AL, Langouët-Astrié CJ, Kavanaugh JS, Schmidt EP, Moore GD, Horswill AR, Doran KS. Group B Streptococcus adaptation promotes survival in a hyperinflammatory diabetic wound environment. SCIENCE ADVANCES 2022; 8:eadd3221. [PMID: 36367946 PMCID: PMC9651866 DOI: 10.1126/sciadv.add3221] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 06/03/2022] [Accepted: 09/22/2022] [Indexed: 06/16/2023]
Abstract
Diabetic wounds have poor healing outcomes due to the presence of numerous pathogens and a dysregulated immune response. Group B Streptococcus (GBS) is commonly isolated from diabetic wound infections, but the mechanisms of GBS virulence during these infections have not been investigated. Here, we develop a murine model of GBS diabetic wound infection and, using dual RNA sequencing, demonstrate that GBS infection triggers an inflammatory response. GBS adapts to this hyperinflammatory environment by up-regulating virulence factors including those known to be regulated by the two-component system covRS, such as the surface protein pbsP, and the cyl operon, which is responsible for hemolysin/pigmentation production. We recover hyperpigmented/hemolytic GBS colonies from the murine diabetic wound, which we determined encode mutations in covR. We further demonstrate that GBS mutants in cylE and pbsP are attenuated in the diabetic wound. This foundational study provides insight into the pathogenesis of GBS diabetic wound infections.
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Affiliation(s)
- Rebecca A. Keogh
- Department of Immunology and Microbiology, University of Colorado Anschutz, Aurora, CO, USA
| | - Amanda L. Haeberle
- Department of Immunology and Microbiology, University of Colorado Anschutz, Aurora, CO, USA
| | | | - Jeffrey S. Kavanaugh
- Department of Immunology and Microbiology, University of Colorado Anschutz, Aurora, CO, USA
| | - Eric P. Schmidt
- Department of Medicine–Pulmonary Sciences and Critical Care, University of Colorado Anschutz, Aurora, CO, USA
| | - Garrett D. Moore
- Department of Orthopedics, University of Colorado, Anschutz Medical Campus, Aurora, CO, USA
| | - Alexander R. Horswill
- Department of Immunology and Microbiology, University of Colorado Anschutz, Aurora, CO, USA
- Department of Veterans Affairs Eastern Colorado Healthcare System, Aurora, CO, USA
| | - Kelly S. Doran
- Department of Immunology and Microbiology, University of Colorado Anschutz, Aurora, CO, USA
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21
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Keith MF, Gopalakrishna KP, Bhavana VH, Hillebrand GH, Elder JL, Megli CJ, Sadovsky Y, Hooven TA. Nitric Oxide Production and Effects in Group B Streptococcus Chorioamnionitis. Pathogens 2022; 11:1115. [PMID: 36297171 PMCID: PMC9608865 DOI: 10.3390/pathogens11101115] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2022] [Revised: 09/21/2022] [Accepted: 09/23/2022] [Indexed: 11/16/2022] Open
Abstract
Intrauterine infection, or chorioamnionitis, due to group B Streptococcus (GBS) is a common cause of miscarriage and preterm birth. To cause chorioamnionitis, GBS must bypass maternal-fetal innate immune defenses including nitric oxide (NO), a microbicidal gas produced by nitric oxide synthases (NOS). This study examined placental NO production and its role in host-pathogen interactions in GBS chorioamnionitis. In a murine model of ascending GBS chorioamnionitis, placental NOS isoform expression quantified by RT-qPCR revealed a four-fold expression increase in inducible NOS, no significant change in expression of endothelial NOS, and decreased expression of neuronal NOS. These NOS expression results were recapitulated ex vivo in freshly collected human placental samples that were co-incubated with GBS. Immunohistochemistry of wild type C57BL/6 murine placentas with GBS chorioamnionitis demonstrated diffuse inducible NOS expression with high-expression foci in the junctional zone and areas of abscess. Pregnancy outcomes between wild type and inducible NOS-deficient mice did not differ significantly although wild type dams had a trend toward more frequent preterm delivery. We also identified possible molecular mechanisms that GBS uses to survive in a NO-rich environment. In vitro exposure of GBS to NO resulted in dose-dependent growth inhibition that varied by serovar. RNA-seq on two GBS strains with distinct NO resistance phenotypes revealed that both GBS strains shared several detoxification pathways that were differentially expressed during NO exposure. These results demonstrate that the placental immune response to GBS chorioamnionitis includes induced NO production and indicate that GBS activates conserved stress pathways in response to NO exposure.
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Affiliation(s)
- Mary Frances Keith
- Department of Pediatrics, Vanderbilt University School of Medicine, Nashville, TN 37232, USA
| | | | | | - Gideon Hayden Hillebrand
- Department of Pediatrics, University of Pittsburgh School of Medicine, Pittsburgh, PA 15224, USA
| | - Jordan Lynn Elder
- Manual Hematology and Coagulation Department, The Cleveland Clinic, Cleveland, OH 44195, USA
| | - Christina Joann Megli
- Department of Obstetrics, Gynecology, and Reproductive Sciences, University of Pittsburgh School of Medicine, Pittsburgh, PA 15213, USA
- UPMC Magee-Womens Research Institute, Pittsburgh, PA 15213, USA
| | - Yoel Sadovsky
- Department of Obstetrics, Gynecology, and Reproductive Sciences, University of Pittsburgh School of Medicine, Pittsburgh, PA 15213, USA
- UPMC Magee-Womens Research Institute, Pittsburgh, PA 15213, USA
| | - Thomas Alexander Hooven
- Department of Pediatrics, University of Pittsburgh School of Medicine, Pittsburgh, PA 15224, USA
- UPMC Magee-Womens Research Institute, Pittsburgh, PA 15213, USA
- UPMC Children’s Hospital of Pittsburgh Richard King Mellon Institute for Pediatric Research, Pittsburgh, PA 15224, USA
- UPMC Children’s Hospital of Pittsburgh, 4401 Penn Ave. Rangos Research Building #8128, Pittsburgh, PA 15224, USA
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22
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Furuta A, Brokaw A, Manuel G, Dacanay M, Marcell L, Seepersaud R, Rajagopal L, Adams Waldorf K. Bacterial and Host Determinants of Group B Streptococcal Infection of the Neonate and Infant. Front Microbiol 2022; 13:820365. [PMID: 35265059 PMCID: PMC8899651 DOI: 10.3389/fmicb.2022.820365] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2021] [Accepted: 01/27/2022] [Indexed: 12/15/2022] Open
Abstract
Group B streptococci (GBS) are Gram-positive β-hemolytic bacteria that can cause serious and life-threatening infections in neonates manifesting as sepsis, pneumonia, meningitis, osteomyelitis, and/or septic arthritis. Invasive GBS infections in neonates in the first week of life are referred to as early-onset disease (EOD) and thought to be acquired by the fetus through exposure to GBS in utero or to vaginal fluids during birth. Late-onset disease (LOD) refers to invasive GBS infections between 7 and 89 days of life. LOD transmission routes are incompletely understood, but may include breast milk, household contacts, nosocomial, or community sources. Invasive GBS infections and particularly meningitis may result in significant neurodevelopmental injury and long-term disability that persists into childhood and adulthood. Globally, EOD and LOD occur in more than 300,000 neonates and infants annually, resulting in 90,000 infant deaths and leaving more than 10,000 infants with a lifelong disability. In this review, we discuss the clinical impact of invasive GBS neonatal infections and then summarize virulence and host factors that allow the bacteria to exploit the developing neonatal immune system and target organs. Specifically, we consider the mechanisms known to enable GBS invasion into the neonatal lung, blood vessels and brain. Understanding mechanisms of GBS invasion and pathogenesis relevant to infections in the neonate and infant may inform the development of therapeutics to prevent or mitigate injury, as well as improve risk stratification.
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Affiliation(s)
- Anna Furuta
- Center for Global Infectious Disease Research, Seattle Children's Research Institute, Seattle, WA, United States.,Department of Global Health, University of Washington, Seattle, WA, United States
| | - Alyssa Brokaw
- Center for Global Infectious Disease Research, Seattle Children's Research Institute, Seattle, WA, United States.,Department of Global Health, University of Washington, Seattle, WA, United States
| | - Gygeria Manuel
- Morehouse School of Medicine, Atlanta, GA, United States
| | - Matthew Dacanay
- Department of Obstetrics & Gynecology, University of Washington, Seattle, WA, United States
| | - Lauren Marcell
- Department of Obstetrics & Gynecology, University of Washington, Seattle, WA, United States
| | - Ravin Seepersaud
- Center for Global Infectious Disease Research, Seattle Children's Research Institute, Seattle, WA, United States
| | - Lakshmi Rajagopal
- Center for Global Infectious Disease Research, Seattle Children's Research Institute, Seattle, WA, United States.,Department of Global Health, University of Washington, Seattle, WA, United States.,Department of Pediatrics, University of Washington, Seattle, WA, United States
| | - Kristina Adams Waldorf
- Department of Global Health, University of Washington, Seattle, WA, United States.,Department of Obstetrics & Gynecology, University of Washington, Seattle, WA, United States.,Department of Obstetrics and Gynecology, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
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23
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Perry EK, Meirelles LA, Newman DK. From the soil to the clinic: the impact of microbial secondary metabolites on antibiotic tolerance and resistance. Nat Rev Microbiol 2022; 20:129-142. [PMID: 34531577 PMCID: PMC8857043 DOI: 10.1038/s41579-021-00620-w] [Citation(s) in RCA: 37] [Impact Index Per Article: 18.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/02/2021] [Indexed: 02/08/2023]
Abstract
Secondary metabolites profoundly affect microbial physiology, metabolism and stress responses. Increasing evidence suggests that these molecules can modulate microbial susceptibility to commonly used antibiotics; however, secondary metabolites are typically excluded from standard antimicrobial susceptibility assays. This may in part account for why infections by diverse opportunistic bacteria that produce secondary metabolites often exhibit discrepancies between clinical antimicrobial susceptibility testing results and clinical treatment outcomes. In this Review, we explore which types of secondary metabolite alter antimicrobial susceptibility, as well as how and why this phenomenon occurs. We discuss examples of molecules that opportunistic and enteric pathogens either generate themselves or are exposed to from their neighbours, and the nuanced impacts these molecules can have on tolerance and resistance to certain antibiotics.
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Affiliation(s)
- Elena K Perry
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA, USA
| | - Lucas A Meirelles
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA, USA
| | - Dianne K Newman
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA, USA.
- Division of Geological and Planetary Sciences, California Institute of Technology, Pasadena, CA, USA.
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24
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Shahi I, Llaneras CN, Perelman SS, Torres VJ, Ratner AJ. Genome-Wide CRISPR-Cas9 Screen Does Not Identify Host Factors Modulating Streptococcus agalactiae β-Hemolysin/Cytolysin-Induced Cell Death. Microbiol Spectr 2022; 10:e0218621. [PMID: 35196804 PMCID: PMC8865549 DOI: 10.1128/spectrum.02186-21] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2021] [Accepted: 01/07/2022] [Indexed: 11/20/2022] Open
Abstract
Pore-forming toxins (PFTs) are commonly produced by pathogenic bacteria, and understanding them is key to the development of virulence-targeted therapies. Streptococcus agalactiae, or group B Streptococcus (GBS), produces several factors that enhance its pathogenicity, including the PFT β-hemolysin/cytolysin (βhc). Little is understood about the cellular factors involved in βhc pore formation. We conducted a whole-genome CRISPR-Cas9 forward genetic screen to identify host genes that might contribute to βhc pore formation and cell death. While the screen identified the established receptor, CD59, in control experiments using the toxin intermedilysin (ILY), no clear candidate genes were identified that were required for βhc-mediated lethality. Of the top targets from the screen, two genes involved in membrane remodeling and repair represented candidates that might modulate the kinetics of βhc-induced cell death. Upon attempted validation of the results using monoclonal cell lines with targeted disruption of these genes, no effect on βhc-mediated cell lysis was observed. The CRISPR-Cas9 screen results are consistent with the hypothesis that βhc does not require a single nonessential host factor to mediate target cell death. IMPORTANCE CRISPR-Cas9 forward genetic screens have been used to identify host cell targets required by bacterial toxins. They have been used successfully to both verify known targets and elucidate novel host factors required by toxins. Here, we show that this approach fails to identify host factors required for cell death due to βhc, a toxin required for GBS virulence. These data suggest that βhc may not require a host cell receptor for toxin function or may require a host receptor that is an essential gene and would not be identified using this screening strategy.
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Affiliation(s)
- Ifrah Shahi
- Department of Microbiology, New York University Grossman School of Medicine, New York, New York, USA
| | - Cristina N. Llaneras
- Department of Microbiology, New York University Grossman School of Medicine, New York, New York, USA
| | - Sofya S. Perelman
- Department of Microbiology, New York University Grossman School of Medicine, New York, New York, USA
| | - Victor J. Torres
- Department of Microbiology, New York University Grossman School of Medicine, New York, New York, USA
- Antimicrobial-Resistant Pathogens Program, New York University Grossman School of Medicine, New York, New York, USA
| | - Adam J. Ratner
- Department of Microbiology, New York University Grossman School of Medicine, New York, New York, USA
- Antimicrobial-Resistant Pathogens Program, New York University Grossman School of Medicine, New York, New York, USA
- Department of Pediatrics, New York University Grossman School of Medicine, New York, New York, USA
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25
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Sun Z, Huang W, Zheng Y, Liu P, Yang W, Guo Z, Kong D, Lv Q, Zhou X, Du Z, Jiang H, Jiang Y. Fpr2/CXCL1/2 Controls Rapid Neutrophil Infiltration to Inhibit Streptococcus agalactiae Infection. Front Immunol 2021; 12:786602. [PMID: 34899755 PMCID: PMC8652123 DOI: 10.3389/fimmu.2021.786602] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2021] [Accepted: 11/05/2021] [Indexed: 11/24/2022] Open
Abstract
Streptococcus agalactiae, also known as group B streptococcus (GBS), can cause pneumonia, meningitis, and bacteremia, making it a pathogen that can increase the risk of death in newborns and immunodeficient individuals. Neutrophils are the first barrier to a host's innate immune defense against these infections. Fpr2(Formyl peptide receptor 2) is an important chemotactic receptor of neutrophils, though its activation would cause pro- and anti-inflammatory effects. In this study, we found that mice without Fpr2 receptor were highly susceptible to GBS infections. These mice demonstrated decreased chemotaxis to neutrophils, decreased bactericidal ability of neutrophils, and high mortality. RNA-seq and Luminex assay indicated that Fpr2 activates key signal molecules downstream and produces chemokines CXCL1/2 to chemotaxis neutrophils. Like Fpr2-/-, CXCL1/2 or neutrophil depletion impairs host's ability to defend against GBS infection. Altogether, these data indicate that Fpr2 contributes to a host's ability to control GBS infection and that a lack of Fpr2 was associated with selective impairment during the production of chemokines CXCL1 and CXCL2 as well as neutrophil recruitment. Here, We clarified that Fpr2, as a chemotactic receptor, could not only directly chemotactic neutrophils, but also regulate the production of chemokines to control infection by chemotactic neutrophils.
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Affiliation(s)
- Zeyu Sun
- State Key Laboratory of Pathogen and Biosecurity, Institute of Microbiology and Epidemiology, Academy of Military Medical Sciences, Beijing, China
| | - Wenhua Huang
- State Key Laboratory of Pathogen and Biosecurity, Institute of Microbiology and Epidemiology, Academy of Military Medical Sciences, Beijing, China
| | - Yuling Zheng
- State Key Laboratory of Pathogen and Biosecurity, Institute of Microbiology and Epidemiology, Academy of Military Medical Sciences, Beijing, China
| | - Peng Liu
- State Key Laboratory of Pathogen and Biosecurity, Institute of Microbiology and Epidemiology, Academy of Military Medical Sciences, Beijing, China
| | - Wenbo Yang
- Changchun University of Chinese Medicine, Changchun, China
| | - Zinan Guo
- State Key Laboratory of Pathogen and Biosecurity, Institute of Microbiology and Epidemiology, Academy of Military Medical Sciences, Beijing, China
| | - Decong Kong
- State Key Laboratory of Pathogen and Biosecurity, Institute of Microbiology and Epidemiology, Academy of Military Medical Sciences, Beijing, China
| | - Qingyu Lv
- State Key Laboratory of Pathogen and Biosecurity, Institute of Microbiology and Epidemiology, Academy of Military Medical Sciences, Beijing, China
| | - Xinyu Zhou
- State Key Laboratory of Pathogen and Biosecurity, Institute of Microbiology and Epidemiology, Academy of Military Medical Sciences, Beijing, China
| | - Zongmin Du
- State Key Laboratory of Pathogen and Biosecurity, Institute of Microbiology and Epidemiology, Academy of Military Medical Sciences, Beijing, China
| | - Hua Jiang
- State Key Laboratory of Pathogen and Biosecurity, Institute of Microbiology and Epidemiology, Academy of Military Medical Sciences, Beijing, China
| | - Yongqiang Jiang
- State Key Laboratory of Pathogen and Biosecurity, Institute of Microbiology and Epidemiology, Academy of Military Medical Sciences, Beijing, China
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26
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Dong Y, Ma K, Cao Q, Huang H, Nie M, Liu G, Jiang M, Lu C, Liu Y. CRISPR-dependent endogenous gene regulation is required for virulence in piscine Streptococcus agalactiae. Emerg Microbes Infect 2021; 10:2113-2124. [PMID: 34727007 PMCID: PMC8592606 DOI: 10.1080/22221751.2021.2002127] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The clustered regularly interspaced palindromic repeats (CRISPR)-Cas (CRISPR-associated) system is a prokaryotic defence against invading mobile genetic elements, such as bacteriophages or exogenous plasmids. Beyond this, this system has been shown to play an important role in controlling the virulence of some bacterial pathogens. Streptococcus agalactiae strain GD201008-001, a causative agent of septicemia and meningitis in tilapia, contains a single type II CRISPR-Cas system with Cas9 as a signature protein. In this study, we found that the deletion of CRISPR significantly reduced adhesion, invasion, cytotoxicity and haemolysis, and caused severely attenuated virulence in the piscine S. agalactiae strain. RNA-Seq identified 236 endogenous genes regulated by CRISPR, with 159 genes upregulated and 77 genes downregulated. The resulting change in gene transcription by CRISPR was much more pronounced than that by cas9 in this bacterium, indicating CRISPR-mediated endogenous gene regulation was mostly independently of cas9. Subsequent studies showed that CovR/S two-component system was transcriptionally upregulated due to CRISPR deletion, which repressed the expression of the cylE gene coding for a cytolytic toxin, and thus decreased the activity of β-haemolysin/cytolysin. However, upregulation of CovR/S was not the contributor to the attenuation phenotype of ΔCRISPR. Further, we demonstrated that CRISPR is capable of repressing the expression of Toll-like receptor 2 (TLR2)-activating lipoprotein Sag0671 and thus dampens the innate immune response. This study revealed that the CRISPR system of S. agalactiae exhibited extraordinary potential capability in the regulation of endogenous transcripts, which contributes to bacterial innate immune evasion and virulence.
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Affiliation(s)
- Yuhao Dong
- Joint International Research Laboratory of Animal Health and Food Safety, College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, People's Republic of China
| | - Ke Ma
- Joint International Research Laboratory of Animal Health and Food Safety, College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, People's Republic of China
| | - Qing Cao
- Joint International Research Laboratory of Animal Health and Food Safety, College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, People's Republic of China
| | - Hao Huang
- Joint International Research Laboratory of Animal Health and Food Safety, College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, People's Republic of China
| | - Meng Nie
- Joint International Research Laboratory of Animal Health and Food Safety, College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, People's Republic of China
| | - Guangjin Liu
- Joint International Research Laboratory of Animal Health and Food Safety, College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, People's Republic of China
| | - Mingguo Jiang
- Guangxi Key Laboratory for Polysaccharide Materials and Modifications, School of Marine Sciences and Biotechnology, Guangxi University for Nationalities, Nanning, People's Republic of China
| | - Chengping Lu
- Joint International Research Laboratory of Animal Health and Food Safety, College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, People's Republic of China
| | - Yongjie Liu
- Joint International Research Laboratory of Animal Health and Food Safety, College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, People's Republic of China
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27
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Campeau A, Uchiyama S, Sanchez C, Sauceda C, Nizet V, Gonzalez DJ. The S Protein of Group B Streptococcus Is a Critical Virulence Determinant That Impacts the Cell Surface Virulome. Front Microbiol 2021; 12:729308. [PMID: 34721327 PMCID: PMC8551713 DOI: 10.3389/fmicb.2021.729308] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2021] [Accepted: 09/13/2021] [Indexed: 11/14/2022] Open
Abstract
Group B Streptococcus (GBS, S. agalactiae) is a human commensal and occasional pathogen that remains a leading cause of neonatal sepsis and meningitis with increasing disease burden in adult populations. Although programs for universal screening in pregnancy to guide intrapartum prophylaxis have reduced GBS invasive disease burden resulting from mother-to-newborn transfer during birth, better knowledge of disease mechanisms may elucidate new strategies to reduce antibiotic exposure. In our efforts to expand the knowledge base required for targeted anti-virulence therapies, we identified a GBS homolog for a recently identified virulence determinant of group A Streptococcus, S protein, and evaluated its role in GBS pathogenesis. A GBS S protein deletion mutant, Δess, showed altered cell-surface properties compared to the WT parent strain, including defective retention of its surface polysaccharide. Quantitative proteome analysis of enzymatically shaved surface epitopes of the GBS Δess mutant revealed a dysregulated cell surface virulome, with reduced abundance of several protein and glycoprotein components. The Δess mutant showed markedly attenuated virulence in a murine model of GBS systemic infection, with increased proteasome activity detected in the spleens of animals infected with the Δess mutant. These results expand the key roles S protein plays in streptococcal pathogenesis and introduces a new GBS virulence determinant and potential target for therapy development.
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Affiliation(s)
- Anaamika Campeau
- Department of Pharmacology, University of California San Diego, La Jolla, CA, United States.,Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California San Diego, La Jolla, CA, United States.,Center for Microbiome Innovation, University of California San Diego, La Jolla, CA, United States
| | - Satoshi Uchiyama
- Department of Pediatrics, University of California San Diego, La Jolla, CA, United States
| | - Concepcion Sanchez
- Department of Pharmacology, University of California San Diego, La Jolla, CA, United States.,Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California San Diego, La Jolla, CA, United States.,Center for Microbiome Innovation, University of California San Diego, La Jolla, CA, United States
| | - Consuelo Sauceda
- Department of Pharmacology, University of California San Diego, La Jolla, CA, United States.,Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California San Diego, La Jolla, CA, United States.,Center for Microbiome Innovation, University of California San Diego, La Jolla, CA, United States
| | - Victor Nizet
- Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California San Diego, La Jolla, CA, United States.,Center for Microbiome Innovation, University of California San Diego, La Jolla, CA, United States.,Department of Pediatrics, University of California San Diego, La Jolla, CA, United States
| | - David J Gonzalez
- Department of Pharmacology, University of California San Diego, La Jolla, CA, United States.,Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California San Diego, La Jolla, CA, United States.,Center for Microbiome Innovation, University of California San Diego, La Jolla, CA, United States
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28
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Avalos M, Garbeva P, Vader L, van Wezel GP, Dickschat JS, Ulanova D. Biosynthesis, evolution and ecology of microbial terpenoids. Nat Prod Rep 2021; 39:249-272. [PMID: 34612321 DOI: 10.1039/d1np00047k] [Citation(s) in RCA: 45] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Covering: through June 2021Terpenoids are the largest class of natural products recognised to date. While mostly known to humans as bioactive plant metabolites and part of essential oils, structurally diverse terpenoids are increasingly reported to be produced by microorganisms. For many of the compounds biological functions are yet unknown, but during the past years significant insights have been obtained for the role of terpenoids in microbial chemical ecology. Their functions include stress alleviation, maintenance of cell membrane integrity, photoprotection, attraction or repulsion of organisms, host growth promotion and defense. In this review we discuss the current knowledge of the biosynthesis and evolution of microbial terpenoids, and their ecological and biological roles in aquatic and terrestrial environments. Perspectives on their biotechnological applications, knowledge gaps and questions for future studies are discussed.
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Affiliation(s)
- Mariana Avalos
- Institute of Biology, Leiden University, Sylviusweg 72, 2333 BE Leiden, The Netherlands. .,Department of Microbial Ecology, Netherlands Institute of Ecology (NIOO-KNAW), Droevendaalsesteeg 10, 6708 PB Wageningen, The Netherlands
| | - Paolina Garbeva
- Department of Microbial Ecology, Netherlands Institute of Ecology (NIOO-KNAW), Droevendaalsesteeg 10, 6708 PB Wageningen, The Netherlands
| | - Lisa Vader
- Institute of Biology, Leiden University, Sylviusweg 72, 2333 BE Leiden, The Netherlands.
| | - Gilles P van Wezel
- Institute of Biology, Leiden University, Sylviusweg 72, 2333 BE Leiden, The Netherlands. .,Department of Microbial Ecology, Netherlands Institute of Ecology (NIOO-KNAW), Droevendaalsesteeg 10, 6708 PB Wageningen, The Netherlands
| | - Jeroen S Dickschat
- Department of Microbial Ecology, Netherlands Institute of Ecology (NIOO-KNAW), Droevendaalsesteeg 10, 6708 PB Wageningen, The Netherlands.,University of Bonn, Kekulé-Institute of Organic Chemistry and Biochemistry, Gerhard-Domagk-Straße 1, 53121 Bonn, Germany
| | - Dana Ulanova
- Faculty of Agriculture and Marine Science, Kochi University, 200 Otsu, Monobe, Nankoku, Kochi 783-8502, Japan.
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29
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Brokaw A, Furuta A, Dacanay M, Rajagopal L, Adams Waldorf KM. Bacterial and Host Determinants of Group B Streptococcal Vaginal Colonization and Ascending Infection in Pregnancy. Front Cell Infect Microbiol 2021; 11:720789. [PMID: 34540718 PMCID: PMC8446444 DOI: 10.3389/fcimb.2021.720789] [Citation(s) in RCA: 30] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2021] [Accepted: 08/09/2021] [Indexed: 12/17/2022] Open
Abstract
Group B streptococcus (GBS) is a gram-positive bacteria that asymptomatically colonizes the vaginal tract. However, during pregnancy maternal GBS colonization greatly predisposes the mother and baby to a wide range of adverse outcomes, including preterm birth (PTB), stillbirth, and neonatal infection. Although many mechanisms involved in GBS pathogenesis are partially elucidated, there is currently no approved GBS vaccine. The development of a safe and effective vaccine that can be administered during or prior to pregnancy remains a principal objective in the field, because current antibiotic-based therapeutic strategies do not eliminate all cases of invasive GBS infections. Herein, we review our understanding of GBS disease pathogenesis at the maternal-fetal interface with a focus on the bacterial virulence factors and host defenses that modulate the outcome of infection. We follow GBS along its path from an asymptomatic colonizer of the vagina to an invasive pathogen at the maternal-fetal interface, noting factors critical for vaginal colonization, ascending infection, and vertical transmission to the fetus. Finally, at each stage of infection we emphasize important host-pathogen interactions, which, if targeted therapeutically, may help to reduce the global burden of GBS.
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Affiliation(s)
- Alyssa Brokaw
- Center for Global Infectious Disease Research, Seattle Children's Research Institute, Seattle, WA, United States.,Department of Global Health, University of Washington, Seattle, WA, United States
| | - Anna Furuta
- Center for Global Infectious Disease Research, Seattle Children's Research Institute, Seattle, WA, United States.,Department of Global Health, University of Washington, Seattle, WA, United States
| | - Matthew Dacanay
- Department of Obstetrics & Gynecology, University of Washington, Seattle, WA, United States
| | - Lakshmi Rajagopal
- Center for Global Infectious Disease Research, Seattle Children's Research Institute, Seattle, WA, United States.,Department of Global Health, University of Washington, Seattle, WA, United States.,Department of Pediatrics, University of Washington, Seattle, WA, United States
| | - Kristina M Adams Waldorf
- Department of Global Health, University of Washington, Seattle, WA, United States.,Department of Obstetrics & Gynecology, University of Washington, Seattle, WA, United States.,Department of Obstetrics and Gynecology, University of Washington and Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
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30
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NAD+ pool depletion as a signal for the Rex regulon involved in Streptococcus agalactiae virulence. PLoS Pathog 2021; 17:e1009791. [PMID: 34370789 PMCID: PMC8376106 DOI: 10.1371/journal.ppat.1009791] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2020] [Revised: 08/19/2021] [Accepted: 07/08/2021] [Indexed: 12/16/2022] Open
Abstract
In many Gram-positive bacteria, the redox-sensing transcriptional repressor Rex controls central carbon and energy metabolism by sensing the intra cellular balance between the reduced and oxidized forms of nicotinamide adenine dinucleotide; the NADH/NAD+ ratio. Here, we report high-resolution crystal structures and characterization of a Rex ortholog (Gbs1167) in the opportunistic pathogen, Streptococcus agalactiae, also known as group B streptococcus (GBS). We present structures of Rex bound to NAD+ and to a DNA operator which are the first structures of a Rex-family member from a pathogenic bacterium. The structures reveal the molecular basis of DNA binding and the conformation alterations between the free NAD+ complex and DNA-bound form of Rex. Transcriptomic analysis revealed that GBS Rex controls not only central metabolism, but also expression of the monocistronic rex gene as well as virulence gene expression. Rex enhances GBS virulence after disseminated infection in mice. Mechanistically, NAD+ stabilizes Rex as a repressor in the absence of NADH. However, GBS Rex is unique compared to Rex regulators previously characterized because of its sensing mechanism: we show that it primarily responds to NAD+ levels (or growth rate) rather than to the NADH/NAD+ ratio. These results indicate that Rex plays a key role in GBS pathogenicity by modulating virulence factor gene expression and carbon metabolism to harvest nutrients from the host.
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31
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Identification of essential genes for Escherichia coli aryl polyene biosynthesis and function in biofilm formation. NPJ Biofilms Microbiomes 2021; 7:56. [PMID: 34215744 PMCID: PMC8253772 DOI: 10.1038/s41522-021-00226-3] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2020] [Accepted: 06/16/2021] [Indexed: 01/04/2023] Open
Abstract
Aryl polyenes (APEs) are specialized polyunsaturated carboxylic acids that were identified in silico as the product of the most widespread family of bacterial biosynthetic gene clusters (BGCs). They are present in several Gram-negative host-associated bacteria, including multidrug-resistant human pathogens. Here, we characterize a biological function of APEs, focusing on the BGC from a uropathogenic Escherichia coli (UPEC) strain. We first perform a genetic deletion analysis to identify the essential genes required for APE biosynthesis. Next, we show that APEs function as fitness factors that increase protection from oxidative stress and contribute to biofilm formation. Together, our study highlights key steps in the APE biosynthesis pathway that can be explored as potential drug targets for complementary strategies to reduce fitness and prevent biofilm formation of multi-drug resistant pathogens.
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32
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Dammann AN, Chamby AB, Catomeris AJ, Davidson KM, Tettelin H, van Pijkeren JP, Gopalakrishna KP, Keith MF, Elder JL, Ratner AJ, Hooven TA. Genome-Wide fitness analysis of group B Streptococcus in human amniotic fluid reveals a transcription factor that controls multiple virulence traits. PLoS Pathog 2021; 17:e1009116. [PMID: 33684178 PMCID: PMC7971860 DOI: 10.1371/journal.ppat.1009116] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2020] [Revised: 03/18/2021] [Accepted: 02/18/2021] [Indexed: 02/06/2023] Open
Abstract
Streptococcus agalactiae (group B Streptococcus; GBS) remains a dominant cause of serious neonatal infections. One aspect of GBS that renders it particularly virulent during the perinatal period is its ability to invade the chorioamniotic membranes and persist in amniotic fluid, which is nutritionally deplete and rich in fetal immunologic factors such as antimicrobial peptides. We used next-generation sequencing of transposon-genome junctions (Tn-seq) to identify five GBS genes that promote survival in the presence of human amniotic fluid. We confirmed our Tn-seq findings using a novel CRISPR inhibition (CRISPRi) gene expression knockdown system. This analysis showed that one gene, which encodes a GntR-class transcription factor that we named MrvR, conferred a significant fitness benefit to GBS in amniotic fluid. We generated an isogenic targeted deletion of the mrvR gene, which had a growth defect in amniotic fluid relative to the wild type parent strain. The mrvR deletion strain also showed a significant biofilm defect in vitro. Subsequent in vivo studies showed that while the mutant was able to cause persistent murine vaginal colonization, pregnant mice colonized with the mrvR deletion strain did not develop preterm labor despite consistent GBS invasion of the uterus and the fetoplacental units. In contrast, pregnant mice colonized with wild type GBS consistently deliver prematurely. In a sepsis model the mrvR deletion strain showed significantly decreased lethality. In order to better understand the mechanism by which this newly identified transcription factor controls GBS virulence, we performed RNA-seq on wild type and mrvR deletion GBS strains, which revealed that the transcription factor affects expression of a wide range of genes across the GBS chromosome. Nucleotide biosynthesis and salvage pathways were highly represented among the set of differentially expressed genes, suggesting that MrvR may be involved in regulating nucleotide availability. Group B Streptococcus (GBS) is a species of Gram-positive bacteria that often colonizes the healthy adult intestinal and reproductive tracts without causing serious symptoms. During pregnancy, however, GBS can invade the pregnant uterus, where it can cause infection of the placenta, fetal membranes, and fetus—a condition known as chorioamnionitis. Chorioamnionitis is associated with serious adverse pregnancy outcomes, including stillbirth, preterm labor, and severe infection of the newborn. GBS can survive in human amniotic fluid, which is low in bacterial nutrients and contains immune molecules that limit microbial persistence, and this ability likely contributes to GBS chorioamnionitis. This study is focused on a single GBS gene that encodes a genetic regulator we called MrvR, which we show is important for GBS resistance to human amniotic fluid. Using a series of genetic techniques combined with animal models of GBS colonization and infection, we show that MrvR also plays a key role in allowing GBS to invade the bloodstream and trigger the inflammatory responses that lead to preterm labor and stillbirth. The study concludes with a survey of other GBS genes whose activity is regulated by MrvR, which seems to be an important contributor to GBS virulence.
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Affiliation(s)
- Allison N. Dammann
- Department of Pediatrics, New York University School of Medicine, New York, New York, United States of America
| | - Anna B. Chamby
- University of Vermont Larner College of Medicine, Burlington, Vermont, United States of America
| | - Andrew J. Catomeris
- Georgetown University School of Medicine, Washington, District of Columbia, United States of America
| | - Kyle M. Davidson
- Department of Pediatrics, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, United States of America
| | - Hervé Tettelin
- Department of Microbiology and Immunology, University of Maryland School of Medicine, Baltimore, Maryland, United States of America
- Institute for Genome Sciences, University of Maryland School of Medicine, Baltimore, Maryland, United States of America
| | - Jan-Peter van Pijkeren
- Department of Food Science, University of Wisconsin, Madison, Wisconsin, United States of America
| | - Kathyayini P. Gopalakrishna
- Department of Pediatrics, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, United States of America
| | - Mary F. Keith
- Department of Pediatrics, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, United States of America
| | - Jordan L. Elder
- Department of Pediatrics, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, United States of America
| | - Adam J. Ratner
- Department of Pediatrics, New York University School of Medicine, New York, New York, United States of America
- Department of Microbiology, New York University, New York, New York, United States of America
| | - Thomas A. Hooven
- Department of Pediatrics, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, United States of America
- Richard King Mellon Institute for Pediatric Research, UPMC Children’s Hospital of Pittsburgh, Pittsburgh, Pennsylvania, United States of America
- * E-mail:
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33
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Bonavita R, Laukkanen MO. Common Signal Transduction Molecules Activated by Bacterial Entry into a Host Cell and by Reactive Oxygen Species. Antioxid Redox Signal 2021; 34:486-503. [PMID: 32600071 DOI: 10.1089/ars.2019.7968] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Significance: An increasing number of pathogens are acquiring resistance to antibiotics. Efficient antimicrobial drug regimens are important even for the most advanced therapies, which range from cutting-edge invasive clinical protocols, such as robotic surgeries, to the treatment of harmless bacterial diseases and to minor scratches to the skin. Therefore, there is an urgent need to survey alternative antimicrobial drugs that can reinforce or replace existing antibiotics. Recent Advances: Bacterial proteins that are critical for energy metabolism, promising novel anticancer thiourea derivatives, and the use of synthetic molecules that increase the sensitivity of currently used antibiotics are among the recently discovered antimicrobial drugs. Critical Issues: In the development of new drugs, serious consideration should be given to the previous bacterial evolutionary selection caused by antibiotics, by the high proliferation rate of bacteria, and by the simple prokaryotic structure of bacteria. Future Directions: The survey of drug targets has mainly focused on bacterial proteins, although host signaling molecules involved in the treatment of various pathologies may have unknown antimicrobial characteristics. Recent data have suggested that small molecule inhibitors might enhance the effect of antibiotics, for example, by limiting bacterial entry into host cells. Phagocytosis, the mechanism by which host cells internalize pathogens through β-actin cytoskeletal rearrangement, induces calcium signaling, small GTPase activation, and phosphorylation of the phosphatidylinositol 3-kinase-serine/threonine-specific protein kinase B pathway. Antioxid. Redox Signal. 34, 486-503.
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Affiliation(s)
- Raffaella Bonavita
- Experimental Institute of Endocrinology and Oncology G. Salvatore, IEOS CNR, Naples, Italy
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Jusuf S, Dong PT, Hui J, Ulloa ER, Liu GY, Cheng JX. Granadaene Photobleaching Reduces the Virulence and Increases Antimicrobial Susceptibility of Streptococcus agalactiae. Photochem Photobiol 2021; 97:816-825. [PMID: 33502005 DOI: 10.1111/php.13389] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2020] [Accepted: 01/20/2021] [Indexed: 12/14/2022]
Abstract
Streptococcus agalactiae, also known as Group B Streptococcus (GBS), is increasingly recognized as a major cause of soft tissue and invasive diseases in the elderly and diabetic populations. Antibiotics like penicillin are used with great frequency to treat these infections, although antimicrobial resistance is increasing among GBS strains and underlines a need for alternative methods not reliant on traditional antibiotics. GBS granadaene pigment is related to the hemolysin/cytolysin of GBS, which is critical for the pathogenesis of GBS diseases. Here, we show that photobleaching granadaene dampens the hemolytic activity of GBS. Furthermore, photobleaching of this antioxidant was found to increase GBS susceptibility to killing by reactive oxygen species like hydrogen peroxide. Treatment with light was also shown to affect GBS membrane permeability and contribute to increased susceptibility to the cell membrane-targeting antibiotic daptomycin. Overall, our study demonstrates dual effects of photobleaching on the virulence and antimicrobial susceptibility of GBS and suggests a novel approach for the treatment of GBS infection.
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Affiliation(s)
- Sebastian Jusuf
- Department of Biomedical Engineering, Boston University, Boston, MA
| | - Pu-Ting Dong
- Department of Chemistry, Boston University, Boston, MA
| | - Jie Hui
- Department of Electrical & Computer Engineering, Boston University, Boston, MA
| | - Erlinda R Ulloa
- Department of Pediatrics, University of California Irvine School of Medicine, Irvine, CA
| | - George Y Liu
- Division of Pediatric Infectious Diseases, University of California San Diego School of Medicine, La Jolla, CA
| | - Ji-Xin Cheng
- Department of Biomedical Engineering, Boston University, Boston, MA.,Department of Chemistry, Boston University, Boston, MA.,Department of Electrical & Computer Engineering, Boston University, Boston, MA.,Photonics Center, Boston University, Boston, MA
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Saeed K, Sendi P, Arnold WV, Bauer TW, Coraça-Huber DC, Chen AF, Choe H, Daiss JL, Ghert M, Hickok NJ, Nishitani K, Springer BD, Stoodley P, Sculco TP, Brause BD, Parvizi J, McLaren AC, Schwarz EM. Bacterial toxins in musculoskeletal infections. J Orthop Res 2021; 39:240-250. [PMID: 32255540 PMCID: PMC7541548 DOI: 10.1002/jor.24683] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/20/2019] [Revised: 02/27/2020] [Accepted: 04/01/2020] [Indexed: 02/04/2023]
Abstract
Musculoskeletal infections (MSKIs) remain a major health burden in orthopaedics. Bacterial toxins are foundational to pathogenesis in MSKI, but poorly understood by the community of providers that care for patients with MSKI, inducing an international group of microbiologists, infectious diseases specialists, orthopaedic surgeons and biofilm scientists to review the literature in this field to identify key topics and compile the current knowledge on the role of toxins in MSKI, with the goal of illuminating potential impact on biofilm formation and dispersal as well as therapeutic strategies. The group concluded that further research is needed to maximize our understanding of the effect of toxins on MSKIs, including: (i) further research to identify the roles of bacterial toxins in MSKIs, (ii) establish the understanding of the importance of environmental and host factors and in vivo expression of toxins throughout the course of an infection, (iii) establish the principles of drug-ability of antitoxins as antimicrobial agents in MSKIs, (iv) have well-defined metrics of success for antitoxins as antiinfective drugs, (v) design a cocktail of antitoxins against specific pathogens to (a) inhibit biofilm formation and (b) inhibit toxin release. The applicability of antitoxins as potential antimicrobials in the era of rising antibiotic resistance could meet the needs of day-to-day clinicians.
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Affiliation(s)
- Kordo Saeed
- University Hospital Southampton NHS Foundation Trust, Department of Microbiology, Microbiology Innovation and Research Unit (MIRU), Southampton, UK; and University of Southampton, School of Medicine, Southampton UK
| | - Parham Sendi
- Institute for Infectious Diseases, University of Bern, Bern, Switzerland
- Department of Infectious Diseases and Hospital Epidemiology/ Department of Orthopaedics and Traumatology, University Hospital Basel, University Basel, Basel, Switzerland
| | - William V. Arnold
- Department of Orthopaedic Surgery, Rothman Institute at Thomas Jefferson University Hospital, Philadelphia, PA, USA
| | - Thomas W. Bauer
- Department of Pathology and Laboratory Medicine, Weill Cornell Medical College, Hospital for Special Surgery, New York, NY, USA
| | - Débora C. Coraça-Huber
- Research Laboratory for Implant Associated Infections (Biofilm Lab), Experimental Orthopaedics, Department of Orthopaedic Surgery, Medical University of Innsbruck, Innsbruck, Austria
| | - Antonia F. Chen
- Department of Orthopaedic Surgery, Brigham and Women’s Hospital, Harvard Medical School, Boston, MA, USA
| | - Hyonmin Choe
- Department of Orthopaedic Surgery, Yokohama City University, Yokohama, Kanagawa, Japan
| | - John L. Daiss
- Center for Musculoskeletal Research, School of Medicine and Dentistry University of Rochester, Rochester, NY, USA
| | - Michelle Ghert
- Department of Surgery, Division of Orthopaedic Surgery, McMaster University, Hamilton, ON, Canada
| | - Noreen J. Hickok
- Department of Orthopaedic Surgery, Sidney Kimmel Medical College of Thomas Jefferson University, Philadelphia, PA, USA
| | - Kohei Nishitani
- Department of Orthopaedic Surgery, Kyoto University, Kyoto, Japan
| | - Bryan D. Springer
- OrthoCarolina Hip and Knee Center, Atrium Musculoskeletal Institute, Charlotte, NC, USA
| | - Paul Stoodley
- Departments of Microbial Infection and Immunity and OrthopedicsInfectious Diseases Institute, The Ohio State University, 716 Biomedical Research Tower, 460 West 12th Avenue, Columbus OH, Canada
- National Centre for Microbial Tribology at Southampton (nCATS), National Biofilm Innovation Centre (NBIC), Mechanical Engineering, University of Southampton, Southampton, UK.
| | - Thomas P. Sculco
- Department of Orthopaedic Surgery, Weill Cornell Medicine, Hospital for Special Surgery, New York, NY, USA
| | - Barry D. Brause
- Department of Infectious Diseases, Weill Cornell Medicine, Hospital for Special Surgery, New York, NY, USA
| | - Javad Parvizi
- Department of Orthopaedics, Rothman Institute at Thomas Jefferson University Hospital, Philadelphia, PA, USA
| | - Alex C. McLaren
- Department of Orthopaedic Surgery, University of Arizona, College of Medicine-Phoenix, Phoenix, AZ, USA
| | - Edward M. Schwarz
- Center for Musculoskeletal Research, Department of Orthopaedics, University of Rochester, Rochester, NY, USA
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Pieranski M, Sitkiewicz I, Grinholc M. Increased photoinactivation stress tolerance of Streptococcus agalactiae upon consecutive sublethal phototreatments. Free Radic Biol Med 2020; 160:657-669. [PMID: 32916279 DOI: 10.1016/j.freeradbiomed.2020.09.003] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/03/2020] [Revised: 08/24/2020] [Accepted: 09/02/2020] [Indexed: 02/08/2023]
Abstract
Streptococcus agalactiae (Group B Streptococcus, GBS) is a common commensal bacterium in adults but remains a leading source of invasive infections in newborns, pregnant women, and the elderly, and more recently, causes an increased incidence of invasive disease in nonpregnant adults. Reduced penicillin susceptibility and emerging resistance to non-β-lactams pose challenges for the development and implementation of novel, nonantimicrobial strategies to reduce the burden of GBS infections. Antimicrobial photodynamic inactivation (aPDI) via the production of singlet oxygen or other reactive oxygen species leads to the successful eradication of pathogenic bacteria, affecting numerous cellular targets of microbial pathogens and indicating a low risk of resistance development. Nevertheless, we have previously reported possible aPDI tolerance development upon repeated sublethal aPDI applications; thus, the current work was aimed at investigating whether aPDI tolerance could be observed for GBS and what mechanisms could cause it. To address this problem, 10 cycles of sublethal aPDI treatments employing rose bengal as a photosensitizer, were applied to the S. agalactiae ATCC 27956 reference strain and two clinical isolates (2306/02 and 2974/07, serotypes III and V, respectively). We demonstrated aPDI tolerance development and stability after 5 cycles of subculturing with no aPDI exposure. Though the treatment resulted in a stable phenotype, no increases in mutation rate or accumulated genetic alterations were observed (employing a RIF-, CIP-, STR-resistant mutant selection assay and cyl sequencing, respectively). qRT-PCR analysis demonstrated that 10 sublethal aPDI exposures led to increased expression of all tested major oxidative stress response elements; changes in sodA, ahpC, npx, cylE, tpx and recA expression indicate possible mechanisms of developed tolerance. Increased expression upon sublethal aPDI treatment was reported for all but two genes, namely, ahpC and cylE. aPDI targeting cylE was further supported by colony morphology changes induced with 10 cycles of aPDI (increased SCV population, increased hemolysis, increased numbers of dark- and unpigmented colonies). In oxidant killing assays, aPDI-tolerant strains demonstrated no increased tolerance to hypochlorite, superoxide (paraquat), singlet oxygen (new methylene blue) or oxidative stress induced by aPDI employing a structurally different photosensitizer, i.e., zinc phthalocyanine, indicating a lack of cross resistance. The results indicate that S. agalactiae may develop stable aPDI tolerance but not resistance when subjected to multiple sublethal phototreatments, and this risk should be considered significant when defining efficient anti-S. agalactiae aPDI protocols.
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Affiliation(s)
- Michal Pieranski
- Intercollegiate Faculty of Biotechnology, Laboratory of Molecular Diagnostics, University of Gdansk and Medical University of Gdansk, Abrahama 58, 80-307, Gdansk, Poland
| | - Izabela Sitkiewicz
- Department of Drug Biotechnology and Bioinformatics, National Medicines Institute, Chelmska 30/34, 00-725, Warszawa, Poland
| | - Mariusz Grinholc
- Intercollegiate Faculty of Biotechnology, Laboratory of Molecular Diagnostics, University of Gdansk and Medical University of Gdansk, Abrahama 58, 80-307, Gdansk, Poland.
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Genetic Basis Underlying the Hyperhemolytic Phenotype of Streptococcus agalactiae Strain CNCTC10/84. J Bacteriol 2020; 202:JB.00504-20. [PMID: 32958630 DOI: 10.1128/jb.00504-20] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2020] [Accepted: 09/11/2020] [Indexed: 01/30/2023] Open
Abstract
Streptococcus agalactiae (group B streptococcus [GBS]) is a major cause of infections in newborns, pregnant women, and immunocompromised patients. GBS strain CNCTC10/84 is a clinical isolate that has high virulence in animal models of infection and has been used extensively to study GBS pathogenesis. Two unusual features of this strain are hyperhemolytic activity and hypo-CAMP factor activity. These two phenotypes are typical of GBS strains that are functionally deficient in the CovR-CovS two-component regulatory system. A previous whole-genome sequencing study found that strain CNCTC10/84 has intact covR and covS regulatory genes. We investigated CovR-CovS regulation in CNCTC10/84 and discovered that a single-nucleotide insertion in a homopolymeric tract in the covR promoter region underlies the strong hemolytic activity and weak CAMP activity of this strain. Using isogenic mutant strains, we demonstrate that this single-nucleotide insertion confers significantly decreased expression of covR and covS and altered expression of CovR-CovS-regulated genes, including that of genes encoding β-hemolysin and CAMP factor. This single-nucleotide insertion also confers significantly increased GBS survival in human whole blood ex vivo IMPORTANCE Group B streptococcus (GBS) is the leading cause of neonatal sepsis, pneumonia, and meningitis. GBS strain CNCTC10/84 is a highly virulent blood isolate that has been used extensively to study GBS pathogenesis for over 20 years. Strain CNCTC10/84 has an unusually strong hemolytic activity, but the genetic basis is unknown. In this study, we discovered that a single-nucleotide insertion in an intergenic homopolymeric tract is responsible for the elevated hemolytic activity of CNCTC10/84.
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Armistead B, Quach P, Snyder JM, Santana-Ufret V, Furuta A, Brokaw A, Rajagopal L. Hemolytic Membrane Vesicles of Group B Streptococcus Promote Infection. J Infect Dis 2020; 223:1488-1496. [PMID: 32861213 DOI: 10.1093/infdis/jiaa548] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2020] [Accepted: 08/25/2020] [Indexed: 01/12/2023] Open
Abstract
BACKGROUND Group B streptococci (GBS) are β-hemolytic, Gram-positive bacteria associated with fetal injury, preterm birth, spontaneous abortion, and neonatal infections. A key factor promoting GBS virulence is the β-hemolysin/cytolysin, a pigmented ornithine rhamnolipid (also known as granadaene) associated with the bacterial surface. METHODS A previous study indicated that GBS produce small structures known as membrane vesicles (MVs), which contain virulence-associated proteins. In this study, we show that GBS MVs are pigmented and hemolytic, indicating that granadaene is functionally active in MVs. RESULTS In addition, MVs from hyperhemolytic GBS induced greater cell death of neutrophils, T cells, and B cells compared with MVs from isogenic nonhemolytic GBS, implicating MVs as a potential mechanism for granadaene-mediated virulence. Finally, hemolytic MVs reduced oxidative killing of GBS and aggravated morbidity and mortality of neonatal mice infected with GBS. CONCLUSIONS These studies, taken together, reveal a novel mechanism by which GBS deploy a crucial virulence factor to promote bacterial dissemination and pathogenesis.
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Affiliation(s)
- Blair Armistead
- Department of Global Health, University of Washington, Seattle, Washington, USA.,Center for Global Infectious Disease Research, Seattle Children's Research Institute, Seattle, Washington, USA
| | - Phoenicia Quach
- Center for Global Infectious Disease Research, Seattle Children's Research Institute, Seattle, Washington, USA
| | - Jessica M Snyder
- Department of Comparative Medicine, University of Washington School of Medicine, Seattle, Washington, USA
| | - Verónica Santana-Ufret
- Center for Global Infectious Disease Research, Seattle Children's Research Institute, Seattle, Washington, USA
| | - Anna Furuta
- Department of Global Health, University of Washington, Seattle, Washington, USA.,Center for Global Infectious Disease Research, Seattle Children's Research Institute, Seattle, Washington, USA
| | - Alyssa Brokaw
- Department of Global Health, University of Washington, Seattle, Washington, USA.,Center for Global Infectious Disease Research, Seattle Children's Research Institute, Seattle, Washington, USA
| | - Lakshmi Rajagopal
- Department of Global Health, University of Washington, Seattle, Washington, USA.,Center for Global Infectious Disease Research, Seattle Children's Research Institute, Seattle, Washington, USA.,Department of Pediatrics, University of Washington School of Medicine, Seattle, Washington, USA
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Hui J, Dong PT, Liang L, Mandal T, Li J, Ulloa ER, Zhan Y, Jusuf S, Zong C, Seleem MN, Liu GY, Cui Q, Cheng JX. Photo-Disassembly of Membrane Microdomains Revives Conventional Antibiotics against MRSA. ADVANCED SCIENCE (WEINHEIM, BADEN-WURTTEMBERG, GERMANY) 2020; 7:1903117. [PMID: 32195102 PMCID: PMC7080515 DOI: 10.1002/advs.201903117] [Citation(s) in RCA: 29] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/03/2019] [Revised: 12/29/2019] [Indexed: 05/21/2023]
Abstract
Confronted with the rapid evolution and dissemination of antibiotic resistance, there is an urgent need to develop alternative treatment strategies for drug-resistant pathogens. Here, an unconventional approach is presented to restore the susceptibility of methicillin-resistant S. aureus (MRSA) to a broad spectrum of conventional antibiotics via photo-disassembly of functional membrane microdomains. The photo-disassembly of microdomains is based on effective photolysis of staphyloxanthin, the golden carotenoid pigment that gives its name. Upon pulsed laser treatment, cell membranes are found severely disorganized and malfunctioned to defense antibiotics, as unveiled by membrane permeabilization, membrane fluidification, and detachment of membrane protein, PBP2a. Consequently, the photolysis approach increases susceptibility and inhibits development of resistance to a broad spectrum of antibiotics including penicillins, quinolones, tetracyclines, aminoglycosides, lipopeptides, and oxazolidinones. The synergistic therapy, without phototoxicity to the host, is effective in combating MRSA both in vitro and in vivo in a mice skin infection model. Collectively, this endogenous chromophore-targeted phototherapy concept paves a novel platform to revive conventional antibiotics to combat drug-resistant S. aureus infections as well as to screen new lead compounds.
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Affiliation(s)
- Jie Hui
- Department of Electrical and Computer Engineering Boston University Boston MA 02215 USA
- Boston University Photonics Center Boston MA 02215 USA
| | - Pu-Ting Dong
- Boston University Photonics Center Boston MA 02215 USA
- Department of Chemistry Boston University Boston MA 02215 USA
| | - Lijia Liang
- Department of Electrical and Computer Engineering Boston University Boston MA 02215 USA
- State Key Laboratory of Supramolecular Structure and Materials Institute of Theoretical Chemistry Jilin University Changchun 130012 China
| | | | - Junjie Li
- Department of Electrical and Computer Engineering Boston University Boston MA 02215 USA
- Boston University Photonics Center Boston MA 02215 USA
| | - Erlinda R Ulloa
- Collaborative to Halt Antibiotic-Resistant Microbes (CHARM) Department of Pediatrics University of California San Diego School of Medicine La Jolla CA 92093 USA
- Division of Infectious Disease Department of Pediatrics Children's Hospital of Philadelphia Philadelphia PA 19104 USA
| | - Yuewei Zhan
- Department Biomedical Engineering Boston University Boston MA 02215 USA
| | - Sebastian Jusuf
- Department Biomedical Engineering Boston University Boston MA 02215 USA
| | - Cheng Zong
- Department of Electrical and Computer Engineering Boston University Boston MA 02215 USA
- Boston University Photonics Center Boston MA 02215 USA
| | - Mohamed N Seleem
- College of Veterinary Medicine Purdue University West Lafayette IN 47907 USA
| | - George Y Liu
- Collaborative to Halt Antibiotic-Resistant Microbes (CHARM) Department of Pediatrics University of California San Diego School of Medicine La Jolla CA 92093 USA
- Division of Infectious Diseases Rady Children's Hospital San Diego CA 92123 USA
| | - Qiang Cui
- Department of Chemistry Boston University Boston MA 02215 USA
- Department Biomedical Engineering Boston University Boston MA 02215 USA
| | - Ji-Xin Cheng
- Department of Electrical and Computer Engineering Boston University Boston MA 02215 USA
- Boston University Photonics Center Boston MA 02215 USA
- Department of Chemistry Boston University Boston MA 02215 USA
- Department Biomedical Engineering Boston University Boston MA 02215 USA
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Tsai CM, Riestra AM, Ali SR, Fong JJ, Liu JZ, Hughes G, Varki A, Nizet V. Siglec-14 Enhances NLRP3-Inflammasome Activation in Macrophages. J Innate Immun 2019; 12:333-343. [PMID: 31805552 PMCID: PMC7383293 DOI: 10.1159/000504323] [Citation(s) in RCA: 30] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2019] [Accepted: 10/23/2019] [Indexed: 12/17/2022] Open
Abstract
Pathogenic microorganisms are sensed by the inflammasome, resulting in the release of the pro-immune and proinflammatory cytokine interleukin-1β (IL-1β). In humans, the paired <underline>s</underline>ialic acid-binding Ig-like lectin receptors Siglec-5 (inhibitory) and Siglec-14 (activating) have been shown to have reciprocal roles in regulating macrophage immune responses, but their interaction with IL-1β signaling and the inflammasome has not been characterized. Here we show that in response to known inflammasome activators (ATP, nigericin) or the sialic acid-expressing human bacterial pathogen group B Streptococcus (GBS), the presence of Siglec-14 enhances, whereas Siglec-5 reduces, inflammasome activation and macrophage IL-1β release. Human THP-1 macrophages stably transfected with Siglec-14 exhibited increased caspase-1 activation, IL-1β release and pyroptosis after GBS infection, in a manner blocked by a specific inhibitor of nucleotide-binding domain leucine-rich repeat protein 3 (NLRP3), a protein involved in inflammasome assembly. Another leading pathogen, Streptococcus pneumoniae, lacks sialic acid but rather prominently expresses a sialidase, which cleaves sialic acid from macrophages, eliminating cis- interactions with the lectin receptor, thus attenuating Siglec-14 induced IL-1β secretion. Vimentin, a cytoskeletal protein released during macrophage inflammatory activation is known to induce the inflammasome. We found that vimentin has increased interaction with Siglec-14 compared to Siglec-5, and this interaction heightened IL-1β production by Siglec-14-expressing cells. Siglec-14 is absent from some humans because of a SIGLEC5/14 fusion polymorphism, and we found increased IL-1β expression in primary macrophages from SIGLEC14+/+ individuals compared to those with the SIGLEC14-/+ and SIGLEC14-/- genotypes. Collectively, our results identify a new immunoregulatory role of Siglec-14 as a positive regulator of NLRP3 inflammasome activation.
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Affiliation(s)
- Chih-Ming Tsai
- Glycobiology Research and Training Center, UC San Diego, La Jolla, California, USA.,Collaborative to Halt Antibiotic-Resistant Microbes, Department of Pediatrics, UC San Diego, La Jolla, California, USA
| | - Angelica M Riestra
- Collaborative to Halt Antibiotic-Resistant Microbes, Department of Pediatrics, UC San Diego, La Jolla, California, USA
| | - Syed Raza Ali
- Glycobiology Research and Training Center, UC San Diego, La Jolla, California, USA.,Collaborative to Halt Antibiotic-Resistant Microbes, Department of Pediatrics, UC San Diego, La Jolla, California, USA
| | - Jerry J Fong
- Glycobiology Research and Training Center, UC San Diego, La Jolla, California, USA.,Department of Cellular and Molecular Medicine, UC San Diego, La Jolla, California, USA
| | - Janet Z Liu
- Glycobiology Research and Training Center, UC San Diego, La Jolla, California, USA.,Collaborative to Halt Antibiotic-Resistant Microbes, Department of Pediatrics, UC San Diego, La Jolla, California, USA
| | - Gillian Hughes
- Collaborative to Halt Antibiotic-Resistant Microbes, Department of Pediatrics, UC San Diego, La Jolla, California, USA
| | - Ajit Varki
- Glycobiology Research and Training Center, UC San Diego, La Jolla, California, USA.,Collaborative to Halt Antibiotic-Resistant Microbes, Department of Pediatrics, UC San Diego, La Jolla, California, USA.,Department of Cellular and Molecular Medicine, UC San Diego, La Jolla, California, USA
| | - Victor Nizet
- Glycobiology Research and Training Center, UC San Diego, La Jolla, California, USA, .,Collaborative to Halt Antibiotic-Resistant Microbes, Department of Pediatrics, UC San Diego, La Jolla, California, USA, .,Department of Cellular and Molecular Medicine, UC San Diego, La Jolla, California, USA, .,Department of Medicine, UC San Diego, La Jolla, California, USA, .,Skaggs School of Pharmacy and Pharmaceutical Sciences, UC San Diego, La Jolla, California, USA,
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Siemens N, Oehmcke-Hecht S, Hoßmann J, Skorka SB, Nijhuis RHT, Ruppen C, Skrede S, Rohde M, Schultz D, Lalk M, Itzek A, Pieper DH, van den Bout CJ, Claas ECJ, Kuijper EJ, Mauritz R, Sendi P, Wunderink HF, Norrby-Teglund A. Prothrombotic and Proinflammatory Activities of the β-Hemolytic Group B Streptococcal Pigment. J Innate Immun 2019; 12:291-303. [PMID: 31743913 DOI: 10.1159/000504002] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2019] [Accepted: 10/06/2019] [Indexed: 12/29/2022] Open
Abstract
A prominent feature of severe streptococcal infections is the profound inflammatory response that contributes to systemic toxicity. In sepsis the dysregulated host response involves both immunological and nonimmunological pathways. Here, we report a fatal case of an immunocompetent healthy female presenting with toxic shock and purpura fulminans caused by group B streptococcus (GBS; serotype III, CC19). The strain (LUMC16) was pigmented and hyperhemolytic. Stimulation of human primary cells with hyperhemolytic LUMC16 and STSS/NF-HH strains and pigment toxin resulted in a release of proinflammatory mediators, including tumor necrosis factor, interleukin (IL)-1β, and IL-6. In addition, LUMC16 induced blood clotting and showed factor XII activity on its surface, which was linked to the presence of the pigment. The expression of pigment was not linked to a mutation within the CovR/S region. In conclusion, our study shows that the hemolytic lipid toxin contributes to the ability of GBS to cause systemic hyperinflammation and interferes with the coagulation system.
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Affiliation(s)
- Nikolai Siemens
- Center for Infectious Medicine, Department of Medicine Huddinge, Karolinska Institutet, Karolinska University Hospital, Huddinge, Sweden, .,Center for Functional Genomics of Microbes, Department of Molecular Genetics and Infection Biology, University of Greifswald, Greifswald, Germany,
| | - Sonja Oehmcke-Hecht
- Institute of Medical Microbiology, Virology, and Hygiene, University Medicine Rostock, Rostock, Germany
| | - Jörn Hoßmann
- Microbial Interactions and Processes, Helmholtz Centre for Infection Research - HZI, Braunschweig, Germany
| | - Sebastian B Skorka
- Center for Functional Genomics of Microbes, Department of Molecular Genetics and Infection Biology, University of Greifswald, Greifswald, Germany
| | - Roel H T Nijhuis
- Department of Medical Microbiology, Leiden University Medical Center, Leiden, The Netherlands.,Department of Medical Microbiology and Medical Immunology, Meander Medical Center, Amersfoort, The Netherlands
| | - Corinne Ruppen
- Institute for Infectious Diseases, University of Bern, Bern, Switzerland
| | - Steinar Skrede
- Department of Medicine, Haukeland University Hospital, Bergen, Norway.,Department of Clinical Science, University of Bergen, Bergen, Norway
| | - Manfred Rohde
- Central Facility for Microscopy, Helmholtz Centre for Infection Research - HZI, Braunschweig, Germany
| | - Daniel Schultz
- Institute of Biochemistry, University of Greifswald, Greifswald, Germany
| | - Michael Lalk
- Institute of Biochemistry, University of Greifswald, Greifswald, Germany
| | - Andreas Itzek
- Microbial Interactions and Processes, Helmholtz Centre for Infection Research - HZI, Braunschweig, Germany
| | - Dietmar H Pieper
- Microbial Interactions and Processes, Helmholtz Centre for Infection Research - HZI, Braunschweig, Germany
| | | | - Eric C J Claas
- Department of Medical Microbiology, Leiden University Medical Center, Leiden, The Netherlands
| | - Ed J Kuijper
- Department of Medical Microbiology, Leiden University Medical Center, Leiden, The Netherlands
| | - Robert Mauritz
- Department of Intensive Care Medicine, Leiden University Medical Center, Leiden, The Netherlands
| | - Parham Sendi
- Institute for Infectious Diseases, University of Bern, Bern, Switzerland
| | - Herman F Wunderink
- Department of Medical Microbiology, Leiden University Medical Center, Leiden, The Netherlands.,Department of Medical Microbiology, University Medical Center Utrecht, Utrecht, The Netherlands
| | - Anna Norrby-Teglund
- Center for Infectious Medicine, Department of Medicine Huddinge, Karolinska Institutet, Karolinska University Hospital, Huddinge, Sweden
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Le Guennec L, Coureuil M, Nassif X, Bourdoulous S. Strategies used by bacterial pathogens to cross the blood-brain barrier. Cell Microbiol 2019; 22:e13132. [PMID: 31658405 DOI: 10.1111/cmi.13132] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2019] [Revised: 10/11/2019] [Accepted: 10/13/2019] [Indexed: 12/15/2022]
Abstract
The skull, spine, meninges, and cellular barriers at the blood-brain and the blood-cerebrospinal fluid interfaces well protect the brain and meningeal spaces against microbial invasion. However, once in the bloodstream, a range of pathogenic bacteria is able to reach the brain and cause meningitis. Despite advances in antibacterial therapy, bacterial meningitis remains one of the most important infectious diseases worldwide. The most common causative bacteria in children and adults are Streptococcus pneumoniae and Neisseria meningitidis associated with high morbidity and mortality, while among neonates, most cases of bacterial meningitis are due to group B Streptococcus and Escherichia coli. Here we summarise our current knowledge on the strategies used by these bacterial pathogens to survive in the bloodstream, to colonise the brain vasculature and to cross the blood-brain barrier.
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Affiliation(s)
- Loic Le Guennec
- Inserm (Institut National de la Sante et de la Recherche Medicale), U1016, Institut Cochin, Paris, France.,CNRS (Centre National de la recherche Scientifique), UMR8104, Paris, France.,Université Paris Descartes, Sorbonne Paris Cité, Paris, France
| | - Mathieu Coureuil
- Inserm (Institut National de la Sante et de la Recherche Medicale), unité U1151, Institut-Necker-Enfants-Malades, Paris, France.,CNRS (Centre National de la recherche Scientifique), UMR 8253, Paris, France.,Université Paris Descartes, Sorbonne Paris Cité, Faculté de médecine, Paris, France
| | - Xavier Nassif
- Inserm (Institut National de la Sante et de la Recherche Medicale), unité U1151, Institut-Necker-Enfants-Malades, Paris, France.,CNRS (Centre National de la recherche Scientifique), UMR 8253, Paris, France.,Université Paris Descartes, Sorbonne Paris Cité, Faculté de médecine, Paris, France.,Assistance Publique - Hôpitaux de Paris, Hôpital Necker Enfants Malades, Paris, France
| | - Sandrine Bourdoulous
- Inserm (Institut National de la Sante et de la Recherche Medicale), U1016, Institut Cochin, Paris, France.,CNRS (Centre National de la recherche Scientifique), UMR8104, Paris, France.,Université Paris Descartes, Sorbonne Paris Cité, Paris, France
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Liu Y, Li L, Huang T, Wu W, Liang W, Chen M. The Interaction between Phagocytes and Streptococcus agalactiae (GBS) Mediated by the Activated Complement System is the Key to GBS Inducing Acute Bacterial Meningitis of Tilapia. Animals (Basel) 2019; 9:ani9100818. [PMID: 31623233 PMCID: PMC6826838 DOI: 10.3390/ani9100818] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2019] [Revised: 10/02/2019] [Accepted: 10/10/2019] [Indexed: 12/14/2022] Open
Abstract
Simple Summary Streptococcus agalactiae (GBS) is a serious threat to farmed tilapia, which results in high mortality and seriously hinders tilapia farming development. The pathogenic mechanism of tilapia infected with GBS which die rapidly in production remains unknown. We provided a comprehensive comparative analysis of the tilapias infected with fish-derived GBS attenuated strain YM001 and its parental virulent strain HN016. The present study indicates that the interaction between phagocytes and GBS mediated by the activated complement system is key to GBS inducing tilapia acute bacterial meningitis. The low survival ability caused by reduced β-lactam antibiotics resistance is one of the important reasons YM001 lost its pathogenicity to tilapia. Our study provided a comprehensive cognition of the mechanism of acute bacterial meningitis caused by GBS. Abstract Streptococcus agalactiae is an important pathogen for tilapia meningitis. Most of the infected tilapia die rapidly in production, when the way to study the pathogenic mechanism of bacteria on host through chronic infection in laboratory is not comprehensive and accurate enough to elucidate the real pathogenic mechanism. The objective of this study was to investigate the mechanism of acute bacterial meningitis of tilapia caused by Streptococcus agalactiae (GBS), and provide a theoretical basis for its prevention and treatment. Duel RNA-seq, proteome analysis, histopathological analysis, plasma biochemical indexes, and blood routine examination were performed on tilapias infected with fish-derived GBS attenuated strain YM001 and its parental virulent strain HN016. The results showed that the contents of white blood cell (WBC), monocytes (MON), and neutrophil (NEU) were significantly lower in the HN016 group compared to that in the YM001 group (p < 0.05). Histopathological examination showed that there were partially lesions in the examined tissues of tilapia infected by HN016, while no obvious histopathological changes occurred in the YM001 group. The differential expressed genes (DEGs) and differential expressed proteins (DEPs) between YM001 and HN016 were mainly enriched in the beta-lactam resistance pathway (oppA1, oppA2, oppB, oppC, oppD, oppF, and mrcA). The DEGs DEPs between YM001-brain and HN016-brain were mainly enriched in the complement and coagulation cascades signaling pathway (C2a, c4b, c3b, c7, CD59, ITGB2, and ITGAX). The present study indicates that the interaction between phagocytes and GBS mediated by the activated complement system is the key to GBS inducing tilapia acute bacterial meningitis. The low survival ability caused by reduced β-lactam antibiotics resistance is one of the important reasons for why YM001 lost its pathogenicity to tilapia.
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Affiliation(s)
- Yu Liu
- Guangxi Academy of Fishery Sciences, Fish diseases control and prevention lab, Qingshan Road NO.8, Nanning 530021, China.
| | - Liping Li
- Guangxi Academy of Fishery Sciences, Fish diseases control and prevention lab, Qingshan Road NO.8, Nanning 530021, China.
| | - Ting Huang
- Guangxi Academy of Fishery Sciences, Fish diseases control and prevention lab, Qingshan Road NO.8, Nanning 530021, China.
| | - Wende Wu
- Guangxi University, Daxuedong Road NO.100, Nanning 530004, China.
| | - Wanwen Liang
- Guangxi Academy of Fishery Sciences, Fish diseases control and prevention lab, Qingshan Road NO.8, Nanning 530021, China.
| | - Ming Chen
- Guangxi Academy of Fishery Sciences, Fish diseases control and prevention lab, Qingshan Road NO.8, Nanning 530021, China.
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Li L, Liu Y, Huang T, Liang W, Chen M. Development of an attenuated oral vaccine strain of tilapia Group B Streptococci serotype Ia by gene knockout technology. FISH & SHELLFISH IMMUNOLOGY 2019; 93:924-933. [PMID: 31374315 DOI: 10.1016/j.fsi.2019.07.081] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/06/2019] [Revised: 07/26/2019] [Accepted: 07/29/2019] [Indexed: 06/10/2023]
Abstract
Our previous studies demonstrated that the deletion of D2 fragment in tilapia Streptococcus agalactiae(GBS) attenuated strain YM001 is the main reason for the loss of virulence to tilapia. In this study, a Δ2 mutant that deletion of D2 fragment in parental virulent strain HN016 was constructed, and the safety, stability, immunogenicity, and growth characteristics, as well as the virulence mechanism of Δ2 mutant were evaluated. The results showed that Δ2 mutant was not pathogenic to tilapia, and the virulent revertants were not observed after 50 generations of passage. The RPS reached 96.11% at 15 days and 93.05% at 30 days, respectively, after intraperitoneal injection, while RPS reached 74.80% at 15 days and 53.16% at 30 days, respectively, after oral immunization. The growth of Δ2 mutant was significantly faster than YM001, and genes that were enriched in the nitrogen metabolism and arginine biosynthesis signaling pathway (arc, glnA, and gdhA) were identified as important candidate genes responsible for growth rate of S. agalactiae. The absence of D2 fragment affected the expression of Sip, therefore influencing the bacterial virulence. Altogether, this study demonstrated that deletion of D2 fragment in HN016 causes the loss of virulence to tilapia, and Δ2 mutant is a promising, better attenuated oral vaccine strain of S. agalactiae compared to YM001.
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Affiliation(s)
- Liping Li
- Guangxi Academy of Fishery Sciences, Qingshan Road NO.8, Nanning, 530021, China
| | - Yu Liu
- Guangxi Academy of Fishery Sciences, Qingshan Road NO.8, Nanning, 530021, China
| | - Ting Huang
- Guangxi Academy of Fishery Sciences, Qingshan Road NO.8, Nanning, 530021, China
| | - Wanwen Liang
- Guangxi Academy of Fishery Sciences, Qingshan Road NO.8, Nanning, 530021, China
| | - Ming Chen
- Guangxi Academy of Fishery Sciences, Qingshan Road NO.8, Nanning, 530021, China.
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Glutathione Synthesis Contributes to Virulence of Streptococcus agalactiae in a Murine Model of Sepsis. J Bacteriol 2019; 201:JB.00367-19. [PMID: 31331978 DOI: 10.1128/jb.00367-19] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2019] [Accepted: 07/10/2019] [Indexed: 01/09/2023] Open
Abstract
Streptococcus agalactiae, a leading cause of sepsis and meningitis in neonates, utilizes multiple virulence factors to survive and thrive within the human host during an infection. Unique among the pathogenic streptococci, S. agalactiae uses a bifunctional enzyme encoded by a single gene (gshAB) to synthesize glutathione (GSH), a major antioxidant in most aerobic organisms. Since S. agalactiae can also import GSH, similar to all other pathogenic streptococcal species, the contribution of GSH synthesis to the pathogenesis of S. agalactiae disease is not known. In the present study, gshAB deletion mutants were generated in strains representing three of the most prevalent clinical serotypes of S. agalactiae and were compared against isogenic wild-type and gshAB knock-in strains. When cultured in vitro in a chemically defined medium under nonstress conditions, each mutant and its corresponding wild type had comparable growth rates, generation times, and growth yields. However, gshAB deletion mutants were found to be more sensitive than wild-type or gshAB knock-in strains to killing and growth inhibition by several different reactive oxygen species. Furthermore, deletion of gshAB in S. agalactiae strain COH1 significantly attenuated virulence compared to the wild-type or gshAB knock-in strains in a mouse model of sepsis. Taken together, these data establish that GSH is a virulence factor important for resistance to oxidative stress and that de novo GSH synthesis plays a crucial role in S. agalactiae pathogenesis and further suggest that the inhibition of GSH synthesis may provide an opportunity for the development of novel therapies targeting S. agalactiae disease.IMPORTANCE Approximately 10 to 30% of women are naturally and asymptomatically colonized by Streptococcus agalactiae However, transmission of S. agalactiae from mother to newborn during vaginal birth is a leading cause of neonatal meningitis. Although colonized mothers who are at risk for transmission to the newborn are treated with antibiotics prior to delivery, S. agalactiae is becoming increasingly resistant to current antibiotic therapies, and new treatments are needed. This research reveals a critical stress resistance pathway, glutathione synthesis, that is utilized by S. agalactiae and contributes to its pathogenesis. Understanding the role of this unique bifunctional glutathione synthesis enzyme in S. agalactiae during sepsis may help elucidate why S. agalactiae produces such an abundance of glutathione compared to other bacteria.
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Marziali G, Foschi C, Parolin C, Vitali B, Marangoni A. In-vitro effect of vaginal lactobacilli against group B Streptococcus. Microb Pathog 2019; 136:103692. [PMID: 31445119 DOI: 10.1016/j.micpath.2019.103692] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2019] [Revised: 07/29/2019] [Accepted: 08/21/2019] [Indexed: 01/31/2023]
Abstract
Streptococcus agalactiae(GBS) is a leading cause of infection during pregnancy, preterm birth and neonatal infection, with a significant clinical and socio-economic impact. To prevent maternal GBS vaginal colonization, new antibiotic-free approaches, based on lactobacilli probiotics, are advisable. The aim of this study was to assess the anti-GBS activity of 14 vaginal Lactobacillus strains, belonging to different species (L. crispatus, L. gasseri, L. vaginalis), isolated from healthy pre-menopausal women. In particular, we performed 'inhibition' experiments, evaluating the ability of both Lactobacillus cells and culture supernatants in reducing Streptococcus viability, after 60 min contact time. First, we demonstrated that the acidic milieu, produced by vaginal lactobacilli metabolism, is crucial in counteracting GBS growth in a pH-dependent manner. Experiments with organic/inorganic acid solutions confirmed the strict correlation between pH levels and the anti-GBS activity. GBS was more sensitive to lactic acid than to hydrochloric acid, indicating that the presence of H+ ions is necessary but not sufficient for the inhibitory activity. Moreover, experiments with Lactobacillus pH-adjusted supernatants led to exclude a direct role in the anti-GBS activity by other bioactive molecules. Second, we found that only a few Lactobacillus strains were able to reduce Streptococcus viability by means of cell pellets. The anti-GBS effect displayed by Lactobacillus cells was related to the their ability to interact and aggregate with Streptococcus cells. We found that the anti-GBS activity was retained after methanol/proteinase K treatment, but lost after lysozyme exposure of Lactobacillus cells. Therefore, we supposed that non-proteinaceous components of Lactobacillus cell wall could be responsible for the anti-GBS activity. In conclusion, we identified specific Lactobacillus strains able to interfere with GBS viability by multiple strategies and we elucidated some of the mechanisms of action. These strains could serve as probiotic formulations for the prevention of GBS vaginal colonization.
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Affiliation(s)
- Giacomo Marziali
- Microbiology, DIMES, University of Bologna, Via Massarenti 9, Bologna, Italy
| | - Claudio Foschi
- Microbiology, DIMES, University of Bologna, Via Massarenti 9, Bologna, Italy.
| | - Carola Parolin
- Department of Pharmacy and Biotechnology, University of Bologna, Via San Donato 19/2, Bologna, Italy
| | - Beatrice Vitali
- Department of Pharmacy and Biotechnology, University of Bologna, Via San Donato 19/2, Bologna, Italy
| | - Antonella Marangoni
- Microbiology, DIMES, University of Bologna, Via Massarenti 9, Bologna, Italy
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Spencer BL, Deng L, Patras KA, Burcham ZM, Sanches GF, Nagao PE, Doran KS. Cas9 Contributes to Group B Streptococcal Colonization and Disease. Front Microbiol 2019; 10:1930. [PMID: 31497003 PMCID: PMC6712506 DOI: 10.3389/fmicb.2019.01930] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2019] [Accepted: 08/05/2019] [Indexed: 12/20/2022] Open
Abstract
Group B Streptococcus (GBS) is a major opportunistic pathogen in certain adult populations, including pregnant women, and remains a leading etiologic agent of newborn disease. During pregnancy, GBS asymptomatically colonizes the vaginal tract of 20-30% of healthy women, but can be transmitted to the neonate in utero or during birth resulting in neonatal pneumonia, sepsis, meningitis, and subsequently 10-15% mortality regardless of antibiotic treatment. While various GBS virulence factors have been implicated in vaginal colonization and invasive disease, the regulation of many of these factors remains unclear. Recently, CRISPR-associated protein-9 (Cas9), an endonuclease known for its role in CRISPR/Cas immunity, has also been observed to modulate virulence in a number of bacterial pathogens. However, the role of Cas9 in GBS colonization and disease pathogenesis has not been well-studied. We performed allelic replacement of cas9 in GBS human clinical isolates of the hypervirulent sequence-type 17 strain lineage to generate isogenic Δcas9 mutants. Compared to parental strains, Δcas9 mutants were attenuated in murine models of hematogenous meningitis and vaginal colonization and exhibited significantly decreased invasion of human brain endothelium and adherence to vaginal epithelium. To determine if Cas9 alters transcription in GBS, we performed RNA-Seq analysis and found that 353 genes (>17% of the GBS genome) were differentially expressed between the parental WT and Δcas9 mutant strain. Significantly dysregulated genes included those encoding predicted virulence factors, metabolic factors, two-component systems (TCS), and factors important for cell wall formation. These findings were confirmed by qRT-PCR and suggest that Cas9 may regulate a significant portion of the GBS genome. We studied one of the TCS regulators, CiaR, that was significantly downregulated in the Δcas9 mutant strain. RNA-Seq analysis of the WT and ΔciaR strains demonstrated that almost all CiaR-regulated genes were also significantly regulated by Cas9, suggesting that Cas9 may modulate GBS gene expression through other regulators. Further we show that CiaR contributes to GBS vaginal colonization and persistence. Altogether, these data highlight the potential complexity and importance of the non-canonical function of Cas9 in GBS colonization and disease.
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Affiliation(s)
- Brady L. Spencer
- Department of Immunology & Microbiology, University of Colorado Anschutz Medical Campus, Aurora, CO, United States
| | - Liwen Deng
- Department of Immunology & Microbiology, University of Colorado Anschutz Medical Campus, Aurora, CO, United States
- Department of Biology, San Diego State University, San Diego, CA, United States
| | - Kathryn A. Patras
- Department of Biology, San Diego State University, San Diego, CA, United States
| | - Zachary M. Burcham
- Department of Animal Sciences, Colorado State University, Fort Collins, CO, United States
| | - Glenda F. Sanches
- Department of Immunology & Microbiology, University of Colorado Anschutz Medical Campus, Aurora, CO, United States
- Roberto Alcântara Gomes Biology Institute, Rio de Janeiro State University, Rio de Janeiro, Brazil
| | - Prescilla E. Nagao
- Roberto Alcântara Gomes Biology Institute, Rio de Janeiro State University, Rio de Janeiro, Brazil
| | - Kelly S. Doran
- Department of Immunology & Microbiology, University of Colorado Anschutz Medical Campus, Aurora, CO, United States
- Department of Biology, San Diego State University, San Diego, CA, United States
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48
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Xue L, Chen YY, Yan Z, Lu W, Wan D, Zhu H. Staphyloxanthin: a potential target for antivirulence therapy. Infect Drug Resist 2019; 12:2151-2160. [PMID: 31410034 PMCID: PMC6647007 DOI: 10.2147/idr.s193649] [Citation(s) in RCA: 49] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2018] [Accepted: 02/13/2019] [Indexed: 12/24/2022] Open
Abstract
Staphylococcus aureus is an important and common Gram-positive bacteria which causes clinical infections and food-poisoning cases. Therapeutic schedules for treatment of S. aureus infections are facing a challenge because of the emergence of multidrug resistance strains. It is urgent to find new antiinfective drugs to control S. aureus infection. S. aureus strains are capable of producing the golden carotenoid pigment: staphyloxanthin, which acts as an important virulence factor and a potential target for antivirulence drug design. This review is aimed at presenting an updated overview of this golden carotenoid pigment of S. aureus from the biosynthesis of staphyloxanthin, its function, and the genes involved in pigment production to staphyloxanthin: a novel target for antivirulence therapy.
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Affiliation(s)
- Lijun Xue
- College of Pharmaceutical Sciences and Traditional Chinese Medicine, Southwest University, Chongqing 400715, People's Republic of China.,College of Pharmaceutical Engineering, Chongqing Chemical Industry Vocational College, Chongqing, 400020, People's Republic of China
| | - Yang Yizhi Chen
- College of Pharmaceutical Sciences and Traditional Chinese Medicine, Southwest University, Chongqing 400715, People's Republic of China
| | - Zhiyun Yan
- Wuhan Wusteel Good Life Service Co. LTD, Wuhan, 430000, People's Republic of China
| | - Wei Lu
- College of Pharmaceutical Sciences and Traditional Chinese Medicine, Southwest University, Chongqing 400715, People's Republic of China
| | - Dong Wan
- Department of Emergency and Critical Care Medicine, The First Affiliated Hospital of Chongqing Medical University, Chongqing, 400016, People's Republic of China
| | - Huifeng Zhu
- College of Pharmaceutical Sciences and Traditional Chinese Medicine, Southwest University, Chongqing 400715, People's Republic of China
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49
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Gendrin C, Merillat S, Vornhagen J, Coleman M, Armistead B, Ngo L, Aggarwal A, Quach P, Berrigan J, Rajagopal L. Diminished Capsule Exacerbates Virulence, Blood-Brain Barrier Penetration, Intracellular Persistence, and Antibiotic Evasion of Hyperhemolytic Group B Streptococci. J Infect Dis 2019; 217:1128-1138. [PMID: 29301010 DOI: 10.1093/infdis/jix684] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2017] [Accepted: 12/28/2017] [Indexed: 12/21/2022] Open
Abstract
Group B streptococci (GBS) are encapsulated, β-hemolytic bacteria that are a common cause of infections in human newborns and certain adults. Two factors important for GBS virulence are the sialic acid capsular polysaccharide that promotes immune evasion and the hemolytic pigment that induces host cell cytotoxcity. These virulence factors are often oppositely regulated by the CovR/CovS two-component system. Clinical GBS strains exhibiting hyperhemolysis and low capsule due to pathoadaptive covR/S mutations have been isolated from patients. Given the importance of capsule to GBS virulence, we predicted that a decrease or loss of capsule would attenuate the virulence of covR/S mutants. Surprisingly, hyperhemolytic GBS with low or no capsule exhibit increased virulence, intracellular persistence, and blood-brain barrier penetration, which was independent of a Trojan horse mechanism of barrier penetration. Additionally, intracellular persistence enabled both hemolytic and hyperhemolytic GBS to evade antibiotics routinely used to treat these infections. The finding that diminished capsule expression promotes GBS virulence, intracellular persistence, and antibiotic evasion has important implications for sustained antibiotic therapy and efficacy of capsule-based vaccines.
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Affiliation(s)
- Claire Gendrin
- Department of Pediatrics, University of Washington.,Center for Global Infections Disease Research, Seattle Children's Research Institute
| | - Sean Merillat
- Center for Global Infections Disease Research, Seattle Children's Research Institute
| | - Jay Vornhagen
- Department of Pediatrics, University of Washington.,Center for Global Infections Disease Research, Seattle Children's Research Institute.,Department of Global Health, University of Washington, Seattle
| | - Michelle Coleman
- Department of Pediatrics, University of Washington.,Center for Global Infections Disease Research, Seattle Children's Research Institute
| | - Blair Armistead
- Department of Pediatrics, University of Washington.,Center for Global Infections Disease Research, Seattle Children's Research Institute.,Department of Global Health, University of Washington, Seattle
| | - Lisa Ngo
- Center for Global Infections Disease Research, Seattle Children's Research Institute
| | - Anjali Aggarwal
- Center for Global Infections Disease Research, Seattle Children's Research Institute
| | - Phoenicia Quach
- Center for Global Infections Disease Research, Seattle Children's Research Institute
| | - Jacob Berrigan
- Center for Global Infections Disease Research, Seattle Children's Research Institute
| | - Lakshmi Rajagopal
- Department of Pediatrics, University of Washington.,Center for Global Infections Disease Research, Seattle Children's Research Institute.,Department of Global Health, University of Washington, Seattle
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50
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Kim BJ, Shusta EV, Doran KS. Past and Current Perspectives in Modeling Bacteria and Blood-Brain Barrier Interactions. Front Microbiol 2019; 10:1336. [PMID: 31263460 PMCID: PMC6585309 DOI: 10.3389/fmicb.2019.01336] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2019] [Accepted: 05/29/2019] [Indexed: 01/18/2023] Open
Abstract
The central nervous system (CNS) barriers are highly specialized cellular barriers that promote brain homeostasis while restricting pathogen and toxin entry. The primary cellular constituent regulating pathogen entry in most of these brain barriers is the brain endothelial cell (BEC) that exhibits properties that allow for tight regulation of CNS entry. Bacterial meningoencephalitis is a serious infection of the CNS and occurs when bacteria can cross specialized brain barriers and cause inflammation. Models have been developed to understand the bacterial - BEC interaction that lead to pathogen crossing into the CNS, however, these have been met with challenges due to these highly specialized BEC phenotypes. This perspective provides a brief overview and outlook of the in vivo and in vitro models currently being used to study bacterial brain penetration, and opinion on improved models for the future.
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Affiliation(s)
- Brandon J Kim
- Institute for Hygiene and Microbiology, University of Würzburg, Würzburg, Germany
| | - Eric V Shusta
- Department of Chemical and Biological Engineering, University of Wisconsin, Madison, WI, United States
| | - Kelly S Doran
- Department of Immunology and Microbiology, University of Colorado School of Medicine, Aurora, CO, United States
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