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Armistead B, Whidbey C, Iyer LM, Herrero-Foncubierta P, Quach P, Haidour A, Aravind L, Cuerva JM, Jaspan HB, Rajagopal L. The cyl Genes Reveal the Biosynthetic and Evolutionary Origins of the Group B Streptococcus Hemolytic Lipid, Granadaene. Front Microbiol 2020; 10:3123. [PMID: 32038561 PMCID: PMC6985545 DOI: 10.3389/fmicb.2019.03123] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2019] [Accepted: 12/24/2019] [Indexed: 01/31/2023] Open
Abstract
Group B Streptococcus (GBS) is a β-hemolytic, Gram-positive bacterium that commonly colonizes the female lower genital tract and is associated with fetal injury, preterm birth, spontaneous abortion, and neonatal infections. A major factor promoting GBS virulence is the β-hemolysin/cytolysin, which is cytotoxic to several host cells. We recently showed that the ornithine rhamnolipid pigment, Granadaene, produced by the gene products of the cyl operon, is hemolytic. Here, we demonstrate that heterologous expression of the GBS cyl operon conferred hemolysis, pigmentation, and cytoxicity to Lactococcus lactis, a model non-hemolytic Gram-positive bacterium. Similarly, pigment purified from L. lactis is hemolytic, cytolytic, and identical in structure to Granadaene extracted from GBS, indicating the cyl operon is sufficient for Granadaene production in a heterologous host. Using a systematic survey of phyletic patterns and contextual associations of the cyl genes, we identify homologs of the cyl operon in physiologically diverse Gram-positive bacteria and propose undescribed functions of cyl gene products. Together, these findings bring greater understanding to the biosynthesis and evolutionary foundations of a key GBS virulence factor and suggest that such potentially toxic lipids may be encoded by other bacteria.
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Affiliation(s)
- Blair Armistead
- Department of Global Health, University of Washington, Seattle, WA, United States.,Center for Global Infectious Disease Research, Seattle Children's Research Institute, Seattle, WA, United States
| | - Christopher Whidbey
- Department of Global Health, University of Washington, Seattle, WA, United States.,Center for Global Infectious Disease Research, Seattle Children's Research Institute, Seattle, WA, United States
| | - Lakshminarayan M Iyer
- Computational Biology Branch, National Center for Biotechnology Information, National Institutes of Health, Bethesda, MD, United States
| | | | - Phoenicia Quach
- Center for Global Infectious Disease Research, Seattle Children's Research Institute, Seattle, WA, United States
| | - Ali Haidour
- Department of Organic Chemistry, University of Granada, Granada, Spain
| | - L Aravind
- Computational Biology Branch, National Center for Biotechnology Information, National Institutes of Health, Bethesda, MD, United States
| | | | - Heather B Jaspan
- Department of Global Health, University of Washington, Seattle, WA, United States.,Center for Global Infectious Disease Research, Seattle Children's Research Institute, Seattle, WA, United States.,Department of Pediatrics, University of Washington School of Medicine, Seattle, WA, United States.,Department of Pathology, Institute of Infectious Disease and Molecular Medicine, University of Cape Town, Cape Town, South Africa
| | - Lakshmi Rajagopal
- Department of Global Health, University of Washington, Seattle, WA, United States.,Center for Global Infectious Disease Research, Seattle Children's Research Institute, Seattle, WA, United States.,Department of Pediatrics, University of Washington School of Medicine, Seattle, WA, United States
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Whidbey C, Vornhagen J, Gendrin C, Boldenow E, Samson JM, Doering K, Ngo L, Ezekwe EAD, Gundlach JH, Elovitz MA, Liggitt D, Duncan JA, Adams Waldorf KM, Rajagopal L. A streptococcal lipid toxin induces membrane permeabilization and pyroptosis leading to fetal injury. EMBO Mol Med 2015; 7:488-505. [PMID: 25750210 PMCID: PMC4403049 DOI: 10.15252/emmm.201404883] [Citation(s) in RCA: 60] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023] Open
Abstract
Group B streptococci (GBS) are Gram-positive bacteria that cause infections in utero and in newborns. We recently showed that the GBS pigment is hemolytic and increased pigment production promotes bacterial penetration of human placenta. However, mechanisms utilized by the hemolytic pigment to induce host cell lysis and the consequence on fetal injury are not known. Here, we show that the GBS pigment induces membrane permeability in artificial lipid bilayers and host cells. Membrane defects induced by the GBS pigment trigger K+ efflux leading to osmotic lysis of red blood cells or pyroptosis in human macrophages. Macrophages lacking the NLRP3 inflammasome recovered from pigment-induced cell damage. In a murine model of in utero infection, hyperpigmented GBS strains induced fetal injury in both an NLRP3 inflammasome-dependent and NLRP3 inflammasome-independent manner. These results demonstrate that the dual mechanism of action of the bacterial pigment/lipid toxin leading to hemolysis or pyroptosis exacerbates fetal injury and suggest that preventing both activities of the hemolytic lipid is likely critical to reduce GBS fetal injury and preterm birth.
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Affiliation(s)
- Christopher Whidbey
- Department of Pediatric Infectious Diseases, University of Washington and Seattle Children's Research Institute, Seattle, WA, USA Department of Global Health, University of Washington, Seattle, WA, USA
| | - Jay Vornhagen
- Department of Pediatric Infectious Diseases, University of Washington and Seattle Children's Research Institute, Seattle, WA, USA Department of Global Health, University of Washington, Seattle, WA, USA
| | - Claire Gendrin
- Department of Pediatric Infectious Diseases, University of Washington and Seattle Children's Research Institute, Seattle, WA, USA
| | - Erica Boldenow
- Department of Pediatric Infectious Diseases, University of Washington and Seattle Children's Research Institute, Seattle, WA, USA
| | - Jenny Mae Samson
- Department of Physics, University of Washington, Seattle, WA, USA
| | - Kenji Doering
- Department of Physics, University of Washington, Seattle, WA, USA
| | - Lisa Ngo
- Department of Pediatric Infectious Diseases, University of Washington and Seattle Children's Research Institute, Seattle, WA, USA
| | - Ejiofor A D Ezekwe
- Department of Medicine, Division of Infectious Diseases and Pharmacology, School of Medicine and Lineberger Comprehensive Cancer Center University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - Jens H Gundlach
- Department of Physics, University of Washington, Seattle, WA, USA
| | - Michal A Elovitz
- Maternal and Child Health Research Program, Department of Obstetrics and Gynecology, Center for Research on Reproduction and Women's Health Perelman School of Medicine University of Pennsylvania, Philadelphia, PA, USA
| | - Denny Liggitt
- Department of Comparative Medicine, School of Medicine University of Washington, Seattle, WA, USA
| | - Joseph A Duncan
- Department of Medicine, Division of Infectious Diseases and Pharmacology, School of Medicine and Lineberger Comprehensive Cancer Center University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - Kristina M Adams Waldorf
- Department of Obstetrics and Gynecology, School of Medicine University of Washington, Seattle, WA, USA
| | - Lakshmi Rajagopal
- Department of Pediatric Infectious Diseases, University of Washington and Seattle Children's Research Institute, Seattle, WA, USA Department of Global Health, University of Washington, Seattle, WA, USA
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Dubos R. THE RELATION OF THE BACTERIOSTATIC ACTION OF CERTAIN DYES TO OXIDATION-REDUCTION PROCESSES. ACTA ACUST UNITED AC 2010; 49:575-92. [PMID: 19869565 PMCID: PMC2131571 DOI: 10.1084/jem.49.4.575] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
Oxidized indophenols and methylene blue are bacteriostatic for Pneumococcus and hemolytic streptococci of human and bovine origin, while the indigoes, malachite green and litmus are not toxic. 2-Chloroindophenol, the most positive of the indicators of oxidation-reduction potentials used, is also the only one to have a bacteriostatic action on cheese strains of Streptococcus haemolyticus. Methylene blue and the indophenols are no longer bacteriostatic when present in a reduced form in a medium capable of maintaining them in such a condition. A comparison of these results with the growth in plain broth of the organisms studied suggests that the "inhibiting" dyes "poise" the medium at an oxidation potential outside the range in which the inhibited organisms can grow.
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Affiliation(s)
- R Dubos
- Hospital of The Rockefeller Institute for Medical Research
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Abstract
A streptococcus epidemic of moderate extent and severity was characterized by clinical symptoms different from the usual septic sore throat, though the organism found was culturally Streptococcus epidemicus. The infection was traced to the milk from a single quarter of the udder of a cow in a dairy of 112 cows producing an otherwise excellent grade of raw milk. A number of the milkers on the dairy farm were found infected. It was impossible to trace the infection of the cow's udder to any one of the milkers, though such an infection seems probable since the streptococcus isolated from the cow was in every respect like streptococci isolated from patients and milkers, and different from those usually found in normal cows or cows with garget. Certain recommendations are made to safeguard producers of raw milk against the occurrence of such epidemics.
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Affiliation(s)
- J H Brown
- Department of Comparative Pathology of Harvard Medical School, and the Department of Animal Pathology of The Rockefeller Institute for Medical Research, Princeton, N. J
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