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Berardi A, Cattelani C, Creti R, Berner R, Pietrangiolillo Z, Margarit I, Maione D, Ferrari F. Group B streptococcal infections in the newborn infant and the potential value of maternal vaccination. Expert Rev Anti Infect Ther 2015; 13:1387-99. [PMID: 26295167 DOI: 10.1586/14787210.2015.1079126] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Group B Streptococcus (GBS) is a leading cause of neonatal bacterial infections in developed countries. Early-onset disease (EOD) occurs at day 0-6 and late-onset disease occurs at day 7-89. Currently, the prevention of EOD relies upon intrapartum antibiotic prophylaxis (IAP) given to women who are GBS positive at prenatal screening or women with risk factors for EOD. Although successfully implemented, IAP has not fully eradicated EOD, and incidence rates of late-onset disease remain unchanged. Furthermore, antibiotic resistance may result from widespread antibiotic use. New prophylactic strategies are therefore of critical importance. A vaccine active against GBS, administered during pregnancy and combined with targeted IAP, could overcome these problems and reduce the mortality and morbidity associated with invasive diseases.
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Affiliation(s)
- Alberto Berardi
- a 1 Terapia Intensiva Neonatale, Azienda Ospedaliero-Universitaria Policlinico, Modena, Italy
| | - Chiara Cattelani
- a 1 Terapia Intensiva Neonatale, Azienda Ospedaliero-Universitaria Policlinico, Modena, Italy
| | - Roberta Creti
- b 2 Reparto di Malattie Batteriche, Respiratorie e Sistemiche, Dipartimento MIPI, Istituto Superiore di Sanità, Roma, Italy
| | - Reinhard Berner
- c 3 Department of Pediatrics, University Hospital Carl Gustav Carus, Technische Universität, Dresden, Germany
| | - Zaira Pietrangiolillo
- a 1 Terapia Intensiva Neonatale, Azienda Ospedaliero-Universitaria Policlinico, Modena, Italy
| | | | - Domenico Maione
- d 4 Novartis Vaccines and Diagnostics S.r.l. - A GSK Company, Siena, Italy
| | - Fabrizio Ferrari
- a 1 Terapia Intensiva Neonatale, Azienda Ospedaliero-Universitaria Policlinico, Modena, Italy
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Gendrin C, Vornhagen J, Ngo L, Whidbey C, Boldenow E, Santana-Ufret V, Clauson M, Burnside K, Galloway DP, Adams Waldorf KM, Piliponsky AM, Rajagopal L. Mast cell degranulation by a hemolytic lipid toxin decreases GBS colonization and infection. SCIENCE ADVANCES 2015; 1:e1400225. [PMID: 26425734 PMCID: PMC4584422 DOI: 10.1126/sciadv.1400225] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/16/2014] [Accepted: 06/04/2015] [Indexed: 05/08/2023]
Abstract
Ascending infection of microbes from the lower genital tract into the amniotic cavity increases the risk of preterm birth, stillbirth, and newborn infections. Host defenses that are critical for preventing ascending microbial infection are not completely understood. Group B Streptococcus (GBS) are Gram-positive bacteria that frequently colonize the lower genital tract of healthy women but cause severe infections during pregnancy, leading to preterm birth, stillbirth, or early-onset newborn infections. We recently described that the GBS pigment is hemolytic, and increased pigment expression promotes GBS penetration of human placenta. Here, we show that the GBS hemolytic pigment/lipid toxin and hyperpigmented GBS strains induce mast cell degranulation, leading to the release of preformed and proinflammatory mediators. Mast cell-deficient mice exhibit enhanced bacterial burden, decreased neutrophil mobilization, and decreased immune responses during systemic GBS infection. In a vaginal colonization model, hyperpigmented GBS strains showed increased persistence in mast cell-deficient mice compared to mast cell-proficient mice. Consistent with these observations, fewer rectovaginal GBS isolates from women in their third trimester of pregnancy were hyperpigmented/hyperhemolytic. Our work represents the first example of a bacterial hemolytic lipid that induces mast cell degranulation and emphasizes the role of mast cells in limiting genital colonization by hyperpigmented GBS.
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Affiliation(s)
- Claire Gendrin
- Department of Pediatric Infectious Diseases, University of Washington, Seattle, WA 98101, USA
- Seattle Children’s Research Institute, Seattle, WA 98101, USA
| | - Jay Vornhagen
- Seattle Children’s Research Institute, Seattle, WA 98101, USA
- Department of Global Health, University of Washington, Seattle, WA 98195, USA
| | - Lisa Ngo
- Seattle Children’s Research Institute, Seattle, WA 98101, USA
| | - Christopher Whidbey
- Seattle Children’s Research Institute, Seattle, WA 98101, USA
- Department of Global Health, University of Washington, Seattle, WA 98195, USA
| | - Erica Boldenow
- Seattle Children’s Research Institute, Seattle, WA 98101, USA
| | | | - Morgan Clauson
- Seattle Children’s Research Institute, Seattle, WA 98101, USA
| | - Kellie Burnside
- Department of Pediatric Infectious Diseases, University of Washington, Seattle, WA 98101, USA
| | - Dionne P. Galloway
- Department of Obstetrics and Gynecology, University of Washington, Seattle, WA 98195, USA
| | | | - Adrian M. Piliponsky
- Department of Pediatric Infectious Diseases, University of Washington, Seattle, WA 98101, USA
- Seattle Children’s Research Institute, Seattle, WA 98101, USA
| | - Lakshmi Rajagopal
- Department of Pediatric Infectious Diseases, University of Washington, Seattle, WA 98101, USA
- Seattle Children’s Research Institute, Seattle, WA 98101, USA
- Department of Global Health, University of Washington, Seattle, WA 98195, USA
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Burnside K, Lembo A, de los Reyes M, Iliuk A, BinhTran NT, Connelly JE, Lin WJ, Schmidt BZ, Richardson AR, Fang FC, Tao WA, Rajagopal L. Regulation of hemolysin expression and virulence of Staphylococcus aureus by a serine/threonine kinase and phosphatase. PLoS One 2010; 5:e11071. [PMID: 20552019 PMCID: PMC2884019 DOI: 10.1371/journal.pone.0011071] [Citation(s) in RCA: 123] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2010] [Accepted: 05/14/2010] [Indexed: 02/02/2023] Open
Abstract
Exotoxins, including the hemolysins known as the alpha (alpha) and beta (beta) toxins, play an important role in the pathogenesis of Staphylococcus aureus infections. A random transposon library was screened for S. aureus mutants exhibiting altered hemolysin expression compared to wild type. Transposon insertions in 72 genes resulting in increased or decreased hemolysin expression were identified. Mutations inactivating a putative cyclic di-GMP synthetase and a serine/threonine phosphatase (Stp1) were found to reduce hemolysin expression, and mutations in genes encoding a two component regulator PhoR, LysR family transcriptional regulator, purine biosynthetic enzymes and a serine/threonine kinase (Stk1) increased expression. Transcription of the hla gene encoding alpha toxin was decreased in a Deltastp1 mutant strain and increased in a Deltastk1 strain. Microarray analysis of a Deltastk1 mutant revealed increased transcription of additional exotoxins. A Deltastp1 strain is severely attenuated for virulence in mice and elicits less inflammation and IL-6 production than the Deltastk1 strain. In vivo phosphopeptide enrichment and mass spectrometric analysis revealed that threonine phosphorylated peptides corresponding to Stk1, DNA binding histone like protein (HU), serine-aspartate rich fibrinogen/bone sialoprotein binding protein (SdrE) and a hypothetical protein (NWMN_1123) were present in the wild type and not in the Deltastk1 mutant. Collectively, these studies suggest that Stk1 mediated phosphorylation of HU, SrdE and NWMN_1123 affects S. aureus gene expression and virulence.
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Affiliation(s)
- Kellie Burnside
- Department of Pediatric Infectious Diseases, University of Washington and Seattle Children's Hospital Research Institute, Seattle, Washington, United States of America
| | - Annalisa Lembo
- Department of Pediatric Infectious Diseases, University of Washington and Seattle Children's Hospital Research Institute, Seattle, Washington, United States of America
| | - Melissa de los Reyes
- Department of Pediatric Infectious Diseases, University of Washington and Seattle Children's Hospital Research Institute, Seattle, Washington, United States of America
| | - Anton Iliuk
- Department of Biochemistry, Purdue University, West Lafayette, Indiana, United States of America
| | - Nguyen-Thao BinhTran
- Department of Pediatric Infectious Diseases, University of Washington and Seattle Children's Hospital Research Institute, Seattle, Washington, United States of America
| | - James E. Connelly
- Department of Pediatric Infectious Diseases, University of Washington and Seattle Children's Hospital Research Institute, Seattle, Washington, United States of America
| | - Wan-Jung Lin
- Department of Pediatric Infectious Diseases, University of Washington and Seattle Children's Hospital Research Institute, Seattle, Washington, United States of America
| | - Byron Z. Schmidt
- Department of Pediatric Infectious Diseases, University of Washington and Seattle Children's Hospital Research Institute, Seattle, Washington, United States of America
| | - Anthony R. Richardson
- Departments of Laboratory Medicine and Microbiology, University of Washington, Seattle, Washington, United States of America
| | - Ferric C. Fang
- Departments of Laboratory Medicine and Microbiology, University of Washington, Seattle, Washington, United States of America
| | - Weiguo Andy Tao
- Department of Biochemistry, Purdue University, West Lafayette, Indiana, United States of America
| | - Lakshmi Rajagopal
- Department of Pediatric Infectious Diseases, University of Washington and Seattle Children's Hospital Research Institute, Seattle, Washington, United States of America
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Rajagopal L. Understanding the regulation of Group B Streptococcal virulence factors. Future Microbiol 2009; 4:201-21. [PMID: 19257847 DOI: 10.2217/17460913.4.2.201] [Citation(s) in RCA: 138] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
Bacterial infections remain a significant threat to the health of newborns and adults. Group B Streptococci (GBS) are Gram-positive bacteria that are common asymptomatic colonizers of healthy adults. However, this opportunistic organism can also subvert suboptimal host defenses to cause severe invasive disease and tissue damage. The increasing emergence of antibiotic-resistant GBS raises more concerns for sustained measures in treatment of the disease. A number of factors that are important for virulence of GBS have been identified. This review summarizes the functions of some well-characterized virulence factors, with an emphasis on how GBS regulates their expression. Regulatory and signaling molecules are attractive drug targets in the treatment of bacterial infections. Consequently, understanding signaling responses of GBS is essential for elucidation of pathogenesis of GBS infection and for the identification of novel therapeutic agents.
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Affiliation(s)
- Lakshmi Rajagopal
- Department of Pediatric Infectious Diseases, University of Washington & Seattle Children's Hospital Research Institute, 1900 Ninth Avenue, Seattle, WA 98101-91304, USA.
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