All Journals > The Journal of Infectious Diseases > 15 September 2007 > S. aureus Capsule Masks ClfA

Article Tools

Search for Related Articles

  • By Author
  • Search In

Press Release

Unique Collaboration Charts the Migrations of a Parasite that Affected History
Researchers Sequence Louse DNA from Mummies and Propose New Model for its Development


In the News

Featured in Scientific American
"Stomach Bug May Ward Off Asthma" July 16, 2008
Helicobacter pylori Colonization Is Inversely Associated with Childhood Asthma
Yu Chen, Martin J. Blaser
"...scientists analyzed data from more than 7,000 participants in a national health and nutrition survey. They found that children between the ages of three and 13 are less than half as likely to have asthma if they carry H. pylori. They also had half the incidence of hay fever and other allergies. The results appear online in the July 15th issue of The Journal of Infectious Diseases."

Featured in U.S. News & World Report
"Stomach Germ May Protect Against Asthma" July 15, 2008
Helicobacter pylori Colonization Is Inversely Associated with Childhood Asthma

Yu Chen, Martin J. Blaser
"A stomach bacterium called Helicobacter pylori may reduce a child's risk of developing asthma by as much as 50 percent, a new study suggests.  H. pylori has been present in the human stomach probably since humans were humans. However, the germ began disappearing over the course of the 20th century with the introduction of antibiotics and cleaner water and homes, perhaps making children more susceptible to asthma, the study authors suggested."

Featured in Wired News
"Internal Bacterial Imbalance Leads to Asthma" July 15, 2008
Helicobacter pylori Colonization Is Inversely Associated with Childhood Asthma
Yu Chen, Martin J. Blaser
"In a study published yesterday in the Journal of Infectious Diseases, researchers showed that Heliobacter pylori, an intestinal microbe that co-evolved with humans, appears to protect children from asthma.  Asthma rates have nearly doubled in the United States since 1970, and are swelling in the developing world. Underlying the rise is a constellation of causes -- and one of these may be the loss of H. pylori, a vanishing member of the rich bacterial ecosystems in our stomachs."

Featured in Reuters
"Zinc reduces common cold symptoms" April 17, 2008
Duration and Severity of Symptoms and Levels of Plasma Interleukin-1 Receptor Antagonist, Soluble Tumor Necrosis Factor Receptor, and Adhesion Molecules in Patients with Common Cold Treated with Zinc Acetate
Ananda S. Prasad, Frances W. J. Beck, Bin Bao, Diane Snell, and James T. Fitzgerald
Zinc acetate lozenges taken within 24 hours of developing symptoms of the common cold reduce the duration and severity of symptoms, according to a report in The Journal of Infectious Diseases.

Featured in National Public Radio
"Peruvian Mummies' Lice Came from Africa" February 7, 2008
Molecular Identification of Lice from Pre-Columbian Mummies

Didier Raoult, David L. Reed, Katharina Dittmar, Jeremy J. Kirchman, Jean-Marc Rolain, Sonia Guillen, and Jessica E. Light
When humans migrated out of Africa 100,000 years ago, they were likely carrying stowaways. Scientists who've tested head lice taken from Peruvian mummies found the strains of these little parasites were nearly identical to those that were irritating our ancestors in Africa.

Featured in New York Times
"Scientists Say Mummies' Lice Show Pre-Columbian Origins" February 7, 2008
Molecular Identification of Lice from Pre-Columbian Mummies
Didier Raoult, David L. Reed, Katharina Dittmar, Jeremy J. Kirchman, Jean-Marc Rolain, Sonia Guillen, and Jessica E. Light
[In a new paper for the JID, scientists] establish that lice had accompanied their human hosts in the original peopling of the Americas, probably as early as 15,000 years ago. The DNA matched that of the most common type of louse known to exist worldwide now and also before Europeans colonized the New World.

Featured in Reuters
"Head lice came with us out of Africa" February 6, 2008
Molecular Identification of Lice from Pre-Columbian Mummies
Didier Raoult, David L. Reed, Katharina Dittmar, Jeremy J. Kirchman, Jean-Marc Rolain, Sonia Guillen, and Jessica E. Light
Head lice taken from 1,000-year-old mummies in Peru support the idea that the little creatures accompanied humans on their first migration out of Africa, 100,000 years ago, researchers reported on Wednesday.

15 September 2007

Volume 196, Number 6
The Journal of Infectious Diseases 2007;196:919–927
© 2007 by the Infectious Diseases Society of America. All rights reserved.
0022-1899/2007/19606-0017$15.00
DOI: 10.1086/520932
MAJOR ARTICLE

Capsular Polysaccharide Masks Clumping Factor A–Mediated Adherence of Staphylococcus aureus to Fibrinogen and Platelets

Allison L. Risley,1

Anthony Loughman,2

Colette Cywes-Bentley,1

Timothy J. Foster,2 and

Jean C. Lee1

1Channing Laboratory, Brigham and Women's Hospital and Harvard Medical School, Boston, Massachusetts; 2Microbiology Department, Moyne Institute of Preventive Medicine, Trinity College, Dublin, Ireland

Background.  Clumping factor A (ClfA) is a Staphylococcus aureus cell wall–associated adhesin that mediates staphylococcal binding to fibrinogen and platelets. Our goals were to determine whether expression of capsular polysaccharide (CP) affected ClfA-mediated adherence of S. aureus and to assess whether the length of the ClfA repeat region influenced this interaction.

Methods.  ClfA constructs with repeat regions of different lengths were introduced into isogenic S. aureus strains that expressed CP5, CP8, or no CP. S. aureus binding to fibrinogen was assessed in rabbit plasma and on fibrinogen-coated microtiter plates. Adherence of S. aureus strains to platelets was evaluated by flow cytometry and confocal microscopy.

Results.  As the length of the ClfA repeat region increased, binding of acapsular S. aureus to fibrinogen-coated microtiter plates was enhanced. By contrast, encapsulated S. aureus expressing the full-length ClfA were poorly adherent. The acapsular S. aureus mutant strain showed a 2-fold increase in platelet binding, compared with the isogenic encapsulated strains. By contrast, platelet aggregation was unaffected by CP production.

Conclusion.  CP expression inhibits S. aureus ClfA-mediated binding to fibrinogen and platelets, and a full-length repeat region cannot overcome this inhibition. These findings have important implications for vaccine development, given that CP may mask surface adhesins.

Received 16 November 2006; accepted 11 April 2007; electronically published 10 August 2007.

Reprints or correspondence: Jean C. Lee, Channing Laboratory, 181 Longwood Ave., Boston, MA 02115 ().

Cited by

John R Middleton. (2008) Staphylococcus aureus antigens and challenges in vaccine development . Expert Review of Vaccines 7:6, 805-815
Online publication date: 1-Sep-2008.
CrossRef

  • Potential conflicts of interest: T.J.F. is a member of the scientific advisory board of Inhibitex, Inc., and holds the US patent on S. aureus clumping factor A. All other authors report no conflicts.

    Presented in part: 104th General Meeting of the American Society for Microbiology, New Orleans, 23–27 May 2004 (abstract D-254).

    Financial support: National Institutes of Health (grants AI29040 and Fogarty Foundation TW006264 to J.C.L.); Science Foundation Ireland (grant 03/IN3/B370 to T.J.F.); Health Research Board of Ireland (grant RPO09/2002 to T.J.F.).

Back to Top
Close Popup