The impact of the ancillary pilus‐1 protein RrgA of Streptococcus pneumoniae on colonization and disease. Issue 3 (17th March 2020)

• Record Type: Journal Article
• Authors: Iovino, Federico; Nannapaneni, Priyanka; Henriques‐Normark, Birgitta; Normark, Staffan
• Other Names: Buchrieser Carmen guestEditor.
• Is Part Of: Molecular microbiology. Volume 113:Issue 3(2019)
• Page Start: 650
• Page End: 658
• Publication Date: 2020-03-17
• Subjects: colonization -- meningitis -- pili -- pneumococci -- RrgA adhesin -- Streptococcus pneumoniae; Molecular microbiology -- Periodicals; 572.829
• DOI: 10.1111/mmi.14451
• Languages: English
• ISSNs: 0950-382X

Abstract

Abstract: The Gram‐positive bacterium Streptococcus pneumoniae, the pneumococcus, is an important commensal resident of the human nasopharynx. Carriage is usually asymptomatic, however, S. pneumoniae can become invasive and spread from the upper respiratory tract to the lungs causing pneumonia, and to other organs to cause severe diseases such as bacteremia and meningitis. Several pneumococcal proteins important for its disease‐causing capability have been described and many are expressed on the bacterial surface. The surface located pneumococcal type‐1 pilus has been associated with virulence and the inflammatory response, and it is present in 20%–30% of clinical isolates. Its tip protein RrgA has been shown to be a major adhesin to human cells and to promote invasion through the blood‐brain barrier. In this review we discuss recent findings of the impact of RrgA on bacterial colonization of the upper respiratory tract and on pneumococcal virulence, and use epidemiological data and genome‐mining to suggest trade‐off mechanisms potentially explaining the rather low prevalence of pilus‐1 expressing pneumococci in humans. Abstract : The impact of RrgA in Streptococcus pneumoniae pathogenicity. Even though pneumococcal carriage is usually asymptomatic, colonization of the nasopharynx is considered the starting point for onset of invasive disease. S. pneumoniae colonizing the upper respiratory tract can cross human cell barriers to cause pneumonia and septicemia, and passage the endothelial blood‐brain barrier and spread into human tissues and organs such as the brain, causing severe infectious diseases such as meningitis. The broad involvement of RrgA in pneumococcal‐host interaction suggests RrgA as a vaccine candidate for a novel protein‐based vaccine.