Interkingdom signaling induces Streptococcus pneumoniae biofilm dispersion and transition from asymptomatic colonization to disease
Authors: Paul R Knight
Anders P Hakansson
Laura R Marks
Bruce A Davidson
Journal: mBio (2013)
Discipline: MICROBIOLOGY
Keywords: Streptococcus pneumoniae; nasopharyngeal commensal; colonization; respiratory disease; infection
Affiliations: Department of Microbiology and Immunology, University at Buffalo, State University of New York, Buffalo, New York, USA., Department of Anesthesiology, University at Buffalo, State University of New York, Buffalo, New York, USA, Department of Medicine, Veterans Affair Medical Center, Buffalo, New York, USA, Department of Microbiology and Immunology, University at Buffalo, State University of New York, Buffalo, New York, USA, The Witebsky Center for Microbial Pathogenesis and Immunology, University at Buffalo, State University of New York, Buffalo, New York, USA, New York State Center of Excellence in Bioinformatics and Life Sciences, Buffalo, New York, USA

Abstract:  Streptococcus pneumoniae is a common human nasopharyngeal commensal colonizing 10% to 40% of healthy individuals, depending on age. Despite a low invasive disease rate, widespread carriage ensures that infection occurs often enough to make S. pneumoniae a leading bacterial cause of respiratory disease worldwide. However, the mechanisms behind transition from asymptomatic colonization to dissemination and disease in otherwise sterile sites remain poorly understood but are epidemiologically strongly linked to infection with respiratory viruses. In this report, we show that infection with influenza A virus and treatment with the resulting host signals (febrile-range temperatures, norepinephrine, extracytoplasmic ATP, and increased nutrient availability) induce the release of bacteria from biofilms in a newly developed biofilm model on live epithelial cells both in vitro and during in vivo colonization. These dispersed bacteria have distinct phenotypic properties different from those of both biofilm and broth-grown, planktonic bacteria, with the dispersed population showing differential virulence gene expression characteristics resulting in a significantly increased ability to disseminate and cause infection of otherwise sterile sites, such as the middle ear, lungs, and bloodstream. The results offer novel and important insights into the role of interkingdom signaling between microbe and host during biofilm dispersion and transition to acute disease. Importance: This report addresses the mechanisms involved in transition from pneumococcal asymptomatic colonization to disease. In this study, we determined that changes in the nasopharyngeal environment result in the release of bacteria from colonizing biofilms with a gene expression and virulence phenotype different not only from that of colonizing biofilm bacteria but also from that of the broth-grown planktonic bacteria commonly used for pathogenesis studies. The work importantly also identifies specific host factors responsible for the release of bacteria and their changed phenotype. We show that these interkingdom signals are recognized by bacteria and are induced by influenza virus infection, which is epidemiologically strongly associated with transition to secondary pneumococcal disease. As virus infection is a common inducer of transition to disease among species occupying the nasopharynx, the results of this study may provide a basis for better understanding of the signals involved in the transition from colonization to disease in the human nasopharynx. 

Retracted: No

PubPeer comments:
 image duplication ![file] Disclaimer: These potential image duplications have been detected automatically using ImageTwin http: dx.doi.org 10.1145 3019612.3019875 Although results have been curated, the automatic algorithm may have generated false positive results and cannot take into account all scientific explanations for apparent duplications like stripped and reprobed blots, time series, serial sections and reused controls. ,