Streptococcus pneumoniae Elaborates Persistent and Prolonged Competent State during Pneumonia-Derived Sepsis.

Autor:	Lin J; Department of Pathobiology, College of Veterinary Medicine, University of Illinois at Urbana-Champaign, Urbana, Illinois, USA., Park P; Department of Pathobiology, College of Veterinary Medicine, University of Illinois at Urbana-Champaign, Urbana, Illinois, USA., Li H; Department of Pathobiology, College of Veterinary Medicine, University of Illinois at Urbana-Champaign, Urbana, Illinois, USA., Oh MW; Department of Pathobiology, College of Veterinary Medicine, University of Illinois at Urbana-Champaign, Urbana, Illinois, USA., Dobrucki IT; Molecular Imaging Laboratory, Beckman Institute For Advanced Science and Technology, University of Illinois at Urbana-Champaign, Urbana, Illinois, USA., Dobrucki W; Molecular Imaging Laboratory, Beckman Institute For Advanced Science and Technology, University of Illinois at Urbana-Champaign, Urbana, Illinois, USA.; Department of Bioengineering, University of Illinois at Urbana-Champaign, Urbana, Illinois, USA., Lau GW; Department of Pathobiology, College of Veterinary Medicine, University of Illinois at Urbana-Champaign, Urbana, Illinois, USA geelau@illinois.edu.
Jazyk:	angličtina
Zdroj:	Infection and immunity [Infect Immun] 2020 Mar 23; Vol. 88 (4). Date of Electronic Publication: 2020 Mar 23 (Print Publication: 2020).
DOI:	10.1128/IAI.00919-19
Abstrakt:	The competence regulon of pneumococcus regulates both genetic transformation and virulence. However, competence induction during host infection has not been examined. By using the serotype 2 strain D39, we transcriptionally fused the firefly luciferase ( luc ) to competence-specific genes and spatiotemporally monitored the competence development in a mouse model of pneumonia-derived sepsis. In contrast to the universally reported short transient burst of competent state in vitro , the naturally developed competent state was prolonged and persistent during pneumonia-derived sepsis. The competent state began at approximately 20 h postinfection (hpi) and facilitated systemic invasion and sepsis development and progressed in different manners. In some mice, acute pneumonia quickly led to sepsis and death, accompanied by increasing intensity of the competence signal. In the remaining mice, pneumonia lasted longer, with the competence signal decreasing at first but increasing as the infection became septic. The concentration of pneumococcal inoculum (1 × 10 6 to 1 × 10 8 CFU/mouse) and postinfection lung bacterial burden did not appreciably impact the kinetics of competence induction. Exogenously provided competence stimulating peptide 1 (CSP1) failed to modulate the onset kinetics of competence development in vivo The competence shutoff regulator DprA was highly expressed during pneumonia-derived sepsis but failed to turn off the competent state in mice. Competent D39 bacteria propagated the competence signal through cell-to-cell contact rather than the classically described quorum-sensing mechanism. Finally, clinical pneumococcal strains of different serotypes were also able to develop natural competence during pneumonia-derived sepsis. (Copyright © 2020 American Society for Microbiology.)
Databáze:	MEDLINE
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