scholarly journals Streptococcus parasanguinis

2020 ◽  
Author(s):  
Keyword(s):  
Streptococcus Parasanguinis

scholarly journals Differential Roles of Individual Domains in Selection of Secretion Route of a Streptococcus parasanguinis Serine-Rich Adhesin, Fap1

2007 ◽  
Vol 189 (21) ◽  
pp. 7610-7617 ◽  
Author(s):  
Qiang Chen ◽  
Baiming Sun ◽  
Hui Wu ◽  
Zhixiang Peng ◽  
Paula M. Fives-Taylor
Keyword(s):  
Signal Peptide ◽  
Wild Type ◽  
Secretion Pathway ◽  
C Terminus ◽  
Region I ◽  
Minimal Sequences ◽  
Region Ii ◽  
Dependent Pathway ◽  
Selection Of ◽  
Streptococcus Parasanguinis

ABSTRACT Fimbria-associated protein 1 (Fap1) is a high-molecular-mass glycosylated surface adhesin required for fimbria biogenesis and biofilm formation in Streptococcus parasanguinis. The secretion of mature Fap1 is dependent on the presence of SecA2, a protein with some homology to, but with a different role from, SecA. The signals that direct the secretion of Fap1 to the SecA2-dependent secretion pathway rather than the SecA-dependent secretion pathway have not yet been identified. In this study, Fap1 variants containing different domains were expressed in both secA2 wild-type and mutant backgrounds and were tested for their ability to be secreted by the SecA- or SecA2-dependent pathway. The presence or absence of the cell wall anchor domain (residues 2531 to 2570) at the C terminus did not alter the selection of the Fap1 secretion route. The Fap1 signal peptide (residues 1 to 68) was sufficient to support the secretion of a heterologous protein via the SecA-dependent pathway, suggesting that the signal peptide was sufficient for recognition by the SecA-dependent pathway. The minimal sequences of Fap1 required for the SecA2-dependent pathway included the N-terminal signal peptide, nonrepetitive region I (residues 69 to 102), and part of nonrepetitive region II (residues 169 to 342). The two serine-rich repeat regions (residues 103 to 168 and 505 to 2530) were not required for Fap1 secretion. However, they were both involved in the specific inhibition of Fap1 secretion via the SecA-dependent pathway.

scholarly journals Complete Genome and Transcriptomes of Streptococcus parasanguinis FW213: Phylogenic Relations and Potential Virulence Mechanisms

PLoS ONE ◽  
2012 ◽  
Vol 7 (4) ◽  
pp. e34769 ◽  
Author(s):  
Jianing Geng ◽  
Cheng-Hsun Chiu ◽  
Petrus Tang ◽  
Yaping Chen ◽  
Hui-Ru Shieh ◽  
...  
Keyword(s):  
Complete Genome ◽  
Streptococcus Parasanguinis

scholarly journals Oral Streptococci and Nitrite-Mediated Interference of Pseudomonas aeruginosa

2014 ◽  
Vol 83 (1) ◽  
pp. 101-107 ◽  
Author(s):  
Jessica A. Scoffield ◽  
Hui Wu
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Underlying Mechanism ◽  
Dependent Manner ◽  
Oral Streptococci ◽  
Content Type ◽  
Production Of Hydrogen ◽  
Diverse Community ◽  
Oral Microbes ◽  
Systemic Infections ◽  
Streptococcus Parasanguinis

The oral cavity harbors a diverse community of microbes that are physiologically unique. Oral microbes that exist in this polymicrobial environment can be pathogenic or beneficial to the host. Numerous oral microbes contribute to the formation of dental caries and periodontitis; however, there is little understanding of the role these microbes play in systemic infections. There is mounting evidence that suggests that oral commensal streptococci are cocolonized withPseudomonas aeruginosaduring cystic fibrosis pulmonary infections and that the presence of these oral streptococci contributes to improved lung function. The goal of this study was to examine the underlying mechanism by whichStreptococcus parasanguinisantagonizes pathogenicP. aeruginosa. In this study, we discovered that oral commensal streptococci, includingStreptococcus parasanguinis,Streptococcus sanguinis, andStreptococcus gordonii, inhibit the growth ofP. aeruginosaand that this inhibition is mediated by the presence of nitrite and the production of hydrogen peroxide (H2O2) by oral streptococci. The requirement of both H2O2and nitrite for the inhibition ofP. aeruginosais due to the generation of reactive nitrogenous intermediates (RNI), including peroxynitrite. Transposon mutagenesis showed that aP. aeruginosamutant defective in a putative ABC transporter permease is resistant to both streptococcus/nitrite- and peroxynitrite-mediated killing. Furthermore,S. parasanguinisprotectsDrosophila melanogasterfrom killing byP. aeruginosain a nitrite-dependent manner. Our findings suggest that the combination of nitrite and H2O2may represent a unique anti-infection strategy by oral streptococci during polymicrobial infections.

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