scholarly journals Total Synthesis of Xanthoangelol B and Its Various Fragments: Toward Inhibition of Virulence Factor Production of Staphylococcus aureus

2018 ◽  
Vol 61 (23) ◽  
pp. 10473-10487 ◽  
Author(s):  
Pushpak Mizar ◽  
Rekha Arya ◽  
Truc Kim ◽  
Soyoung Cha ◽  
Kyoung-Seok Ryu ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Total Synthesis ◽  
Virulence Factor ◽  
Factor Production ◽  
Virulence Factor Production

scholarly journals Staphylococcus aureus Formyl-Methionyl Transferase Mutants Demonstrate Reduced Virulence Factor Production and Pathogenicity

2013 ◽  
Vol 57 (7) ◽  
pp. 2929-2936 ◽  
Author(s):  
Thomas Lewandowski ◽  
Jianzhong Huang ◽  
Frank Fan ◽  
Shannon Rogers ◽  
Daniel Gentry ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Virulence Factor ◽  
Survival Rates ◽  
Extracellular Proteins ◽  
High Survival ◽  
Invasive Infection ◽  
Loss Of Function ◽  
Content Type ◽  
Factor Production ◽  
Virulence Factor Production

ABSTRACTInhibitors of peptide deformylase (PDF) represent a new class of antibacterial agents with a novel mechanism of action. Mutations that inactivate formyl methionyl transferase (FMT), the enzyme that formylates initiator methionyl-tRNA, lead to an alternative initiation of protein synthesis that does not require deformylation and are the predominant cause of resistance to PDF inhibitors inStaphylococcus aureus. Here, we report that loss-of-function mutations in FMT impart pleiotropic effects that include a reduced growth rate, a nonhemolytic phenotype, and a drastic reduction in production of multiple extracellular proteins, including key virulence factors, such as α-hemolysin and Panton-Valentine leukocidin (PVL), that have been associated withS. aureuspathogenicity. Consequently,S. aureusFMT mutants are greatly attenuated in neutropenic and nonneutropenic murine pyelonephritis infection models and show very high survival rates compared with wild-typeS. aureus. These newly discovered effects on extracellular virulence factor production demonstrate that FMT-null mutants have a more severe fitness cost than previously anticipated, leading to a substantial loss of pathogenicity and a restricted ability to produce an invasive infection.

scholarly journals Staphylococcal Virulence Factors on the Skin of Atopic Dermatitis Patients

mSphere ◽  
2019 ◽  
Vol 4 (6) ◽  
Author(s):  
Mary C. Moran ◽  
Michael P. Cahill ◽  
Matthew G. Brewer ◽  
Takeshi Yoshida ◽  
Sara Knowlden ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Atopic Dermatitis ◽  
Virulence Factors ◽  
Virulence Factor ◽  
Protein Level ◽  
Content Type ◽  
Factor Production ◽  
First Time ◽  
Virulence Factor Production ◽  
Specific Virulence

ABSTRACT Staphylococcus aureus is the leading cause of skin and soft tissue infections, bacteremia, infective endocarditis, osteoarticular, pleuropulmonary, and device-related infections. Virulence factors secreted by S. aureus, including superantigens and cytotoxins, play significant roles in driving disease. The ability to identify virulence factors present at the site of infection will be an important tool in better identifying and understanding how specific virulence factors contribute to disease. Previously, virulence factor production has been determined by culturing S. aureus isolates and detecting the mRNA of specific virulence factors. We demonstrated for the first time that virulence factors can be directly detected at the protein level from human samples, removing the need to first culture isolated bacteria. Superantigens and cytotoxins were detected and quantified with a Western dot blot assay by using reconstituted skin swabs obtained from patients with atopic dermatitis. This methodology will significantly enhance our ability to investigate the complex host-microbe environment and the effects various therapies have on virulence factor production. Overall, the ability to directly quantify virulence factors present at the site of infection or colonization will enhance our understanding of S. aureus-related diseases and help identify optimal treatments. IMPORTANCE For the first time, we show that secreted staphylococcal virulence factors can be quantified at the protein level directly from skin swabs obtained from the skin of atopic dermatitis patients. This technique eliminates the need to culture Staphylococcus aureus and then test the strain’s potential to produce secreted virulence factors. Our methodology shows that secreted virulence factors are present on the skin of atopic patients and provides a more accurate means of evaluating the physiological impact of S. aureus in inflammatory diseases such as atopic dermatitis.

Inhibition of biofilm and biofilm-associated virulence factor production in methicillin-resistant Staphylococcus aureus by docosanol

2020 ◽  
Vol 317 ◽  
pp. 59-69
Author(s):  
Selvaraj Alagu Lakshmi ◽  
James Prabhanand Bhaskar ◽  
Venkateswaran Krishnan ◽  
Sivasamy Sethupathy ◽  
Selvapandi Pandipriya ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Virulence Factor ◽  
Methicillin Resistant Staphylococcus Aureus ◽  
Methicillin Resistant ◽  
Factor Production ◽  
Virulence Factor Production

scholarly journals Fatty Acids Regulate Stress Resistance and Virulence Factor Production for Listeria monocytogenes

2012 ◽  
Vol 194 (19) ◽  
pp. 5274-5284 ◽  
Author(s):  
Y. Sun ◽  
B. J. Wilkinson ◽  
T. J. Standiford ◽  
H. T. Akinbi ◽  
M. X. D. O'Riordan
Keyword(s):  
Fatty Acids ◽  
Listeria Monocytogenes ◽  
Virulence Factor ◽  
Stress Resistance ◽  
Factor Production ◽  
Virulence Factor Production

scholarly journals Cyclo(valine–valine) inhibits Vibrio cholerae virulence gene expression

Microbiology ◽  
2014 ◽  
Vol 160 (6) ◽  
pp. 1054-1062 ◽  
Author(s):  
Amit Vikram ◽  
Vanessa M. Ante ◽  
X. Renee Bina ◽  
Qin Zhu ◽  
Xinyu Liu ◽  
...  
Keyword(s):  
Vibrio Cholerae ◽  
Virulence Factor ◽  
Inhibitory Activity ◽  
Virulence Gene ◽  
Side Chains ◽  
Cyclic Dipeptides ◽  
Virulence Gene Expression ◽  
Factor Production ◽  
Virulence Regulator ◽  
Virulence Factor Production

Vibrio cholerae has been shown to produce a cyclic dipeptide, cyclo(phenylalanine–proline) (cFP), that functions to repress virulence factor production. The objective of this study was to determine if heterologous cyclic dipeptides could repress V. cholerae virulence factor production. To that end, three synthetic cyclic dipeptides that differed in their side chains from cFP were assayed for virulence inhibitory activity in V. cholerae. The results revealed that cyclo(valine–valine) (cVV) inhibited virulence factor production by a ToxR-dependent process that resulted in the repression of the virulence regulator aphA. cVV-dependent repression of aphA was found to be independent of known aphA regulatory genes. The results demonstrated that V. cholerae was able to respond to exogenous cyclic dipeptides and implicated the hydrophobic amino acid side chains on both arms of the cyclo dipeptide scaffold as structural requirements for inhibitory activity. The results further suggest that cyclic dipeptides have potential as therapeutics for cholera treatment.

Impact ofd-amino acid dehydrogenase on virulence factor production by aPseudomonas aeruginosa

2013 ◽  
Vol 59 (9) ◽  
pp. 598-603 ◽  
Author(s):  
Kathryn E. Oliver ◽  
Laura Silo-Suh
Keyword(s):  
Amino Acid ◽  
Virulence Factor ◽  
Bacterial Pathogen ◽  
Optimal Production ◽  
Acid Dehydrogenase ◽  
Amino Acid Dehydrogenase ◽  
Factor Production ◽  
Lung Dysfunction ◽  
Production Of Hydrogen ◽  
Virulence Factor Production

Chronic Pseudomonas aeruginosa infections remain the leading cause of lung dysfunction and mortality for cystic fibrosis (CF) patients. Many other bacteria inhabit the CF lung, but P. aeruginosa utilizes novel strategies that allow it to colonize this environment as the predominant bacterial pathogen. d-Amino acid dehydrogenase encoded by dadA is highly expressed by P. aeruginosa within the CF lung, and it is required for optimal production of hydrogen cyanide by some CF-adapted isolates. To better understand the increased significance of d-amino acid dehydrogenase in P. aeruginosa physiology, we characterized the contribution of the dad operon to virulence factor production. In this study, we determined that DadA is required for optimal production of pyocyanin, pyoverdine, and rhamnolipid by CF-adapted and non-CF-adapted isolates of P. aeruginosa. In addition, DadA is required for optimal production of alginate, biofilm formation, and virulence of a CF-adapted isolated of P. aeruginosa in an alfalfa seedling model of infection. Taken together, the results indicate that DadA plays a pleiotropic role in the production of important virulence factors by P. aeruginosa.

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