scholarly journals Characterization of structural elements in native autoinducing peptides and non-native analogues that permit the differential modulation of AgrC-type quorum sensing receptors in Staphylococcus aureus

2016 ◽  
Vol 14 (1) ◽  
pp. 113-121 ◽  
Author(s):  
Yftah Tal-Gan ◽  
Monika Ivancic ◽  
Gabriel Cornilescu ◽  
Helen E. Blackwell
Keyword(s):  
Staphylococcus Aureus ◽  
Quorum Sensing ◽  
Structural Elements ◽  
Differential Modulation ◽  
Autoinducing Peptides

Structural analyses of autoinducing peptides and analogues thereof reveal motifs critical for modulation of quorum sensing receptors inS. aureus.

scholarly journals Identification and Characterization of a Monofunctional Glycosyltransferase from Staphylococcus aureus

2001 ◽  
Vol 183 (16) ◽  
pp. 4779-4785 ◽  
Author(s):  
Q. May Wang ◽  
Robert B. Peery ◽  
Robert B. Johnson ◽  
William E. Alborn ◽  
Wu-Kuang Yeh ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Structural Elements ◽  
Homogeneity Analysis ◽  
Hydrophobic Domain ◽  
Penicillin Binding Proteins ◽  
Class A ◽  
Calculated Molecular Weight ◽  
Identification And Characterization ◽  
Secondary Structural Elements

ABSTRACT A gene (mgt) encoding a monofunctional glycosyltransferase (MGT) from Staphylococcus aureus has been identified. This first reported gram-positive MGT shared significant homology with several MGTs from gram-negative bacteria and the N-terminal glycosyltransferase domain of class A high-molecular-mass penicillin-binding proteins from different species.S. aureus MGT contained an N-terminal hydrophobic domain perhaps involved with membrane association. It was expressed inEscherichia coli cells as a truncated protein lacking the hydrophobic domain and purified to homogeneity. Analysis by circular dichroism revealed that secondary structural elements of purified truncated S. aureus MGT were consistent with predicted structural elements, indicating that the protein might exhibit the expected folding. In addition, purified S. aureus MGT catalyzed incorporation of UDP-N-acetylglucosamine into peptidoglycan, proving that it was enzymatically active. MGT activity was inhibited by moenomycin A, and the reaction product was sensitive to lysozyme treatment. Moreover, a protein matching the calculated molecular weight ofS. aureus MGT was identified from an S. aureus cell lysate using antibodies developed against purified MGT. Taken together, our results suggest that this enzyme is natively present in S. aureus cells and that it may play a role in bacterial cell wall biosynthesis.

scholarly journals Gaussia Luciferase as a Reporter for Quorum Sensing in Staphylococcus aureus

Sensors ◽  
2020 ◽  
Vol 20 (15) ◽  
pp. 4305
Author(s):  
Isobel Blower ◽  
Carmen Tong ◽  
Xiaohui Sun ◽  
Ewan Murray ◽  
Jeni Luckett ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Quorum Sensing ◽  
Quantitative Assessment ◽  
Chemical Agent ◽  
Secreted Protein ◽  
Human Pathogen ◽  
Gaussia Luciferase ◽  
Bacterial Pathogenicity ◽  
Autoinducing Peptides

Gaussia luciferase (GLuc) is a secreted protein with significant potential for use as a reporter of gene expression in bacterial pathogenicity studies. To date there are relatively few examples of its use in bacteriology. In this study we show that GLuc can be functionally expressed in the human pathogen Staphylococcus aureus and furthermore show that it can be used as a biosensor for the agr quorum sensing (QS) system which employs autoinducing peptides to control virulence. GLuc was linked to the P3 promoter of the S. aureusagr operon. Biosensor strains were validated by evaluation of chemical agent-mediated activation and inhibition of agr. Use of GLuc enabled quantitative assessment of agr activity. This demonstrates the utility of Gaussia luciferase for in vitro monitoring of agr activation and inhibition.

Phylogeny Characterization of Seb Gene Encoding Enterotoxins in Staphylococcus aureus Isolated from Raw Milk and Cheese

2019 ◽  
Vol 9 (o3) ◽  
Author(s):  
Fatima N. Aziz ◽  
Laith Abdul Hassan Mohammed-Jawad
Keyword(s):  
Staphylococcus Aureus ◽  
Food Poisoning ◽  
Raw Milk ◽  
Staphylococcal Enterotoxin B ◽  
Human Pathogen ◽  
Conventional Pcr ◽  
Biochemical Tests ◽  
Specific Primers ◽  
Gene Encoding

Food poisoning due to the bacteria is a big global problem in economically and human's health. This problem refers to an illness which is due to infection or the toxin exists in nature and the food that use. Milk is considered a nutritious food because it contains proteins and vitamins. The aim of this study is to detect and phylogeny characterization of staphylococcal enterotoxin B gene (Seb). A total of 200 milk and cheese samples were screened. One hundred ten isolates of Staphylococcus aureus pre-confirmed using selective and differential media with biochemical tests. Genomic DNA was extracted from the isolates and the SEB gene detects using conventional PCR with specific primers. Three staphylococcus aureus isolates were found to be positive for Seb gene using PCR and confirmed by sequencing. Sequence homology showed variety range of identity starting from (100% to 38%). Phylogenetic tree analyses show that samples (6 and 5) are correlated with S. epidermidis. This study discovered that isolates (A6-RLQ and A5-RLQ) are significantly clustered in a group with non- human pathogen Staphylococcus agnetis.

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