scholarly journals Expression of Four Methionine Sulfoxide Reductases inStaphylococcus aureus

2012 ◽  
Vol 2012 ◽  
pp. 1-8 ◽  
Author(s):  
Kuldeep Singh ◽  
Vineet K. Singh
Keyword(s):  
Staphylococcus Aureus ◽  
Stationary Phase ◽  
Expression Pattern ◽  
Growth Phase ◽  
Methionine Sulfoxide ◽  
Phase Growth ◽  
Methionine Sulfoxide Reductases ◽  
Reporter Strains

Staphylococcus aureuspossesses three MsrA enzymes (MsrA1, MsrA2, MsrA3) that reduce the S-epimer of methionine sulfoxide (MetO) and an MsrB enzyme that reduces R-MetO. The fourmsrgenes are expressed from three different promoters. ThemsrA1/msrBgenes are coexpressed. To determine the expression pattern ofmsrgenes, three independent reporter strains were constructed wheremsrpromoter was cloned in front of a promoterlesslacZand the resulting construct was integrated in the chromosome. Using these strains, it was determined that themsrA1/Bexpression is significantly higher inS. aureuscompared tomsrA2ormsrA3. Expression ofmsrA1/Bwas highest during stationary phase growth, but the expression ofmsrA2andmsrA3was highest during the early to midexponential growth phase. Expression ofmsrA1/Bwas induced by oxacillin and the expression ofmsrA3was upregulated by salt. Expression ofmsrA2remained unchanged under all tested conditions.

scholarly journals Regulation of Expression of Oxacillin-Inducible Methionine Sulfoxide Reductases inStaphylococcus aureus

2015 ◽  
Vol 2015 ◽  
pp. 1-9 ◽  
Author(s):  
Kyle R. Baum ◽  
Zulfiqar Ahmad ◽  
Vineet K. Singh
Keyword(s):  
Staphylococcus Aureus ◽  
Cell Wall ◽  
Methionine Sulfoxide ◽  
Galactosidase Activity ◽  
Growth Phases ◽  
Wild Type ◽  
Regulation Of Expression ◽  
Methionine Sulfoxide Reductases ◽  
Reporter Strains ◽  
Dna Fragment

Cell wall-active antibiotics cause induction of a locus that leads to elevated synthesis of two methionine sulfoxide reductases (MsrA1 and MsrB) inStaphylococcus aureus. To understand the regulation of this locus, reporter strains were constructed by integrating a DNA fragment consisting of themsrA1/msrBpromoter in front of a promoterlesslacZgene in the chromosome of wild-type and MsrA1-, MsrB-, MsrA1/MsrB-, and SigB-deficient methicillin-sensitiveS. aureusstrain SH1000 and methicillin-resistantS. aureusstrain COL. These reporter strains were cultured in TSB and the cellular levels ofβ-galactosidase activity in these cultures were assayed during different growth phases.β-galactosidase activity assays demonstrated that the lack of MsrA1, MsrB, and SigB upregulated themsrA1/msrBpromoter inS. aureusstrain SH1000. InS. aureusstrain COL, the highest level ofβ-galactosidase activity was observed under the conditions when both MsrA1 and MsrB proteins were absent. The data suggest that themsrA1/msrBlocus, in part, is negatively regulated by MsrA1, MsrB, and SigB inS. aureus.

scholarly journals The Nature of Antibacterial Adaptive Immune Responses against Staphylococcus aureus Is Dependent on the Growth Phase and Extracellular Peptidoglycan

2019 ◽  
Vol 88 (1) ◽  
Author(s):  
Payal P. Balraadjsing ◽  
Lisbeth D. Lund ◽  
Yuri Souwer ◽  
Sebastian A. J. Zaat ◽  
Hanne Frøkiær ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Cell Wall ◽  
T Cell ◽  
Stationary Phase ◽  
Growth Phase ◽  
Cell Response ◽  
Th17 Cell ◽  
Exponential Phase ◽  
Th1 Cell ◽  
Content Type

ABSTRACT Staphylococcus aureus has evolved different strategies to evade the immune response, which play an important role in its pathogenesis. The bacteria express and shed various cell wall components and toxins during different stages of growth that may affect the protective T cell responses to extracellular and intracellular S. aureus. However, if and how the dendritic cell (DC)-mediated T cell response against S. aureus changes during growth of the bacterium remain elusive. In this study, we show that exponential-phase (EP) S. aureus bacteria were endocytosed very efficiently by human DCs, and these DCs strongly promoted production of the T cell polarizing factor interleukin-12 (IL-12). In contrast, stationary-phase (SP) S. aureus bacteria were endocytosed less efficiently by DCs, and these DCs produced small amounts of IL-12. The high level of IL-12 production induced by EP S. aureus led to the development of a T helper 1 (Th1) cell response, which was inhibited after neutralization of IL-12. Furthermore, preincubation with the staphylococcal cell wall component peptidoglycan (PGN), characteristically shed during the exponential growth phase, modulated the DC response to EP S. aureus. PGN preincubation appeared to inhibit IL-12p35 expression, leading to downregulation of IL-12 and an increase of IL-23 production by DCs, enhancing Th17 cell development. Taken together, our data indicate that exponential-phase S. aureus bacteria induce a stronger IL-12-dependent Th1 cell response than stationary-phase S. aureus and that this Th1 cell response shifted toward a Th17 cell response in the presence of PGN.

scholarly journals Methionine Sulfoxide Reductases Protect against Oxidative Stress in Staphylococcus aureus Encountering Exogenous Oxidants and Human Neutrophils

2013 ◽  
Vol 6 (3) ◽  
pp. 353-364 ◽  
Author(s):  
Yun Yun Pang ◽  
Jamie Schwartz ◽  
Sarah Bloomberg ◽  
Jeffrey M. Boyd ◽  
Alexander R. Horswill ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Staphylococcus Aureus ◽  
Methionine Sulfoxide ◽  
Human Neutrophils ◽  
Methionine Sulfoxide Reductases

GROWTH OF PENICILLIN-RESISTANT AND PENICILLIN-SENSITIVE STRAINS OF STAPHYLOCOCCUS AUREUS

1963 ◽  
Vol 9 (2) ◽  
pp. 179-186
Author(s):  
Wendall E. Allen ◽  
Ilda McVeigh
Keyword(s):  
Staphylococcus Aureus ◽  
Stationary Phase ◽  
Growth Phase ◽  
Growth Curves ◽  
Viable Cell ◽  
Fresh Medium ◽  
Logarithmic Growth Phase ◽  
Resistant Strains ◽  
Logarithmic Growth

Ten strains of naturally penicillin-resistant Staphylococcus aureus (obtained from patients), two in vitro derived resistant strains, and two sensitive strains, were grown at 37 C in Antibiotic Assay broth, and viable cell determinations were made at intervals. From these data, growth curves were plotted for each of the strains. The curves for the naturally penicillin-resistant and the sensitive strains are very similar. Little, if any, lag in growth of these strains occurred on transfer from maximum stationary-phase cultures to fresh medium. They grew at approximately the same rate during the logarithmic growth phase, which lasted for 3 to 4 hours; during the maximum stationary phase, about the same number of cells was present per milliliter in cultures of each of these strains. In contrast, the in vitro derived resistant strains underwent a lag of 2 to 6 hours on transfer to fresh medium and grew at a slower rate during the logarithmic growth phase. However, during the maximum stationary phase, which occurred after an incubation period of 24 to 32 hours, the cell titers were approximately the same as those of the naturally resistant and the sensitive strains. When grown in competition with either of the sensitive strains in Antibiotic Assay broth in the absence of penicillin, one of the naturally resistant strains persisted for 14 successive subcultures without any apparent change in ability to tolerate the antibiotic.

scholarly journals Growth-phase dependence of susceptibility to antimicrobial peptides in Staphylococcus aureus

Microbiology ◽  
2011 ◽  
Vol 157 (6) ◽  
pp. 1786-1797 ◽  
Author(s):  
Miki Matsuo ◽  
Yuichi Oogai ◽  
Fuminori Kato ◽  
Motoyuki Sugai ◽  
Hitoshi Komatsuzawa
Keyword(s):  
Staphylococcus Aureus ◽  
Cell Surface ◽  
Antimicrobial Peptides ◽  
Stationary Phase ◽  
Surface Charge ◽  
Growth Phase ◽  
Exponential Phase ◽  
Dependent Manner ◽  
Phase Dependence ◽  
Cell Surface Charge

Bacterial cell surface charge is responsible for susceptibility to cationic antimicrobial peptides. Previously, Staphylococcus aureus dlt and mprF were identified as factors conferring a positive charge upon cell surfaces. In this study, we investigated the regulation of cell surface charge during growth. Using a group of S. aureus MW2 mutants, which are gene-inactivated in 15 types of two-component systems (TCSs), we tested dltC and mprF expression and found that two TCSs, aps and agr, were associated with dltC and mprF expression in a growth phase-dependent manner. The first of these, aps, which had already been identified as a sensor of antimicrobial peptides and a positive regulator of dlt and mprF expression, was expressed strongly in the exponential phase, while its expression was significantly suppressed by agr in the stationary phase, resulting in higher expression of dltC and mprF in the exponential phase and lower expression in the stationary phase. Since both types of expression affected the cell surface charge, the susceptibility to antimicrobial peptides and cationic antibiotics was changed during growth. Furthermore, we found that the ability to sense antimicrobial peptides only functioned in the exponential phase. These results suggest that cell surface charge is tightly regulated during growth in S. aureus.

scholarly journals Significance of Four Methionine Sulfoxide Reductases in Staphylococcus aureus

PLoS ONE ◽  
2015 ◽  
Vol 10 (2) ◽  
pp. e0117594 ◽  
Author(s):  
Vineet K. Singh ◽  
Manisha Vaish ◽  
Trintje R. Johansson ◽  
Kyle R. Baum ◽  
Robert P. Ring ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Methionine Sulfoxide ◽  
Methionine Sulfoxide Reductases

scholarly journals The Role of Methionine Sulfoxide Reductases in Oxidative Stress Tolerance and Virulence of Staphylococcus aureus and Other Bacteria

Antioxidants ◽  
2018 ◽  
Vol 7 (10) ◽  
pp. 128 ◽  
Author(s):  
Vineet Singh ◽  
Kuldeep Singh ◽  
Kyle Baum
Keyword(s):  
Oxidative Stress ◽  
Staphylococcus Aureus ◽  
Cell Wall ◽  
Regulatory Network ◽  
Current Knowledge ◽  
Methionine Sulfoxide ◽  
Oxidative Stress Tolerance ◽  
Methionine Sulfoxide Reductases ◽  
Encoding Genes

Methionine sulfoxide reductases (MSRA1 and MSRB) are proteins overproduced in Staphylococcus aureus during exposure with cell wall-active antibiotics. Later studies identified the presence of two additional MSRA proteins (MSRA2 and MSRA3) in S. aureus. These MSR proteins have been characterized in many other bacteria as well. This review provides the current knowledge about the conditions and regulatory network that mimic the expression of these MSR encoding genes and their role in defense from oxidative stress and virulence.

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