scholarly journals The Cell Wall Polymer Lipoteichoic Acid Becomes Nonessential inStaphylococcus aureusCells Lacking the ClpX Chaperone

mBio ◽  
2016 ◽  
Vol 7 (4) ◽  
Author(s):  
Kristoffer T. Bæk ◽  
Lisa Bowman ◽  
Charlotte Millership ◽  
Mia Dupont Søgaard ◽  
Volkhard Kaever ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Cell Wall ◽  
Cell Division ◽  
Lipoteichoic Acid ◽  
Growth Defect ◽  
Gram Positive ◽  
Functional Connection ◽  
Antibiotic Resistant ◽  
Gram Positive Bacteria ◽  
Autolytic Activity

ABSTRACTLipoteichoic acid (LTA) is an important cell wall component of Gram-positive bacteria and a promising target for the development of vaccines and antimicrobial compounds againstStaphylococcus aureus. Here we demonstrate that mutations in the conditionally essentialltaS(LTA synthase) gene arise spontaneously in anS. aureusmutant lacking the ClpX chaperone. A wide variety ofltaSmutations were selected, and among these, a substantial portion resulted in premature stop codons and other changes predicted to abolish LtaS synthesis. Consistent with this assumption, theclpX ltaSdouble mutants did not produce LTA, and genetic analyses confirmed that LTA becomes nonessential in the absence of the ClpX chaperone. In fact, inactivation ofltaSalleviated the severe growth defect conferred by theclpXdeletion. Microscopic analyses showed that the absence of ClpX partly alleviates the septum placement defects of an LTA-depleted strain, while other phenotypes typical of LTA-negativeS. aureusmutants, including increased cell size and decreased autolytic activity, are retained. In conclusion, our results indicate that LTA has an essential role in septum placement that can be bypassed by inactivating the ClpX chaperone.IMPORTANCELipoteichoic acid is an essential component of theStaphylococcus aureuscell envelope and an attractive target for the development of vaccines and antimicrobials directed against antibiotic-resistant Gram-positive bacteria such as methicillin-resistantS. aureusand vancomycin-resistant enterococci. In this study, we showed that the lipoteichoic acid polymer is essential for growth ofS. aureusonly as long as the ClpX chaperone is present in the cell. Our results indicate that lipoteichoic acid and ClpX play opposite roles in a pathway that controls two key cell division processes inS. aureus, namely, septum formation and autolytic activity. The discovery of a novel functional connection in the genetic network that controls cell division inS. aureusmay expand the repertoire of possible strategies to identify compounds or compound combinations that kill antibiotic-resistantS. aureus.

scholarly journals Gram-positive bacteria cell wall-derived lipoteichoic acid induces inflammatory alveolar bone loss through prostaglandin E production in osteoblasts

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Tsukasa Tominari ◽  
Ayumi Sanada ◽  
Ryota Ichimaru ◽  
Chiho Matsumoto ◽  
Michiko Hirata ◽  
...  
Keyword(s):  
Cell Wall ◽  
Bone Loss ◽  
Alveolar Bone ◽  
Osteoclast Differentiation ◽  
Lipoteichoic Acid ◽  
Alveolar Bone Loss ◽  
Gram Negative Bacteria ◽  
Gram Positive ◽  
Gram Negative ◽  
Gram Positive Bacteria

AbstractPeriodontitis is an inflammatory disease associated with severe alveolar bone loss and is dominantly induced by lipopolysaccharide from Gram-negative bacteria; however, the role of Gram-positive bacteria in periodontal bone resorption remains unclear. In this study, we examined the effects of lipoteichoic acid (LTA), a major cell-wall factor of Gram-positive bacteria, on the progression of inflammatory alveolar bone loss in a model of periodontitis. In coculture of mouse primary osteoblasts and bone marrow cells, LTA induced osteoclast differentiation in a dose-dependent manner. LTA enhanced the production of PGE2 accompanying the upregulation of the mRNA expression of mPGES-1, COX-2 and RANKL in osteoblasts. The addition of indomethacin effectively blocked the LTA-induced osteoclast differentiation by suppressing the production of PGE2. Using ex vivo organ cultures of mouse alveolar bone, we found that LTA induced alveolar bone resorption and that this was suppressed by indomethacin. In an experimental model of periodontitis, LTA was locally injected into the mouse lower gingiva, and we clearly detected alveolar bone destruction using 3D-μCT. We herein demonstrate a new concept indicating that Gram-positive bacteria in addition to Gram-negative bacteria are associated with the progression of periodontal bone loss.

Covalent Sortase A Inhibitor ML346 Prevents Staphylococcus aureus Infection of Galleria mellonella

2021 ◽  
Author(s):  
Xiang-Na Guan ◽  
Tao Zhang ◽  
Teng Yang ◽  
Ze Dong ◽  
Song Yang ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Cell Wall ◽  
Galleria Mellonella ◽  
Surface Proteins ◽  
Sortase A ◽  
Gram Positive ◽  
Gram Positive Bacteria ◽  
Aureus Infection ◽  
Cell Wall Peptidoglycan

The housekeeping sortase A (SrtA), a membrane-associated cysteine transpeptidase, is responsible for anchoring surface proteins to the cell wall peptidoglycan in Gram-positive bacteria. This process is essential for the regulation...

scholarly journals A Comparative Genome Analysis Identifies Distinct Sorting Pathways in Gram-Positive Bacteria

2004 ◽  
Vol 72 (5) ◽  
pp. 2710-2722 ◽  
Author(s):  
David Comfort ◽  
Robert T. Clubb
Keyword(s):  
Staphylococcus Aureus ◽  
Cell Wall ◽  
Surface Proteins ◽  
Sequence Motifs ◽  
Comparative Genome Analysis ◽  
Gram Positive ◽  
Microbial Genomes ◽  
Searchable Database ◽  
Gram Positive Bacteria ◽  
Related Proteins

ABSTRACT Surface proteins in gram-positive bacteria are frequently required for virulence, and many are attached to the cell wall by sortase enzymes. Bacteria frequently encode more than one sortase enzyme and an even larger number of potential sortase substrates that possess an LPXTG-type cell wall sorting signal. In order to elucidate the sorting pathways present in gram-positive bacteria, we performed a comparative analysis of 72 sequenced microbial genomes. We show that sortase enzymes can be partitioned into five distinct subfamilies based upon their primary sequences and that most of their substrates can be predicted by making a few conservative assumptions. Most bacteria encode sortases from two or more subfamilies, which are predicted to function nonredundantly in sorting proteins to the cell surface. Only ∼20% of sortase-related proteins are most closely related to the well-characterized Staphylococcus aureus SrtA protein, but nonetheless, these proteins are responsible for anchoring the majority of surface proteins in gram-positive bacteria. In contrast, most sortase-like proteins are predicted to play a more specialized role, with each anchoring far fewer proteins that contain unusual sequence motifs. The functional sortase-substrate linkage predictions are available online (http://www.doe-mbi.ucla.edu/Services/Sortase/ ) in a searchable database.

scholarly journals L-Ficolin Specifically Binds to Lipoteichoic Acid, a Cell Wall Constituent of Gram-Positive Bacteria, and Activates the Lectin Pathway of Complement

2004 ◽  
Vol 172 (2) ◽  
pp. 1198-1202 ◽  
Author(s):  
Nicholas J. Lynch ◽  
Silke Roscher ◽  
Thomas Hartung ◽  
Siegfried Morath ◽  
Misao Matsushita ◽  
...  
Keyword(s):  
Cell Wall ◽  
Lipoteichoic Acid ◽  
Lectin Pathway ◽  
Gram Positive ◽  
Gram Positive Bacteria ◽  
Cell Wall Constituent ◽  
A Cell

scholarly journals Antimicrobial Biophotonic Treatment of Ampicillin-Resistant Pseudomonas aeruginosa with Hypericin and Ampicillin Cotreatment Followed by Orange Light

Pharmaceutics ◽  
2019 ◽  
Vol 11 (12) ◽  
pp. 641 ◽  
Author(s):  
Seemi Tasnim Alam ◽  
Tram Anh Ngoc Le ◽  
Jin-Soo Park ◽  
Hak Cheol Kwon ◽  
Kyungsu Kang
Keyword(s):  
Staphylococcus Aureus ◽  
Pseudomonas Aeruginosa ◽  
Cell Wall ◽  
Gram Positive ◽  
Gram Negative ◽  
Gram Positive Bacteria ◽  
Wall Structures ◽  
Global Issue ◽  
Life Threatening ◽  
Bacteria And Fungi

Bacterial antibiotic resistance is an alarming global issue that requires alternative antimicrobial methods to which there is no resistance. Antimicrobial photodynamic therapy (APDT) is a well-known method to combat this problem for many pathogens, especially Gram-positive bacteria and fungi. Hypericin and orange light APDT efficiently kill Staphylococcus aureus, methicillin-resistant Staphylococcus aureus (MRSA), and the yeast Candida albicans. Although Gram-positive bacteria and many fungi are readily killed with APDT, Gram-negative bacteria are difficult to kill due to their different cell wall structures. Pseudomonas aeruginosa is one of the most important opportunistic, life-threatening Gram-negative pathogens. However, it cannot be killed successfully by hypericin and orange light APDT. P. aeruginosa is ampicillin resistant, but we hypothesized that ampicillin could still damage the cell wall, which can promote photosensitizer uptake into Gram-negative cells. Using hypericin and ampicillin cotreatment followed by orange light, a significant reduction (3.4 log) in P. aeruginosa PAO1 was achieved. P. aeruginosa PAO1 inactivation and gut permeability improvement by APDT were successfully shown in a Caenorhabditis elegans model.

scholarly journals Molecules from Staphylococcus aureus that bind CD14 and stimulate innate immune responses.

1995 ◽  
Vol 182 (6) ◽  
pp. 1673-1682 ◽  
Author(s):  
T Kusunoki ◽  
E Hailman ◽  
T S Juan ◽  
H S Lichenstein ◽  
S D Wright
Keyword(s):  
Staphylococcus Aureus ◽  
Inflammatory Response ◽  
Minor Component ◽  
Lipoteichoic Acid ◽  
Cell Types ◽  
Abundant Species ◽  
Gram Positive ◽  
Gram Negative ◽  
Free Phenol ◽  
Gram Positive Bacteria

Mammals mount a rapid inflammatory response to gram-negative bacteria by recognizing lipopolysaccharide (LPS, endotoxin). LPS binds to CD14, and the resulting LPS-CD14 complex induces synthesis of cytokines and up-regulation of adhesion molecules in a variety of cell types. Gram-positive bacteria provoke a very similar inflammatory response, but the molecules that provoke innate responses to these bacteria have not been defined. Here we show that protein-free, phenol extracts of Staphylococcus aureus contain a minor component that stimulates adhesion of neutrophils and cytokine production in monocytes and in the astrocytoma cell line, U373. Responses to this component do not absolutely require CD14, but addition of soluble CD14 enhances sensitivity of U373 cells by up to 100-fold, and blocking CD14 on monocytes decreases sensitivity nearly 1,000-fold. Deletion of residues 57-64 of CD14, which are required for responses to LPS, also eliminates CD14-dependent responses to S. aureus molecules. The stimulatory component of S. aureus binds CD14 and blocks binding of radioactive LPS. Unlike LPS, the activity of S. aureus molecules was neither enhanced by LPS binding protein nor inhibited by bactericidal/permeability increasing protein. The active factor in extracts of S. aureus is also structurally and functionally distinct from the abundant species known as lipoteichoic acid (LTA). Cell-stimulating activity fractionates differently from LTA on a reverse-phase column, pure LTA fails to stimulate cells, and LTA antagonizes the action of LPS in assays of IL-6 production. These studies suggest that mammals may use CD14 in innate responses to both gram-negative and gram-positive bacteria, and that gram-positive bacteria may contain an apparently unique, CD14-binding species that initiates cellular responses.

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