scholarly journals LcpB Is a Pyrophosphatase Responsible for Wall Teichoic Acid Synthesis and Virulence in Staphylococcus aureus Clinical Isolate ST59

2021 ◽  
Vol 12 ◽  
Author(s):  
Ting Pan ◽  
Jing Guan ◽  
Yujie Li ◽  
Baolin Sun

The community-associated methicillin-resistant Staphylococcus aureus (CA-MRSA) causes severe pandemics primarily consisting of skin and soft tissue infections. However, the underlying pathomechanisms of the bacterium are yet to fully understood. The present study identifies LcpB protein, which belongs to the LytR-A-Psr (LCP) family, is crucial for cell wall synthesis and virulence in S. aureus. The findings revealed that LcpB is a pyrophosphatase responsible for wall teichoic acid synthesis. The results also showed that LcpB regulates enzyme activity through specific key arginine sites in its LCP domain. Furthermore, knockout of lcpB in the CA-MRSA isolate ST59 resulted in enhanced hemolytic activity, enlarged of abscesses, and increased leukocyte infiltration. Meanwhile, we also found that LcpB regulates virulence in agr-independent manner and the key sites for pyrophosphatase of LcpB play critical roles in regulating the virulence. In addition, the results showed that the role of LcpB was different between methicillin-resistant Staphylococcus aureus (MRSA) and methicillin-sensitive Staphylococcus aureus (MSSA). This study therefore highlights the dual role of LcpB in cell wall synthesis and regulation of virulence. These insights on the underlying molecular mechanisms can thus guide the development of novel anti-infective strategies.

2021 ◽  
Vol 8 ◽  
Author(s):  
Kristoffer T. Bæk ◽  
Camilla Jensen ◽  
Maya A. Farha ◽  
Tobias K. Nielsen ◽  
Ervin Paknejadi ◽  
...  

Staphylococcus aureus is a leading cause of bacterial infections world-wide. Staphylococcal infections are preferentially treated with β-lactam antibiotics, however, methicillin-resistant S. aureus (MRSA) strains have acquired resistance to this superior class of antibiotics. We have developed a growth-based, high-throughput screening approach that directly identifies cell wall synthesis inhibitors capable of reversing β-lactam resistance in MRSA. The screen is based on the finding that S. aureus mutants lacking the ClpX chaperone grow very poorly at 30°C unless specific steps in teichoic acid synthesis or penicillin binding protein (PBP) activity are inhibited. This property allowed us to exploit the S. aureus clpX mutant as a unique screening tool to rapidly identify biologically active compounds that target cell wall synthesis. We tested a library of ∼50,000 small chemical compounds and searched for compounds that inhibited growth of the wild type while stimulating growth of the clpX mutant. Fifty-eight compounds met these screening criteria, and preliminary tests of 10 compounds identified seven compounds that reverse β-lactam resistance of MRSA as expected for inhibitors of teichoic acid synthesis. The hit compounds are therefore promising candidates for further development as novel combination agents to restore β-lactam efficacy against MRSA.


2006 ◽  
Vol 188 (23) ◽  
pp. 8313-8316 ◽  
Author(s):  
Michael A. D'Elia ◽  
Kathryn E. Millar ◽  
Terry J. Beveridge ◽  
Eric D. Brown

ABSTRACT An extensive literature has established that the synthesis of wall teichoic acid in Bacillus subtilis is essential for cell viability. Paradoxically, we have recently shown that wall teichoic acid biogenesis is dispensable in Staphylococcus aureus (M. A. D'Elia, M. P. Pereira, Y. S. Chung, W. Zhao, A. Chau, T. J. Kenney, M. C. Sulavik, T. A. Black, and E. D. Brown, J. Bacteriol. 188:4183-4189, 2006). A complex pattern of teichoic acid gene dispensability was seen in S. aureus where the first gene (tarO) was dispensable and later acting genes showed an indispensable phenotype. Here we show, for the first time, that wall teichoic acid synthesis is also dispensable in B. subtilis and that a similar gene dispensability pattern is seen where later acting enzymes display an essential phenotype, while the gene tagO, whose product catalyzes the first step in the pathway, could be deleted to yield viable mutants devoid of teichoic acid in the cell wall.


2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Noëlle Mistretta ◽  
Marina Brossaud ◽  
Fabienne Telles ◽  
Violette Sanchez ◽  
Philippe Talaga ◽  
...  

2019 ◽  
Vol 63 (10) ◽  
Author(s):  
Bibek G C ◽  
Gyan S. Sahukhal ◽  
Mohamed O. Elasri

ABSTRACT Staphylococcus aureus is an important human pathogen in both community and health care settings. One of the challenges with S. aureus as a pathogen is its acquisition of antibiotic resistance. Previously, we showed that deletion of the msaABCR operon reduces cell wall thickness, resulting in decreased resistance to vancomycin in vancomycin-intermediate S. aureus (VISA). In this study, we investigated the nature of the cell wall defect in the msaABCR operon mutant in the Mu50 (VISA) and USA300 LAC methicillin-resistant Staphylococcus aureus (MRSA) strains. Results showed that msaABCR mutant cells had decreased cross-linking in both strains. This defect is typically due to increased murein hydrolase activity and/or nonspecific processing of murein hydrolases mediated by increased protease activity in mutant cells. The defect was enhanced by a decrease in teichoic acid content in the msaABCR mutant. Therefore, we propose that deletion of the msaABCR operon results in decreased peptidoglycan cross-linking, leading to increased susceptibility toward cell wall-targeting antibiotics, such as β-lactams and vancomycin. Moreover, we also observed significantly downregulated transcription of early cell wall-synthesizing genes, supporting the finding that msaABCR mutant cells have decreased peptidoglycan synthesis. More specifically, the msaABCR mutant in the USA300 LAC strain (MRSA) showed significantly reduced expression of the murA gene, whereas the msaABCR mutant in the Mu50 strain (VISA) showed significantly reduced expression of glmU, murA, and murD. Thus, we conclude that the msaABCR operon controls the balance between cell wall synthesis and cell wall hydrolysis, which is required for maintaining a robust cell wall and acquiring resistance to cell wall-targeting antibiotics, such as vancomycin and the β-lactams.


1969 ◽  
Vol 111 (1) ◽  
pp. 1-5 ◽  
Author(s):  
D C Ellwood ◽  
D. W. Tempest

1. Quantitative determination of the anionic polymers present in the walls of Bacillus subtilis var. niger organisms undergoing transition, in a chemostat culture, from either Mg2+-limitation to PO43−-limitation or K+-limitation to PO43−-limitation showed that teichuronic acid synthesis started immediately the culture became PO43−-limited and proceeded at a rate substantially faster than the rate of biomass synthesis. 2. Simultaneously, the cell-wall teichoic acid content diminished at a rate greater than that due to dilution by newly synthesized wall material, and fragments of teichoic acid and mucopeptide accumulated in the culture extracellular fluid. 3. Equally rapid reverse changes occurred when a PO43−-limited B. subtilis var. niger culture was returned to being Mg2+-limited. 4. It is concluded that in this organism both teichoic acid and teichuronic acid syntheses are expressions of a single genotype, and a mechanism for the control of synthesis of both polymers is suggested. 5. These results are discussed with reference to the constantly changing environmental conditions that obtain in a batch culture and the variation in bacterial cell-wall composition that is reported to occur throughout the growth cycle.


1998 ◽  
Vol 180 (3) ◽  
pp. 753-758 ◽  
Author(s):  
Wei Liu ◽  
Stephen Eder ◽  
F. Marion Hulett

ABSTRACT The tagAB and tagDEF operons, which are adjacent and divergently transcribed, encode genes responsible for cell wall teichoic acid synthesis in Bacillus subtilis. TheBacillus data presented here suggest that PhoP and PhoR are required for direct repression of transcription of the two operons under phosphate starvation conditions but have no regulatory role under phosphate-replete conditions. These data identify for the first time that PhoP∼P has a negative role in Pho regulon gene regulation.


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