scholarly journals Unprotonated Short-Chain Alkylamines Inhibit Staphylolytic Activity of Lysostaphin in a Wall Teichoic Acid-Dependent Manner

2018 ◽  
Vol 84 (14) ◽  
Author(s):  
Xia Wu ◽  
Seok Joon Kwon ◽  
Domyoung Kim ◽  
Jian Zha ◽  
Mauricio Mora-Pale ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Respiratory Infections ◽  
Teichoic Acid ◽  
Inhibitory Effect ◽  
Short Chain ◽  
Dependent Manner ◽  
Cell Binding ◽  
Wall Teichoic Acid ◽  
Content Type ◽  
The Impact

ABSTRACTLysostaphin (Lst) is a potent bacteriolytic enzyme that killsStaphylococcus aureus, a common bacterial pathogen of humans and animals. With high activity against both planktonic cells and biofilms, Lst has the potential to be used in industrial products, such as commercial cleansers, for decontamination. However, Lst is inhibited in the presence of monoethanolamine (MEA), a chemical widely used in cleaning solutions and pharmaceuticals, and the underlying mechanism of inhibition remains unknown. In this study, we examined the cell binding and killing capabilities of Lst againstS. aureusATCC 6538 in buffered salt solution with MEA at different pH values (7.5 to 10.5) and discovered that only the unprotonated form of MEA inhibited Lst binding to the cell surface, leading to low Lst activity, despite retention of its secondary structure. This reduced enzyme activity could be largely recovered via a reduction in wall teichoic acid (WTA) biosynthesis through tunicamycin treatment, indicating that the suppression of Lst activity was dependent on the presence and amount of WTA. We propose that the decreased cell binding and killing capabilities of Lst are associated with the influence of uncharged MEA on the conformation of WTA. A similar effect was confirmed with other short-chain alkylamines. This study offers new insight into the impact of short-chain alkylamines on both Lst and WTA structure and function and provides guidance for the application of Lst in harsh environments.IMPORTANCELysostaphin (Lst) effectively and selectively killsStaphylococcus aureus, the bacterial culprit of many hospital- and community-acquired skin and respiratory infections and food poisoning. Lst has been investigated in animal models and clinical trials, industrial formulations, and environmental settings. Here, we studied the mechanistic basis of the inhibitory effect of alkylamines, such as monoethanolamine (MEA), a widely used chemical in commercial detergents, on Lst activity, for the potential incorporation of Lst in disinfectant solutions. We have found that protonated MEA has little influence on Lst activity, while unprotonated MEA prevents Lst from binding toS. aureuscells and hence dramatically decreases the enzyme's bacteriolytic efficacy. Following partial removal of the wall teichoic acid, an important component of the bacterial cell envelope, the inhibitory effect of unprotonated MEA on Lst is reduced. This phenomenon can be extended to other short-chain alkylamines. This mechanistic report of the impact of alkylamines on Lst functionality will help guide future applications of Lst in disinfection and decontamination of health-related commercial products.

scholarly journals Surface Glycopolymers Are Crucial forIn VitroAnti-Wall Teichoic Acid IgG-Mediated Complement Activation and Opsonophagocytosis of Staphylococcus aureus

2015 ◽  
Vol 83 (11) ◽  
pp. 4247-4255 ◽  
Author(s):  
Jong-Ho Lee ◽  
Na-Hyang Kim ◽  
Volker Winstel ◽  
Kenji Kurokawa ◽  
Jesper Larsen ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Teichoic Acid ◽  
Complement C3 ◽  
Glycerol Phosphate ◽  
Glycosylation Pattern ◽  
Wall Teichoic Acid ◽  
Content Type ◽  
Gram Positive Bacteria ◽  
Capsule Production ◽  
Cell Envelopes

ABSTRACTThe cell envelopes of many Gram-positive bacteria contain wall teichoic acids (WTAs).Staphylococcus aureusWTAs are composed of ribitol phosphate (RboP) or glycerol phosphate (GroP) backbones substituted withd-alanine andN-acetyl-d-glucosamine (GlcNAc) orN-acetyl-d-galactosamine (GalNAc). Two WTA glycosyltransferases, TarM and TarS, are responsible for modifying the RboP WTA with α-GlcNAc and β-GlcNAc, respectively. We recently reported that purified human serum anti-WTA IgG specifically recognizes β-GlcNAc of the staphylococcal RboP WTA and then facilitates complement C3 deposition and opsonophagocytosis ofS. aureuslaboratory strains. This prompted us to examine whether anti-WTA IgG can induce C3 deposition on a diverse set of clinicalS. aureusisolates. To this end, we compared anti-WTA IgG-mediated C3 deposition and opsonophagocytosis abilities using 13 different staphylococcal strains. Of note, the majority ofS. aureusstrains tested was recognized by anti-WTA IgG, resulting in C3 deposition and opsonophagocytosis. A minority of strains was not recognized by anti-WTA IgG, which correlated with either extensive capsule production or an alteration in the WTA glycosylation pattern. Our results demonstrate that the presence of WTAs with TarS-mediated glycosylation with β-GlcNAc in clinically isolatedS. aureusstrains is an important factor for induction of anti-WTA IgG-mediated C3 deposition and opsonophagocytosis.

scholarly journals Wall Teichoic Acid Glycosylation Governs Staphylococcus aureus Nasal Colonization

mBio ◽  
2015 ◽  
Vol 6 (4) ◽  
Author(s):  
Volker Winstel ◽  
Petra Kühner ◽  
Ferdinand Salomon ◽  
Jesper Larsen ◽  
Robert Skov ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Risk Factor ◽  
Epithelial Cells ◽  
Teichoic Acid ◽  
Nasal Colonization ◽  
Human Pathogen ◽  
Wall Teichoic Acid ◽  
Content Type ◽  
Human Nasal Epithelial Cells ◽  
Key Factor

ABSTRACT Nasal colonization by the human pathogen Staphylococcus aureus is a major risk factor for hospital- and community-acquired infections. A key factor required for nasal colonization is a cell surface-exposed zwitterionic glycopolymer, termed wall teichoic acid (WTA). However, the precise mechanisms that govern WTA-mediated nasal colonization have remained elusive. Here, we report that WTA GlcNAcylation is a pivotal requirement for WTA-dependent attachment of community-acquired methicillin-resistant S. aureus (MRSA) and emerging livestock-associated MRSA to human nasal epithelial cells, even under conditions simulating the nutrient composition and dynamic flow of nasal secretions. Depending on the S. aureus strain, WTA O-GlcNAcylation occurs in either α or β configuration, which have similar capacities to mediate attachment to human nasal epithelial cells, suggesting that many S. aureus strains maintain redundant pathways to ensure appropriate WTA glycosylation. Strikingly, a lack of WTA glycosylation significantly abrogated the ability of MRSA to colonize cotton rat nares in vivo. These results indicate that WTA glycosylation modulates S. aureus nasal colonization and may help to develop new strategies for eradicating S. aureus nasal colonization in the future. IMPORTANCE Nasal colonization by the major human pathogen Staphylococcus aureus is a risk factor for severe endogenous infections and contributes to the spread of this microbe in hospitals and the community. Here, we show that wall teichoic acid (WTA) O-GlcNAcylation is a key factor required for S. aureus nasal colonization. These data provide a mechanistic explanation for the capacity of WTA to modulate S. aureus nasal colonization and may stimulate research activities to establish valuable strategies to eradicate S. aureus nasal colonization in high-risk hospitalized patients and in the general community.

scholarly journals The impact of Staphylococcus aureus cell wall glycosylation on langerin recognition and Langerhans cell activation

2020 ◽  
Author(s):  
A Hendriks ◽  
R van Dalen ◽  
S Ali ◽  
D Gerlach ◽  
GA van der Marel ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Cell Wall ◽  
Cell Activation ◽  
Teichoic Acid ◽  
Binding Studies ◽  
Wall Teichoic Acid ◽  
Linkage Position ◽  
Antigen Presenting ◽  
The Impact

AbstractStaphylococcus aureus is the leading cause of skin and soft tissue infections. It remains incompletely understood how skin-resident immune cells respond to S. aureus invasion and contribute to an effective immune response. Langerhans cells (LCs), the only professional antigen-presenting cell type in the epidermis, sense S. aureus through their pattern-recognition receptor langerin, triggering a pro-inflammatory response. Langerin specifically recognizes the β-1,4-linked N-acetylglucosamine (β-GlcNAc) modification, which requires the glycosyltransferase TarS, on the cell wall glycopolymer Wall Teichoic Acid (WTA). Recently, an alternative WTA glycosyltransferase, TarP, was identified in methicillin-resistant S. aureus strains belonging to clonal complexes (CC) 5 and CC398. TarP also modifies WTA with β-GlcNAc but at the C-3 position of the WTA ribitol phosphate (RboP) subunit. Here, we aimed to unravel the impact of β-GlcNAc linkage position for langerin binding and LC activation. In addition, we performed structure-binding studies using a small panel of unique chemically-synthesized WTA molecules to assess langerin-WTA binding requirements. Using FITC-labeled recombinant human langerin and genetically-modified S. aureus strains, we observed that langerin similarly recognized bacteria that produce either TarS- or TarP-modified WTA. Furthermore, using chemically-synthesized WTA, representative of the different S. aureus WTA glycosylation patterns, established that β-GlcNAc is sufficient to confer langerin binding. Functionally, tarP-expressing S. aureus induce increased cytokine production and maturation of in vitro-generated LCs compared to tarSexpressing S. aureus. Overall, our data suggest that LCs are able to sense all β-GlcNAc-WTA producing S. aureus strains, likely performing an important role as first responders upon S. aureus skin invasion.

scholarly journals Langerhans Cells SenseStaphylococcus aureusWall Teichoic Acid through Langerin To Induce Inflammatory Responses

mBio ◽  
2019 ◽  
Vol 10 (3) ◽  
Author(s):  
Rob van Dalen ◽  
Jacinto S. De La Cruz Diaz ◽  
Matevž Rumpret ◽  
Felix F. Fuchsberger ◽  
Nienke H. van Teijlingen ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Langerhans Cells ◽  
Molecular Mechanisms ◽  
Inflammatory Responses ◽  
Teichoic Acid ◽  
Infection Model ◽  
Wall Teichoic Acid ◽  
Content Type ◽  
Staphylococcal Species ◽  
Specific Subset

ABSTRACTStaphylococcus aureusis a major cause of skin and soft tissue infections and aggravator of the inflammatory skin disease atopic dermatitis (AD [eczema]). Epicutaneous exposure toS. aureusinduces Th17 responses through skin Langerhans cells (LCs), which paradoxically contribute to host defense but also to AD pathogenesis. The molecular mechanisms underlying the interaction betweenS. aureusand LCs are poorly understood. Here we demonstrate that human LCs directly interact withS. aureusthrough the pattern recognition receptor langerin (CD207). Human, but not mouse, langerin interacts withS. aureusthrough the conserved β-N-acetylglucosamine (GlcNAc) modifications on wall teichoic acid (WTA), thereby discriminatingS. aureusfrom other staphylococcal species. Importantly, the specificS. aureusWTA glycoprofile strongly influences the level of proinflammatory cytokines that are produced byin vitro-generated LCs. Finally, in a murine epicutaneous infection model,S. aureusstrongly upregulated transcripts ofCxcl1,Il6, andIl17, which required the presence of both human langerin and WTA β-GlcNAc. Our findings provide molecular insight into the unique proinflammatory capacities ofS. aureusin relation to skin inflammation.IMPORTANCEThe bacteriumStaphylococcus aureusis an important cause of skin infections and is also associated with the occurrence and severity of eczema. Langerhans cells (LCs), a specific subset of skin immune cells, participate in the immune response toS. aureus, but it is yet unclear how LCs recognizeS. aureus. Therefore, we investigated the molecular mechanism underlying the interaction between LCs andS. aureus. We identified that wall teichoic acid, an abundant polymer on theS. aureussurface, is recognized by langerin, a receptor unique to LCs. This interaction allows LCs to discriminateS. aureusfrom other related staphylococcal species and initiates a proinflammatory response similar to that observed in patients with eczema. Our data therefore provide important new insights into the relationship betweenS. aureus, LCs, and eczema.

scholarly journals An Antibiotic That Inhibits a Late Step in Wall Teichoic Acid Biosynthesis Induces the Cell Wall Stress Stimulon in Staphylococcus aureus

2012 ◽  
Vol 56 (4) ◽  
pp. 1810-1820 ◽  
Author(s):  
Jennifer Campbell ◽  
Atul K. Singh ◽  
Jonathan G. Swoboda ◽  
Michael S. Gilmore ◽  
Brian J. Wilkinson ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Cell Wall ◽  
Osmotic Stress ◽  
Late Stage ◽  
Teichoic Acid ◽  
Wall Stress ◽  
Wall Teichoic Acid ◽  
Content Type ◽  
Cell Wall Stress

ABSTRACTWall teichoic acids (WTAs) are phosphate-rich, sugar-based polymers attached to the cell walls of most Gram-positive bacteria. InStaphylococcus aureus, these anionic polymers regulate cell division, protect cells from osmotic stress, mediate host colonization, and mask enzymatically susceptible peptidoglycan bonds. Although WTAs are not required for survivalin vitro, blocking the pathway at a late stage of synthesis is lethal. We recently discovered a novel antibiotic, targocil, that inhibits a late acting step in the WTA pathway. Its target is TarG, the transmembrane component of the ABC transporter (TarGH) that exports WTAs to the cell surface. We examined here the effects of targocil onS. aureususing transmission electron microscopy and gene expression profiling. We report that targocil treatment leads to multicellular clusters containing swollen cells displaying evidence of osmotic stress, strongly induces the cell wall stress stimulon, and reduces the expression of key virulence genes, includingdltABCDand capsule genes. We conclude that WTA inhibitors that act at a late stage of the biosynthetic pathway may be useful as antibiotics, and we present evidence that they could be particularly useful in combination with beta-lactams.

scholarly journals Staphylococcus aureus Metabolic Adaptations during the Transition from a Daptomycin Susceptibility Phenotype to a Daptomycin Nonsusceptibility Phenotype

2015 ◽  
Vol 59 (7) ◽  
pp. 4226-4238 ◽  
Author(s):  
Rosmarie Gaupp ◽  
Shulei Lei ◽  
Joseph M. Reed ◽  
Henrik Peisker ◽  
Susan Boyle-Vavra ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Tricarboxylic Acid Cycle ◽  
Teichoic Acid ◽  
Common Mechanism ◽  
Virulence Determinants ◽  
Wall Teichoic Acid ◽  
Content Type ◽  
Adaptive Resistance ◽  
Peptidoglycan Biosynthesis ◽  
Delayed Transition

ABSTRACTStaphylococcus aureusis a major cause of nosocomial and community-acquired infections. The success ofS. aureusas a pathogen is due in part to its many virulence determinants and resistance to antimicrobials. In particular, methicillin-resistantS. aureushas emerged as a major cause of infections and led to increased use of the antibiotics vancomycin and daptomycin, which has increased the isolation of vancomycin-intermediateS. aureusand daptomycin-nonsusceptibleS. aureusstrains. The most common mechanism by whichS. aureusacquires intermediate resistance to antibiotics is by adapting its physiology and metabolism to permit growth in the presence of these antibiotics, a process known as adaptive resistance. To better understand the physiological and metabolic changes associated with adaptive resistance, six daptomycin-susceptible and -nonsusceptible isogenic strain pairs were examined for changes in growth, competitive fitness, and metabolic alterations. Interestingly, daptomycin nonsusceptibility coincides with a slightly delayed transition to the postexponential growth phase and alterations in metabolism. Specifically, daptomycin-nonsusceptible strains have decreased tricarboxylic acid cycle activity, which correlates with increased synthesis of pyrimidines and purines and increased carbon flow to pathways associated with wall teichoic acid and peptidoglycan biosynthesis. Importantly, these data provided an opportunity to alter the daptomycin nonsusceptibility phenotype by manipulating bacterial metabolism, a first step in developing compounds that target metabolic pathways that can be used in combination with daptomycin to reduce treatment failures.

scholarly journals Metabolic Mitigation of Staphylococcus aureus Vancomycin Intermediate-Level Susceptibility

2017 ◽  
Vol 62 (1) ◽  
Author(s):  
Stewart G. Gardner ◽  
Darrell D. Marshall ◽  
Robert S. Daum ◽  
Robert Powers ◽  
Greg A. Somerville
Keyword(s):  
Staphylococcus Aureus ◽  
Teichoic Acid ◽  
Tca Cycle ◽  
Amino Sugar ◽  
Pentose Phosphate ◽  
Metabolic Changes ◽  
Purine Biosynthesis ◽  
Wall Teichoic Acid ◽  
Content Type ◽  
Adaptive Resistance

ABSTRACTStaphylococcus aureusis a major human pathogen whose infections are increasingly difficult to treat due to increased antibiotic resistance, including resistance to vancomycin. Vancomycin-intermediateS. aureus(VISA) strains develop resistance to vancomycin through adaptive changes that are incompletely understood. Central to this adaptation are metabolic changes that permit growth in the presence of vancomycin. To define the metabolic changes associated with adaptive resistance to vancomycin inS. aureus, the metabolomes of a vancomycin-sensitive and VISA strain pair isolated from the same patient shortly after vancomycin therapy began and following vancomycin treatment failure were analyzed. The metabolic adaptations included increases in acetogenesis, carbon flow through the pentose phosphate pathway, wall teichoic acid and peptidoglycan precursor biosynthesis, purine biosynthesis, and decreased tricarboxylic acid (TCA) cycle activity. The significance of these metabolic pathways for vancomycin-intermediate susceptibility was determined by assessing the synergistic potential of human-use-approved inhibitors of these pathways in combination with vancomycin against VISA strains. Importantly, inhibitors of amino sugar and purine biosynthesis acted synergistically with vancomycin to kill a diverse set of VISA strains, suggesting that combinatorial therapy could augment the efficacy of vancomycin even in patients infected with VISA strains.

scholarly journals Inactivation of the Monofunctional Peptidoglycan Glycosyltransferase SgtB AllowsStaphylococcus aureusTo Survive in the Absence of Lipoteichoic Acid

2018 ◽  
Vol 201 (1) ◽  
Author(s):  
Eleni Karinou ◽  
Christopher F. Schuster ◽  
Manuel Pazos ◽  
Waldemar Vollmer ◽  
Angelika Gründling
Keyword(s):  
Staphylococcus Aureus ◽  
Cell Wall ◽  
Mutant Strain ◽  
Teichoic Acid ◽  
Fold Increase ◽  
Lipoteichoic Acid ◽  
Wall Teichoic Acid ◽  
Content Type ◽  
Anionic Polymers ◽  
Peptidoglycan Structure

ABSTRACTThe cell wall ofStaphylococcus aureusis composed of peptidoglycan and the anionic polymers lipoteichoic acid (LTA) and wall teichoic acid. LTA is required for growth and normal cell morphology inS. aureus. Strains lacking LTA are usually viable only when grown under osmotically stabilizing conditions or after the acquisition of compensatory mutations. LTA-negative suppressor strains with inactivating mutations ingdpP, which resulted in increased intracellular c-di-AMP levels, were described previously. Here, we sought to identify factors other than c-di-AMP that allowS. aureusto survive without LTA. LTA-negative strains able to grow in unsupplemented medium were obtained and found to contain mutations insgtB,mazE,clpX, orvraT. The growth improvement through mutations inmazEandsgtBwas confirmed by complementation analysis. We also showed that anS. aureussgtBtransposon mutant, with the monofunctional peptidoglycan glycosyltransferase SgtB inactivated, displayed a 4-fold increase in the MIC of oxacillin, suggesting that alterations in the peptidoglycan structure could help bacteria compensate for the lack of LTA. Muropeptide analysis of peptidoglycans isolated from a wild-type strain andsgtBmutant strain did not reveal any sizable alterations in the peptidoglycan structure. In contrast, the peptidoglycan isolated from an LTA-negativeltaSmutant strain showed a significant reduction in the fraction of highly cross-linked peptidoglycan, which was partially rescued in thesgtB ltaSdouble mutant suppressor strain. Taken together, these data point toward an important function of LTA in cell wall integrity through its necessity for proper peptidoglycan assembly.IMPORTANCEThe bacterial cell wall acts as a primary defense against environmental insults such as changes in osmolarity. It is also a vulnerable structure, as defects in its synthesis can lead to growth arrest or cell death. The important human pathogenStaphylococcus aureushas a typical Gram-positive cell wall, which consists of peptidoglycan and the anionic polymers LTA and wall teichoic acid. Several clinically relevant antibiotics inhibit the synthesis of peptidoglycan; therefore, it and teichoic acids are considered attractive targets for the development of new antimicrobials. We show that LTA is required for efficient peptidoglycan cross-linking inS. aureusand inactivation of a peptidoglycan glycosyltransferase can partially rescue this defect, together revealing an intimate link between peptidoglycan and LTA synthesis.

scholarly journals VraSR Two-Component Regulatory System Contributes tomprF-Mediated Decreased Susceptibility to Daptomycin inIn Vivo-Selected Clinical Strains of Methicillin-Resistant Staphylococcus aureus

2011 ◽  
Vol 56 (1) ◽  
pp. 92-102 ◽  
Author(s):  
Shrenik Mehta ◽  
Arabela X. Cuirolo ◽  
Konrad B. Plata ◽  
Sarah Riosa ◽  
Jared A. Silverman ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Cell Wall ◽  
Regulatory System ◽  
Dependent Manner ◽  
Wild Type ◽  
Methicillin Resistant ◽  
Content Type ◽  
Clinical Strains ◽  
Two Component ◽  
The Impact

ABSTRACTDaptomycin (DAP) is a new class of cyclic lipopeptide antibiotic highly active against methicillin-resistantStaphylococcus aureus(MRSA) infections. Proposed mechanisms involve disruption of the functional integrity of the bacterial membrane in a Ca-dependent manner. In the present work, we investigated the molecular basis of DAP resistance in a group of isogenic MRSA clinical strains obtained from patients withS. aureusinfections after treatment with DAP. Different point mutations were found in themprFgene in DAP-resistant (DR) strains. Investigation of themprFL826F mutation in DR strains was accomplished by inactivation and transcomplementation of either full-length wild-type or mutatedmprFin DAP-susceptible (DS) strains, revealing that they were mechanistically linked to the DR phenotype. However, our data suggested thatmprFwas not the only factor determining the resistance to DAP. Differential gene expression analysis showed upregulation of the two-component regulatory systemvraSR. Inactivation ofvraSRresulted in increased DAP susceptibility, while complementation ofvraSRmutant strains restored DAP resistance to levels comparable to those observed in the corresponding DR wild-type strain. Electron microscopy analysis showed a thicker cell wall in DR CB5012 than DS CB5011, an effect that was related to the impact ofvraSRandmprFmutations in the cell wall. Moreover, overexpression ofvraSRin DS strains resulted in both increased resistance to DAP and decreased resistance to oxacillin, similar to the phenotype observed in DR strains. These results support the suggestion that, in addition to mutations inmprF,vraSRcontributes to DAP resistance in the present group of clinical strains.

scholarly journals Impact of Antibiotics with Various Target Sites on the Metabolome of Staphylococcus aureus

2014 ◽  
Vol 58 (12) ◽  
pp. 7151-7163 ◽  
Author(s):  
Kirsten Dörries ◽  
Rabea Schlueter ◽  
Michael Lalk
Keyword(s):  
Staphylococcus Aureus ◽  
Tricarboxylic Acid Cycle ◽  
Pentose Phosphate ◽  
Outer Cell ◽  
Primary Metabolism ◽  
Metabolic Profiles ◽  
Dependent Manner ◽  
Content Type ◽  
Morphological Alterations ◽  
The Impact

ABSTRACTIn this study, global intra- and extracellular metabolic profiles were exploited to investigate the impact of antibiotic compounds with different cellular targets on the metabolome ofStaphylococcus aureusHG001. Primary metabolism was largely covered, yet uncommon staphylococcal metabolites were detected in the cytosol ofS. aureus, including sedoheptulose-1,7-bisphosphate and the UDP-MurNAc-pentapeptide with an alanine-seryl residue. By comparing the metabolic profiles of unstressed and stressed staphylococcal cells in a time-dependent manner, we found far-ranging effects within the metabolome. For each antibiotic compound, accumulation as well as depletion of metabolites was detected, often comprising whole biosynthetic pathways, such as central carbon and amino acid metabolism and peptidoglycan, purine, and pyrimidine synthesis. Ciprofloxacin altered the pool of (deoxy)nucleotides as well as peptidoglycan precursors, thus linking stalled DNA and cell wall synthesis. Erythromycin tended to increase the amounts of intermediates of the pentose phosphate pathway and lysine. Fosfomycin inhibited the first enzymatic step of peptidoglycan synthesis, which was followed by decreased levels of peptidoglycan precursors but enhanced levels of substrates such as UDP-GlcNAc and alanine-alanine. In contrast, vancomycin and ampicillin inhibited the last stage of peptidoglycan construction on the outer cell surface. As a result, the amounts of UDP-MurNAc-peptides drastically increased, resulting in morphological alterations in the septal region and in an overall decrease in central metabolite levels. Moreover, each antibiotic affected intracellular levels of tricarboxylic acid cycle intermediates.

Sign in / Sign up

Export Citation Format

Share Document