Electron transport in staphylococci. Properties of a particle preparation from exponential phase Staphylococcus aureus

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.

Download Full-text

Metabolism of pyrithiamine by the pyrithiamine-requiring mutant of Staphylococcus aureus

Biochemical Journal ◽

10.1042/bj1070165 ◽

1968 ◽

Vol 107 (2) ◽

pp. 165-169 ◽

Cited By ~ 5

Author(s):

Asru K. Sinha ◽

G. C. Chatterjee

Keyword(s):

Staphylococcus Aureus ◽

Mutant Strain ◽

Parent Strain ◽

Culture Broth ◽

Exponential Phase ◽

Optimum Growth ◽

Solvent Fractionation ◽

Prolonged Incubation ◽

Inhibition Index

1. A mutant strain of Staphylococcus aureus that requires pyrithiamine for its optimum growth was found to utilize pyrithiamine during the exponential phase of growth. 2. Pyrithiamine was deaminated by the organism to form oxypyrithiamine, the reaction being enzymic with no cofactor requirement. 3. On prolonged incubation of S. aureus A cultures, the concentration of deaminating enzyme increased in the culture broth, from which pyrithiamine-deaminating enzyme could be isolated by solvent fractionation. 4. Oxypyrithiamine is not a competitive analogue of thiamine although it inhibited the growth of the parent strain of S. aureus; the inhibition index of this compound, however, was lower than that of pyrithiamine.

Download Full-text

Growth-inhibitory activities of some 1,4-naphthoquinones and related compounds on Staphylococcus aureus and Escherichia coli

Canadian Journal of Microbiology ◽

10.1139/m68-110 ◽

1968 ◽

Vol 14 (6) ◽

pp. 661-666 ◽

Cited By ~ 4

Author(s):

G. J. Leahy ◽

D. J Currie ◽

H. L. Holmes ◽

J. R. Maltman

Keyword(s):

Escherichia Coli ◽

Staphylococcus Aureus ◽

Electron Transport ◽

Electron Transport Chain ◽

Growth Inhibitory ◽

Transport Chain ◽

Half Wave ◽

Inhibitory Activities ◽

Related Compounds

Growth-inhibitory activities of some or all of 98 1,4-naphthoquinones and 16 related compounds on Escherichia coli and two strains of Staphylococcus aureus were determined alone or in combination. These values, when plotted against their polarographic half-wave potentials and those of their C2-n-butylthio analogs support the hypothesis that these compounds, or the products resulting from their reaction with a protein nucleophile, function by short-circuiting one or other of the quinones present in the electron-transport chain.

Download Full-text

Tomatidine Inhibits Replication of Staphylococcus aureus Small-Colony Variants in Cystic Fibrosis Airway Epithelial Cells

Antimicrobial Agents and Chemotherapy ◽

10.1128/aac.01468-10 ◽

2011 ◽

Vol 55 (5) ◽

pp. 1937-1945 ◽

Cited By ~ 29

Author(s):

Gabriel Mitchell ◽

Mariza Gattuso ◽

Gilles Grondin ◽

Éric Marsault ◽

Kamal Bouarab ◽

...

Keyword(s):

Cystic Fibrosis ◽

Staphylococcus Aureus ◽

Electron Transport ◽

Epithelial Cells ◽

Airway Epithelial Cells ◽

Plant Secondary Metabolite ◽

Airway Epithelial ◽

Small Colony Variants ◽

Content Type ◽

Small Colony

ABSTRACTSmall-colony variants (SCVs) often are associated with chronicStaphylococcus aureusinfections, such as those encountered by cystic fibrosis (CF) patients. We report here that tomatidine, the aglycon form of the plant secondary metabolite tomatine, has a potent growth inhibitory activity against SCVs (MIC of 0.12 μg/ml), whereas the growth of normalS. aureusstrains was not significantly altered by tomatidine (MIC, >16 μg/ml). The specific action of tomatidine was bacteriostatic for SCVs and was clearly associated with their dysfunctional electron transport system, as the presence of the electron transport inhibitor 4-hydroxy-2-heptylquinoline-N-oxide (HQNO) caused normalS. aureusstrains to become susceptible to tomatidine. Inversely, the complementation of SCVs' respiratory deficiency conferred resistance to tomatidine. Tomatidine provoked a general reduction of macromolecular biosynthesis but more specifically affected the incorporation of radiolabeled leucine in proteins of HQNO-treatedS. aureusat a concentration corresponding to the MIC against SCVs. Furthermore, tomatidine inhibited the intracellular replication of a clinical SCV in polarized CF-like epithelial cells. Our results suggest that tomatidine eventually will find some use in combination therapy with other traditional antibiotics to eliminate persistent forms ofS. aureus.

Download Full-text

Electron Transport through Early Exponential-Phase Anode-GrownGeobacter sulfurreducensBiofilms

ChemElectroChem ◽

10.1002/celc.201402168 ◽

2014 ◽

Vol 1 (11) ◽

pp. 1957-1965 ◽

Cited By ~ 15

Author(s):

Sarah M. Strycharz-Glaven ◽

Jared Roy ◽

Darryl Boyd ◽

Rachel Snider ◽

Jeffrey S. Erickson ◽

...

Keyword(s):

Electron Transport ◽

Exponential Phase ◽

Early Exponential Phase

Download Full-text

CtaM Is Required for Menaquinol Oxidaseaa3Function inStaphylococcus aureus

mBio ◽

10.1128/mbio.00823-16 ◽

2016 ◽

Vol 7 (4) ◽

Cited By ~ 17

Author(s):

Neal D. Hammer ◽

Lici A. Schurig-Briccio ◽

Svetlana Y. Gerdes ◽

Robert B. Gennis ◽

Eric P. Skaar

Keyword(s):

Staphylococcus Aureus ◽

Electron Transport ◽

Electron Transport Chain ◽

Molecular Mechanisms ◽

Carbon Sources ◽

Spectroscopic Studies ◽

Uncharacterized Protein ◽

Terminal Oxidases ◽

Transport Chain ◽

Genes Encoding

ABSTRACTStaphylococcus aureusis the leading cause of skin and soft tissue infections, bacteremia, osteomyelitis, and endocarditis in the developed world. The ability ofS. aureusto cause substantial disease in distinct host environments is supported by a flexible metabolism that allows this pathogen to overcome challenges unique to each host organ. One feature of staphylococcal metabolic flexibility is a branched aerobic respiratory chain composed of multiple terminal oxidases. Whereas previous biochemical and spectroscopic studies reported the presence of three different respiratory oxygen reductases (otype,bdtype, andaa3type), the genome contains genes encoding only two respiratory oxygen reductases,cydABandqoxABCD. Previous investigation showed thatcydABandqoxABCDare required to colonize specific host organs, the murine heart and liver, respectively. This work seeks to clarify the relationship between the genetic studies showing the unique roles of thecydABandqoxABCDin virulence and the respiratory reductases reported in the literature. We establish that QoxABCD is anaa3-type menaquinol oxidase but that this enzyme is promiscuous in that it can assemble as abo3-type menaquinol oxidase. However, thebo3form of QoxABCD restricts the carbon sources that can support the growth ofS. aureus. In addition, QoxABCD function is supported by a previously uncharacterized protein, which we have named CtaM, that is conserved in aerobically respiringFirmicutes. In total, these studies establish the heme A biosynthesis pathway inS. aureus, determine that QoxABCD is a typeaa3menaquinol oxidase, and reveal CtaM as a new protein required for typeaa3menaquinol oxidase function in multiple bacterial genera.IMPORTANCEStaphylococcus aureusrelies upon the function of two terminal oxidases, CydAB and QoxABCD, to aerobically respire and colonize distinct host tissues. Previous biochemical studies support the conclusion that a third terminal oxidase is also present. We establish the components of theS. aureuselectron transport chain by determining the heme cofactors that interact with QoxABCD. This insight explains previous observations by revealing that QoxABCD can utilize different heme cofactors and confirms that the electron transport chain ofS. aureusis comprised of two terminal menaquinol oxidases. In addition, a newly identified protein, CtaM, is found to be required for the function of QoxABCD. These results provide a more complete assessment of the molecular mechanisms that support staphylococcal respiration.

Download Full-text

σB Activity in a Staphylococcus aureus hemB Mutant

Journal of Bacteriology ◽

10.1128/jb.187.21.7397-7406.2005 ◽

2005 ◽

Vol 187 (21) ◽

pp. 7397-7406 ◽

Cited By ~ 27

Author(s):

Maria M. Senn ◽

Markus Bischoff ◽

Christof von Eiff ◽

Brigitte Berger-Bächi

Keyword(s):

Staphylococcus Aureus ◽

Growth Period ◽

Growth Cycle ◽

Exponential Phase ◽

Altered Expression ◽

Global Regulators ◽

Transcription Profiles ◽

Altered Expression Pattern ◽

Small Colony ◽

And Control

ABSTRACT Inactivation of hemB in Staphylococcus aureus strain Newman resulted in a small-colony phenotype and was accompanied by an altered expression pattern of global regulators and control of virulence factor production. Transcription profiles followed over 15 h by Northern blot analyses revealed that transcripts of the global regulators arl, rot, sae, sarR, sarS, srr, svrA, and sigB disappeared after the exponential phase and that both agr transcripts were completely absent in the hemB mutant. Apart from a general concentration of transcriptional activity to the exponential phase, premature gene expression was observed for rot, hla, and spa. Nevertheless, reported σB-dependent transcripts, such as sarC and clfA, were produced throughout the 15-h growth period monitored. The absence of these transcripts in a hemB sigB double mutant demonstrated their dependence on σB and indicated an unexpected, permanent σB activity in the hemB mutant. Variations in the extents of the directly σB-controlled asp23, rsbVW-sigB, and sarC transcripts argue for additional factors modulating σB activity. This study provides the first extended synopsis of the transcriptional patterns of different regulators over the entire growth cycle in the widely used Newman strain.

Download Full-text