Staphylococcus aureus Pathogenesis - Gene exchanges - Gene regulation - - PowerPoint PPT Presentation

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Staphylococcus aureus Pathogenesis - Gene exchanges - Gene regulation - - PowerPoint PPT Presentation

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Staphylococcus aureus Pathogenesis - Gene exchanges - Gene regulation - Gene products - Gene product cooperation Brussels 07 Some Staphylococcal Species from Mammals Host Species Coagulase Clumping factor Virulence Human ++ ++ +++ S.

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SLIDE 1

Staphylococcus aureus Pathogenesis

  • Gene exchanges
  • Gene regulation
  • Gene products
  • Gene product cooperation

Brussels 07

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SLIDE 2

Host Species Coagulase Clumping factor Virulence Human and other primates

  • S. aureus
  • S. epidermidis
  • S. capitis
  • S. caprae
  • S. saccharolyticus
  • S. warneri
  • S. pasteuri
  • S. haemolyticus
  • S. hominis
  • S. lugdunensis
  • S. auricularis
  • S. saprophyticus
  • S. cohnii
  • S. xilosus
  • S. simulans
  • S. schleiferi

++

  • +
  • +

++

  • +
  • +

+++ + (+) (+)

  • +

(+) + (+) +

  • +

Carnivores S. intermedius

  • S. felis

+

  • ++

++

Some Staphylococcal Species from Mammals

Brussels 07

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SLIDE 3

Baba T et al. Lancet 2002;359:1819

Whole genomes of S. aureus MW2, N315 and Mu50

MW2 N315 Mu50

Brussels 07

  • GC content
  • Gene comparison
  • Codon usage
  • Genometrics
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SLIDE 4

From Linguistics to Genometrics

theicaacisagreatconférenceparcequellegathermanygreatscientists theicaacisagreatconférenceparcequellegathermanygreatscientists

http://www2.unil.ch/comparativegenometrics/ CA Roten and L. Guy

Brussels 07

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SLIDE 5

Guy Lionel, Thesis 2007

Brussels 07

  • S. aureus Genometric Analysis
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SLIDE 6

Baba T et al. Lancet 2002;359:1819

Methicillin resistance

Whole genomes of S. aureus MW2, N315 and Mu50

MW2 N315 Mu50 Provirus encoding

PVL toxin tst1 set

Brussels 07

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SLIDE 7
  • DNA region (up to 200 kb) of foreign origin
  • Contain pathogenic genes
  • May have a different GC content
  • Flanked by direct repats of IS
  • Associated with tRNA genes
  • Contain relics of integrase/excisase genes
  • r of phage genes

Define Pathogenicity Islands

Brussels 07

Hacker J et al. Mol Microbiol 1997; 23:1089-97

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SLIDE 8
  • Transformation
  • Conjugation
  • Transduction (generalized)

How do they move ?

Brussels 07

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SLIDE 9

att att int The example of SaPI1

Moving Genes Around

Brussels 07

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SLIDE 10

att att int xis

Moving Genes Around

The example of SaPI1

Brussels 07

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SLIDE 11

att att int xis

Moving Genes Around

The example of SaPI1

Brussels 07

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SLIDE 12

Moving Genes Around

The example of SaPI1

Brussels 07

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SLIDE 13

att att int

Moving Genes Around

The example of SaPI1

Brussels 07

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SLIDE 14

Novick, Schlievert, Ruzin. Microbes and Infect 2001; 3:585

Moving SaPI1 with Phage 80α

Brussels 07

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SLIDE 15

Staphylococcus aureus Pathogenesis

  • Gene exchanges
  • Gene regulation
  • Gene products
  • Gene product cooperation

Brussels 07

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SLIDE 16

Time Growth

Transcription

  • f exoproteins

Transcription

  • f adhesins

agr-Regulation of Virulence Determinants During in vitro Growth of S. aureus (1)

Adapted from R.P. Novick ASM press, 2000

Brussels 07

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SLIDE 17

AIP = auto-inducing peptide

A C D B

P2 P3

AgrB AIP AgrC AgrA

δ

RNAIII

P

Novick et al. Curr. Op. Microbiol. 1999;2:40-45

Virulence Gene Regulation by Peptides in S. aureus (1)

Brussels 07

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SLIDE 18

A C D B

P2 P3

AgrB AIP AIP = auto-inducing peptide AgrC AgrA

δ

RNAIII

AgrA P

Activation of Tx

Virulence Gene Regulation by Peptides in S. aureus (2)

Novick et al. Curr. Op. Microbiol. 1999;2:40-45

Translation

  • f exoproteins

Brussels 07

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SLIDE 19

Regulation of S. aureus super-antigens

Action of regulatory genes Gene Product Activity/function agr Sae- RS rot sarA sarS sarT tst Superantigens sea Enterotoxin A Food poisoning, TSS seb Enterotoxin B Food poisoning, TSS

+ b

  • sec

Enterotoxin C Food poisoning, TSS

+

sed Enterotoxin D Food poisoning, TSS

+

eta Exfoliatin A Scalded skin syndrome

+

etb Exfoliatin B Scalded skin syndrome

+

tst Toxic shock toxin-1 Toxic shock syndrome

+

  • b
  • 0, no effect of gene on expression; +, upregulated; -, downregulated.
  • b. Controversial.

Brussels 07

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SLIDE 20

Host:

  • Lack of anti-TSST antibodies

Environment:

  • High protein concentration
  • Neutral pH
  • High pCO2
  • High pO2

Conditions for Developing Toxic Shock Syndrome

Brussels 07

Altered Ecology !

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SLIDE 21

Staphylococcus aureus Pathogenesis

  • Gene exchanges
  • Gene regulation
  • Gene products
  • Gene product cooperation

Brussels 07

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SLIDE 22

Gene Protein Function Implication in disease

spa Protein A Binds Fc fragment Sepsis, osteoarthritis clfA Clumping factor A Binding to fibrinogen Endocarditis clfB Clumping factor B Binding to fibrinogen

  • cna

Collagen binding protein Binding to collagen Osteomyelitis fnA Fn-binding protein A Binding to fibronectin Endocarditis, persistence fnB Fn-binding protein B Binding to fibronectin

  • sdrC

Serine-aspartate repeat prot Binding to fibrinogen

  • sdrD

Serine-aspartate repeat prot Binding to fibrinogen ?

  • sdrE

Serine-aspartate repeat prot Binding to fibrinogen ?

  • pls

Plasmin-sensitive protein Binding to nasal mucosa Nasal colonization? fmtB Methicillin resistance Putative cell-wall building Expression of methi-R sasA

  • S. aureus surface protein A

Undetermined

  • sasB
  • S. aureus surface protein B

Undetermined

  • sasC
  • S. aureus surface protein C

Undetermined

  • sasE
  • S. aureus surface protein E

Undetermined

  • sasF
  • S. aureus surface protein F

Undetermined

  • sasG
  • S. aureus surface protein G

Binding to nasal mucosa Invasive disease sasH

  • S. aureus surface protein H

Undetermined Invasive disease sasI

  • S. aureus surface protein I

Undetermined

  • sasJ
  • S. aureus surface protein J

Undetermined

  • sasK
  • S. aureus surface protein K

Undetermined

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SLIDE 23

Understanding Pathogenic Factors

Wild Type Coa- Coa-/ClfA- Coa-/ClfA-/Fnb- Coagulation

Vegetations

Platelet Factors Tissue factor

? ? ? ? ? ? ? ? ? ? ?

Brussels 07

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SLIDE 24

Transfer or Staphylococcal Pathogenic genes into less Virulent Bacteria

  • S. aureus donor

(Coa+/ClfA+/Fnb+) Lactococcus recipient (ClfA-)

1: Transfer of S.aureus clfA gene into viridans group streptococcus 2: Select clumping-positive recombinants

Lactococcus recombinant (ClfA+)

Que et al. I&I 2000; 68:3516-22

Brussels 07

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SLIDE 25

Adherence of L. lactis to PMMA coverslips coated with fibronectin

8325-4 pIL253 FnbpA (+) 8325-4 Adherent CFU (x103/coverslip) 20 40 60 80 100 Soluble concentration of Fn (µg/ml) 0.0 0.25 0.50 0.75

Que et al, I&I 2001; 69:6296-302

Brussels 07

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SLIDE 26

Experimental Endocarditis

Brussels 07

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SLIDE 27

% Infected Vegetations

100 20 40 60 80

  • L. lactis parent ClfA+ FnBPA+

Inoculum = 104 105 106 107 104 105 106 107 104 105 106 107

Infectivity of L. lactis Recombinants Binding to Fibrinogen or Fibronectin

Que et al. Infect. Immun. 2001

Brussels 07

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SLIDE 28

Log CFU/g Vegetations 10 2 4 6 8

  • L. lactis parent ClfA+ FnBPA+

Time after infection (h) = 2 12 48 72 2 12 48 72 2 12 48 72

Dynamic of L. lactis Endocarditis

Brussels 07

Que et al. J. Exp. Med . 2005

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SLIDE 29

Experimental Endocarditis

Brussels 07

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SLIDE 30

Neighboring Aorta of Valves Infected with ClfA-positive Lactococci /Gram Stain

Que YA, J. Exp. Med 2005;201:1627

Brussels 07

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SLIDE 31

Que YA, J. Exp. Med 2005;201:1627

Brussels 07

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SLIDE 32

Membrane Peptidoglycan

Binding Domains of FnBPA

Binding to Fibrinogen Fibonectin ClfA +++

  • FnBPA ++

+++

and Piroth et al. 2007, submitted Que YA, J. Exp. Med 2005;201:1627

M-LPXTG W D1-4 Du C B A L

  • Fibronect. Fibronect. Fibronect. Fibrinogen

Leader

Brussels 07

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SLIDE 33

Membrane Peptidoglycan

Binding Domains of FnBPA

M-LPXTG W L M-LPXTG W D1-4 Du C L M-LPXTG W A L M-LPXTG W D1-4 Du C B A L

  • Fibronect. Fibronect. Fibronect. Fibrinogen

Leader

Brussels 07

and Piroth et al. 2007, submitted Que YA, J. Exp. Med 2005;201:1627

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SLIDE 34

Binding Domains of FnBPA

Surrogate recombinant Binding Infection Internalization Persistence Fg +++

  • Fn
  • +++
  • cis Fn/Fg

+++ +++ +++ trans Fn/Fg +++ +++ +++

Brussels 07

and Piroth et al. 2007, submitted Que YA, J. Exp. Med 2005;201:1627

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SLIDE 35
  • S. aureus needs both fibrinogen- and fibronectin-

binding domains to be fully infective

  • Fibronectin-binding protein represents an example
  • f intra-molecular domain cooperation
  • Fibronectin- and fibrinogen-binding represent an

example of inter-molecular domain cooperation

Brussels 07

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SLIDE 36
  • E. Widmer et al. I&I , submitted

Brussels 07

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SLIDE 37

Que YA, J. Exp. Med 2005;201:1627

Brussels 07

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SLIDE 38

Que YA, J. Exp. Med 2005;201:1627

Brussels 07

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SLIDE 39

Que YA, J. Exp. Med 2005;201:1627

LPXTG-proteins Toxins

  • S. aureus

21 > 30

  • S. epidermidis > 10

No

  • S. haemolyticus

6 No

  • S. saprophyticus

1 No But all have prophages and genomic islands, including the SCC staphylococcal K7 chromosome

Brussels 07

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SLIDE 40

Staphylooccus aureus

a paradigm of host-parasite evolution

  • N. Widmer
  • M. Giddey
  • J. Entenza
  • S. Piu
  • J. Vouillamoz

YA Que L Piroth

  • CA. Roten
  • L. Guy
  • F. Collyn
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SLIDE 41
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SLIDE 42

Subcutaneous Infection of Mice with 108 CFU of AIP I

  • S. aureus supplemented or not with AIP II

Lesion size in mm2

1000 200 400 600 800 Day 1 Day 5

n = 4 4 3 4 4 4 3 4 Strain 6390B, agr+ Strain 6911 , agr- 6390B + 10 μg AIP II 6390B + 5 μg AIP II Mayville et al. PNAS 1999; 96:1218-1223

Brussels 07

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SLIDE 43
  • No, not sensu stricto
  • All Staphylococcus spp. carry an agr
  • agr is also required for regulation
  • f house-keeping genes

Is agr a Virulence Factor ?

Brussels 07