31-10-2009

1

Team SDU-Denmark

Us at Harvard(of course we like

MIT too)

The idea

Our goal is to create a

bandage, which inhibits S.

aureus biofilm formation in wounds.

Such a bandage would

improve the efficiency of conventional antibiotics.

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2

The problem

Hospital acquired infections

are a huge and growing

problem.

They lead to prolonged illness and higher mortality

among patients.

S. aureus is the leading cause of hospital-acquired

infections.

The problem

S. aureus often infects

surgical wounds.

This disrupts the healing process, can cause

sepsis and may require implanted devices to be removed.

The increased use of antibiotics promotes

resistance as seen with MRSA.

Biofilm formation

Biofilm is a layer of microbes embedded in

extracellular slime.

Biofilm formation in wounds protects

S. aureus from antibiotics.

Quorum sensing enables bacteria

to form biofilms.

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3

Quorum sensing

S. aureus and other Gram positives

agrCagrA RNAIII

AgrC

P2

AgrA

P3

RNAIII+

AIP

agrD agrB

AgrB

AgrD

+

Our system

S. Aureus

Infection

Antibiotics

Resistance

Biofilm

Quorum

sensingSensing

RIP

+

AgrC

AgrA

RIP

AIPE. coli

RIPcon. pro. P3agrA agrC

S. aureusOur system

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4

A bandage containing E. coli producing RIP, sealed in

a semipermeable membrane.

The membrane prevents the bacteria from entering

the blood, but allows RIP to diffuse into the wound and disrupt quorum sensing.

E. coli

Membrane

Cover

RIPAIP

Wound

BactoBandage

Constitutive promotor

RBS RIP Double terminator

Our system

DNA sequencing

Restriction-sites Composite promoter and RBS RIP Double terminator

Results

Northern blot

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5

Results

0,00

0,10

0,20

0,30

0,40

0,50

0,60

Cell culture Supernatant Lysate

No

rmali

zed

ab

so

rban

ce

MG1655 + RIP

MG1655

Biofilm assay

In conclusion

What we achieved

� RIP submitted part

� RIP mRNA confirmed by Northern blot

� S. aureus biofilm formation reduced by RIP cell culture

�First expression of RIP outside original host

Acknowledgements

Fabulously fantastic advisors &

University of Southern Denmark