Download Polymer brushes vs bacteria

Skapandet av "oslemmiga" ytor
Olena Rzhepishevska, Umeå Universitet
Vilka är vi?
Madeleine Ramstedt,
kemist, docent
Shoghik Hakobyan, kemist, doktorand &
Olena Rzhepishevska, mikrobiolog, forskare
What’s biofilm?
Kaneko, Y., J Clin Invest , 2007
Rzhepishevska & Ramstedt,
unpublished
Deffinition:
complex communities of microorganisms
attached to a surface or interface enclosed in an
exsopolysacchraride matrix of microbial and
host origin to produce a spatially organized three
dimentional structure (Costerton et al. 1995)
Biofilm is a natural way to exist for microorganisms
The biofilm on pyritic sediments, Richmond
mine, California
Edwards et al., Science, 2000
Bacteria appear red around the vessel wall. Red blood cells within
the lumen appear pink, and DAPI stained host cell nuclei appear
blue. Schaber et al. Infect Immun. 2007
Importance of biofilms
Biofilms
Industry
Pharmathutical
Processing
Shipping
Clinical
Prosthesis &
Biomaterials
Orthopaedics
Catheters
Contact lenses
Shunts
Pins/staples
Infusion lines
Tissue
Dental
Gut
Urinary tract
Lungs
Bone
Heart
Teeth
Gums
Tongue
Implants
Public health
Water
Distribution pipes
Drinking water
Food
Process surfaces
Home
Modified from Jass, Surman, Walker, 2003
Biofilms are responsible for approximately 80% of all microbial infections,
and cause 100,000 deaths annually in the USA alone.
Surfaces and bacteria - catheters
Most common infections
Pseudomonas aeruginosa
Staphylococcus aureus
Biofilms are responsible for approximately 80% of all microbial infections
and cause 100,000 deaths annually in the USA alone.
Pseudomonas
aeruginosa
Planctonic cells
Steps in biofilm formation
monolayer
Reversible Irreversible
attachment
Microcolonies
Macrocolonies
(mashroom bodies)
Modified from Caiazza & O’Toole, 2004
Primary
attachment
Accumulative
growth
Red tails are single protein molecules
Mack et al. 2004
Staphylococcus aureus &
Staphylococcus epidermidis
Steps in biofilm formation
Vibrio cholerea
Van Dellen et al.,
JBact., 2008
Planctonic
cells
Monolayer
Reversible
(transient)
attachment
Irreversible
(permanent)
attachment
Host (TCP)
Environment/host (VPS)
Sea water (Ca2+)
TCP - toxin-coregulated pilus
VPS - Vibrio polysaccharide
Flagella and pili are needed to build biofilm
Flagella
Pili
Biofilm, CLSM, 1:1 mixture of yellow fluorescent P. aeruginosa PAO1 wt & cyan fluorescent P.
aeruginosa pilA, Klausen et al, 2003
Matrix - the slime
Exopolysaccharides (EPS) - physical & chemical protection
Alginate – P.aeruginosa; colanic acid – E.coli
Mono-rhamnolipid
Rhamnolipids - support mashroom structures
Proteins -attachment, protection from host
DNA -support structure , antibiotic resistance
Day 2
pretreatment
Day 3
post-treatment
DNAse treatment of S.aureus biofilm, Mann et al, 2009
Di-rhamnolipid
Communication is everywhere – quorum sensing
homoserine lactone
N-(3-oxohexanoyl) homoserine lactone,
Vibrio fischeri & a shining squid
Our contribution to the field
1. The surface charge of anti-bacterial coatings alters motility and biofilm architecture
Rzhepishevska O, Hakobyan S, Ruhal R, Gautrot J, Barbero D, Ramstedt M
RSC Biomaterials Science 2013 March
2. The antibacterial activity of Ga3+ is influenced by ligand complexation as well as the bacterial
carbon source
Rzhepishevska O, Ekstrand-Hammarström B, Popp M, Björn E, Bucht A, Sjöstedt A, Antti H, Ramstedt M
Antimicrobial Agents & Chemotherapy 2011 Dec
3. The Gallium-saliciliden acylhydrazide complex shows synergistic anti-biofilm effect and inhibits toxin
Production by Pseudomonas aeruginosa
Journal of Inorganic Biochemistry 2014
Rzhepishevska O, Hakobyan S, Ekstrand-Hammarström B, Nygren Y, Karlsson T, Bucht A, Elofsson M,
Boily JF, Ramstedt M
Polymer brushes vs bacteria
or
POLIMER BRUSH WITH
POLIMER BRUSH WITH
NEGATIVE CHARGE
POSITIVE CHARGE
Polymer brushes vs bacteria
Surface
charge:
PMMA
neutral
POEGMA
-2mV
MEDSAH
-16mV
PMMA
POEGMA
SPM
-35mV
MEDSAH
METAC
+27mV
SPM
Polymer brushes vs bacteria- confocal microscopy
Flow breakers
Bubble traps
Flow chamber
Waste
Fresh medium
Polymer brushes vs bacteria- confocal microscopy
Biofilm, name of the polymer brush, and its
charge in mV
Structure of
polymer
n
O
METAC
+27mV
+
O
n
O
m
POEGMA
-2mV
N Cl
OH
O
O
PMMA
neutral
NO MODIFICATION
n
SPM
-35mV
S O-3 K +
O
O
MEDSAH
-16mV
n
O
O
+
N
S O3-
Fluorescence intensity, 515nm
GLASS
O
n
1200
1000
800
600
400
200
0
BIOFILM AFTER 3 DAYS
Polymer brushes vs bacteria - motility
?
Antibiotics & gallium
Penicillin –
blocks the key enzyme in
bacterial cell wall synthesis
Red–dead; green-alive
Bacteria produce beta-lactamase
to break penicillin
Streptomycine –
sabotages bacterial
protein synthesis
Bacteria mutate in a ribosomal
proteins
GaNO3
Torbamycin
Y. Kaneko, 2007
Gallium
Hemoproteinsrespiration
Enzyme active centermetabolic reactions
Iron
Fe3+
Fe2+
Signaling-regulation
of gene expression
Iron has many functions
in a bacterial cell
Hemoproteinsrespiration
Enzyme active centermetabolic reactions
Gallium
Ga3+
Signaling-regulation
of gene expression
Y. Kaneko, 2007
Bernstein, L. R. 1998
Gallium protects cells from bacteria
Bacteria, no Ga
No bacteria
Bacteria +Ga citrate
Bacteria+Ga DFO
Gallium against bacterial toxins
O
H
N
H2N
OH
N
O
Ga
H2O
H2O
O
H2O
OH
Ongoing work
O
O
H
N
H2N
H2N
OH
H2O
Ga
H2O
H2O
OH
H2O
H
N
H2N
N
Ga
O
O
OH
O
N
O
H2O
H
N
O
H2O
OH
OH
N
O
Ga
H2O
H2O
O
H2O
OH
Conclusions
Biofilm is a natural way of living for bacteria
Biofilms are both good and bad
On certain surfaces biofilms grow better that on other
There are special methods to fight biofilms and these methods are improving
Tack!!