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Activity of antibiotics against extracellular and intracellular forms of Staphylococcus aureus Pharmacodynamic studies in vitro using a model of human THP-1 macrophages Maritza Barcia-Macay (Patterson) Unité de Pharmacologie cellulaire et moléculaire

Maritza Barcia-Macay (Patterson) - UCLouvain...Maritza Barcia-Macay (Patterson) Unité de Pharmacologie cellulaire et moléculaire I. INTRODUCTION Staphylococcus aureus Bacteria with

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Page 1: Maritza Barcia-Macay (Patterson) - UCLouvain...Maritza Barcia-Macay (Patterson) Unité de Pharmacologie cellulaire et moléculaire I. INTRODUCTION Staphylococcus aureus Bacteria with

Activity of antibiotics against extracellular

and intracellular forms

of Staphylococcus aureus

Pharmacodynamic studies in vitro using a model

of human THP-1 macrophages

Maritza Barcia-Macay

(Patterson)

Unité de Pharmacologie cellulaire et moléculaire

Page 2: Maritza Barcia-Macay (Patterson) - UCLouvain...Maritza Barcia-Macay (Patterson) Unité de Pharmacologie cellulaire et moléculaire I. INTRODUCTION Staphylococcus aureus Bacteria with

I. INTRODUCTION

Page 3: Maritza Barcia-Macay (Patterson) - UCLouvain...Maritza Barcia-Macay (Patterson) Unité de Pharmacologie cellulaire et moléculaire I. INTRODUCTION Staphylococcus aureus Bacteria with

Staphylococcus aureus

Bacteria with thegreatest

pathogenic potentialin human

infections.

A major causeof

nosocomial

and community-acquired

infections.

Page 4: Maritza Barcia-Macay (Patterson) - UCLouvain...Maritza Barcia-Macay (Patterson) Unité de Pharmacologie cellulaire et moléculaire I. INTRODUCTION Staphylococcus aureus Bacteria with

furuncle abscesscellulitis

erysipelasimpetigo

1. skin and soft tissue infections

S. aureus infections

Page 5: Maritza Barcia-Macay (Patterson) - UCLouvain...Maritza Barcia-Macay (Patterson) Unité de Pharmacologie cellulaire et moléculaire I. INTRODUCTION Staphylococcus aureus Bacteria with

2. food-poisoning

S. aureus infections

Page 6: Maritza Barcia-Macay (Patterson) - UCLouvain...Maritza Barcia-Macay (Patterson) Unité de Pharmacologie cellulaire et moléculaire I. INTRODUCTION Staphylococcus aureus Bacteria with

endocarditis pneumonia

3. Deep-organ infections

osteomyelitis

S. aureus infections

Page 7: Maritza Barcia-Macay (Patterson) - UCLouvain...Maritza Barcia-Macay (Patterson) Unité de Pharmacologie cellulaire et moléculaire I. INTRODUCTION Staphylococcus aureus Bacteria with

All these infections are difficult to treat :

• recurrence / persistence in relation with the intracellular character of S. aureus

selection of antibiotics based on pharmacokinetic / pharmacodynamics properties

• resistance to currently available antibioticsneed of drugs acting on multiresistant strains

S. aureus infections

Page 8: Maritza Barcia-Macay (Patterson) - UCLouvain...Maritza Barcia-Macay (Patterson) Unité de Pharmacologie cellulaire et moléculaire I. INTRODUCTION Staphylococcus aureus Bacteria with

All these infections are difficult to treat :

• recurrence / persistence in relation with the intracellular character of S. aureus

selection of antibiotics based on pharmacokinetic / pharmacodynamics properties

• resistance to currently available antibioticsneed of drugs acting on multiresistant strains

S. aureus infections

Page 9: Maritza Barcia-Macay (Patterson) - UCLouvain...Maritza Barcia-Macay (Patterson) Unité de Pharmacologie cellulaire et moléculaire I. INTRODUCTION Staphylococcus aureus Bacteria with

Normal process of phagocytosis

5) digestion and release of microbial debris

4) bacterial destruction

3) fusion lysosome and

phagosome

1) attachment to phagocyte

membrane

2) ingestion (phagosome)

Intracellular infection by S. aureus

Page 10: Maritza Barcia-Macay (Patterson) - UCLouvain...Maritza Barcia-Macay (Patterson) Unité de Pharmacologie cellulaire et moléculaire I. INTRODUCTION Staphylococcus aureus Bacteria with

Incomplete phagocytosis of S. aureus

5) digestion and release of microbial debris

4) bacterial destruction

3) fusion lysosome and

phagosome

1) attachment to phagocyte

membrane

2) ingestion (phagosome)

X X

Intracellular infection by S. aureus

Page 11: Maritza Barcia-Macay (Patterson) - UCLouvain...Maritza Barcia-Macay (Patterson) Unité de Pharmacologie cellulaire et moléculaire I. INTRODUCTION Staphylococcus aureus Bacteria with

Bacteria able to survive in different host cells : phagocytes

and non-phagocytes

Intracellular infection by S. aureus

Mammary epithelial cells Enterocytes Keratinocytes Osteoblasts Fibroblasts Endothelial cells

Neutrophils Macrophages

Brouillette et al, Vet Microbiol (2004) 101:253-262; Microb Pathog. (2003) 35:159-68.

Page 12: Maritza Barcia-Macay (Patterson) - UCLouvain...Maritza Barcia-Macay (Patterson) Unité de Pharmacologie cellulaire et moléculaire I. INTRODUCTION Staphylococcus aureus Bacteria with

All these infections are difficult to treat :

• recurrence / persistence in relation with the intracellular character of S. aureus

selection of antibiotics based on pharmacokinetic / pharmacodynamics properties

• resistance to currently available antibioticsneed of drugs acting on multiresistant strains

S. aureus infections

Page 13: Maritza Barcia-Macay (Patterson) - UCLouvain...Maritza Barcia-Macay (Patterson) Unité de Pharmacologie cellulaire et moléculaire I. INTRODUCTION Staphylococcus aureus Bacteria with

Dosageregimen

Concentrationversus timein serum

Concentrationversus timein tissues andother body fluids

Concentrationversus timeat site of infection

Pharmacologic or toxicologic effect

Antimicrobial effect versus time

absorption distribution elimination

PHARMACOKINETICS PHARMACODYNAMICS

Craig CID (1998) 26:1-10

general concept

Antibiotic pharmacokinetics / pharmacodynamics

Page 14: Maritza Barcia-Macay (Patterson) - UCLouvain...Maritza Barcia-Macay (Patterson) Unité de Pharmacologie cellulaire et moléculaire I. INTRODUCTION Staphylococcus aureus Bacteria with

intracellularly

Carryn et al, Infect Dis Clin North Am. (2003) 17:615-34 PHARMACOKINETICS PHARMACODYNAMICS

Antibiotic pharmacokinetics / pharmacodynamics

Page 15: Maritza Barcia-Macay (Patterson) - UCLouvain...Maritza Barcia-Macay (Patterson) Unité de Pharmacologie cellulaire et moléculaire I. INTRODUCTION Staphylococcus aureus Bacteria with

All these infections are difficult to treat :

• recurrence / persistence in relation with the intracellular character of S. aureus

selection of antibiotics based on pharmacokinetic / pharmacodynamics properties

• resistance to currently available antibioticsneed of drugs acting on multiresistant strains

S. aureus infections

Page 16: Maritza Barcia-Macay (Patterson) - UCLouvain...Maritza Barcia-Macay (Patterson) Unité de Pharmacologie cellulaire et moléculaire I. INTRODUCTION Staphylococcus aureus Bacteria with

Macrolides, 1952

Methicillin, 1960

OxazolidinonesAminoglycosides, 1950

YEAR OF REPORTED RESISTANCE

The world first commercially available antibiotic appeared in 1941

1941 1960 2000

Introduction ofPenicillin

Quinolones,Streptogramins, 1962

Glycopeptides,

1956

S. aureus resistance

Page 17: Maritza Barcia-Macay (Patterson) - UCLouvain...Maritza Barcia-Macay (Patterson) Unité de Pharmacologie cellulaire et moléculaire I. INTRODUCTION Staphylococcus aureus Bacteria with

Most worrying resistance phenotypes having emerged over time

S. aureus resistance

year phenotype first description1960 HA-MRSA England

1967 MDR HA-MRSA Europe, Australia, Japan

1980 Genta-R MRSA USA, Ireland, UK

1993 CA-MRSA Australia

1997 VISA Japan

2002 VRSA USA

Grundmann et al., Lancet (2006) 368:874-85

Page 18: Maritza Barcia-Macay (Patterson) - UCLouvain...Maritza Barcia-Macay (Patterson) Unité de Pharmacologie cellulaire et moléculaire I. INTRODUCTION Staphylococcus aureus Bacteria with

S. aureus resistance

Percentage of MRSA resistance in Europe in 2004: S. aureus proportion of invasive isolates MRSA in 2004

Data from the European antimicrobial resistant surveillance system, EARSS.

Page 19: Maritza Barcia-Macay (Patterson) - UCLouvain...Maritza Barcia-Macay (Patterson) Unité de Pharmacologie cellulaire et moléculaire I. INTRODUCTION Staphylococcus aureus Bacteria with

Prevalence of resistance to other antibiotic classes

S. aureus resistance

Fluit et al., J Clin Microbiol (2001) 39: 3727-3732

amoxiam

oxi-cla

vglyc

opeptide

smac

rolid

eslin

cosa

midessyn

ergist

ins

aminoglyco

sides

tetrac

yclin

esrifa

mpicin

fluoro

quino

lones

0

20

40

60

80

100MSSAMRSA

% re

sist

ance

Page 20: Maritza Barcia-Macay (Patterson) - UCLouvain...Maritza Barcia-Macay (Patterson) Unité de Pharmacologie cellulaire et moléculaire I. INTRODUCTION Staphylococcus aureus Bacteria with

All these infections are difficult to treat :

• recurrence / persistence in relation with the intracellular character of S. aureus

selection of antibiotics based on pharmacokinetic / pharmacodynamics properties

• resistance to currently available antibioticsneed of drugs acting on multiresistant strains

S. aureus infections

Page 21: Maritza Barcia-Macay (Patterson) - UCLouvain...Maritza Barcia-Macay (Patterson) Unité de Pharmacologie cellulaire et moléculaire I. INTRODUCTION Staphylococcus aureus Bacteria with

8Sympo – S. aureus – 11/01/07 -

recent and novel agents for S. aureus

recently brought on the Belgian market

on the market; not yet

in Belgium

(late) stage of clinical

developmentinvestigational

moxifloxacinlinezolid

synerciddaptomycintigecycline

telavancinoritavancindalbavancinceftobiprole

CS-023/PZ-601MX-2401API-1252

WCK-771

iclaprimretapamulin

DK-619

What will be your choice ?

new oxazolidinonesnew ketolides

...

F. Van Bambeke, symposium on S. aureus – Brussels, 11-1-2007

A lot of drugs in the pipeline …

Need for new antistaphylococcal agents

Page 22: Maritza Barcia-Macay (Patterson) - UCLouvain...Maritza Barcia-Macay (Patterson) Unité de Pharmacologie cellulaire et moléculaire I. INTRODUCTION Staphylococcus aureus Bacteria with

II. AIM OF THE STUDY

Page 23: Maritza Barcia-Macay (Patterson) - UCLouvain...Maritza Barcia-Macay (Patterson) Unité de Pharmacologie cellulaire et moléculaire I. INTRODUCTION Staphylococcus aureus Bacteria with

• recurrence / persistence in relation with the intracellular character of S. aureus

selection of antibiotics based on pharmacokinetic / pharmacodynamics properties

• resistance to currently available antibioticsneed of drugs acting on multiresistant strains

To develop an intracellular model allowing to compare the activity of antibiotics on a pharmacodynamic basis

To evaluate the cellular pharmacokinetics and the intracellular activity towards multiresistant strains of a new antibiotic in development

Page 24: Maritza Barcia-Macay (Patterson) - UCLouvain...Maritza Barcia-Macay (Patterson) Unité de Pharmacologie cellulaire et moléculaire I. INTRODUCTION Staphylococcus aureus Bacteria with

III. METHODOLOGY

Page 25: Maritza Barcia-Macay (Patterson) - UCLouvain...Maritza Barcia-Macay (Patterson) Unité de Pharmacologie cellulaire et moléculaire I. INTRODUCTION Staphylococcus aureus Bacteria with

Method

1) opsonization of S. aureus with human serum

2) phagocytosis of the bacteria by THP-1 macrophages (ratio 4 bacteria vs 1 macrophage)

3) elimination of extracellular S. aureus(gentamicin 100 X MIC). Rinse of infected macrophages (time-zero)

4) intracellularly infected macrophages, ready to test antibiotic activity

5) maintenance of gentamicin at its MIC during the whole incubation period for controls to avoid extracellular contamination

Setting-up of the intracellular model

Page 26: Maritza Barcia-Macay (Patterson) - UCLouvain...Maritza Barcia-Macay (Patterson) Unité de Pharmacologie cellulaire et moléculaire I. INTRODUCTION Staphylococcus aureus Bacteria with

cell line ?Setting-up of the intracellular model

THP-1= many features of human monocytes/macrophages

parameter characteristics

morphological features morphology resembling that of monocytic leukemia cells: - diameter 12-14 µm - moderate basophile cytoplasm - small azurophiles granules, few vacuoles - nuclei irregular in shape

cytochemical features - positive for α-naphthyl butyrate esterase - negative reaction with periodic acid-Schiff and Sudan black B - diploid (46,XY) chromosome number

surface antigens and receptors

CD4, CD30, Factor X receptor, Factor Xa receptor, FcRI, FcRII, GM-CSF-receptor, HDL receptor, LDL receptor, TNF receptor, C3b receptor, LFA-1 receptor, Fibronectin receptor, Leu M1, Leu M2, Leu M3, HLA-DR antigens, scavengers receptors

secreted proteins - hormones, cytokines: TNF-α, IL-1, IL-1b, CSF-1, M-CSF, erythrocyte differentiation factor, PDGF-1 and –2, thymosin B4, killer T cell activating factor, monocyte chemotactic factor

- enzymes: lipoprotein lipase, lyzozyme - binding proteins: apoprotein E

functional features - phagocytosis - production of lyzozyme - capacity to restore the lympocyte T mitogenic responsiveness

Tsuchiya, Int. J. Cancer (1980) 26:171-176; Auwerx, Experientia (1991) 47:22-31

Page 27: Maritza Barcia-Macay (Patterson) - UCLouvain...Maritza Barcia-Macay (Patterson) Unité de Pharmacologie cellulaire et moléculaire I. INTRODUCTION Staphylococcus aureus Bacteria with

bacterial strain ?

Setting-up of the intracellular model

ATCC 25923

• clinical isolate from 1976• fully susceptible• widely used as a standard for microbiological testing of

antibiotics

useful to compare all antibiotics towards a single strain, but may differ in virulence with current strains …

Page 28: Maritza Barcia-Macay (Patterson) - UCLouvain...Maritza Barcia-Macay (Patterson) Unité de Pharmacologie cellulaire et moléculaire I. INTRODUCTION Staphylococcus aureus Bacteria with

antibiotics ?

Setting-up of the intracellular model

• Beta-lactams: first choice for susceptible strains

• Aminoglycosides: highly bactericidal extracellularly

• Rifampicin: considered as first choice for intracellular infections

• Macrolides, quinolones: high cellular accumulation

• Glycopeptides: alternative for MRSA• Linezolid: recently introduced, active on MRSA

Page 29: Maritza Barcia-Macay (Patterson) - UCLouvain...Maritza Barcia-Macay (Patterson) Unité de Pharmacologie cellulaire et moléculaire I. INTRODUCTION Staphylococcus aureus Bacteria with

S. aureus intracellular model

gentamicin prevents extracellular contamination

Bacteria multiply in phagolysosomeswhere pH is acidic

membrane bond vacuole

Page 30: Maritza Barcia-Macay (Patterson) - UCLouvain...Maritza Barcia-Macay (Patterson) Unité de Pharmacologie cellulaire et moléculaire I. INTRODUCTION Staphylococcus aureus Bacteria with

Assessment of antibiotic

extracellular

and intracellular activity INTRACELLULAR

4 bacteria/cell

Collection and lysis of cells (sonication)

CFU/protein contentAntibiotic concentration (microbiological, radiochemical, fluorimetric assays)

106 CFU/mg protein

EXTRACELLULAR

106 CFU/ml

Incubation over 24 h with antibiotics

Colony counting(CFU/ml)

General protocol

Page 31: Maritza Barcia-Macay (Patterson) - UCLouvain...Maritza Barcia-Macay (Patterson) Unité de Pharmacologie cellulaire et moléculaire I. INTRODUCTION Staphylococcus aureus Bacteria with

IV. RESULTS

Page 32: Maritza Barcia-Macay (Patterson) - UCLouvain...Maritza Barcia-Macay (Patterson) Unité de Pharmacologie cellulaire et moléculaire I. INTRODUCTION Staphylococcus aureus Bacteria with

First goal of this thesis

Human macrophages Fully susceptible strain

Page 33: Maritza Barcia-Macay (Patterson) - UCLouvain...Maritza Barcia-Macay (Patterson) Unité de Pharmacologie cellulaire et moléculaire I. INTRODUCTION Staphylococcus aureus Bacteria with

Antibiotics accumulate to variable levels in THP-1 macrophages

moderate level:aminoglycosideold glycopeptidesquinolones

low level:linezolid β-lactams

High level:macrolidesoritavancinrifampin

Page 34: Maritza Barcia-Macay (Patterson) - UCLouvain...Maritza Barcia-Macay (Patterson) Unité de Pharmacologie cellulaire et moléculaire I. INTRODUCTION Staphylococcus aureus Bacteria with

influence

of time on activity

GEN, RIF, ORIquickly cidal

OXA, MXF, ORIslowly cidal

• in all cases, intracellular activity <<

extracellular

activity• no direct relation between accumulation and intracellular activity

low to moderateaccumulation

moderate to highaccumulation

Page 35: Maritza Barcia-Macay (Patterson) - UCLouvain...Maritza Barcia-Macay (Patterson) Unité de Pharmacologie cellulaire et moléculaire I. INTRODUCTION Staphylococcus aureus Bacteria with

concentration-effect relationships

• sigmoidal

relationships

Page 36: Maritza Barcia-Macay (Patterson) - UCLouvain...Maritza Barcia-Macay (Patterson) Unité de Pharmacologie cellulaire et moléculaire I. INTRODUCTION Staphylococcus aureus Bacteria with

concentration-effect relationships

• sigmoidal

relationships• Emax

intra

<<

Emax

extra

Emax

EmaxEmax

Emax

Page 37: Maritza Barcia-Macay (Patterson) - UCLouvain...Maritza Barcia-Macay (Patterson) Unité de Pharmacologie cellulaire et moléculaire I. INTRODUCTION Staphylococcus aureus Bacteria with

concentration-effect relationships

• sigmoidal

relationships• Emax

intra

<<

Emax

extra• EC50

extra =

EC50

intra

for OXA and MXF• EC50

extra

<

EC50

intra

for GEN and ORI

EC50EC50

EC50 EC50

Page 38: Maritza Barcia-Macay (Patterson) - UCLouvain...Maritza Barcia-Macay (Patterson) Unité de Pharmacologie cellulaire et moléculaire I. INTRODUCTION Staphylococcus aureus Bacteria with

intracellular killing is visible !

control

OXA

ORI

Page 39: Maritza Barcia-Macay (Patterson) - UCLouvain...Maritza Barcia-Macay (Patterson) Unité de Pharmacologie cellulaire et moléculaire I. INTRODUCTION Staphylococcus aureus Bacteria with

extracellular

versus intracellular activity

-5-4-3-2-10

TELAZM

LNZRIF

GENTEC VAN

ORI

PEN VNAFAMP

OXALVXGRN

MXF

CIP

TLV

growth killing

growth

killing

extracellularΔ log CFU from time 0

-5

-4

-3

-2

-1

0

Poorly active against extra and intraS. aureus

intr

acel

lula

log

CFU

from

tim

e 0

Page 40: Maritza Barcia-Macay (Patterson) - UCLouvain...Maritza Barcia-Macay (Patterson) Unité de Pharmacologie cellulaire et moléculaire I. INTRODUCTION Staphylococcus aureus Bacteria with

extracellular

versus intracellular activity

-5-4-3-2-10

TELAZM

LNZRIF

GENTEC VAN

ORI

PEN VNAFAMP

OXALVXGRN

MXF

CIP

TLV

growth killing

growth

killing

extracellularΔ log CFU from time 0

-5

-4

-3

-2

-1

0

Active against extraS. aureus

intr

acel

lula

log

CFU

from

tim

e 0

Page 41: Maritza Barcia-Macay (Patterson) - UCLouvain...Maritza Barcia-Macay (Patterson) Unité de Pharmacologie cellulaire et moléculaire I. INTRODUCTION Staphylococcus aureus Bacteria with

extracellular

versus intracellular activity

-5-4-3-2-10

TELAZM

LNZRIF

GENTEC VAN

ORI

PEN VNAFAMP

OXALVXGRN

MXF

CIP

TLV

growth killing

growth

killing

extracellularΔ log CFU from time 0

-5

-4

-3

-2

-1

0

Best choice for activity against extra and intra S. aureus

intr

acel

lula

log

CFU

from

tim

e 0

Page 42: Maritza Barcia-Macay (Patterson) - UCLouvain...Maritza Barcia-Macay (Patterson) Unité de Pharmacologie cellulaire et moléculaire I. INTRODUCTION Staphylococcus aureus Bacteria with

conclusion

model of infection of human macrophages by S. aureus over 24 h allowing for the study of

• influence of time and concentration on antibiotic activity• relation between activity and accumulation

intracellular activity <<

extracellular

activity

• no correlation with level of accumulation• impairing effect of acidic pH on some antibiotics

optimizing

antibiotic efficacy

• choice of the drug (active extra and intracellularly)• optimization of exposure ( time and concentration)

Page 43: Maritza Barcia-Macay (Patterson) - UCLouvain...Maritza Barcia-Macay (Patterson) Unité de Pharmacologie cellulaire et moléculaire I. INTRODUCTION Staphylococcus aureus Bacteria with

Second goal of this thesis

New drug in developmentDifferent phenotypes

of resistance

Page 44: Maritza Barcia-Macay (Patterson) - UCLouvain...Maritza Barcia-Macay (Patterson) Unité de Pharmacologie cellulaire et moléculaire I. INTRODUCTION Staphylococcus aureus Bacteria with

Telavancin, a new

glycopeptideHemi-synthetic derivative of

vancomycin, with new mode of action and new

pharmacokinetic

profile

• permeabilization of bacterial membrane• prolonged half-life

• dimerization and cooperative binding to peptidoglycan precursors

• shortening of half-life

Page 45: Maritza Barcia-Macay (Patterson) - UCLouvain...Maritza Barcia-Macay (Patterson) Unité de Pharmacologie cellulaire et moléculaire I. INTRODUCTION Staphylococcus aureus Bacteria with

MIC and MBC against S. aureus with different resistance phenotypes

• more active than VAN against VISA and VRSA• bactericidal against all strains

MIC and MBC of

vancomycin

and telavancin against the S. aureus strains

used.

vancomycin

telavancinphenotype

strain

MIC

MBC

MIC

MBC

MSSA ATCC25923 1 1 0.5 0.5ATCC29213 1 1 0.5 0.5

MRSA ATCC33591 2 4 0.5 1ATCC43300 2 2 0.5 0.5

VISA NRS23 4 4 0.5 0.5NRS52 4 4 0.5 0.5

VRSA VRS1 >128 >256 4 8VRS2 16 64 2 8

Page 46: Maritza Barcia-Macay (Patterson) - UCLouvain...Maritza Barcia-Macay (Patterson) Unité de Pharmacologie cellulaire et moléculaire I. INTRODUCTION Staphylococcus aureus Bacteria with

Influence of time on EXTRACELLULAR activity

Telavancin is more rapidly cidal than vancomycin

VAN vs TLV –

MSSA ATCC 25923

Page 47: Maritza Barcia-Macay (Patterson) - UCLouvain...Maritza Barcia-Macay (Patterson) Unité de Pharmacologie cellulaire et moléculaire I. INTRODUCTION Staphylococcus aureus Bacteria with

Influence of concentration on EXTRACELLULAR activity

• at 3 h, TEL shows bimodal conc-dependent effects• at 24 h, both drugs are bactericidal at high concentrations

VAN vs TLV –

MSSA ATCC 25923

Page 48: Maritza Barcia-Macay (Patterson) - UCLouvain...Maritza Barcia-Macay (Patterson) Unité de Pharmacologie cellulaire et moléculaire I. INTRODUCTION Staphylococcus aureus Bacteria with

EXTRACELLULAR activity of telavancin: comparison of different strains

at 3 h, TEL shows bimodal conc-dependent effects towards MSSA and MRSA

TLV versus MSSA, MRSA, VISA, VRSA

Page 49: Maritza Barcia-Macay (Patterson) - UCLouvain...Maritza Barcia-Macay (Patterson) Unité de Pharmacologie cellulaire et moléculaire I. INTRODUCTION Staphylococcus aureus Bacteria with

INTRACELLULAR activity of vancomycin and telavancin towards different strains

TEL shows bimodal conc-dependent effects towards MSSA / MRSA VAN is only static intracellulalry

VAN and TLV versus MSSA, MRSA, VISA, VRSA

Page 50: Maritza Barcia-Macay (Patterson) - UCLouvain...Maritza Barcia-Macay (Patterson) Unité de Pharmacologie cellulaire et moléculaire I. INTRODUCTION Staphylococcus aureus Bacteria with

Why bimodal effects for telavancin ?

-2 -1 0 1 2 3-5

-4

-3

-2

-1

0

1

2

3vancomycintelavancin

log concentration (µg/ml)

Δ lo

g C

FU fr

om ti

me

0

VAN and TLV: inhibition of peptidoglycan synthesis

TLV: membrane permeabilization

Higgins et al., AAC (2004) 49:1127-34

In MSSA and MRSA, telavancin can exert multiple modes of action

Page 51: Maritza Barcia-Macay (Patterson) - UCLouvain...Maritza Barcia-Macay (Patterson) Unité de Pharmacologie cellulaire et moléculaire I. INTRODUCTION Staphylococcus aureus Bacteria with

Telavancin cellular

pharmacokinetic

data

rationalizing its intracellular activity

(studies with J774 macrophages)

Page 52: Maritza Barcia-Macay (Patterson) - UCLouvain...Maritza Barcia-Macay (Patterson) Unité de Pharmacologie cellulaire et moléculaire I. INTRODUCTION Staphylococcus aureus Bacteria with

subcellular distribution of telavancin

Same distribution as a lysosomal enzyme

High concentration in the compartment

where S. aureus sojourns !

Page 53: Maritza Barcia-Macay (Patterson) - UCLouvain...Maritza Barcia-Macay (Patterson) Unité de Pharmacologie cellulaire et moléculaire I. INTRODUCTION Staphylococcus aureus Bacteria with

conclusion

model of infection of human macrophages by S. aureus over 24 h applicable to

multiresistant

strains

vancomycin

• slowly bactericidal extracellularly (MSSA and MRSA)• poorly or not active on VISA and VRSA• static intracellularly

telavancin• bactericidal extra- and intracellularly,

including against resistant strains• bimodal effect against MSSA and MRSA could be related to multiple modes of action

• high accumulation in the infected compartment

Page 54: Maritza Barcia-Macay (Patterson) - UCLouvain...Maritza Barcia-Macay (Patterson) Unité de Pharmacologie cellulaire et moléculaire I. INTRODUCTION Staphylococcus aureus Bacteria with

V. GENERAL CONCLUSION: can we do better ?

Page 55: Maritza Barcia-Macay (Patterson) - UCLouvain...Maritza Barcia-Macay (Patterson) Unité de Pharmacologie cellulaire et moléculaire I. INTRODUCTION Staphylococcus aureus Bacteria with

Limitations of the model and perspectives for future work

Constant concentrations (pharmacokinetic

variations not taken into account):

develop dynamic models

Protein binding (free fraction is active and able to accumulate)

develop in vivo models

Phagocytic

cells (S. aureus also infects

non

phagocytic

cells

where its fate may be different)develop models of infection in non-phagocytic cells

Testing of antibiotics alone (combinations often used in the clinics to cope with resistance)

testing of drug combinations

Page 56: Maritza Barcia-Macay (Patterson) - UCLouvain...Maritza Barcia-Macay (Patterson) Unité de Pharmacologie cellulaire et moléculaire I. INTRODUCTION Staphylococcus aureus Bacteria with

THANKYOU !

Page 57: Maritza Barcia-Macay (Patterson) - UCLouvain...Maritza Barcia-Macay (Patterson) Unité de Pharmacologie cellulaire et moléculaire I. INTRODUCTION Staphylococcus aureus Bacteria with

THANKS TO :

Prof. M.-P. Mingeot-LeclercqDr. C. Seral (Spain)Prof. J.- P. Herveg

Prof. V. PréatProf. M. DelméeProf. Y. GlupczynskiProf. B. Gallez

Prof. A. Pascual (Spain)Prof. M. Struelens (ULB)

Theravance (USA)

Page 58: Maritza Barcia-Macay (Patterson) - UCLouvain...Maritza Barcia-Macay (Patterson) Unité de Pharmacologie cellulaire et moléculaire I. INTRODUCTION Staphylococcus aureus Bacteria with

HURRA FACM !!!

Special thanks to O. Meert and M.-C. Cambier

Page 59: Maritza Barcia-Macay (Patterson) - UCLouvain...Maritza Barcia-Macay (Patterson) Unité de Pharmacologie cellulaire et moléculaire I. INTRODUCTION Staphylococcus aureus Bacteria with

THANKS TO YOU ALL