antibiotic accumulation and efflux in eukaryotic cellscraig (1998) cid 26:1-10. isap classical view...

Antibiotic Antibiotic accumulation and effluxaccumulation and effluxin eukaryotic cells:in eukaryotic cells:

a journey at the frontier a journey at the frontier of pharmacokinetics of pharmacokinetics and and pharmacodynamics

“corpora non agunt nisi fixata”

Ehrlich’s “magic bullet” theory

pharmacodynamics

Unité de Pharmacologiecellulaire et moléculaire

F. Van Bambeke

Magic bullets need to reach their target

Magic bullets need to reach their target

glycopeptides

β-lactams

quinolones

macrolides aminoglycosides

for appropriate time and in sufficient concentration …

Birth of antibiotic “PK-PD”

Concentrationversus timein tissues andother body fluids

Pharmacologicor toxicologiceffect

Concentrationversus timein serum

Dosageregimen

Concentrationversus timeat siteof infection

Antimicrobial effect versustime

absorptiondistributionelimination

PHARMACOKINETICS PHARMACODYNAMICS

Craig (1998) CID 26:1-10

ISAP classical view of PK/PD

but classical PD predicts concentration-effectsfor all drugs ….

but classical PD predicts concentration-effectsfor all drugs ….

ampicillingentamicin

S. aureus; 24 h Barcia-Macay et al, submitted; Lemaire et al (2005) JAC in press

Can we conciliate both theories ?

Cmin Cmax

conc.-dependent

Cmin Cmax

PD profile in the clinics

time -dependentampicillingentamicin

S. aureus; 24 h Barcia-Macay et al, submitted; Lemaire et al (2005) JAC in press

Target accessibility becomes critical for intracellular activity

Main routes of drug entry in cells

passive

diffusionchannel

transporter transporterendocytosis

active

Intracellular “PK-PD”

Concentrationversus timein non-infectedcells


Concentrationversus timein cells

Dosageregimen

Concentrationversus timeat intracellularsite of infection


penetrationdistributionefflux






Dosageregimen

Concentrationversus timeat intracellular site of infection


penetrationpenetrationdistributiondistributionefflux

glycopeptides






Dosageregimen


Antimicrobial Antimicrobial effect versuseffect versustimetime


glycopeptides




PharmacologicPharmacologicor or toxicologictoxicologiceffecteffect


Dosageregimen




glycopeptides






Dosageregimen



penetrationdistributioneffluxefflux

macrolidesquinolones






Dosageregimen






Accumulation of magic bullets in eukaryotic cells

glycopeptides

Vancomycin, the parent compound

O O

NH

HN

NH

HN

NH

O

HOCl

O

O

O

O

HOOH

ONH CH3

H N

O

HOOC

OH

CONH2

Cl

O OH

HOHO

OO

H3C

CH3H2NHO

OH

O O

NH

HN

NH

HN

NH

O

OCl

O

O

O

O

HOOH

ONH CH3

H N

O

HOOC

OH

CONH2

Cl

O OH

HOHO

OO

H3C

CH3HN

OH

Cl

O

H2N

CH3

HOH3C

OH

The glycopeptide oritavancin, a voluminous, amphiphilic molecule

From vancomycin to oritavancin

O O

NH

HN

NH

HN

NH

O

HOCl

O

O

O

O

HOOH

ONH CH3

H N

O

HOOC

OH

CONH2

Cl

O OH

HOHO

OO

H3C

CH3H2N

OHepi-vancosamine

OH


O O

NH

HN

NH

HN

NH

O

OCl

O

O

O

O

HOOH

ONH CH3

H N

O

HOOC

OH

CONH2

Cl

O OH

HOHO

OO

H3C

CH3H2N

OHO

H2N

CH3

HOH3C

OH4-epi-vancosamine

self-association capacity

LY264626


O O

NH

HN

NH

HN

NH

O

OCl

O

O

O

O

HOOH

ONH CH3

H N

HOOC

OH

CONH2

Cl

O OH

HOHO

OO

H3C

CH3HN

OH

Cl

lipophilic side chainactivity including against resistant enterococci

OHO

O

O

H2N

CH3

HOH3C

Cooper et al (1996) J Antibiot 49: 575-81

Oritavancin, a cationic amphiphile

O O

NH

HN

NH

HN

NH

O

OCl

O

O

O

O

HOOH

ONH CH3

H N

O

HOOC

OH

CONH2

Cl

O OH

HOHO

OO

H3C

CH3HN

OH

Cl

O

H2N

CH3

HOH3C

OH

lipophilic side chain

additional protonable amine

Oritavancin, a cationic amphiphile

New chemical entity

New pharmacodynamic properties ?

New pharmacokinetic profile ?

But also ... new potential side effects ?

Spectrum of activity

bacteria resistance vancomycin oritavancin

enterococci susc.VanAVanB

1-2>1288-128

0.06-0.25 1-4

0.125

S. aureus Methi-SMethi-RGISAGRSA

1-21-48

> 128

1 1-21-80.5

•highly active on susc. enterococci•active on VAN-resistant strains

Van Bambeke et al. (2004) Drugs 64:913-36

Pharmacodynamic profile

VANCOMYCIN: modestly bactericidal • slow • no or little conc. effect

oritavancin

0 6 12 18 24time (h)

ORITAVANCIN:highly bactericidal:• rapid• conc. dependent

vancomycin

0 6 12 18 24-6

-4

-2

0

2

4

time (h)

∆lo

g C

FU fr

om ti

me

0

1 X MIC10 X MIC

control

40 X MIC

S. aureus Barcia-Macay et al. submitted

Pharmacokinetic properties

parameter Vancomycin(15 mg/kg)

Oritavancin(3 mg/kg)

peak (mg/L)

trough (mg/L)

protein binding

terminal t½ (h)

20-50 31

5-12(24 h)

1.7 (24 h)

10-55 % 90 %

4-8 360

• daily administration• retention in the organism ?

Van Bambeke et al. (2004) Drugs 64:913-36

Aim of the study

• activity against (multi-resistant) Gram-positive (S. aureus)• rapid bactericidal activity• retention in the organism

any place for intracellular infections?

accumulation and subcellulardistribution in eukaryotic cells

cellular pharmacokinetics:

activity against intracellular S. aureus

cellular pharmacodynamics:

morphological and biochemical alterations

cellular toxicity:

Aim of the study

• activity against (multi-resistant) Gram-positive (S. aureus)• rapid bactericidal activity• retention in the organism


accumulation and accumulation and subcellularsubcellulardistributiondistribution inin eukaryotic cellseukaryotic cells

cellular pharmacokinetics:cellular pharmacokinetics:

activity against intracellular bacteria



cellular toxicity:

Kinetics of accumulation-efflux

Oritavancin accumulation and release are slow

J774 macrophages; extracell. conc. 25 mg/L; 24 h Van Bambeke et al. (2004) AAC 48:2853-60

Comparison with other antibiotics

Oritavancin reaches exceptional cellular accumulation levels

vancomycin azithromycin0

100

200

300

400

accu

mul

atio

n ra

tio

oritavancin

J774 macrophages; extracell. conc. 25 mg/L; 24 h Van Bambeke et al. (2004) AAC 48:2853-60

Subcellular localization

lysosomes

mitochondria

membrane

N-acetyl-β-glucosaminidase

cytochrome c-oxydase

inosine diphosphatase

Van Bambeke et al. (2004) AAC 48:2853-60

Subcellular localization

Oritavancin is a lysosomotropic antibiotic

lysosomes

mitochondria

membrane

N-acetyl-β-glucosaminidase

cytochrome c-oxydase

inosine diphosphatase


Mechanism of cellular accumulation

chloroquineazithromycin

+++

HRPlatex beads

Mechanism of cellular accumulation

Oritavancin kinetics of accumulation are very similar to those of tracers of (adsorptive) endocytosis

accu

mul

atio

n ra

tio

kinetics of accumulation


Aim of the study

• activity against multi-resistant Gram-positive (S. aureus)• rapid bactericidal activity• retention in the organism


accumulation and distribution in eukaryotic cells


activity against activity against intracellular bacteriaintracellular bacteria

cellular pharmacodynamics:cellular pharmacodynamics:


cellular toxicity:

Intracellular activity on S. aureus

cont

rol

orita

vanc

in

Oritavancincan destroy intracellular bacteria

THP-1 macrophages; extracell. conc. 25 mg/L; 24 h Barcia-Macay et al. submitted

Time-effect for intracellular activity

0 5 10 15 20 25101

103

time (h)

CFU

/mg

prot

105

107 vancomycinoritavancin

Oritavancin shows time- and concentration-dependent intracellular bactericidal effects

2.5 µg/ml

25 µg/ml

0.25 µg/ml

10 µg/ml

50 µg/ml

control

J774 macrophages Seral et al (2003) AAC 47: 2283-92

Dose-effect for extracell. vs intracell. activity

intracellular activity < extracellular activity

extra intra

staticconc. 0.3 X MIC 4.8 X MIC

max. effect - 5.55 log - 3.15 log

THP-1 macrophages; 24 h Barcia-Macay et al. submitted

Dose-effect

intracellular activity < extracellular activity, but bactericidal effects reached at clinically-relevant concentrations

Cmin Cmax

Barcia-Macay et al. submitted

Comparison with other antibiotics

MIC10 X MICCmax

oritavancin is one of the most active drugs against intracellular S. aureus

THP-1 macrophages; 24 h Barcia-Macay et al. submitted

Aim of the study

• activity against multi-resistant Gram-positive (S. aureus)• rapid bactericidal activity• retention in the organism


accumulation and subcellulardistribution in eukaryotic cells


activity against intracellular bacteria



cellular toxicity:

Morphological studies

macrophages fibroblastspolar lipids

Rat embryo fibroblasts; 25 mg/L; 3 daysJ774 macrophages, 25 mg/L; 1 day Van Bambeke et al. (2005) AAC – in press

Biochemical studies : time-effects

accumulation of phospholipids and cholesterol develops in parallel with oritavancin cellular concentration

drug-free medium

drug-free medium

drug-free medium

Rat embryo fibroblasts; 25 mg/L Van Bambeke et al. (2005) AAC – in press

Biochemical studies : dose-effects

Rat embryo fibroblasts, 3 daysJ774 macrophages, 1 day Van Bambeke et al. (2005) AAC – in press

Model of the interaction of oritavancin with eukaryotic cells

S. aureus

polar lipids

oritavancin

undefined material

Can we dissociate activity from toxicity ?

cellular alterations co-exist with destroyed bacteria ….

THP-1 macrophages; 25 mg/L; 24 h


comparison with two other lysosomotropic cationic antibiotics

O

O

O

CHH2N

NH2

OH

HNH3C

CH3 OHHO

H2NO HN

R1

R2

gentamicin

• polycationic, hydrophilic• endocytosis• phospholipidosis

O

CH3

OH

OH

OH

CH3

CH2CH3 O

O

CH3

CH3

CH3

O

O

OOH

N(CH3)2

CH3

OH

N

CH3

CH3

CH3

OCH3 CH3

azithromycin

• dicationic• diffusion/segregation• accumulation of phospholipids

and cholesterol

Lysosomotropic antibiotics and activity on S. aureus

GEN and ORI are both conc.-dependent intracellularly

J774 macrophages

Lysosomotropic antibiotics and activity on S. aureus

But GEN activity limited at clinically-relevant conditions

J774 macrophages

Lysosomotropic antibiotics and phospholipidosis

Phospholipidosis developing on a conc.-dependent manner

Rat embryo fibroblasts

Lysosomotropic antibiotics and phospholipidosis

Toxic potential variable at clinically-relevant conditions

Rat embryo fibroblasts


both processes are dependent on cellular concentration …

-3-2-10100

120

140

160

180

intracellular activity

cellu

lar t

oxic

ity

GEN

AZM

ORI

… and develop in parallel

Conclusion amphiphilic glycopeptides, a new type of « magic bullets»

pharmacokinetics:lysosomotropic accumulation

bactericidal, conc-dep.activity

pharmacodynamics:

conc. and time-dependentcellular toxicity

cellular toxicity:

Morphological studies

Rat embryo fibroblasts; 25 mg/L; 3 daysJ774 macrophages, 25 mg/L; 1 day

macrophages fibroblastspolar lipids

Van Bambeke et al. (2005) AAC – in press

conc. and time-dependentbactericidal activitytowards extra AND intraS. aureus


Dose-effect

intracellular activity < extracellular activity, but bactericidal effects reached at clinically-relevant concentrations

Barcia-Macay et al. submitted

Cmin Cmax

Questions for future work

S. aureus

polar lipids

oritavancin

undefined material

?

binding site?

reasons for reduction in activity

intracellularly

in vivo

? mechanismof accumulation

?

Take home message

cellular accumulation, the best and the worse of properties…

drug developmentactivity

toxicity





Dosageregimen






Efflux of magic bullets from eukaryotic cells


Why efflux transporters ?

polar drug

lipophilic drug

physico-chemical properties are inadequate for reaching an intracellular target !

Van Bambeke et al. (2000) Biochem. Pharmacol. 60:457-70


amphipathic drug

most drugs are amphipathic by design,to be able to cross membrane barriers !



But a diffusible compound may have

potentially harmful effects !Van Bambeke et al. (2000) Biochem. Pharmacol. 60:457-70


Extrusion by efflux pumps



Extrusion by efflux pumps

general mean of protectionagainst cell invasion by diffusible molecules


Mechanisms of active efflux

ATP ADP+Pi

membrane insertion / release

vacuum cleaner

flippaseflip-flop


Antibiotics as substrates of efflux pumps

Antibiotic bacteria fungi superiorclass Gram (+) Gram(-) eucaryotesβ-lactamsfusidic acidmacrolidesstreptograminstetracyclinesaminoglycosideschloramphenicolrifamycinssulfamidestrimethoprimfluoroquinolones


Antibiotics as substrates of efflux pumps

O

H3C

OH

OH

OH

CH3

H3CH2C O

O

CH3

CH3

H3C

O

O

OHO(H3C)2N

CH3

OH

N

CH3

CH3

H3C

H3C

H3CO

azithromycin

ciprofloxacin

N

C

O

FOH

O

OCH3

HN N

moxifloxacin

N

O

OH

O

HNN

F

Macrolides and quinolones as cell-associated antibiotics

Aim of the study

amphiphilic antibiotics• accumulating in eucaryotic cells• considered as useful for treating intracellular infections• known substrates of efflux pumps in bacteria

efflux from macrophages ?

macrolides

• phenotypic characterization of the active efflux

• consequences for intracellular activity

quinolones

Aim of the study



macrolides

•• phenotypic characterization phenotypic characterization of the active efflux of the active efflux

• consequences for intracellular activity

quinolones

Efflux pumps expressed in J774 macrophages

ABC multidrug transporters

ATP ADP

MDR-1 (P-glycoprotein) MRP1-10

cationic amphiphiles

anionic amphiphiles

How to inhibit ABC transporters ?

ATP ADP

MDR-1 (P-glycoprotein) MRP1-10


anionic amphiphiles

deoxyglucoseNaN3

How to inhibit ABC transporters ?OCH3

H3CO

CNCH(CH3)2

N

CH3

OCH3

OCH3

NH

C

OHN

H3CO

O

N

H3CO

H3CO

ATP

verapamil


MDR-1 (P-glycoprotein)

GF120918

ADP

How to inhibit ABC transporters ?

COOHSN

O

OC3H7

C3H7

NCl

S

S

HOOC

N(CH3)2

O

ATP

MRP1-10

anionic amphiphilesprobenecid

(CH2)3 C

CH3

CH3

COOHH3C

CH3gemfibrozil

MK571

ADP

Differential recognition by MDR pumps

Influence of ATP-depletion and pump inhibitors on accumulation at equilibrium

ciprofloxacin&

MRP

azithromycin&

P-glycoproteinextracell. conc. 5 mg/L; AZM 3 h; CIP 2 h Michot et al. AAC (2004) 48:2673-82

Aim of the study



macrolides

• phenotypic characterization of the active efflux

• consequences for consequences for intracellular activityintracellular activity

quinolones

Models of intracellular infection

L. monocytogenes S. aureus

phagolysosomescytosol

Influence of pump inhibitors onintracellular activity

azithromycin and L. monocytogenes

L. monocytogenes

verapamil 20 µM; 24 h

AZMAZM

Seral et al (2003) JAC 51:1167-73


azithromycin and S. aureus

S. aureus

AZMAZM

verapamil 20 µM; 24 h Seral et al (2003) JAC 51:1167-73


ciprofloxacin and L. monocytogenes

L. monocytogenes

gemfibrozil 250 µM; 24 h

CIP

Seral et al (2003) JAC 51:1167-73


ciprofloxacin and S. aureus

S. aureus

CIP

gemfibrozil 250 µM; 24 h Seral et al (2003) JAC 51:1167-73

Influence of pump inhibitors on antibiotic distribution

verapamil enhances azithromycin concentrationIn cytosol and vacuoles

L. monocytogenes

AZMAZM

S. aureus

Seral et al (2003) JAC 51:1167-73

Influence of pump inhibitors on antibiotic distribution

gemfibrozil enhances ciprofloxacin cytosolic content

L. monocytogenes

CIP

S. aureus

Seral et al (2003) JAC 51:1167-73

Are these effects clinically-relevant ?

constitutive efflux makes AZM and CIP activity suboptimalin a clinically-meaningful range of concentrations

Aim of the study



macrolidesmacrolides

• cellular pharmacokinetics

• model of interaction with the transporters

quinolonesquinolones

Aim of the study



macrolides

•• cellular pharmacokinetics cellular pharmacokinetics

•• model of interaction model of interaction with the transporterswith the transporters

quinolones

Kinetics of accumulation and effluxfor azithromycin

accumulation markedly increased; efflux marginally affected

extracell. conc. 5 mg/L; verapamil 20 µM Seral et al (2003) AAC 47:1047-51

Kinetics of accumulation and effluxfor ciprofloxacin

both accumulation and efflux markedly affected

extracell. conc. 17 mg/L; probenecid 5 mM Michot et al. AAC (2004) 48:2673-82

Kinetics of accumulation and effluxfor moxifloxacin

neither accumulation nor efflux affected

extracell. conc. 17 mg/L; probenecid 5 mM Michot et al. AAC (2005) – in press

Quinolones as inhibitors of ciprofloxacin efflux

• ciprofloxacin efflux inhibited by ciprofloxacin

Michot et al. AAC (2005) – in press


• ciprofloxacin efflux inhibited by ciprofloxacin• moxifloxacin not affected



• ciprofloxacin efflux inhibited by ciprofloxacin

CIP

CIP

MXF



• ciprofloxacin efflux inhibited by ciprofloxacinmoxifloxacin

CIP MXF

moxifloxacin also able

to interact with the transporter !

CIP


Comparison of kinetic parameters

influx efflux

half-life (min) half-life (min)

control inhibitor

flux(pmol/mg prot/min) control inhibitor

AZM 1 44 71 1 49 53

CIP 5 8 8 6 1.2 7.2

MXF 68 0.2 0.2 66 0.6 0.6

flux(pmol/mg prot/min)

drug

Azithromycin, ‘kick-back’ modelGaj et al. (1998) Biochem. Pharmacol. 55:1199-211

Ciprofloxacin, classical modelKolaczkowski & Goffeau (1997) Pharmacol. Ther. 76:219-42

Moxifloxacin, ‘futile-cycle’ modelEytan et al. (1996) JBC 271:12897-902

Conclusion constitutive efflux of antibiotics in macrophages

pharmacokinetics:suboptimal cellular accumulation

suboptimal intracell.activity

pharmacodynamics:

resistance ?

wide spectrum transporters

pharmacokinetics:

drug interactions ?

differences in affinitywithin a AB class

pharmacology:

Questions for future research

?

mechanismof

transport?

identificationof

transporter

cooperation with bacterial efflux pumps

? ?

drug interactions

metabolicalterations?

Take home message

constitutive efflux is part of the game

Take it into account in the choice of your « magic bullets » …for their optimal targeting

Thanks toThanks to …


Evaluating magic bulletsEvaluating magic bullets

•• pharmacokineticspharmacokineticsH.H. ChanteuxChanteux, M., M. HeremansHeremans, J.M., J.M. MichotMichot

•• pharmacodynamicspharmacodynamicsM. Barcia, N. M. Barcia, N. BlesBles, S., S. CarrynCarryn, S., S. LemaireLemaire, , A. Olivier, C.A. Olivier, C. SeralSeral, S. Van de, S. Van de VeldeVelde

•• toxicodynamicstoxicodynamicsJ.P.J.P. MontenezMontenez, H., H. ServaisServais, D., D. TytecaTyteca

•• biophysicsbiophysics & molecular biology& molecular biologyN.N. CaceresCaceres, N., N. Fa Fa


New magic bulletsNew magic bullets

•• chemistrychemistryE.E. ColacinoColacino, C., C. DaxDax, L., L. EfronEfron, T., T. HappaertsHappaerts, M., M. RenardRenard

•• pharmacologypharmacologyI.I. TytgatTytgat, D. Van, D. Van AckerenAckeren

•• modelingmodelingM.M. PrévostPrévost, M., M. RoomanRooman, S., S. VandevuerVandevuer


Resistance to magic bulletsResistance to magic bullets

•• effluxeffluxL.L. AvrainAvrain, N., N. MesarosMesaros

•• glycopeptidesglycopeptidesP.P. CourvalinCourvalin and his teamand his team


Clinical use of magic bulletsClinical use of magic bullets

•• clinical pharmacyclinical pharmacyE.E. AmpeAmpe, V., V. BasmaBasma, A., A. SpinewineSpinewine


Playing with magic bulletsPlaying with magic bullets

•• technical stafftechnical staffN. Aguilera, M.C.N. Aguilera, M.C. CambierCambier, O., O. MeertMeert, , F.F. RenoirdRenoird, M., M. VergauwenVergauwen

•• secretarysecretaryM.M. BreugelmansBreugelmans


Ehrlich’s colleaguesEhrlich’s colleagues


Inspiring research on magic bulletsInspiring research on magic bullets


Evaluating research on magic bulletsEvaluating research on magic bullets

P. Courvalin, A. Dalhoff, M. Delmée,P. Courvalin, A. Dalhoff, M. Delmée,H. Derendorf,Y. Glupczynski, H. Derendorf,Y. Glupczynski, E. Sonveaux, F. ZechE. Sonveaux, F. Zech


Paying for research on magic bulletsPaying for research on magic bullets


Managing research on magic bulletsManaging research on magic bullets

M.P. MingeotM.P. Mingeot--LeclercqLeclercq

P.M. TulkensP.M. Tulkens

Thank you Thank you for your attentionfor your attention

Antibiotic accumulation and effluxin eukaryotic cells:a journey at the frontier of pharmacokinetics and pharmacodynamicMagic bullets need to reach their targetMagic bullets need to reach their targetBirth of antibiotic “PK-PD”ISAP classical view of PK/PDbut classical PD predicts concentration-effectsfor all drugs ….but classical PD predicts concentration-effectsfor all drugs ….Can we conciliate both theories ?Target accessibility becomes critical for intracellular activity Main routes of drug entry in cellsIntracellular “PK-PD”Intracellular “PK-PD”Intracellular “PK-PD”Intracellular “PK-PD”Intracellular “PK-PD”Intracellular “PK-PD”Accumulation of magic bullets in eukaryotic cellsVancomycin, the parent compoundThe glycopeptide oritavancin, a voluminous, amphiphilic moleculeFrom vancomycin to oritavancinFrom vancomycin to oritavancinFrom vancomycin to oritavancinOritavancin, a cationic amphiphileOritavancin, a cationic amphiphileSpectrum of activityPharmacodynamic profilePharmacokinetic propertiesAim of the studyAim of the studyKinetics of accumulation-effluxComparison with other antibioticsSubcellular localizationSubcellular localizationMechanism of cellular accumulationMechanism of cellular accumulationAim of the studyIntracellular activity on S. aureusTime-effect for intracellular activityDose-effect for extracell. vs intracell. activityDose-effectComparison with other antibioticsAim of the studyMorphological studiesBiochemical studies : time-effectsBiochemical studies : dose-effectsModel of the interaction of oritavancin with eukaryotic cellsCan we dissociate activity from toxicity ?Can we dissociate activity from toxicity ?Lysosomotropic antibiotics and activity on S. aureusLysosomotropic antibiotics and activity on S. aureusLysosomotropic antibiotics and activity on S. aureusLysosomotropic antibiotics and phospholipidosisLysosomotropic antibiotics and phospholipidosisLysosomotropic antibiotics and phospholipidosisLysosomotropic antibiotics and phospholipidosisCan we dissociate activity from toxicity ?ConclusionQuestions for future workTake home messageIntracellular “PK-PD”Intracellular “PK-PD”Efflux of magic bullets from eukaryotic cellsWhy efflux transporters ?Why efflux transporters ?Why efflux transporters ?Why efflux transporters ?Why efflux transporters ?Mechanisms of active effluxAntibiotics as substrates of efflux pumpsAntibiotics as substrates of efflux pumpsMacrolides and quinolones as cell-associated antibioticsAim of the studyAim of the studyEfflux pumps expressed in J774 macrophagesABC multidrug transportersHow to inhibit ABC transporters ?How to inhibit ABC transporters ?How to inhibit ABC transporters ?Differential recognition by MDR pumpsAim of the studyModels of intracellular infectionInfluence of pump inhibitors onintracellular activityInfluence of pump inhibitors onintracellular activityInfluence of pump inhibitors onintracellular activityInfluence of pump inhibitors onintracellular activityInfluence of pump inhibitors on antibiotic distributionInfluence of pump inhibitors on antibiotic distributionAre these effects clinically-relevant ?Aim of the studyAim of the studyKinetics of accumulation and effluxfor azithromycinKinetics of accumulation and effluxfor ciprofloxacinKinetics of accumulation and effluxfor moxifloxacinQuinolones as inhibitors of ciprofloxacin effluxQuinolones as inhibitors of ciprofloxacin effluxQuinolones as inhibitors of ciprofloxacin effluxQuinolones as inhibitors of ciprofloxacin effluxComparison of kinetic parametersComparison of kinetic parametersComparison of kinetic parametersComparison of kinetic parametersComparison of kinetic parametersAzithromycin, ‘kick-back’ modelCiprofloxacin, classical modelMoxifloxacin, ‘futile-cycle’ modelConclusionQuestions for future researchTake home messageThanks to …Thanks to …Thanks to …Thanks to …Thanks to …Thanks to …Thanks to …Thanks to …Thanks to …Thanks to …Thanks to …Thank you for your attention

antibiotic accumulation and efflux in eukaryotic cellscraig (1998) cid 26:1-10. isap classical view...

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ISAP invita a profesionalización en administración pública

ISAP Reading List English

8th ISAP Symposium Developments in Pharmacokinetics and Pharmacodynamics (PK/PD): optimising efficacy and prevention of resistance Nijmegen, The Netherlands,

8th ISAP Symposium Can PK/PD be used in everyday clinical practice? Francesco Scaglione Department of Pharmacology, Toxicology and Chemotherapy, University

ISAP Manual Del Usuario

ISAP PACKAGING REPORT DI SOSTENIBILITÀ · Isap ed Omv creano insieme la prima macchina in Europa per produrre bicchieri in polipropilene 1993 Entra nel laboratorio Isap il primo

User’sManual - UCLA ISAP

Yellowstone & Jackson Hole 2016 ISAP Symposium · 1 2016 ISAP Committees 2016 ISAP Scientific Committee Troy Pauli, Chairman, WRI Jean-Pascal Planche, Co-Chair, WRI Adam Hand, Granite

8th ISAP Symposium