Infectiology award - UCLouvain · CV 0.5 1.0 1.5 2.0 2.5 3.0 3.5 log 10 concentration (X MIC) % control value Bauer, Siala ... Hoang Anh Nguyen. Aurélie Olivier. Youssef Ouadhriri

AWARDS 2013FOUNDATION

ASTRAZENECA AWARDS 2013

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ARDS 2013

Infectiology

award: Bacterial and cellular factors

affecting antibiotic activity towards persistent infections

Françoise Van Bambeke Louvain Drug Research

Institute, UCL



Paul Ehrlich, the father

of anti‐infective

chemotherapy

15 December 2013 2

“corpora non agunt nisi fixata”

Ehrlich’s “magic bullet” theory

“The aim is to find chemical substances that have special affinities for pathogenic organisms and

that, like «magic bullets», go straight to their targets.”



Studying

anti‐infective

pharmacology to improve

antibiotic

treatment

15 December 2013 3

bacteria host cells

antibiotic

patient



Specific

lifestyles

associated with

persistent infections

15 December 2013 4

bacteria host cells

Seral

et al, AAC 1993

Intracellular

infection: an application of the Trojan

horse strategy

Intracellular

Staphylococcusaureus



Specific

lifestyles

associated with


15 December 2013 5

bacterialresponsiveness

physico‐chemicalconditions

cooperation

with

host defences

accumulation and

bioavailability

metabolismbinding

influx

efflux

pharma

cokineti

cspharmacodynamics

bacteria host cells

Carryn

et al, Infect Dis

Clin

North Am., 2003

Intracellular

Staphylococcusaureus



Specific

lifestyles

associated with


15 December 2013 6

bacteria host cells

Bauer, Siala

et al, AAC 2013

lifedead

Biofilms: bacterial

hibernation



Specific

lifestyles

associated with


15 December 2013 7

bacteria host cells

Bauer, Siala

et al, AAC 2013

Biofilms: bacterial

hibernation

Gradient ofnutriments,oxygen

Gradient of

metabolic

activity

and viability

catheter, bone, skin, cardiac

valve, …life

dead



Specific

lifestyles

associated with


15 December 2013 8

Lemaire et al, JAC 2011

-1 0 1 2 3 4 5-5

-4

-3

-2

-1

0

1

2

3

extraintra

log10 concentration (X MIC)

lo

g C

FU fr

om ti

me

0

Intracellular

infection: activity

of the fluoroquinolone

moxifloxacin

on S. aureus



Specific

lifestyles

associated with


15 December 2013 9


close to the MIC even

for antibiotics

accumulating

in cells

Cs ~ intracellular

bacteria

: Measure

of the «

intracellular

MIC

»

• «

Pharmacokinetic‐related

»

parameter:accumulation in the infected

compartmentintracellular

bioavailability

• influence of local environment

on activitypHoxidant

species

-1 0 1 2 3 4 5-5

-4

-3

-2

-1

0

1

2

3

extraintra


lo

g C

FU fr

om ti

me

0

Intracellular

infection: activity


moxifloxacin

on S. aureus

Cs

« rel. potency

»



Specific

lifestyles

associated with


15 December 2013 10


Lower

than

extracellularly, suggesting

poor

bacterial

responsiveness

and/or

antibiotic

expression of activity

Emax

~ intracellular

bacteria: Measure

of killing

capacity

• «

Pharmacodynamic‐related

»

parameter:mode of action of the drugbacterial responsivenesscooperation with host defenses

-1 0 1 2 3 4 5-5

-4

-3

-2

-1

0

1

2

3

extraintra


lo

g C

FU fr

om ti

me

0

Intracellular

infection: activity


moxifloxacin

on S. aureus

Cs

« rel. potency

»

Emax

«

efficacy

»



Specific

lifestyles

associated with


15 December 2013 11

CT0

20

40

60

80

100

120

RFCV

0.5 1.0 1.5 2.0 2.5 3.0 3.5log10 concentration (X MIC)

% c

ontr

ol v

alue

Bauer, Siala

et al, AAC 2013

Emax

«

efficacy

»

C25

« rel. potency

»

Pharmacodynamic

profile similarto that

observed

intracellularly,suggesting

similar

defeating

factors

Biofilm: activity


moxifloxacin

on S. aureus



Active efflux and intrinsic/acquired resistance

to antibiotics

15 December 2013 12

patient

bacteria

antibiotic

+

low

permeability

+ constitutive active efflux

intrinsic

resistance




to antibiotics

15 December 2013 13

Azithromycin

is

inactive on P. aeruginosa

…

medium strain MIC (mg/L)

CA‐MHB PAO1 512




to antibiotics

15 December 2013 14

Azithromycin

is

inactive on P. aeruginosa

…


CA‐MHB PAO1 512

…

but is

successfully

used

in cystic

fibrosis

patients




to antibiotics

15 December 2013 15

Azithromycin

becomes

active on P. aeruginosa

when

efflux systems

are inactivated

Buyck

et al, CID 2012


CA‐MHB PAO1 512

PAO1

(mexAB‐oprM, mexCD‐oprJ,

mexJK, mexXY, mexEF‐oprN)

8




to antibiotics

15 December 2013 16

Azithromycin

becomes

active on P. aeruginosa

when

cultivated

in biological

fluids

Buyck

et al, CID 2012


CA‐MHB PAO1 512

PAO1

(mexAB‐oprM, mexCD‐oprJ,

mexJK, mexXY, mexEF‐oprN)

8

Bronchoalveolar

lavage PAO1 16

CA‐MHB/serum

50:50 8




to antibiotics

15 December 2013 17

Azithromycin

does

express its

activity

on P. aeruginosa

in biological

fluids

by repressing

the expression of its

efflux transporters

Buyck

et al, CID 2012




to antibiotics

15 December 2013 18

patient

bacteria

antibiotic

+

reduced

concentration at

the target

site

risk

of selection

of resistance

(target

mutations)risk

of suboptimal

dosage

+




to antibiotics

15 December 2013 19

Efflux mechanisms

are overexpressed

during

treatment

treatment

with

antibiotics

Pseudomonas

aeruginosa

isolated

from

patients in intensive care units

suffering

from

hospitally‐acquired

pneumonia

Riou

et al, ECCMID 2010



Active efflux and modulation of cellular pharmacokinetics

of antibiotics

15 December 2013 20

patient

host cell

antibiotic

reduced

concentration inside

the cells

alteration

of activity

against

intracellular

bacteriamodification of PK profile

+




of antibiotics

15 December 2013 21

Michot

et al., AAC 2004 & 2005

N

O

OH

O

HNN

F

N

C

O

FOH

O

OCH3

HN N

Differential

recognition of fluoroquinolones

by macrophage efflux transporters

ciprofloxacin

moxifloxacin




of antibiotics

15 December 2013 22

Dupont

et al., ECCMID 2012

0 1 2 3 4 5 6 70

2

4

6

8

10

12

14

16R² = 0.8225

CIP

MXF

MIC change [NorA+/-] (fold dilutions)

Acc

umul

atio

n ch

ange

[Mrp

4+/-]

(fol

d)

But similarity

in recognition of fluoroquinolones

by macrophage and bacterial

efflux transporters

Substrates

of efflux systems

frommacrophages and Gram‐(+) bacteria

Poor

substrates

of efflux systems

frommacrophages and Gram‐(+) bacteria

24 FQ



Studying

anti‐infective

pharmacology to improve

antibiotic

treatment

15 December 2013 23

bacteria host cells

antibiotic

patient

effluxefflux

intracellular

infection

?



Cooperation

between

procaryotic

and eukaryotic

efflux systems

15 December 2013 24

Lismond

et al., AAC 2008

Bacterial

and eukaryotic

efflux pumps

cooperateto make

intracellular

Listeria monocytogenes

resistant

to ciprofloxacin



Cooperation

between

procaryotic

and eukaryotic

efflux systems

15 December 2013 25

Moxifloxacin

intracellular

activity

is

not affected

by eukaryotic

/ bacterial

efflux pumps

Lismond

et al., AAC 2008



Clinical

implications of this

work

15 December 2013 26

1.

Expression of activity is highly dependent on the environment•

Growth medium can influence bacterial physiology•

Intracellular bacteria / biofilms

are refractory to antibiotics importance of testing antibiotic activity in relevant media/models

2.

Screening tests in routine laboratories may need to be revisited•

Susceptibility changes during treatment•

Low level resistance mechanisms (efflux) often escape detection

in routine

but are clinically meaningful

interest of basing dosages on PK/PD approaches and MIC determinations

importance of developing new diagnostic tools

3.

Pertinent in vitro models may be helpful in preclinical evaluation of new drugs•

Intracellular survival is considered as determinant in recurrence /persistence•

Biofilms

are associated to about 80 % of infections in vitro screening may help selecting drug candidates



Acknowledgments

15 December 2013 27

Financial support to this

work

Research

grants

from

pharmaceutical

companies



Acknowledgments

15 December 2013 28

Coworkers over the years in the team ‐

efflux

+Laetitia

Avrain

Julien

Buyck Nancy

Caceres Hussein

Chalhoub

Farid

El Garch

Coralie

ValletMickaël

Riou Hariri

MustafaJean‐Michel

MichotBéatrice

Marquez

Ann

Lismond



Acknowledgments

15 December 2013 29

Coworkers over the years in the team –

intracellular infections & biofilms

Julia

BauerEugénie

Basseres

Wafi

SialaNathalie

Vandevelde

Ahalieyah

AnantharajahMaritza

BarciaPierre

BaudouxJulien

Buyck

Stéphane

CarrynLaetitia

GarciaSandrine

LemaireHoang Anh

NguyenAurélie

Olivier

Youssef

OuadhririFrédéric

PeyrussonCristina

SeralSébastien

Van de Velde



Acknowledgments

15 December 2013 30

Technical staff

Marie‐Claire

CambierCharlotte

MissonVirginie

Mohymont

Pierre

MullerKatia

SantosMartial

Vergauwen

The two

successive « heads »of the team

Paul

Tulkens

Marie‐Paule

Mingeot

Documents

Infectiology award - UCLouvain · CV 0.5 1.0 1.5 2.0 2.5 3.0 3.5 log 10 concentration (X MIC) % control value Bauer, Siala ... Hoang Anh Nguyen. Aurélie Olivier. Youssef Ouadhriri