14/06/2014 XXXth Rocourt Neonatology Meeting 1
Antibiotic Resistance Acquisition
Paul M. Tulkens, MD, PhD
Cellular and Molecular Pharmacology & Center for Clinical Pharmacy Louvain Drug Research Institute, Université catholique de Louvain
Brussels, Belgium
Saturday June 14th, 2014 - Cercle de Wallonie Liège - Esplanade du Val, Seraing
14/06/2014 XXXth Rocourt Neonatology Meeting 2
Disclosures
Financial support from
• the Belgian Fonds de la Recherche Scientifique for basic research on pharmacology antibiotics and related topics
• Université catholique de Louvain for past personal support
• Commercial Relationships:– AstraZeneca, GSK, Sanofi-Aventis, Bayer HealthCare, Cempra
Pharmaceuticals, The Medicines Company, Northern Antibiotics, RibX, Cubist, Galapagos, …
• Other relationships in relation to this talk– Belgian Antibiotic Policy Coordination Committee,
– European Medicines Agency (as expert for the agency and for Industry)
– European Commmittee for Antibiotic Susceptibility Testing (EUCAST)
Slides: http://www.facm.ucl.ac.be Lectures
14/06/2014 XXXth Rocourt Neonatology Meeting 3
Do we have a problem ?
This man discovered the mode of action of penicillin
and died from invasive pneumococcal infection …
http://www.cip.ulg.ac.be/newsite/pdf/jmghuysen.pdf
14/06/2014 XXXth Rocourt Neonatology Meeting 4
But what about this patient ?
Gram stain of Staphylococcus aureus in pustular exudatehttp://www.tjclarkdirect.com/bacterial_diseases/staphylococcus.htm
Last accessed: 10/06/2014
Etok et al. Aetiology and antimicrobial studies of surgical wound infections in University of Uyo
Teaching Hospital (UUTH) Uyo, Akwa Ibom State, Nigeria. 1:341. doi:10.4172/scientificreports.341
14/06/2014 XXXth Rocourt Neonatology Meeting 5
Which problem ?
wild type
14/06/2014 XXXth Rocourt Neonatology Meeting 6
Which problem ?
resistant bacteria
elimination
active effluximpermeabilisation
wild type
attack
inactivation of the antibiotic
(biotransformation)
avoidance
modification of the target
way around
alternativetargetor target multiplication
no more active antibiotic ! "useless" antibiotic "overwhelmed" antibiotic
antibiotic absent or in insufficient concentration
14/06/2014 XXXth Rocourt Neonatology Meeting 7
But be aware ! Several mechanisms may coexist !elimination
active effluximpermeabilisation
wild type
attack
inactivation of the antibiotic
(biotransformation)
avoidance
modification of the target
way around
alternativetargetor target multiplication
multiresistantbacteria
14/06/2014 XXXth Rocourt Neonatology Meeting 8
Which problem ?
resistant bacteria
elimination
active effluximpermeabilisation
wild type
attack
inactivation of the antibiotic
(biotransformation)
avoidance
modification of the target
way around
alternativetargetor target multiplication
no more active antibiotic ! "useless" antibiotic "overwhelmed" antibiotic
antibiotic absent or in insufficient concentration
14/06/2014 XXXth Rocourt Neonatology Meeting 9
Attack: the example of aminoglycosides
Van Bambeke et al. Mechanisms of Action. In: Infectious Diseases (3d edition; J. Cohen,
W. Powderly & S. Opal, eds), chapter 130, pp 1288-1307, Elsevier/Mosby, 2010
14/06/2014 XXXth Rocourt Neonatology Meeting 10
Aminoglycoside resistance in Pseudomonas aeruginosa: an example in Belgium for patients with nososomial pneumonia
0.015
625
0.031
250.0
625
0.125 0.2
5 0.5 1 2 4 8 16 32 64 128
256
512
0
25
50
75
100
gentamicin
MIC (µg/mL)
cum
ulat
ive
perc
enta
ge (%
)
0.015
625
0.031
250.0
625
0.125 0.2
5 0.5 1 2 4 8 16 32 64 128
256
512
0
25
50
75
100amikacin
MIC (µg/mL)
cum
ulat
ive
perc
enta
ge (%
)
Data from Riou et al. Int J Antimicrob Agents. 2010 Dec;36(6):513-22
EUCAST ( > )
CLSI ( ≥
)R breakpoint
14/06/2014 XXXth Rocourt Neonatology Meeting 11
Aminoglycoside resistance in Pseudomonas aeruginosa: the situation may be worse elsewhere
European Centre for Disease Prevention and Control. Antimicrobial resistance surveillance in Europe 2012. Annual Report of the European Antimicrobial Resistance Surveillance Network (EARS-Net). Stockholm: ECDC; 2013.
14/06/2014 XXXth Rocourt Neonatology Meeting 12
And co-resistance in Pseudomonas aeruginosa is frequent
European Centre for Disease Prevention and Control. Antimicrobial resistance surveillance in Europe 2012. Annual Report of the European Antimicrobial Resistance Surveillance Network (EARS-Net). Stockholm: ECDC; 2013.
14/06/2014 XXXth Rocourt Neonatology Meeting 13
Aminoglycosides: can we do something ?
OO
O
CH2H2N
NH2
OH
HNH3C
CH3OH
HO
H2NO
NH2
Plazomicin (ACHN-490): made from sisomicin
OO
O
CH2H2N
NH2
OH
HNH3C
CH3OH
HO
HNO
HN
HOHCNH2
OH
plazomicin
sisomicin
still susceptible to AAC(2’)
(but rare enzyme)
14/06/2014 XXXth Rocourt Neonatology Meeting 14
Plazomycin future ?
Potential to demonstrate a mortality benefit over currently available therapy in the treatment of life-threatening CRE infections.
"We have designed our pivotal Phase 3 trial for plazomicin as a superiority trial with a primary efficacy endpoint of all-cause mortality at 28 days. The trial will compare a plazomicin-based regimen versus a colistin-based regimen for the treatment of CRE bloodstream infections and pneumonia."
http://www.achaogen.com/plazomicin/Last visited: 10/06/2014
14/06/2014 XXXth Rocourt Neonatology Meeting 15
Attack: the example
of the -lactamases
(part 1)
Van Bambeke et al. Mechanisms of Action. In: Infectious Diseases (3d edition; J. Cohen, W. Powderly & S. Opal, eds), chapter 130, pp 1288-1307, Elsevier/Mosby, 2010
14/06/2014 XXXth Rocourt Neonatology Meeting 16
Attack: the example
of the -lactamases
(part 2)
Van Bambeke et al. Mechanisms of Action. In: Infectious Diseases (3d edition; J. Cohen, W. Powderly & S. Opal, eds), chapter 130, pp 1288-1307, Elsevier/Mosby, 2010
14/06/2014 XXXth Rocourt Neonatology Meeting 17
-lactamases: why so many ?
Van Bambeke et al. Mechanisms of Action. In: Infectious Diseases (3d edition; J. Cohen, W. Powderly & S. Opal, eds), chapter 130, pp 1288-1307, Elsevier/Mosby, 2010
14/06/2014 XXXth Rocourt Neonatology Meeting 18
-lactamases and PBPs may be very close
14/06/2014 XXXth Rocourt Neonatology Meeting 19
-lactamases and PBPs may be very close
14/06/2014 XXXth Rocourt Neonatology Meeting 20
and -lactamases are often in mobile, higly transmissible genetic elements (together with other resistance genes)
14/06/2014 XXXth Rocourt Neonatology Meeting 21
and -lactamases are often in mobile, higly transmissible genetic elements (together with other resistance genes)
Schematic representation of blaNDM - associated genetic structures identified among Gram-negative clinical isolates.
(a) Structure found in A. baumannii (part of the composite transposon Tn125).
(b) Structures found in Enterobacteriaceaeand P. aeruginosa where ISAba125 is presented as full or truncated element with bleMBL gene also beingpresent as full or truncated gene.
14/06/2014 XXXth Rocourt Neonatology Meeting 22
and -lactamases are often in mobile, higly transmissible genetic elements (together with other resistance genes)
14/06/2014 XXXth Rocourt Neonatology Meeting 23
and -lactamases are often in mobile, higly transmissible genetic elements (together with other resistance genes)
14/06/2014 XXXth Rocourt Neonatology Meeting 24
Which problem ?
resistant bacteria
elimination
active effluximpermeabilisation
wild type
attack
inactivation of the antibiotic
(biotransformation)
avoidance
modification of the target
way around
alternativetargetor target multiplication
no more active antibiotic ! "useless" antibiotic "overwhelmed" antibiotic
antibiotic absent or in insufficient concentration
14/06/2014 XXXth Rocourt Neonatology Meeting 25
this is where we have a problem
amoxicilin vs.S. pneumoniae (n = 136)
3.9×10
-030.0
0781
30.0
1562
60.0
3125
0.062
50.1
25 0.25 0.5 1 2 4 8 16 32
0
25
50
75
100
MIC50
MIC90
MICs (mg/L)
% o
f str
ains
(cum
ulat
ive)
Amoxicllin and Streptococcus pneumoniae
EUCAST: European Committee on Antimicrobial Susceptibility Testing (http://www.eucast.org) MIC: minimum inhibitory concentrationCAP: community-acquired pneumoniaCOPD: chronic obstructive pulmonary disease
EUCAST wild type
population
• Belgian isolates collected between 2009 and 2012 from patients with confirmed cases of CAP
• the high MICs of amoxicillin is driven by isolates from patients with past COPD
Tulkens, unpublished
14/06/2014 XXXth Rocourt Neonatology Meeting 26
But which breakpoints do we need to use ?
Good Evil
To be honest, I always wondered ...
14/06/2014 XXXth Rocourt Neonatology Meeting 27
amoxicllin vs.S. pneumoniae (n = 136)
3.9×10
-030.0
0781
30.0
1562
60.0
3125
0.062
50.1
25 0.25 0.5 1 2 4 8 16 32
0
25
50
75
100
MIC50
MIC90
MICs (mg/L)
% o
f str
ains
(cum
ulat
ive)
MIC distribution is a continuous variable…
EUCAST wild type
population
EU clinical breakpoints
S ≤
0.5 – R > 2 *
EUCAST: European Committee on Antimicrobial Susceptibility Testing (http://www.eucast.org) MIC: minimum inhibitory concentrationCAP: community-acquired pneumoniaCOPD: chronic obstructive pulmonary dosease
* non-meningitis
• Belgian isolates collected between 2009 and 2012 from patients with confirmed cases of CAP
• the high MICs of amoxicillin is driven by isolates from patients with past COPD
Tulkens, unpublished
14/06/2014 XXXth Rocourt Neonatology Meeting 28
amoxicllin vs.S. pneumoniae (n = 136)
3.9×10
-030.0
0781
30.0
1562
60.0
3125
0.062
50.1
25 0.25 0.5 1 2 4 8 16 32
0
25
50
75
100
MIC50
MIC90
MICs (mg/L)
% o
f str
ains
(cum
ulat
ive)
MIC distribution is a continuous variable…
EUCAST wild type
population
EU clinical breakpoints
S ≤
0.5 – R > 2 *
CLSI clinical breakpoints
S ≤
2 – R ≥
8 *
CLSI: Clinical and Laboratory Standards Institute (http://clsi.org) EUCAST: European Committee on Antimicrobial Susceptibility Testing (http://www.eucast.org) MIC: minimum inhibitory concentrationCAP: community-acquired pneumoniaCOPD: chronic obstructive pulmonary disease
* non-meningitis* non-meningitis
• Belgian isolates collected between 2009 and 2012 from patients with confirmed cases of CAP
• the high MICs of amoxicillin is driven by isolates from patients with past COPD
Tulkens, unpublished
14/06/2014 XXXth Rocourt Neonatology Meeting 29
EUCAST calculations of target attainment rate for amoxicillin against S. pneumoniae
0.5 1 2 4 8 16 320
25
50
75
100
0.5 g 3x 1g 3x 2g 4x
MIC
targ
et a
ttai
nmen
t rat
e (%
)
By increasing the dose and multiplying the number of daily administration, you may cover bacteria with MIC up to 8 mg/L…
but the total daily dose will be very high…
* for f T >MIC = 40%
Graph prepared from data in http://www.eucast.org/fileadmin/src/media/PDFs/EUCAST_files/Rationale_documents/Amoxicillin_rationale_Nov2010_v_1.0.pdf
90 %
14/06/2014 XXXth Rocourt Neonatology Meeting 30
And chlidren may harbour more resistant organisms
Diekema et al. Int. J. Antimicrob. Agents 2002; 412-418* longitudinal surveillance program designed to track antimicrobial resistance trends nationally
and internationally over a 5- to 10-year period and sponsored by Bristol-Myers Squibb
14/06/2014 XXXth Rocourt Neonatology Meeting 31
Staphylococcus aureushttp://www.microbewo rld.org/index.php?opti on=com_jlibrary&vie w=article&id=7611
• Nosocomial pneumonia involving hospital-acquired (HA) S. aureus is becoming increasingly frequent 1,2
• In parallel, pneumonia caused by community-acquired (CA) MRSA while remaining rare in Europe2 are becoming common in several other parts of the world including Asia 3
• As many strains (even MSSA) produce toxins, they cause major tissue damage, and, hence a high mortality 3,4,5
1. Jones, Clin Infect Dis. 2010;51(suppl 1):S81-72. Valour, et al Rev Pneumol Clin. 2013;69:368-82 3. Karampela, et al. Minerva Anestesiol. 2012 Aug;78(8):930-40
Kang & Song. Infect Chemother. 2013;45:22-314. Papazian & Donati. Nosocomial pneumonia. In Infectious Diseases, 3rd Edition,
Cohen, Powderly & Opal, eds. Elsevier (available on line at http://www.expertconsultbook.com ; last visisted: 4 April 2014)
5. Catena, et al Infez Med. 2012;20:205-10 /.MRSA methicillin-resistant Staphylococcus aureusMSSA methicillin-sensitive Staphylococcus aureus
14/06/2014 XXXth Rocourt Neonatology Meeting 32
S. aureushttp://www.microbewo rld.org/index.php?opti on=com_jlibrary&vie w=article&id=7611
• Nosocomial pneumonia involving hospital-acquired (HA) S. aureus is becoming increasingly frequent [1,2]
• In parallel, pneumonia caused by community-acquired (CA) MRSA while remaining rare in Europe [2] are becoming common in several other parts of the world including Asia [3]
• As many strains (even MSSA) produce toxins, they cause major tissue damage, and, hence a high mortality [3,4]
1. Jones Clin Infect Dis 2010;51(suppl 1):S81-72. Valour et al Rev Pneumol Clin. 2013;69:368-82 3. Karampela et al Minerva Anestesiol. 2012 Aug;78(8):930-40 / Kang & Song Infect Chemother 2013;45:22-314. Papazian & Donati Nosocomial pneumonia. In Infectious Diseases, 3rd Edition, Cohen, Powderly & Opal, eds. Elsevier (available on line at
http://www.expertconsultbook.com (Last visisted: 4 April 2014) / Catena et al Infez Med. 2012;20:205-10 /.
Valour, et al Rev Pneumol Clin. 2013;69:368-82
"S. aureus accounts for 2 to 5% of the
etiologies of community-acquired
pneumonia"
"S. aureus represents 20 to 30% of cases of
hospital-acquired pneumonia, including ventilator-associated
pneumonia"
14/06/2014 XXXth Rocourt Neonatology Meeting 33
1. Jones Clin Infect Dis 2010;51(suppl 1):S81-72. Karampela et al Minerva Anestesiol. 2012 Aug;78(8):930-40 / Kang & Song Infect Chemother 2013;45:22-313. Papazian & Donati Nosocomial pneumonia. In Infectious Diseases, 3rd Edition, Cohen, Powderly & Opal, eds. Elsevier (available on line at
http://www.expertconsultbook.com (Last visisted: 4 April 2014) / Catena et al Infez Med. 2012;20:205-10 / Valour et al Rev Pneumol Clin. 2013;69:368-82.
S. aureushttp://www.microbewo rld.org/index.php?opti on=com_jlibrary&vie w=article&id=7611
• Nosocomial pneumonia involving hospital-acquired (HA) S. aureus is becoming increasingly frequent [1]
• In parallel, pneumonia caused by community-acquired (CA) MRSA while rare in Europe are becoming common in several other parts of the world including Asia [2]
• As many strains (even MSSA) produce toxins, they cause major tissue damage, and, hence high mortality [2,3]
Jones, et al. Clin Infect Dis. 2010;51(suppl 1):S81-7
HABP: hospital-acquired bacterial pneumoniaVABP: ventilator-associated bacterial pneumoniaMRSA: methicillin resistant Staphylococcus aureus
14/06/2014 XXXth Rocourt Neonatology Meeting 34
MRSA in AsiaPrevalence of methicillin resistance among S. aureus isolates.Some Asian countries have shown the highest prevalence rates of MRSA
< 1% 1-10% 20-25% 25-50% > 50%
Sri Lanka Singapore
Hong Kong
Taiwan
Japan
Korea
Kang & Song. Infect Chemother 2013;45:22-31MRSA methicillin restistant Staphylococcus aureus
14/06/2014 XXXth Rocourt Neonatology Meeting 35
Could ceftaroline (recently approved) be
a solution ?
An allosteric mechanism !
Otero et al. Proc Natl Acad Sci USA. 2013 Oct 15;110(42):16808-13.
Allosteric site
14/06/2014 XXXth Rocourt Neonatology Meeting 36
CEFTAROLINE: MICs
S. aureus (all; n = 240)
0.031
250.0
625
0.125 0.2
5 0.5 1 2 4 8
0
25
50
75
100
vancomycin linezolidceftaroline
MIC90
MIC50
MICs (mg/L)
N S
trai
ns (c
umul
ativ
epe
rcen
t)
MSSA (n = 83)
0.031
250.0
625
0.125 0.2
5 0.5 1 2 4 8
0
25
50
75
100 MIC90
MIC50
MICs (mg/L)
N S
trai
ns (c
umul
ativ
epe
rcen
t)
S.aureus MIC distributions
MRSA (n = 157)
0.031
250.0
625
0.125 0.2
5 0.5 1 2 4 8
0
25
50
75
100 MIC90
MIC50
MICs (mg/L)
N S
trai
ns (c
umul
ativ
epe
rcen
t)* isolates collected o, Belgium between 2011 and 2012 from patients suffering of wound infections in 3 hospitals (1 in South-East of Brussels; 1 in North of Brussels; 1 in Hainaut)
*
Tulkens et al. 26th ICC, 2013 and unpublished
EUCAST breakpoints of ceftaroline, vancomycin and linezolid
14/06/2014 XXXth Rocourt Neonatology Meeting 37
Which problem ?
resistant bacteria
elimination
active effluximpermeabilisation
wild type
attack
inactivation of the antibiotic
(biotransformation)
avoidance
modification of the target
way around
alternativetargetor target multiplication
no more active antibiotic ! "useless" antibiotic "overwhelmed" antibiotic
antibiotic absent or in insufficient concentration
14/06/2014 XXXth Rocourt Neonatology Meeting 38
The VISA story…
• VISA stands for "Vancomycin Intermediate Staphylococcus Aureus" (but also termed GISA (Glycopeptide-Intermediate Staphylococcus Aureus) and denotes organisms with an increased MIC for vancomycin or teicoplanin
• First identified in Japan in 1997 but since then found in many other countries
• Resistance occurs by a tickening of the cell wall with increased amounts of free D-Ala-D-Ala termini that trap vancomycin (and glycopeptides).
14/06/2014 XXXth Rocourt Neonatology Meeting 39
The VISA story…
• VISA stands for "Vancomycin Intermediate Staphylococcus Aureus" (but also termed GISA (Glycopeptide-Intermediate Staphylococcus Aureus) and denotes organisms with an increased MIC for vancomycin or teicoplanin
• First identified in Japan in 1997 but since then found in many other countries
• Resistance occurs by a tickening of the cell wall with increased amounts of free D-Ala-D-Ala termini that trap vancomycin (and glycopeptides).
14/06/2014 XXXth Rocourt Neonatology Meeting 40
The VISA story…
• The MICs of these strains are above the susceptibility breakpoint of EUCAST (2 mg/L) !
Howden et al. Clin Microbiol Rev 2010;23:99–139.
14/06/2014 XXXth Rocourt Neonatology Meeting 41
Do you need to be afraid of VISA ?
14/06/2014 XXXth Rocourt Neonatology Meeting 42
Do you need to be afraid of VISA ?
14/06/2014 XXXth Rocourt Neonatology Meeting 43
Do you need to be afraid of VISA ?
14/06/2014 XXXth Rocourt Neonatology Meeting 44
VISA and co-resistance: the daptomycin problem
14/06/2014 XXXth Rocourt Neonatology Meeting 45
VISA and co-resistance: the daptomycin problem
daptomycin EUCAST breakpoint
14/06/2014 XXXth Rocourt Neonatology Meeting 46
Which problem ?
resistant bacteria
elimination
active effluximpermeabilisation
wild type
attack
inactivation of the antibiotic
(biotransformation)
avoidance
modification of the target
way around
alternativetargetor target multiplication
no more active antibiotic ! "useless" antibiotic "overwhelmed" antibiotic
antibiotic absent or in insufficient concentration
14/06/2014 XXXth Rocourt Neonatology Meeting 47
An original observation with cancer cells…
14/06/2014 XXXth Rocourt Neonatology Meeting 48
Historical observations on tetracyclines …
14/06/2014 XXXth Rocourt Neonatology Meeting 49
Historical observations on tetracyclines …
McMurry et al., PNAS 1980; 77:3974-3977
Everted membranes
Whole bacteria
14/06/2014 XXXth Rocourt Neonatology Meeting 50
You said "antibiotic eflux"
1960 1970 1980 1990 2000 20100
250
500
750
1000
1250
1500
1750
Year
No.
of p
ublic
atio
ns /
2 ye
ars
No. of publications in PubMed with keywords: "antibiotic AND (efflux OR transporter)"
14/06/2014 XXXth Rocourt Neonatology Meeting 51
1960 1970 1980 1990 2000 20100
250
500
750
1000
1250
1500
1750
Year
No.
of p
ublic
atio
ns /
2 ye
ars
Historical landmarks …
Successive description of efflux- mediated resistance for major classes of antibiotics
tetracyclines
-lactams
fluoroquinolones
macrolides
linezolid
rifampin
aminoglycosides
daptomycin ** in eucaryotic cells
only (so far)
14/06/2014 XXXth Rocourt Neonatology Meeting 52
RoleRole of efflux of efflux pumpspumps in the in the clinicsclinics ……
14/06/2014 XXXth Rocourt Neonatology Meeting 53
Efflux in S. pneumoniae: is it important in the clinics ?
Suspected efflux based on phenotypic analysis (CIP MIC +/- reserpine)
CAP BPCO0
20
40
60
80
100 1 2 2
reserpine effect on MIC (x dilutions)
origin of isolates
% s
trai
ns
Lismond & Degives, unpublished
acute pathology
« one shot »antibiotic exposure
chronic pathology
repetitiveantibiotic exposures
183 strains 107 strains
14/06/2014 XXXth Rocourt Neonatology Meeting 54
Efflux in S. pneumoniae: is it important in the clinics ?
Identification of FQ transporters in clinical isolates
Lismond et al, ECCMID 2010
Inactivation of patA or patB as efficient as reserpine to
reduce MIC
• responsible for FQ efflux in clinical isolates
• work as heterodimers
14/06/2014 XXXth Rocourt Neonatology Meeting 55
Efflux in P. aeruginosa: is it important in the clinics ?
Prevalence of MexA and MexX overexpressers in 62 phylogentically-related pairs of P. aeruginosa isolated from ICU patients (VAP)
DAY x (%)
38.71%
22.58%
20.97%
17.74%
DAY 0 (%)
66.13%
12.90%
11.29%
9.68%
MexA-/MexX-
MexA+/MexX-
MexX+/MexA-
MexA+/MexX+
Riou et al, ECCMID 2010
14/06/2014 XXXth Rocourt Neonatology Meeting 56
amikacin (n=29)
D0 DL1
2
4
8
16
32
64
128
256
a
meropenem (n=28)
D0 DL0.125
0.25
0.5
1
2
4
8
16
32
64
128
256
*
piperacillin-tazobactam (n=31)
D0 DL
2
4
8
16
32
64
128
256
512
1024
*
cefepime (n=29)
D0 DL0.5
1
2
4
8
16
32
64
128
256
512
a
ciprofloxacin (n=11)
D0 DL0.015625
0.03125
0.0625
0.125
0.25
0.5
1
2
4
8
16
32
64
128
MIC
(mg/
L)
Emergence of resistance
during treatment
Riou, et al. Int J Antimicrob Agents. 2010;36:513-22
initial
isolate
Last
P. aeruginosa successive clonalisolates from the same patient(all patients treated with large doses of 1 to 3 antibiotics)
- D0: initial isolate DL: last isolate obtained
- individual values with geometric mean (95 % CI)
- S (lowest line) and R (highest line) EUCAST breakpoints
* p < 0.05 by paired t-test (two- tailed) and Wilcoxon non- parametric test
a p < 0.05 by Wilcoxon non- parametric test only
Note: stratification by time between D0 and DL gave no clue (too low numbers)
14/06/2014 XXXth Rocourt Neonatology Meeting 57
Is this all ?
• Phenotypic "resistance"– small colony variants– dormant/persistent bacteria
http://www.facm.ucl.ac.be/intracellular_chemotherapy.htm Last visited: 10/06/2014
http://cmr.asm.org/content/15/2/167.figures-onlyRodney & Costerton Clin. Microbiol. Rev. 2002, 15(2):167.
http://infekt.ch/2006/10/small-colony-variants-von-staphylococcus- aureus-schwierig-zu-behandelnde-infektionen/Last visited 14/06/2014
14/06/2014 XXXth Rocourt Neonatology Meeting 58
Intracellular infection and S. aureus
Mélard et al. J Antimicrob Chemother. 2013;68:648-58
-4 -3 -2 -1 0 1 2 3-6
-5
-4
-3
-2
-1
0
1
2
3
MIC = 0.25 mg/L (n=1)
MIC = 0.5 mg/L (n=3)
MIC = 1 mg/L (n=2)
Broth
MIC = 0.125 (n=1)MIC = 2 mg/L (n=4)
lo
g cf
u fr
om ti
me
0 (2
4 h)
-3 -2 -1 0 1 2 3-1
0
1
2
3
THP-1
-4 -3 -2 -1 0 1 2 3 4
THP-1Broth
-6
-5
-4
-3
-2
-1
0
1
2
3
log cfu from tim
e 0 (24 h)
log10 concentration (mg/L) log10 concentration (x MIC)
Activity of ceftaroline towards extracellular (broth) and intracellular forms of S. aureus with increasing MICs
14/06/2014 XXXth Rocourt Neonatology Meeting 59
Biofilms and S. pneumoniae
0
20
40
60
80
100
120
day 2day 11
0
20
40
60
80
100
120
naïve model
viability biomassATCC 49619
Perc
enta
ge o
f con
trol
val
ue
Log concentration (x MIC)
Vandevelde et al. Antimicrob Agents Chemother. 2014;58:1348-58.
0
20
40
60
80
100
120
LVX
LVXMXF
MXF
day 2
day 11
0
20
40
60
80
100
120
naïve modelPerc
enta
ge o
f con
trol
val
ue
v iability biomassATCC 49619
Log concentration (x MIC)
14/06/2014 XXXth Rocourt Neonatology Meeting 60
The question that I should have addressed…
• How does all that is acquired and spread ?
overexpression"let cook it first"and serve to those who can pay
existing genomic
informationhorizontal transfer "ready to eat"
for everyone
mutation selection "only the best will get it"
metabolic adaptation
stay in your niche
14/06/2014 XXXth Rocourt Neonatology Meeting 61
The question that I should have addressed…
overexpression"let cook it first"and serve to those who can pay
existing genomic
informationhorizontal transfer "ready to eat"
for everyone
mutation selection "only the best will get it"
metabolic adaptation
stay in your niche
but what can I do ?
hygieneisolation
reduce current antibiotic pressure
don't give a chance to selection
use "non-antibiotic"options
14/06/2014 XXXth Rocourt Neonatology Meeting 62
The real question …
What can do for him/her to have nice dreams … and to wake up in good health ?