Transcript Titolo della Slide

Evoluzione dell’antibiotico-resistenza: miti e realtà
Gian Maria Rossolini
Dip. Biologia Molecolare
Sezione di Microbiologia
Università di Siena
UO Microbiologia e Virologia
Azienda Osp-Univ Senese
.
How do we define resistance?
Broth or agar
dilution tests
Inhibition zones
Interpretation of results
based on clinical breakpoints
MIC values
The clinical breakpoints
Reference MIC/zone values for
interpretation of the results of in vitro
susceptibility testing
Definition of susceptibility category (S/I/R)
referred to clinical use
Clinical breakpoints are defined by
specific committees
Breakpoint committees in Europe
Committee
Country
BSAC
United Kingdom
CA-SFM
France
CRG
The Netherlands
DIN
Germany
NWGA
Norway
SRGA
Sweden
CLSI
USA
with different opinions...
Enterics / cefotaxime
BSAC
CA-SFM
CRG
DIN
CLSI
United Kingdom
France
The Netherlands
Germany
U.S.A.
NWGA
Norway
SRGA
Sweden
S< / R>
1/1
4 / 32
4/8
2/8
8 / 32
1/2
0.5 / 1
Kahlmeter et al – JAC 2003
December 2004
The EUCAST Mission
• to harmonise clinical breakpoints in
Europe
• to determine breakpoints for new
antimicrobials
• to provide standardised methodology
for AST
Setting clinical breakpoints for new
drugs in Europe
 Co-ordinated process between the
Company, EMEA and EUCAST
 When a Company applies for registration
of a new agent:
EUCAST defines the breakpoints
 EMEA decides on all other aspects

 EUCAST breakpoints for new drugs are
the only ones included in the SPC
(Summary of Product Characteristics)
EUCAST clinical breakpoints
Freely available on the WEB
Institutional decision body
(industry has a consulting role
but does not participate in the
decisional process)
Defined by consensus
Rationale for decision disclosed
(rationale documents available)
EUCAST vs. CLSI breakpoints:
a remarkable diversity
Courtesy by G. Kahlmeter
EUCAST vs. CLSI breakpoints:
Pseudomonas aeruginosa
EUCAST
CLSI
S≤
R>
S≤
R>
Cefepime
8
8
8
16
Ceftazidime
8
8
8
16
Imipenem
4
8
4
8
Meropenem
2
8
4
8
16
16
64
64
1
16
8
16
0.5
1
1
2
Gentamicin
4
4
4
8
Tobramycin
4
4
4
8
Amikacin
8
16
16
32
Colistin
2
2
2
4
Pip/Tazo
Aztreonam
Ciprofloxacin
For S: EUCAST 5/11 lower
For R: EUCAST 8/11 lower
EUCAST vs. CLSI breakpoints:
Enterobacteriaceae
(beta-lactams & quinolones)
EUCAST
CLSI
S≤
R>
S≤
R>
Cefepime
1
8
8
16
Ceftriaxone
1
2
8
32
Ceftazidime
1
8
8
16
Ertapenem
0.5
1
2
4
Imipenem
2
8
4
8
Meropenem
2
8
4
8
Pip/Tazo
8
16
16
64
Levofloxacin
1
2
2
4
Ciprofloxacin
0.5
1
1
2
For S: EUCAST 9/9 lower
For R: EUCAST 7/9 lower
EUCAST vs. CLSI breakpoints:
Enterobacteriaceae
(other agents)
EUCAST
CLSI
S≤
R>
S≤
R>
Amikacin
8
16
16
32
Gentamicin
2
4
4
8
Tobramycin
2
4
4
8
Cotrimoxazole
2
4
2
2
Colistin
2
2
NA
NA
Tigecycline
1
2
NA
NA
For S: EUCAST 3/4 lower
For R: EUCAST 3/4 lower, 1/4 higher
EUCAST vs. CLSI
Will the change from CLSI
to EUCAST breakpoint
system significantly
affect the epidemiology of
antibiotic resistance?
EUCAST vs. CLSI
• A comparative analysis of AST
results interpreted according to
CLSI or EUCAST
• Data source: historical records
from clinical microbiology
service, Siena University Hospital
(year 2008)
Pseudomonas aeruginosa
Gentamicin (N = 295)
EUCAST
CLSI
2
4
8
16
MIC (mg/L)
EUCAST: R
CLSI: I
32
64
Pseudomonas aeruginosa
Amikacin (N = 296)
EUCAST
CLSI
2
4
8
16
MIC (mg/L)
EUCAST: I
CLSI: S
EUCAST: R
CLSI: I
32
64
Pseudomonas aeruginosa
Ceftazidime (N = 294)
EUCAST
CLSI
1
2
4
EUCAST: R
CLSI: I
8
MIC (mg/L)
16
32
Pseudomonas aeruginosa
Meropenem (N = 216)
EUCAST
CLSI
2
4
8
EUCAST: I
CLSI: S
16
MIC (mg/L)
32
64
Pseudomonas aeruginosa
Pip/Tazo (N = 289)
EUCAST
CLSI
2
4
8
EUCAST: R
CLSI: S
16
MIC (mg/L)
32
64
Pseudomonas aeruginosa
Aztreonam (N = 133)
EUCAST
CLSI
1
2
EUCAST: I
CLSI: S
4
8
MIC (mg/L)
16
32
Pseudomonas aeruginosa
Ciprofloxacin (N = 295)
EUCAST
CLSI
0.25
0.5
1
2
MIC (mg/L)
EUCAST: I EUCAST: R
CLSI: S
CLSI: I
4
8
% susceptibility
Pseudomonas aeruginosa
CLSI vs. EUCAST
Antibiotics
MRSA impact (USA)
a
in hospital deaths
Boucher & Corey Clin Infec Dis 2008
Resistance trends in major pathogens
Europe
MRSA
E. coli R to 3GC
Countries
8/30
EARSS annual report, 2007
23/30
8/30
1/30
14/30 =
6/30 =
2008:
2008:
2/31
21/30
10/31
0/30
19/31 =
9/31 =
Resistance trends in major pathogens
Europe
Countries
MDR E. coli
(R to 3GC,AG,FQ)
24/30
0/30
6/30 =
EARSS annual report, 2007
E. coli R to 3GC
23/30
1/30
6/30 =
The growing challenge of resistant
Gram-negatives
• MRSA and VRE rates have leveled off or
decreasing in several European countries
• Resistant Gram-negatives are increasing in
most European countries
Major challenges:
• Enterobacteriaceae
 ESBL/AmpC, MDR, XDR (ESC/FQ/AG/NEM)
• Pseudomonas aeruginosa and Acinetobacter
 MDR, XDR (COL-S only)
Rossolini & Mantengoli, CMI 2008
ESBLs: increasing trends
% resistant to 3GC
K. pneumoniae
EARSS database
Year
% resistant to 3GC
ESBLs: increasing trends
E. coli
Year
EARSS database
ESBL-producing Enterobacteriaceae , Italy
%
Spanu et al. - AAC 2002; Luzzaro et al. - JCM 2006; OASIS study, data on file
2003: Proteus mirabilis (isolates from UTIs and ulcers)
MIC (mg/L)
Ampicillin
Amoxi/Clav
Pip/Tazo
Cephalotin
Cefotaxime
Ceftazidime
Cefepime
Ertapenem
>128 R
32 R
4S
32 R
64 R
32 R
2R
S
0.12 S
Amikacin
2S
Gentamicin
4S
Ciprofloxacin >32 R
Levofloxacin
>32 R
Suspect ESBL
Aztreonam
Amoxi/Clav
Resistant to 3rd gen. ceph.
but ESBL-negative
Ceftazidime
Cefotaxime
Ceftriaxone
Same clone detected
in LTCFs
.
P. mirabilis resistant to
3rd gen. cephalosporins
By clonal expansion
Luzzaro et al – IJAA 2009
Clinical features of infections caused
by the P. mirabilis CMY-16+
Mean age: 75±15 yrs
(76±16 for ESBL+; 57±28 for susceptible
strains)
Female/male ratio: 1.1
(1.6 for ESBL+; 2.1 for susceptible strains)
Inpatients
37%
51%
Patients
LTCFs
UTIs
80%
LRTIs
HCAss
SSSIs
CA
BSIs
Sources
Luzzaro et al – IJAA 2009
2007-2008:
P. mirabilis CMY+
spreading in Italy
>30 cases from BSIs
Clonally related isolates detected in Greece and
Poland: an internationally spreading clone
D’Andrea et al – unpublished
ESBLs/AmpC and carbapenem overuse
Increased # ESBL/AmpC
Increased Carb-R
casesstrains
Increased
carbapenem
use
Cross
transmission
of Carb-R
strains
Selection of Carb-R
strains
Courtesy of Vincent Jarlier,
Sept 2009 (modified)
2007-2008: emergence of MDR Klebsiella pneumoniae ERT-R
from several hospitals …
MIC (mg/L)
Ampicillin >16 R
Amoxi/Clav >16 R
Pip/Tazo
>64 R
Cefotaxime >16 R
Ceftazidime >32 R
Cefepime
>16 R
Aztreonam >16 R
Imipenem
≤1
Meropenem 2-4
Ertapenem >4 R
No carbapenemase
Amikacin
>32 R
Gentamicin
>8 R
Tobramycin
>8 R
Ciprofloxacin >32 R
Levofloxacin >32 R
TMP/SXT
>2 R
Tigecycline 1 - 2
Colistin
<1
act.
Production of:
- CTX-M-15 ESBL
- SHV-11
- (OXA-9) (TEM-1)
Nationwide
clonal spread
(ST37)
Reduced porin expression
D’Andrea et al. – 19th ECCMID
Klebsiella pneumoniae with reduced carbapenem
susceptibility due to ESBL prod. + porin loss:
detection and reporting issues
MIC (mg/L)
Ampicillin >16 R
Amoxi/Clav >16 R
Pip/Tazo
>64 R
Cefotaxime >16 R
Ceftazidime >32 R
Cefepime
>16 R
Aztreonam >16 R
Imipenem
≤1 R
Meropenem 2-4 R
Ertapenem
>4 R
ESBL
positive
Amikacin
>32 R
Gentamicin
>8 R
Tobramycin
>8 R
Ciprofloxacin >32 R
Levofloxacin >32 R
TMP/SXT
>2 R
Tigecycline 1 - 2 S
Colistin
<1
Vitek-2 AES:
changes to resistance to all carbapenems
KPC-2
K. oxytoca
Yigit et al. AAC 2003
Brooklyn, New York …
Klebsiella pneumoniae
Due to spread of KPC
carbapenemases
22% of isolates resistant to:
- Aminoglycosides
- Fluoroquonolones
- 3rd 4th gener. Cephems
- Carbapenems
Susceptibility only to:
- Colistin
- Tigecycline
Landman et al – JAC 2007
KPC-type carbapenemases in Israel: a major problem
Nationwide
outbreak
Carbapenem resistance rates
in K. pneumoniae from Israel:
2006: 11%
2007: 22%
2008: 19%
EARSS database
KPC-type carbapenemases: a new pandemic?
7 cases
Two cases, one
with Israel
connection
4 from Greece
2 from Israel
Clonally related
Intercontinental spread
of ST258 KPC+ clone
Clonally related
Villegas et al. AAC 2007
Tsakris et al. JAC 2008
Literacka et al. AAC 2009
Hawser et al. IJAA 2009
Nordmann et al. Lancet ID 2009
KPC-type carbapenemases: emerging in Italy
Florence
 Oct 2008: KPC-3 positive K. pneumoniae
ST258 isolated from a cIAI (high-level
carbapenem resistance)
 No epidemiological link with areas of
endemicity, but patient cared for by a
trainee from Israel
Giani et al - JCM 2009
 May 2009: KPC positive K. pneumoniae
Lecco  Patient transferred from another hospital
 Large outbreak ongoing in that
hospital (26 patients colonized or
infected), variable carbapenem
resistance
 Mostly by clonal spread (ST258), but at
least two clones and also in Enterobacter
Luzzaro et al - unpublished
Santoriello et al - unpublished
 Additional reports
Carbapenem-resistant K. pneumoniae, Greece
Production of
VIM-1 MBL
Multiple clones
Often
susceptible
only to colistin
and tigecycline
(XDR)
Vatopoulos et al. - Eurosurveillance 2008
Psichogiou et al. – JAC 2008
Carbapenemases of clinical relevance
KPC-type
(active-site serine, class A)
Metallo-β-lactamases
OXA-type
(class B)
(active-site serine, class D)
VIM-1 MBL-producing index strain
VR-143/97 (ser. O11; ST227)
VERONA
1997
GM
FEP
COL
TOB
IPM
TZP CAZ
MEM
ATM
PRL
AK
CIP
Lauretti et al. – AAC 1999
Cornaglia et al. – CID 2000
Acquired MBLs in Pseudomonas aeruginosa
first Italian nationwide survey
2004:
Overall prevalence
CREMONA 0.6%
VARESE 2.6%
1.3%
TURIN
0%
PERUGIA 1.1%
PAVIA 1.3%
2008:
Overall prevalence
7%
L’AQUILA
0%
GENOA
0%
FOGGIA 1.2%
ROME 0.3%
SASSARI 0.9%
AVELLINO 1.4%
NEAPLES 9.2%
Rossolini et al. AAC 2008
Luzzaro et al. - unpublished
Conclusions
• CLSI soon replaced by EUCAST: resistance
rates will be affected in some cases
• Resistance in Gram-negatives: now a major
problem
• XDR phenotypes not only in Pseudomonas and
Acinetobacter but also among enterobacteria
• Multiple resistance mechanisms: not easily
deducible from the antibiotype
• Open issues in: lab detection, reporting,
infection control and treatment