Mechanisms of Resistance in Enterobacteriaceae

Arjana Tambić Andrašević University Hospital for Infectious© by Diseasesauthor “Dr. F. Mihaljević” Zagreb, Croatia

ESCMID Online Lecture Library Resistance to antibiotics

 Innate resistance - species characteristic Acquired resistance - multiple resistance mechanisms simultaneously present - emerging new phenotypes - referals to ©referent by author laboratories - rigorous infection control precautions

ESCMID Online Lecture Library

ESCMID Online Lecture Library Resistance mechanisms in gram-negative bacteria

Impermeability Efflux

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ESCMIDDNA gyrase Online mutation LectureRibosome mutation Library Resistance mechanisms in gram- negative bacteria

• MODIFICATION OF THE TARGET – Penicillin binding proteins for beta-lactams (PBP) – DNA gyrase for quinolones

• EFFLUX PHENOMENON – resistance to tetracyclines – resistance to quinolones

• ENZYME PRODUCTION – Beta-lactamases inactivating beta-lactams – Enzymes inactivating© by aminoglycosides author

• IMPERMEABILITY – Resistance to beta-lactams ESCMID Online Lecture Library BETA-LACTAMASES

500 different types of beta-lactamases with variable level of production Different supstrates: – Penicillinases • Penicillinase • Broad spectrum beta-lactamases (TEM, SHV, OXA) • Extended Spectrum β lactamase (ESβL) • Inhibitor Resistant TEM (IRT) – Cephalosporinases • Cefuroximase • Inducible ampC cefalosporinase© by author – Carbapenemases

•TEM => penicillinase named after the patient (TEMoneira) providing the first sample •SHV => SulfHydril reagent Variable •OXA => activeESCMID on OXAcillin, cloxacillin Online Lecture Library EMEA FOCUS BLA p. 6 CLASSIFICATION OF BETA-LACTAMASES

Ambler classification Bush classification

. . group 1 : cephalosporinases / no A: Penicillinase inhibition by clavulanic acid (class C) . B: Metallo beta- . : beta-lactamases sensitive lactamase group 2 to clav. acid (class A and D) . C: Cephalosporinase • 2a: penicillinase in staph . D: Oxacillinase • 2b: acquired penicillinase • 2be: ESBLs • 2br: inhibitor resistant TEM • 2c: carbenicillinase • 2d: Oxacillinases • 2e: cefuroximase © by author• 2f: carbapenemase s . group 3 : metallo beta-lactamases / inhibited by EDTA (mol. class B) . group 4 : penicillinases not inhibited ESCMID Online byLecture clav. acid Library BETA-LACTAMASES

A) SPECIES-SPECIFIC BETA-LACTAMASES  innate, expressed in all isolates of the given species  Chromosomally determined  Evolutionary “old” (existant in pre-antibiotic era)  Natural role: - cell wall synthesis (structurally similar to PBP) - defence against natural beta-lactams - providing nutrients© by author  All enterobacteriaceae except salmonella  Variations in: - level of expression - type of expression (constitutive / inducible) ESCMID Online Lecture Library BETA-LACTAMASES

B) SECONDARY BETA-LACTAMASES . acquired, evolutionary “new” - emerged after the introduction of penicillin - originate from species-specific beta-lactamases . mostly on plasmids . the only role: © by author - to protect the bacterial cell from antibiotics

ESCMID Online Lecture Library BETA-LACTAMASES acquired resistance

. Broad spectrum beta-lactamases (TEM-1, TEM-2, SHV-1) . Extended spectrum beta-lactamases (ESBLs) . Inducible AmpC© by beta author-lactamases . Carbapenemases

ESCMID Online Lecture Library Broad spectrum beta-lactamases

. 1965: TEM-1 . TEM-2, SHV-1, PSE-1,4, OXA-1 (class A, D)  Resistance to: - ampicillin, ticarcillin, I gen cephalosporins, piperacillin (low levels - in vitro ceph. I gen. +++, PIP +++) - If high levels (variations up to 150x) also resistant to: - combinations with beta-lactamase inhibitors - cefoperazone © by author  Sensitivity to: - III gen. cephalosporins (except CFP), aztreonam, carbapenems ESCMID Online Lecture Library BETA-LACTAMASES acquired resistance

. Broad spectrum beta-lactamases (TEM-1, TEM-2, SHV-1) . Extended spectrum beta-lactamases (ESBLs) . Inducible AmpC© by beta author-lactamases . Carbapenemases

ESCMID Online Lecture Library Extended spectrum beta- lactamases (ESBLs)

 Class A and D, Bush group 2  Evolved from the broad spectrum beta-lactamases (TEM-1, SHV-1, OXA-2, -10) – CTX-M : derived from the chromosomal b-lactamase of Kluyvera:  Resistance to all beta-lactams except carbapenems (temocillin, cefamicins)  Inhibited by clavulanic acid  Constitutive  On plasmids  Widely distributed, highly© efficient by author  Variable enzyme activity (TEM-12 weak, TEM-24,-26 strong)  Variable supstrate specificity / ceftazidimase (TEM-5,-9,-26), cefotaxESCMIDimase (TEM-3, -Online4, SHV-2), bothLecture ceph. (SHV Library-5) EARSS 2008 → Escherichia coli

Trends in 3rd Generation Cephalosporins

ESCMID Online Lecture Library

EARSS 2008

Klebsiella pneumoniae

Trends in 3rd generation cephalosporin resistance by country © by author

ESCMID Online Lecture Library BETA-LACTAMASES acquired resistance

. Broad spectrum beta-lactamases (TEM-1, TEM-2, SHV-1) . Extended spectrum beta-lactamases (ESBLs) . Inducible AmpC© by beta author-lactamases . Carbapenemases

ESCMID Online Lecture Library INDUCIBLE AmpC CEPHALOSPORINASES

CAZ  class C, Bush group 1  Resistant to clavulanic acid FOX  Broad spectrum: (penicillins, cephalosporins, monobactams)  chromosomal  evolutionary “old”, species© by- specifiauthorc (present in all enterobacteriaceae but Salmonella spp.) ESCMID Online Lecture Library INDUCIBLE AmpC CEPHALOSPORINASES a) AmpC gen expression induced in the presence of an inducer (antibiotic) INDUCER SUPSTRATE ATB ureidopenicillins - + S* cephalosporins 1st + + R cephalosporins 3rd - + S* carbapenems + - S b) stable derepression of AmpC gen - constitutive beta-lactamase hyperproduction - spontaneous mutation© (Enterobacter by author spp. 10-4, P. aerug. 10-9) *(during therapy with a weak iducer / stable supstrate) c) secondary AmpC beta-lactamases - on aESCMID plasmid, constitutive Online (E. Lecture coli, Klebsiella Library spp.) BETA-LACTAMASES acquired resistance

. Broad spectrum beta-lactamases (TEM-1, TEM-2, SHV-1) . Extended spectrum beta-lactamases (ESBLs) . Inducible AmpC© by beta author-lactamases . Carbapenemases

ESCMID Online Lecture Library Carbapenemases in enterobacteriaceae . Class B metallo beta-lactamases – Less common than in P. aeruginosa – IMP-type, VIM-type (NDM-1, SPM, GIM, SIM, AIM, KHM) – Resistance to all beta -lactams but aztreonam

. Class D - OXA-48 plasmid mediated carbapenemase - K.pneumoniae, E.coli / Turkey, Belgium - UK, India, Lebanon,© Egypt by author

• Class A beta-lactamases – Sme-1, Imi-1, NMC-A, KPC 2-11 – ResistantESCMID to all Onlinebeta-lactams Lecture Library

ESCMID Online Lecture Library Epidemiology of carbapenemases • Greece – 2003: VIMs, low MICs outbreaks – 2007: KPC (ST 258), low MICs outbreaks • Israel – 2004: sporadic KPC – 2006: KPC (ST 258) outbreaks, logaritmic increase in KPC in all hospitals – Tel Aviv SMC: March 2007© by– 180 author new cases / month # 2010 – 30 new cases / month • Poland – 2003: MBLs, sporadic – 2008:ESCMID KPC (ST 258), Online 6 hospitals Lecture endemic situation Library

ESCMID Online Lecture Library Nordmann P et al. Emerg Infect Dis 2011; 17

ESCMID Online Lecture Library NDM-1 carbapenemase

• Metallo-beta-lactamase (class B) • Usually in enterobacteriaceae (K.pneumoniae, E.coli) • First described in 2008 in Sweden (in a patient transferred from India) • India, Pakistan, UK • EU: Sweden, UK, Belgium, France, Germany, the Netherlands (till 25.8.2010.) / 13 EU countries (January 2011) • Resistant to all antibiotics except colistin and tigecycline

The Lancet Infectious ESCMID Online Lecture Library Diseases 2010 EARSS, 2008 Klebsiella pneumoniae Carbapenem resistance

KPC, VIM KPC ESCMID Online Lecture Library

ESCMID Online Lecture Library Nordmann P et al. Emerg Infect Dis 2011; 17

NDM-1 producing K. pneumoniae in Croatia 2009 – 2011 Croatian Committee for Antibiotic Resistance Surveillance

Isolate TZP CTX CRO CAZ MEM IMI ERT CIP AN TIG COL SXT Patient 1 128 >32 >32 >32 24 8 32 >32 3 0.38 0.064 >32 Sept 2009 Patient 2 96 >32 >32 >32 0.38 0.25 1 >32 6 0.19 0.032 >32 Urine isolate May 2011 Patient 2 >256 >32 >32 >32 >32 >32 >32 >32 8 1 0.047 >32 Stool isolate May 2011 © by author

ESCMID Online Lecture Library Carbapenem breakpoints in Enterobacteriaceae

EUCAST

. Breakpoints have been set as “clinical breakpoints” and not to detect carbapenem-inactivating enzymes

Rationale: - MIC distributions of wild-type organisms - MICs of MBL- and KPC-producing organisms - Pk/Pd data - Review of the current clinical literature

. Expert rules (proposed modifications© by ):author - Report S, I or R test results as found - Test for resistance mechanism for epidemiological and/or infection control purposes ESCMID Online Lecture Library Infection control dilemas

ESCMID Online Lecture Library Resistance via weak enzyme + porin loss

. Can confer carbapenem resistance . Ertapenem most vulnerable carbapenem BUT © by author . Porin loss is deleterious, strains not likely to spread ESCMID Online Lecture Library Carbapenemase production

. Class B (MBL), Class D (OXA), Class A (KPC) . Genes encoding these enzymes are associated with mobile genetic elements . Rapid changes in carbapenemase host range . Emergence of novel enzyme types and variants . Emergence of successful clones (ST 258) © by author RIGOROUS INFECTION CONTROL PRECAUTIONS !!! ESCMID Online Lecture Library

ESCMID Online Lecture Library Recommended reading • Carmeli Y et al. Controlling the spread of carbapenemase-producing Gram-negatives: therapeutic approach and infection control. CMI 2010;16:102-111.

• Miriagou V et al. Acquired carbapenemases in Gram-negative bacterial pathogens: detection and surveillance issues. CMI 2010;16:112-122.

• Grundman H et al. Carbapenem-non-susceptible Enterobacteriaceae in Europe: conclusions from a meeting of national experts. Eurosurveillance, Volume 15,© Issue by 46,author 18 November 2010

• Nordmann P et al. Global Spread of Carbapenemase-producing Enterobacteriaceae. Emerg Infect Dis 2011; 17(10) October 2011 ESCMID Online Lecture Library