Gram negative cephalosporium and carbapenem resistance robert bonomo md
New global challenges of Gram negative cephalosporin and carbapenem resistance Robert A. Bonomo, MD Chief, Medical Service Director VISN 10 GRECC Louis Stokes Cleveland VAMC Vice Chairman, Department of Medicine University Hospitals Case Medical Center Professor, Case Western Reserve University School of Medicine Presented at the 41st Annual Symposium“Global Movement of Infectious Pathogens and Improved Laboratory Detection” Eastern PA Branch-American Society for Microbiology November 17, 2011 Thomas Jefferson University, Philadelphia
Disclosures• Support from VA and NIH• Steris Foundation• Pfizer• Excitement rather than give formulas
Objectives• Overview of the problem of ATBR in Gram negative bacteria – A. baumannii, Pseudomonas aeruginosa, and Klebsiella pneumoniae• Summarize the rapidly expanding landscape of resistance determinants• Use this knowledge to devise effective treatment strategies
The clinical challenge of A. baumannii• Multi-Drug Resistant (MDR) A. baumannii are among the most “problematic pathogens” encountered by clinicians
Why? Ab facts…..• Most common (and emerging) drug resistant pathogen in the US and world• 50-70% of Ab clinical isolates are now eXtensively Drug Resistant (XDR; i.e. resistant to all antibiotics except colistin or tigecycline), reflecting a >15- fold increase since 2000.• “Pan Drug” Resistant; strains of Ab, resistant to tige + coli, increasing Perez et al AAC 2007, Talbot and others, 2006, CID; Talbot ERAIT, 2009, Boucher CID 2009
Does resistance matter? Yes• BSI by XDR Ab cause >50-60% mortality• In a recent study 13,796 patients in 1,265 ICUs from 75 countries, Ab was one of only two of 19 microorganisms strongly linked (p<0.01) to increased mortality by multivariate analysis;• Odds ratio for death-1.53• Resistance + virulence: factors? LPS, Fe siderophores, PLD, OMPs, biofilm?? McGowan ICHE 2019, Hoffman et al, ICHE 2010, McGowan AJM 2006 Paterson CID 2006, Perez AAC 2007, Vincent JAMA 2009, Gordon JAC 2009
Survey of “Resistance genes” in A. baumannii bla AMEs QRDR RND OMPs Tet Efflux pumps ADC aacC1 gyrA AdeABC HMP-AB tetA OXA aacC2 parC AdeM OmpA tetB IMP aacC3 AdeIJK 33-36 kDa tetMVIM, GIM aacA4 AdeS 25/29 kDa tetXSIM, SPM, CraS CarO NDM AdeDE PER aphA1 Res Is?? OprD PBPs (43kDA) TEM* aphA6 AbaR 1-10 OmpW SHV aadA1 Col R 44, 47kDa, 22 integrons pmrAB CTX-M rmt* OMVs
“The Resistance Island” 86 Kb, 88 orfs, 82 orfs from another source and 45 resistance genes AbaR1-10!Fournier et al., PLoS Genet. 2006 Jan;2(1):e7. Epub 2006 Jan 13.
Threat 1. Carbapenem R• OXAs and MBLs• Naturally occurring and acquired• OXAs- Types and Groups – Narrow spectrum – Carbapenem hydrolyzing (CHDLs) – ES type• Carbapenemases (Acinetobacter) – Are not ES; do not have both properties – Imipenem> meropenem Poirel et al AAC 2010
Threat 2. ColistinR• Polymyxins (E and B) are cationic polypeptide atbs• Colistin SO4 for PO and Colistimethate Na+ (sodium colistin methanesulphonate, colistin sulfomethate sodium) for IV• Colistin displaces Ca+2 and Mg+2 from PO4-3 groups of membrane lipids; Insertion of polymyxins disrupts the OM and LPS is released ; anti-endotoxin activity ; rapidly bactericidal???• Urban et al. reported a case of polymyxin BR A. baumannii Falgas, et al, CID 2005; Urban 2001 AAC; Li et al AAC 2006; Li et al Int Journal of Antimicrobial Agents, 2005
ColistinR • ColR due to modifications of LPS; pmr (Adams…Bonomo, AAC US) vs. lpxA,-C, and -D (Li and Nation, Australia); Parks lab in S. Korea found the same locus as we did. • Heteroresistance (subpopulations of genetically identical subclones that are more R than the parent ) by Li et al; implications for rx? • “Colistin dependence”. 77 yo diabetic male with FI andMoffatt AAC 2010,Li et al AAC 2006 ; bacteremia; “increasingly luxuriantHawley et al AAC2007, growth”Adams et al AAC 2009
Lower expression of metabolic proteins and OmpA JID 2011
Part II MDR P. aerugoinosaThe resistance challenge of the ages
Pa facts• Colonization rates by Pa are high in the hospital (50%); immunity and burn• Seriously ill patients in ICUs.• Aggregate NNISS and EU data – 20 to 30% of nosocomial pneumonias – 10 to 20% of urinary tract infections – 3% to 10% of bloodstream infections,
Pa and ATBR• ß-lactamases-all classes represented – Cephalosporinases, – class A ESBLs (PER), – OXA ESBLs (OXA-10, -14), – Carbapenemases (KPC and GES), MbLs• Loss of permeability (porins and efflux)• Quinolones and aminoglycosides – Active antimicrobial efflux – Alterations in DNA gyrase – Aminoglycoside-modifying enzymes
Antimicrobial resistance• Efflux pumps – MFS—major facilitator superfamily – ABC—ATP-binding cassette family – RND—resistance nodulation division – SMR—small multidrug resistance – MATE—multidrug and toxic compound extrusion RND and MFS extrude antibiotics and work by proton motive force; In GNRs, RND works with MFP (periplasmic membrane fusion protein) and OEP (outer membrane efflux protein) to get thru both membranes
The mysteries of the biofilm.. Trends in Microbiology Jan 2001; 9(1): 34-39
Why should we be afraid ofKlebsiella pneumoniae KPCs?
KPC K. pneumoniae AMIKACIN R AMPICILLIN R CEFAZOLIN R CEFTAZIDIME R CIPROFLOXACIN R TRIMETH/SULFA RIMI/MERO-PENEM 4 ug/ml → (> 64) GENTAMICIN S AMPICILLIN/SUL R CEFOTETAN R CEFEPIME R PIP/TAZO R
Clinical impact of KPC carbapenemases• “The dependability on “last line” antibiotics is shattered”• The emergence of KPC carbapenemase producing Gram- negatives is a major threat to the clinician – K. pneumoniae, Acinetobacter, E. coli, Enterobacter, Serratia, Pseudomonas,… the list grows Patel and Bonomo, 2011, Current Opinion
Clinical issues with KPC• ATB control ?Cephalosporin and b- Lactam-b-Lactamase Inhibitor restriction policies? special populations? Imipenem restriction ??• How best to implement IC? Carrot or stick?• Detection? ESBL identification? Inoculum effect?• Colistin-as empiric Rx ??? combined with aminoglycosides (gent); rifampin
Status of the KPC global epidemic• Two phenotypes; MIC< 8 and MIC> 32• ST258> ST384, ST388, others…• Plasmids from ST258 and other starins has been transferred to E. coli in patients (Kreiswirth lab).• Colistin resistant ST258• Novel testing methods (ChromAgar, Boronates, PCR/ESI-MS, Microarray methods/Checkpoints
Mainly KPC-2 and KPC-3 (KPC-2 to KPC- Thanks Dr. Endimia 11) Poirel L. et al. Enterobacteriaceae (K. pneumoniae) Outbreaks
Dr. End “Import/Export” of patients carrying blaKPCNaas T et al., AAC 2005 Hammerum AM et al. IJAA 2010 Cuzon G et al.
Thanks Dr. Endimiani Genetic environment of blaKPC (Tn4401) Structure of Tn4401 and insertion sites P.aeruginosa Isoform BTn4401 is at the origin of acquisition anddissemination of blaKPC Possible genesis of Tn4401 Isoform A • Different isoform suggests that this region is polymorphic
Thanks Dr. Endimiani Western Blot No deletion (isoform B) 68-bp deletion Relative copy number100-bp deletion (isoform A) with real-time PCR Molecular characterization of 255-bp deletion (versus rpoB gene) OmpK35 and OmpK36 genes c Frameshift (stop codon after aa 88) Common in ST258
The near futureThe exciting future Clonal typing gyrA, parC mecA, PVL, TSST, mupA, nucA
Options for treatment?“The basis for a new researchagenda in Infectious Diseases”Can I approach this based upon a knowledge of genetics?
Therapy for MDR Ab et al. Colistin? Tigecycline? Minocycline? Rifampin?(Teicoplanin? Vancomycin? Are you crazy!) Do we have enough patients studied properly? Animal models may have (significant) limitations?
Colistin + rif? Colistin + minocycline? Not enough data Antagonistic? Synergy? Sometimes??? Meta-analysis (Falagas IJAA)--no statisticaldifference in cure rates when colistimethate sodium alone was compared with the combinations with meropenem, piperacillin/tazobactam or ampicillin/sulbactam
The colistin “bottom line”• “Efficacy rate” of 57-76% in IV form; “microbiological eradication” of 67-90.9%Renal tox 0-37%• Nebulized colistin (CF studies + others) effective; FDA warning; impact of shift to more resistant strains ; use with IV!!• 32 cases “microbiological eradication” in the CNS with ITh/IVe colistin (safe e 1) (2.5 mg/kg, 10-20 mg ITh)• Colistin was independently associated with higher mortality vs. treatment with sulbactam in patients with A. b infections
Colistin dosing• Administration of a loading dose (300 mg)• Colistin exposure during the first 12 h “may be beneficial, providing enough net killing such that the immune system may be able to eradicate any remaining colistin- resistant cells”
Major concerns…real ?1. Rapid resistance Tigecycline? can emerge;2. Cases of Patients % Improvement breakthrough 25 84 bacteremia reported; 18 503. Adequacy of 17 82.4 blood levels?? 29 30 Pachon and Vila Curr Opin 75 70 Investig Drugs. 2009 Feb;10(2):150-6. 34 68Giamarellou & Poulakou, Drugs. 45 78-90% 2009 bacteremic patients treated with tige failed toMichalopoulos A, Falagas ME. clear their bacteremia 10-fold more commonly Expert Opin Pharmacother. than patients treated with comparator drugs 2010 Apr;11(5):779-88. Gordon JAC 2009, Gardiner CID
My recommendations• Susceptible strains 1. A/S, 3 q6; higher doses? 2. Imipenem; meropenem is worrisome; dori?? Cephalosporins are tricky. 3. Colistin loading dose 5 mg/kg not to exceed 300 mg then (4.5 mg/kg/day) and split it tid (1.5 mg/kg q8). 4. Colistin and rifampin, tigecycline, or minocycline, doripenem?)
If NDM-1? Treatment options►Aztreonam + NXL?►BAL30072, meropenem and ??►Tige?
E-722Activity of the Novel Sulfactam BAL30072,Alone and in Combination withMeropenem, Against Diverse Gram-negative Isolates Carrying NDM-1 β- Dihydropyridonelactamase Gene. T. R. Walsh et al. siderophore monocyclic sulfactamOrganism (N) Ceftazidime Meropenem Aztreonam BAL BAL30072: 30072 MeropenemA. baumannii (23) >256 256 16 4 1P. aeruginosa (2) 256 32 16 0.5 <0.125S. maltophilia (1) 256 64 64 4 1Escherichia coli (3) 256 32 64 32 1K. pneumoniae (2) 256 128 64 32 2C. freundii (3) 128 128 64 8 2 Thanks to Dr. F. Perez
KPC Rx 68 blaKPC-possessing K. pneumoniae including 23 tigecycline- and/or colistin-nonsusceptible strains. By agar dilution, 93% of the overall KpKPC were susceptible (MIC50/90 of 16/64 g/ml, respectively).Notably, 5 out of 6 extremely drug-resistant (tigecycline and colistin nonsusceptible) KpKPC were susceptibleto fosfomycin. Compared to agar dilution, disk diffusion was more accurate than Etest.
Summary• Extraordinary challenge against cunning pathogens• Basic understanding of molecular biology is needed (the complexities of resistance genes will only increase)• Research is needed in therapeutics and infection control• CALL TO ARMS: Coordinate scientific and clinical trials to answer these important questions
Acknowledgments• NIH, VA Merit Review• Drs. Alan Evangelista and Linda Miller• Dr. Barry Kreiswirth• Chris Bethel, Steve Marshall, Magda Taracila, Kristine Hujer and Andrea Hujer• Drs. Krisz Papp-Wallace, Marisa Winkler, Federico Perez, Curtis Donskey, Dror Marcham