Carbapenem Resistance: Defining, Detecting, and Responding Alyssa MacMillan New Jersey Department of Health
Time, 2015
The Highlights: What is carbapenem resistance? What causes it? Why does it matter? How is it detected and characterized? How are clinical & public health labs involved in controlling it?
Carbapenem β-lactam antibiotic agent Broadest spectrum of activity and greatest potency against GN and GP organisms Relatively resistant to β-lactamases First discovered in 1976, first available for treatment in 1985 Now include imipenem, meropenem, ertapenem, doripenem *FDA approved Considered “last resort”: used for complicated or resistant infections The term “carbapenem” is defined as the 4:5 fused ring lactam of penicillins with a double bond between C-2 and C-3 but with the substitution of carbon for sulfur at C-1. Act similarly to other beta lactams by inhibiting cell wall formation and therefore preventing bacterial growth Are effective against infections caused by extended spectrum B lactamase producing bacteria
Credit: Khan Academy
Susceptible Resistant Mutational Events Alter the protein target Reduce permeability of outer membrane (GN) Overexpress drug exporter proteins Gene Acquisition Enzyme-mediated resistance
Horizontal Gene Transfer Mobile genetic elements Allows extremely rapid development of resistance Can be transferred to antibiotic-naïve organisms Can carry additional resistance elements (pan- resistance) Can become permanent and expand clonally Credit: Medbullets
Carbapenemase β-lactamases with ability to hydrolyze penicillins, cephalosporins, monobactams, carbapenems Big Five: KPC: Klebsiella pneumoniae carbapenemase NDM: New Delhi metallo-B-lactamase OXA-48: oxacillinase VIM: Verona integron-mediate metallo-B-lactamase IMP: imipenemase
Global Epidemiology Sporadic spread Outbreaks Endemicity KPC producers OXA-48 producers NDM producers Sporadic spread Outbreaks Endemicity Nordmann & Poirel, CMI 2014
New York/New Jersey: epicenter for KPC-CRE Highest prevalence of CRE in the US 10% K. pneumoniae bacteremia carbapenem resistant Of all CP-CRE, 90%+ KPC-producing NDM: sporadic VIM/IMP/OXA-48: rare Epicenter study performed in 2013 Satlin, Kreiswirth, et al, Antimicrob Agents Chemother, 2017
What’s my risk? Acute and long-term healthcare settings Compromised immune system Cancer or transplantation Ventilators, urinary catheters, central lines, chronic wounds Long term antibiotic use History of medical care abroad 30-70% mortality rate 2-3 times more likely to be fatal than infection with susceptible
Antimicrobial Resistance Laboratory Network CDC-supported initiative established in 2016 Supports state and local health department surveillance Beyond Carbapenem: Clostridium difficile Streptococcus pneumoniae Neisseria gonorrhoeae Mycobacterium tuberculosis Candida auris MRSA 50 states 5 cities and Puerto Rico
ARLN: Carbapenem Resistance NJ Public Health Lab (PHEL) LAB Suspected CRE/CRPA Isolates Clinical Laboratory 1. Collect samples 2. Isolate bacteria 3. Identify 4. Perform AST Confirm ID Confirm susceptibility Phenotypic screen for carbapenemase production Molecular detection of resistance determinants
NJ Public Health Lab (PHEL) Testing Menu Task Method Species ID VITEK 2 or Bruker MALDI ToF Susceptibility Testing Disk Diffusion Carbapenemase Screening Modified Carbapenem Inactivation Method (mCIM) Molecular Detection of AR Determinants Real-time PCR KPC, NDM, OXA-48, IMP, VIM
NJ Public Health Lab (PHEL) Drugs used to confirm and further characterize CRE and CRPA Drug Class CRE CRPA Carbapenems ertapenem, imipenem, meropenem, doripenem imipenem, meropenem, doripenem Cephems ceftazidime, ceftriaxone, cefepime ceftazidime and cefepime β-lactam/β-lactamase inhibitor combinations piperacillin-tazobactam Monobactams aztreonam Combinations ceftazidime-avibactam, ceftolozane-tazobactam Complement rather than duplicate efforts from clinical labs
NJ Public Health Lab (PHEL) Kirby-Bauer test Create suspension of bacteria Inoculate Mueller-Hinton agar plate Place antimicrobial disks on the surface Incubate 18-24 hours Measure zone of inhibition Use up-to-date CLSI guidelines to determine susceptibility or resistance CLSI M100 Ed29 Clinical and Laboratory Standards Institute M100 ed29 published in December NJ Public Health Lab (PHEL) LAB JJM College
Carbapenemase “phenotypic” screen CLSI approved (Enterobacteriaceae, P. aeruginosa) Modified carbapenem inactivation method NJ Public Health Lab (PHEL) LAB Van der Zwaluw, et al. PLoS One 2015
Molecular Determinants of Resistance STRECK ARM-D kit, β-Lactamase Real time PCR TaqMan® assay OXA-48, VIM, IMP, KPC, NDM plus CMY-2, CTX-M-14, CTX-M-15, and DHA Quick DNA extraction ABI 7500 Fast Dx instrument (any 4 channel analyzer) 60 minute run time NJ Public Health Lab (PHEL) LAB
NJ Public Health Lab (PHEL) So now what? NJ Public Health Lab (PHEL) LAB LAB Clinical Laboratory CDC CDC LAB EPI NJ Epi Team (CDS) Healthcare Facility HCF
Alert Values Pan-resistance Possible novel resistance non-KPC CP-CRE CDC CDC LAB Pan-resistance Possible novel resistance Carbapenemase+ but PCR negative non-KPC CP-CRE CP-CRPA Healthcare Facility HCF EPI NJ Epi Team (CDS)
Clinical/Healthcare Labs State & Local Health Depts. Regional Labs CDC
Other ARLN Resources Available to YOU Invasive Streptococcus pneumoniae AST Candida auris ID confirmation and AST Colonization screening for CP-organisms or Candida auris Acinetobacter baumannii AST Hard-to-treat Enterobacteriaceae pan-resistant extended AST Particular epidemiological interest in A. baumannii, multiple outbreaks of in the past couple years
Contact: Special thanks to: Alyssa MacMillan NJ PHL ARLN Team Maria Orsini, Howard Sarubin, Hita Shah, Krupa Patel, Lisa Schlitt Tom Kirn NJ ARLN Epidemiologists Patricia Barrett & Tara Fulton Regional Laboratory Partners: NY DOH Centers for Disease Control & Prevention ARLN Team Funding Submitting clinical lab partners Contact: Alyssa MacMillan alyssa.macmillan@doh.nj.gov (609) 530-8554