1. Carbapenem Resistance: Defining, Detecting, and Responding
Alyssa MacMillan
New Jersey Department of Health

2. Time, 2015

3. 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?

4. 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

5. Credit: Khan Academy

6. Susceptible  Resistant
Mutational Events
Alter the protein target
Reduce permeability of outer membrane (GN)
Overexpress drug exporter proteins
Gene Acquisition
Enzyme-mediated resistance

7. 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

8. 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

9. Global Epidemiology Sporadic spread Outbreaks Endemicity KPC producers
OXA-48 producers
NDM producers
Sporadic spread
Outbreaks
Endemicity
Nordmann & Poirel, CMI 2014

11. 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

12. 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

13. 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

14. 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

15. 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

16. 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

17. NJ Public Health Lab (PHEL)
Kirby-Bauer test
Create suspension of bacteria
Inoculate Mueller-Hinton agar plate
Place antimicrobial disks on the surface
Incubate 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

18. 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

19. 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

20. 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

21. 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)

22. Clinical/Healthcare Labs
State & Local Health Depts.
Regional Labs
CDC

23. 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

24. 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
(609)