1. CARBAPENEM- RESISTANT ENTEROBACTERIACEAE Kristen Richardson

2. Goal After the presentation, the audience will have a general understanding of Carbapenem-resistant Enterobacteriaceae.

3. Objectives After the presentation on Carbapenem-resistant Enterobacteriaceae (CRE), the audience will: 1. Formulate causes, routes of transmission, and symptoms associated with CRE. 2. Differentiate different types of CRE. 3. Evaluate laboratory procedures that aid in the diagnosis of CRE. 4. Confirm prognosis of CRE. 5. Select populations at increased risk for contracting CRE. 6. Prioritize treatment for CRE, including drugs of choice and known resistances. 7. Critique specific prevention techniques in relation to CRE. 8. Assess epidemiology of CRE and predict future implications.

4. What is CRE? CDC defines CRE as: Family of bacteria found normally in gastrointestinal tract, soil, and water that test nonsusceptible to one of the following carbapenems: doripenem, meropenem, or imipenem AND resistant to all of the following third- generation cephalosporins : ceftriaxone, cefotaxime, and ceftazidime

5. Types of CRE Common types of CRE: Klebsiella pneumoniae * Escherichia coli * Salmonella enterica Pseudomonas aeruginosa Acinetobacter baumannii Morganella morganii Enterobacter spp. Proteus spp. Providencia spp. Serratia spp. *most encountered types of CRE in the United States

6. Resistance Mechanisms Resistance can be caused by several different mechanisms: 1. Carbapenemase enzyme 2. Beta-lactamase efflux pumps 3. Mutations 4. Intrinsic resistance

7. Beta-lactamases Periplasmic enzymes hydrolyze β-lactam antibiotics, preventing the drug from reaching the PBP target. Classified into four distinct classes based on structural similarities (classes A, B, C, and D) Class A, C, and D β-lactamases use a serine as a nucleophile to hydrolyze the β-lactam bond. Class B β-lactamases use zinc to inactivate β-lactams and are known as the metallo-beta-lactamases.

8. Carbapenemases Carbapenemases are β-lactamases with versatile hydrolytic capacities. They have the ability to hydrolyze penicillins, cephalosporins, monobactams, and carbapenems. http://www.chem.ucla.edu/harding/IGOC/B/beta_lactam01.jpg

9. Carbapenems First-line agent in treating ESBL-producing organisms Current Carbapenems approved for clinical use: Imipenem Meropenem Ertapenem Doripenem Panipenem Biapenem http://www.uic.edu/pharmacy/_images/druginfogroup/carbapenem.jpg

10. Carbapenemases associated with Enterobacteriaceae KPC (K. pneumoniae carbapenemase) (Class A) = plasmid mediated enzymes CMY (Class C) = plasmid mediated enzymes Associated with E. aerogenes NDM-1 (New Delhi metallo-beta-lactamase) (Class B) Associated with E. coli and K. pneumoniae VIM (Verona Integron-Encoded metallo-beta-lactamase) (Class B) Very rarely associated with Enterobacteriaceae IMP (Imipenemase metallo-beta-lactamase ) (Class B) Common outside the United States

11. Populations at Risk Immunocompromised patients Patients in acute and long-term healthcare settings Patients receiving treatment for other conditions Patients requiring instrumentation: Ventilators Urinary catheters Intravenous catheters Patients taking long courses of antibiotics ICU patients

12. Routes of Transmission Spread through direct or indirect contact with infected or colonized people, particularly via wounds and stools https://www.google.com/search?q=bacteremia&source=lnms&tbm=isch&sa=X&ei= https://www.google.com/search?q=bacteremia&source=lnms&tbm=

13. Symptoms Related to the particular infection, but a variety of symptoms include: Pneumonia Bacteremia Meningitis Endocarditis Wound infections Kidney and bladder infections Gastrointestinal issues Bone infections Eye infections Ear infections Skin infections Rhinoscleroma and ozena https://www.google.com/search?q=bacteremia&source=lnms&tbm=isch&sa=X&ei=7_aMUoqkLYS7k

14. CDC Protocol Day One Aseptically, place one 10-µg ertapenem or meropenem disc in 5 ml trypticase soy broth (TSB) Immediately inoculate the broth with the rectal culture swab Incubate overnight at 35 ± 2ºC, ambient air http://www.pc.maricopa.edu/Biology/rcotter/BIO%2022

15. CDC Protocol Day Two Vortex and subculture 100 µl of the incubated broth culture onto a MacConkey agar plate. Streak for isolation Incubate overnight at 35 ± 2ºC, ambient air http://people.upei.ca/jlewis/Mac3.jpg

16. CDC Protocol Day Three Examine the MacConkey agar for lactose-fermenting (pink-red) colonies. More than one colony morphology may represent different species of Enterobacteriaceae. It may be necessary to subculture representative colonies of each morphology type to a non-selective media for isolation and/or for susceptibility testing. Screen representative isolated colonies using a phenotypic test for carbapenemase production, such as the Modified Hodge Test (MHT) or test for carbapenem susceptibility using a standardized method and follow the CLSI guidelines for identification of carbapenemase- producing Enterobacteriaceae.

17. CDC Protocol Day Four For CRE and/or MHT-positive isolates, perform species- level identification. https://encrypted-tbn2.gstatic.com/images?q=tbn:ANd9GcRZ55nk-gXuFiYKJqSbMDkQYxCgkQO6r3gE27c9v

18. Susceptibility Test Methods Broth microdilution studies have shown false resistance to imipenem in commercially prepared test panels due to degradation of the drug or concentrations of imipenem were too low Disk diffusion Agar gradient diffusion https://www.google.com/search?q=MIC+ID+panel&source=lnms&tbm=iscX

19. Modified Hodge Test 1. Known KPC 2. Carbapenemase negative K. pneumoniae 3. Patient isolate https://www.google.com/search?q=carbapenem+disc&source=lnms&tbm=isch&sa=

20. CLSI Standards In 2008, CLSI recommended that Enterobacteriaceae with MICs to carbapenems between 2-4 ug/mL or reduced disk diffusion zones be tested for carbapenemase production using modified Hodge Test (MHT) In 2010, CLSI reevaluated the carbapenem breakpoints for Enterobacteriaceae and recommended lowering the carbapenem breakpoints for ertapenem, imipenem, and meropenem and established new breakpoints for doripenem. more accurately predicted carbapenem treatment outcomes without the need for a special test to detect carbapenemase production

21. CLSI Standards Clinical and Laboratory Standards Institute Interpretive Criteria for Carbapenems and Enterobacteriaceae Previous breakpoints (M100-S19)MIC (μg/mL)Revised breakpoints (M100-S20)MIC (μg/mL) AgentSusceptibleIntermediateResistantSusceptibleIntermediateResistant Doripenem………≤12≥4 Ertapenem≤24≥8≤0.250.5≥1 Imipenem≤48≥16≤12≥4 Meropenem≤48≥16≤12≥4

22. Prognosis Mortality rates depend on treatment Invasive bloodstream infection = ~ 50% mortality One study showed very high mortality rates: Combination therapy: Tigecycline-gentamicin = 50% Tigecycline-colistin = 64% Carbapenem-colistin = 67% Monotherapy-treated patients: Colistin = 57% Tigecycline = 80%

23. Treatment Options Antibiotics currently in use to treat CRE infections: Aminoglycosides Aztreonam Polymixins Tigecycline Fosfomycin Temocillin Colistin Combination therapy Carbapenem containing regimens? Rifampin? http://4.bp.blogspot.com/-aIFzee5g5kA/TZ85sQql1ZI/AAAAAAAABP0/CnIU2fJRiuI/s1600c

24. Factors Affecting Treatment Increasing resistance to antibiotics Toxicities Timing of treatment Underlying medical conditions

25. Epidemiology 1986-1990 – 2.3% of 1825 Enterobacter isolates tested resistant to Imipenem 2001 – (NC) KPC isolate was first discovered from a clinical specimen Cases concentrated in Northeastern US at that time 2002-2003 – (NYC) 9 out of 602 K. pneumoniae isolates were KPCs 2004 - (NYC) 20 more isolates recovered from 2 hospital outbreaks 2001 to 2011- CREs increased from about 1% to 4% most of which were KPCs, which increased from about 2% to 10%. 2012 – 18% of long-term, acute-care hospitals reported at least 1 CRE 1996- 2008 – 70% of all KPC isolates sent to the CDC revealed a dominant strain ST258 Indicates how easily CREs are spread 92% of CRE infections occurred in patients who had received extensive medical care -- most commonly hospitalization -- within the past year Of the 37 unusual forms of CRE that have been reported in the United States, the last 15 have been reported since July, 2012.

26. www.CDC.gov

28. Epidemiology cont. Emergence in other parts of the world also Some strains of KPC associated with US medical care = intercontinental spread Analysis revealed clonal relationship between US and Israelian KPC isolates from 8 hospitals and 5 chronic care centers Same organisms have spread significantly in other countries.

29. International dissemination of Klebsiella pneumoniae carbapenemase (KPC)–producing Enterobacteriaceae, as of 2011.

30. Prevention techniques Proper hand washing before and after caring for CRE patients Carefully cleaning and disinfecting rooms and medical equipment Wearing gloves and a gown before entering the room of a CRE patient Keeping patients with CRE infections in a single room Dedicating equipment and staff to CRE patients http://images.hngn.com/data/images/full/12948/gloves-and-gowns-don-t-cut-hospital-cars

31. Prevention Techniques cont. Only prescribing antibiotics when necessary Removing temporary medical devices as soon as possible Early screening of potential CRE patients A hospital in New York reduced CRE by more than 50% by implementing CDC's recommended practices. Israel reduced CRE infection rates in all 27 of its hospitals by more than 70% in 1 year with a coordinated prevention program.

32. Recent Outbreak National Institutes of Health Clinical Center: New York woman admitted in June 2011 for a lung transplant while infected with CRE Hospital was aware of infection and patient placed under isolation following CDC guidelines In August, other patients began to pick up infection, about one per week for a total of 18 affected Hospital designates staff only to those patients and begins extreme measures Eventually under control, genome sequencing traced outbreak back to Patient No. 1 11 total deaths, including one 16 year old boy

33. Red arrows -opportunity for a direct transmission event from patients overlapping in the same ward before the recipient culturing positive Black arrows - transmission events that cannot be explained by patient overlap (may result from a more complicated transmission route or an intermediate patient or environmental source) http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3521604/bin/nihms-424107-f0003.jpg

34. Future Implications Agents Under Development: new β-lactamase inhibitors with activity against carbapenemases MK-7655 NXL104 6-alkylidenepenam sulfones bis-indole compounds It can take over a year to be rid of CRE bacteria, with one study determining the average patient requiring 387 days for it to be out of their system.

35. References Carbapenem-resistant enterobacteriaceae (cre) infection: Clinician faqs. (2013). Retrieved from http://www.cdc.gov/hai/organisms/cre/cre-clinicianFAQ.html Cre: What do i need to know? (2012). Retrieved from http://www.ndhealth.gov/disease/Documents/faqs/CRE.pdf Falagas, M. E., Lourida, P., Poulikakos, P., Rafailidis, P. I., & Tansarli, G. S. (2013). Antibiotic treatment of infections due to carbapenem-resistant enterobacteriaceae: Systematic evaluation of the available evidence. Antimicrobial Agents and Chemotherapy. Retrieved from http://aac.asm.org/content/early/2013/09/24/AAC.01222-13.abstract Gilbert, D. N. (2010). The sanford guide to antimicrobial therapy. VA: Sanford Publishers. Guidance for control of carbapenem-resistant enterobacteriaceae (cre). (2013). Retrieved from http://www.cdc.gov/hai/organisms/cre/cre-toolkit/background.html Gupta, N., Limbago, B. M., Patel, J. B., & Kallen, A. J. (2011). Carbapenem-resistant enterobacteriaceae: Epidemiology and prevention. Clinical Infectious Diseases, 53, 60-67. Retrieved from http://cid.oxfordjournals.org/content/53/1/60.full

36. References cont. Kanj, S. S., & Kanafani, Z. A. (2011). Current concepts in antimicrobial therapy against resistant gram- negative organisms: Extended-spectrum β-lactamase–producing enterobacteriaceae, carbapenem-resistant enterobacteriaceae, and multidrug-resistant pseudomonas aeruginosa. Mayo Clinic Proceedings, 86. 250-259. Retrieved from http://www.mayoclinicproceedings.org/article/S0025-6196(11)60160-2/fulltext Laboratory detection of imipenem or meropenem resistance in gram-negative organisms. (2010). Retrieved from http://www.cdc.gov/HAI/pdfs/labSettings/Klebsiella_or_Ecoli.pdf Laboratory protocol for detection of carbapenem-resistant organisms. (2013). Retrieved from http://www.cdc.gov/HAI/pdfs/labSettings/Klebsiella_or_Ecoli.pdf Lehman, D. C., & Manuselis, G. (2010). Textbook of diagnostic microbiology. New York City, NY: Saunders W B Company. Snitkin, E. S., Zelany, A. M., Thomas, P. J., & Stock, F. (2012). Tracking a hospital outbreak of carbapenem-resistant klebsiella pneumoniae with whole- genome sequencing. Sci Transl Med, 4. Retrieved from http://www.ncbi.nlm.nih.gov/pubmed/22914622 Wallace, K. M., Endimiani, A., Taracila, M. A., & Bonomo, R. A. (2011). Carbapenems: past, present, and future. Antimicrobial Agents and Chemotherapy, 55, 4943-4960. Retrieved from http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3195018/