1. Update on ESBLS and Carbapenem Resistant Enterobacteriaceae
Michael Costello, Ph.D.
Technical Director – Microbiology
ACL Laboratories
Resistance genes on plasmids is instrumental in rapid spead

2. Topics To Cover Extended spectrum β lactamases (ESBLs)
Update on the recent changing patterns of different types of ESBLs in the Chicago/Milwaukee area
Implications
Healthcare associated infections (HAI) Vs. community acquired infections
Carbapenemases – more than “just” KPC
Summarize carbapenemases currently found in the Wisconsin/Illinois area
Expand on how and why CREs have spread so rapidly throughout the world.
Define testing algorithms for rapid detection of CRE, faster the better
Talk about new molecular based tests that are becoming available
Molecular assays for identification of bacteria and resistance genes directly from a positive blood culture bottle.
Culture not required

3. Antibiotic Resistance
Gram Negatives
Production of β-lactamases – Enzymatic destruction of antibiotic
Switch from Tem and SHV to CTX-M
Permeability alterations
Porin mutations – antibiotic entry is limited
Porins are barrel shaped proteins that cross cell membranes and act as a port though which nutrients, toxins and antibiotics can diffuse
Antibiotic extrusion by efflux pumps
Rapidly pump out antibiotics before they are effective
Rarely, PBP alterations
PBP 7-8 in A. baumanii
Combinations of the above

4. Changing ESBL patterns out with the old (Tem, Shv) and in with the new [ESBL (CTX-M), carbapenemases (KPC, NDM-1)]
Target is still the same – β-lactam ring
Only difference between peniclliniases, cephalosporinases and carbapenemases
is the preferred substrate

5. Classification of ß-Lactamases Bush-Jacoby-Mederios - Functional Classification
Group
Enzyme Type
Inhibition by Clavulanate
Molecular Class (Ambler)
# of Enzymes
Characteristics
Example 1
Cephalosporinase No C 53
Mainly chromosomal located in gram negative bacteria, but may be plasmid mediated. Resistance to ß-lactams (except carbapenems)
E. Coli 2a
Penicillins
Yes A 20
Narrow spectrum resistance to penicillins only
S. Aureus 2b
Broad spectrum 16
Broad spectrum penicillinases
TEM-1, SHV-1
2be
Extended spectrum 38
ESBL conferring resistance to oxyimino-cephalsporins and monobactams
TEM-3, SHV-2, CTX-M
2br
Inhibitory resistant
Partly 9
Inhibitor resistant ß-lactamases (mostly TEM-types and to a lesser extent SHV derived ESBL
TEM-30, TRC-1 2c
Carbenicillinase 15
Carbenicillinases
BRO-1, CARB-3, PSE-1 2d
Cloxacillinase
Variable
D or A 18
Oxacillinases, partly inhibited by clavulanate
OXA-1, PSE-2 2e 19
Oxacillinases, inhibited by clavulanate
P. vulgaris, Bacteroides fragilis 2f
Carbapenemase 3
Serine active carbepemases, inhibited by clavulanate.
E. cloacae,
Metalloenzyme B
Metallo-ß-lactamases conferring resistance to all ß-lactam drugs except monobactams - aztreonam
S. maltophilia 4 7
Miscellaneous ß-lactamases that do not conform to other groups
B. cepacia
Cephalosporinases because they can mimic carbapamenases in vitro

6. ESBL Pandemics Enterobacteriaceae pan-resistance endemic KPC NDM pAmpC
detected
pAmpC
detected
NDM
detected.

7. ESBL (Extended spectrum β-lactamase) Out With The Old and In With The New!
Old ESBLs - SHV (SulfHydryl Variable) and TEM (Temoneira)
>120 variants
TEM and SHV-1 (initially only hydrolyzed ampicillin) first described in 1960’s
First ESBLs
SHV-2 in 1983
TEM-3 in 1984
TEM and SHV are primarily healthcare associated
Competitive disadvantage outside of a healthcare setting
Require administration of antibiotics to compete
More reactive against ceftazidime than cefotaxime
Rarely carbapenem resistant
New ESBLs – CTX-M (CefoTaXime –Munich)
First described in Japan in 1986 and named in Germany in 1989.
Can show carbapenem resistance, especially in association with a porin mutation

8. CTX-M
CTX-M -lactamases are extended-spectrum β-lactamases (ESBLs) that mainly inactivate cefotaxime and cefriaxone and have less activity against ceftazidime
Sequencing evidence that gene mobilized from Kluyvera spp. (environmental bacteria rarely associated with disease)
Associated with community-acquired UTIs
Highest incidence in E. coli
Plasmid is stable and confers minimal competitive disadvantage when β-lactams are not present
Dramatic world-wide spread in the last decade
Quickly replacing TEM- and SHV-type ESBLs
Detected in both humans and animals (in the food chain)
Present wherever β-lactam antibiotics are used
Associated with other multidrug-resistant genes
Found on plasmids that also include resistance genes to aminoglycosides and fluoroquinolones

9. E. coli ESBL Isolates Total = 619
ANTIBIOGRAMS NEW MORE AGGRESSIVE E. COLI STRAIN ESBL POSITIVE ANTIBIOGRAMS
Hospital
# Isolates
Amikacin (%S)
Ampicillin (%S)
Ampicillin/sulbactam (%S)
Aztreonam (%S)
Cefazolin (%S)
Ceftazidime (%S)
Ceftriaxone (%S)
Cefepime (%S)
Ciprofloxacin (%S)
Gentamicin (%S)
Ertapenem
Imipenem (%S)
Nitrofurantoin (%S)
Piperacillin/tazobactam (%S)
Tobramycin (%S)
Trimethoprim/sulfamethox. (%S)
Gram Negative
CMC
Escherichia coli, ESBL (6%)
205 92 11 2 67
100 84 85 37 53
Bethany
Escherichia coli, ESBL (40%) 29 3 68 93 66 21 46
Good Sam
Escherichia coli, ESBL (2%) 43 12 14 80 88 40
GSH 18 78 94 39
SSUB
Escherichia coli, ESBL (4%) 35 20 54 97 72 77
Trinity 25 16 48 96 36
IMMC 74 7 51 89 32
LGH
Escherichia coli, ESBL (8%)
190 1 6 52 83 90 30 57
E. coli
ESBL
Isolates
Total = 619
Unusual resistance pattern
ESBL
Aminoglycoside resistance
Tobramycin more resistant than Gentamicin
Flouroquinolone resistance Cipro = Levo

11. UROPATHOGENIC E. COLI ST131 MULTIPLE RESISTANCE GENES AND VIRULENCE FACTORS - ALL COMMUNITY ACQUIRED
International Journal of Antimicrobial Agents, accepted for publication 2010.

12. CTX-M Summary
Uropathogenic E. coli clone ST131 from phylogenetic group B2 that have plasmids that produce multiple resistance factors
CTX-M-15 or CTX-M-14
CTX-M-15 is also resistant to Ceftazidime
Different epidemiology – multidrug resistant community onset UTIs
AAC (6’)-lb-cr aminoglycoside/fluoroquinolone acetyltransferase (ACC (6’)-Ib responsible for resistance to kanamycin, tobramycin and amikacin. ACC (6’)-Ib-cr also confers resistance to ciprofloxicin and norfloxicin)
Aminoglycoside modifying enzyme that can also cause quinolone resistance, esp. in norfloxicin and ciprofloxicin (also see resistance to levofloxicin)
Common cause of UTIs in the Chicago area by ESBL-producing E. coli.
Bacteria with multiple resistance genes becoming widespread

13. AmpC detection – differentiate from carbpenemase producers

14. AmpC Chromosomal = MY SPACE bugs
(Morgenella, Y. enterocolitica, Serratia, Providencia, Aeromonas, Citrobacter, Enterobacter)
Inducible = Any MYSPACE containing AmpC plasmid
Organism may develop resistance during prolonged therapy with 3rd generation cephalosporins.
Identified in organisms exhibiting the following:
Resistant to cephamycins
Cefoxitin and Cefotetan
Resistant to penicillin – β-lactam inhibitors
Sensitive to cefepime and carbapenems
Hyperproduction = Any Enterobacteriaceae
Caused by a mutation in the AmpC regulator gene leading to permanent (?) hyperproduction or derepression.
Increased AmpC production and proin mutation can result in carbapenem resistance

15. pAmpC AmpC enzymes in the midwest C. freundii cluster
CMY-2
Enterobacter cluster
MIR-1, ACT-1
M. morganii cluster**
DHA-1
plasmid-encoded inducible cephalosporinase , other plasmid-encoded AmpC enzymes are almost always expressed constitutively
H. alvei cluster
ACC-1
Aeromonas cluster
CMY-1 and FOX-1

16. Detection of AmpC Hyperproducer
Cephamycin – inducible AmpC
Inducible AmpC
Cefotetan
+ cloxacillin
Cefotetan
Hyperproduction of AmpC
> 3 mm difference
Hyperpoduction associated with a mutation
Of the AmpC regulator gene. Cephalosporinase
not regulated and AmpC produced at higher levels
Meropenem
+ Cloxacillin
Meropenem
+ Boronic acid
Meropenem

17. AmpC + Porin Loss = Carbapenem Resistance
Porins - Protein channels through bacterial membrane allow for exchange of water, ions, glucose,
and other nutrients as well as waste products

18. AmpC Summary Gene can be found on plasmids
No longer restricted to MYSPACE bacteria
Morgenella, Y. enterocolitica, Serratia, Providencia, Aeromonas, Citrobacter, Enterobacter
Different AmpC genes with differing ranges
DHA-1 can hydrolyze carbapenems
Carbapenem resistance usually requires overexpression of AmpC (mutation in the regulator gene) and the presence of a porin mutation, restricting migration of antibiotic into the bacteria

19. Carbapenem-Resistant Enterobacteriaceae (CRE)

20. Carbapenemases
Meropenem
Imipenem
Doripenem
Ertapenem

21. The Rise of Carbapenemases

22. Why are Plasmid CRE’s a Public Health Emergency
Limited treatment options for life threatening infections
Co-migrate with other resistance genes
Resistant mechanisms have transferred to plasmids
Plasmids easily spread to other bacterial species
No/few new drugs/drug classes
Rapid detection and effective infection control measures are essential to control spread

23. IPDH New Rule - Reporting Carbapenemases
Major points:
This establishes the mechanism by which carbapenem-resistant Enterobacteriaceae (CRE) are reported to IDPH, starting Sept 1, 2013, for all Illinois healthcare facilities
Beginning September 1, 2013, reporting facilities shall report carbapenem-resistant enterobacteriaceae (e.g., E. coli, Klebsiella species, Enterobacter species, Proteus species, Citrobacter species, Serratia species, Morganella species, or Providentia species) based on laboratory test results
Laboratory tests
Molecular tests (PCR specific for carbapeneamse)
KPC PCR currently offered at Rosemont
Phenotypic test (Modified Hodge Test) specific for carbapeneamse production
Rosemont offers modified Hodge Test and ROSCO Disks – identification of KPC, MBL, hyper AmpC, and Oxa-48 carbapenemases
Phenotypic tests are too slow!
E . coli and Klebsiella species only: nonsusceptible to one of the following carbapenems: doripenem, meropenem, or imipenem and resistant to the following 3rd generation cephalosporins: ceftriaxone, cefotaxime, and ceftazidime
We use this definition for all Enterobacteriaceae
The rationale to use a registry mechanism for reporting, versus the traditional INEDSS, is to allow the database to serve as an inter-facility information exchange for patient-related CRE status. For example, a hospital IP can query the database to see if a newly admitted patient has a history of CRE. Querying is restricted to IDPH-registered personnel  with login access to the XDRO registry    .  

24. Why are CREs So Important?
Invasive infections (e.g., bloodstream infections) with CRE are associated with mortality rates exceeding 40%
Carbapenem-resistant strains frequently possess additional resistance mechanisms that render them resistant to most available antimicrobials
CRE can spread rapidly in health-care settings
Enterobacteriaceae are a common cause of community infections, and CRE have the potential to move from their current niche among health-care–exposed patients into the community
MMWR March 8, 2013 / 62(09);

25. Healthcare-Associated Factors* * * *
* p <0.001
From: CDC webcast 3/19/09 25

26. IDENTIFICATION OF CARBAPENEMASES FOUND IN THE CHICAGO/MILWAUKEE AREA
Hydrolysis Profilea
Inhibition Profileb
Molecular
Class
Functional Group
Enzyme
Penicillins
Early Cephalosporins
Extended Spectrum Cephalosporins
Aztreonam
EDTA/DPA
Clavulanic Acid
Boronic Acid
Cloxacillin
Temocilin A 2f
NMC-A (chromosomal) +
-/+ -
+/-
SME
(chromosomal)
KPC
(plasmid)
IMI#
GES^
(plasmid, low carbapenemase activity) B1 3
NDM, IMP, VIM, GIM, SPM
(most plasmid) D 2d
OXA-48
(plasmid)?
# Selective increased resistance to imipenem
^ Sensitive to AZT; clavulanic Acid +, Boronic Acid and EDTA –
a Hydrolysis Symbols: - +, strong hydrolysis; +/-, weak hydrolysis; -, no measureable hydrolysis
b Inhibition Symbols: +, inhibition; +/-, variable inhibition among β-lactam family members; -, no inhibition
NMC-A = Not MetalloCarbapenease A; SME = Serratia marcescens Enzyme; KPC = Klebsiella pneumoniae carbapenemase;
IMI = imipenem hydrolyzing β-lactamase; GES = Guiana Extended Spectrum β-lactamase; NDM = New Delhi Metallo carbapenemase; IMP = active on imipenem ;
VIM = Verona Integron-encoded Metallo-β-lactamase; GIM = German Imipenemase; SPM = Sao Paulo Metallo-β-lactamase;
DPA = dipicolinic acid (Metallo β-lactamase inhibitor); Boronic Acid (KPC and AmpC inhibitor); Cloxacillin (AmpC inhibitor)

27. CREs Detected in Chicago/Milwaukee Area
CRE Type
Year Detected
Chromosomal or Plasmid
Bacteria
SME
2005
Chromosomal
Serratia marcescens
NMC-A
2004
Enterobacter spp.
KPC
2009
Plasmid
Enterobacteriaceae
NDM-1
2010
K. pneumoniae, E. coli
OXA-48
2012?
Screening started 2013
VIM, IMP
2010?
Chromosomal/plasmid
Screening started 2009

28. Carbapenem Breakpoints Lowered 9/2012

29. Effects of Lowering Carbapenem Breakpoints
Detect chromosomal carbapenemases that are not considered an infection control emergency
More SME (Serratia Marcescens Enzyme)
Carbapenems resistant and 3rd and 4th generation cephalosporins sensitive
More NMC-A (Not Metallo Carbapenemase, in Enterobacter sp.)

30. Acute care
hospital
Need to break
the cycle!
Long term
Care facilities

31. Advocate hospitals – k. pneumoniae Imipenem (% sensitive)
2007
2008
2009
2010
2011
2012
CMC
100 96 94 92 93
Condell - 99
G. Sam 98 95
G. Shep 97
IMMC 91
LGH
SSUB 90
Trinity

32. Vital Signs: Carbapenem-Resistant Enterobacteriaceae
Enterobacteriaceae are gram-negative bacteria that can cause invasive disease but generally have been susceptible to a variety of antibiotics.
Carbapenem-Resistant Enterobacteriaceae (CRE) are Enterobacteriaceae that have become highly resistant to most or all antibiotics through several mechanisms. Carbapenem resistance, while relatively uncommon among Enterobacteriaceae (4% of Enterobacteriaceae in this study), has increased from about 1% during the past decade. CRE bloodstream infections are associated with mortality rates approaching 50%.
MMWR March 8, 2013 / 62(09);

33. Vital Signs: Carbapenem-Resistant Enterobacteriaceae
CRE has now spread throughout the United States but in most areas they remain relatively uncommon; about 4% of acute-care hospitals and 18% of long-term acute-care hospitals reported at least one CRE to the National Healthcare Safety Network in the first 6 months of Nearly all patients with CRE were currently or recently treated in a health-care setting. However, CRE could spread into the community among otherwise healthy persons
MMWR March 8, 2013 / 62(09);

34. Vital Signs: Carbapenem-Resistant Enterobacteriaceae
Preventing spread is important before CRE gains a foothold in more hospitals or in the community. This requires active (rapid) case detection and contact precautions for colonized or infected patients as well as cohorting of patients and staff; appropriate antibiotic use in all settings; and communication about infections when patients transfer. Regional and state-based approaches have been shown to be effective in reducing incidence.
Additional information is available at
MMWR March 8, 2013 / 62(09);

35. Mechanisms of Carbapenem Resistance
Non enzymatic
Modifications of outer membrane permeability
Porin loss
Allow passage molecules include water, ions, glucose, and other nutrients as well as waste products
Up regulation of efflux systems
Enzymatic
Production of carbapenem hydrolyzing β-lactamases
hyperproduction of AmpC β-lactamases
Certain ESBLs with increased capacity to hydrolyze carbapenems
CTX-M
Production of carbapenemases
KPC, NDM-1, others
Combinations of all of the above

36. NEED TO DISTINGUISH MECHANISMS OF CARBAPENEM RESISTANCE – WHY?
KPC (increasing numbers)
Make all penicillins, cephalosporins, inhibitor combinations, aztreonam, and carbapenems resistant
Hyper AmpC (most common)
Make all penicillins, cephalosporins, inhibitor combinations, and aztreonam Resistant
Cefepime may still be effective
Do not change carbapenem interpretations
Metallo β-lactamases (rare, but increasing)
Same as KPC, except do not change aztreonam interpretation
Other carbapenemases
Antibiotic profiles not clear 36

37. Class a - Klebsiella Pneumoniae Carbapenemase (kpc)
1st described in 1998, 2001 in NYC
Now endemic in the Northeastern/Mid-Atlantic region of the United States
surveillance cultures of hospitals in the New York City area reporting rates of carbapenem resistance in K. pneumoniae isolates ranging up to 40%
Reported in Europe, China, Central America, South America – Since 1998
Also reported in Pseudomonas aeruginosa (Columbia)
KPC is a class A b-lactamase (serine residue at the active site)
Confers resistance to all b-lactams including extended- spectrum cephalosporins and carbapenems
Occurs in other Enterobacteriaceae
Most commonly seen in Kliebsiella pneumoniae
Also reported in: K. oxytoca, Citrobacter freundii, Enterobacter spp., Escherichia coli, Salmonella spp., Serratia spp., 37 37

38. BACKGROUND METHODS FIGURES DISCUSSION RESULTS CONCLUSIONS REFERENCES
Carbapenem Resistant Enterobacteriaceae:
Incidence and Risk Factors in a Community-Teaching Hospital
A. Makarem, MD; P. Alvarez, MD; M. Kulkarni, MD; M. Costello, PhD; T. Chou, MPH; J. Kerridge, RN; K. Wickman, RN; J. Malow, MD
BACKGROUND
METHODS
FIGURES
DISCUSSION
Carbapenems are the treatment of choice for multidrug resistant Enterobacteriaceae. However, there have been increasing reports of carbapenem resistant Enterobacteriaceae (CRE), and their prevalence has increased since they were first described in 2001.
CRE are resistant to almost all available antimicrobial agents. Infections with CRE have been associated with high rates of morbidity and mortality, even when treated appropriately, particularly among individuals with prolonged hospitalization and those who are critically ill and exposed to invasive devices.
Outbreaks have been reported in many countries, predominately Asia and South America. In the U.S., CRE were first reported in North Carolina, with the first reported healthcare-related outbreak in New York. Since then, CRE have been reported in at least 32 states.
The study population included adults who were hospitalized in our institution (level 1 trauma community-teaching Hospital, with 551 licensed beds, 2 adult intensive care units and a neonatal intensive care unit) from July 2008 through March 2010 and had positive cultures for CRE.
CRE detection: all bacteria with MIC > 1mcg/ml for any carbapenem and resistance to any 3rd generation cephalosporin are considered screen positive. These are then confirmed as CRE by modified Hodge test and Etest.
Patient records were reviewed for the following: type and location of residence, presence of indwelling devices (ventilator, central line, urinary catheter, and gastrostomy tubes), recent antibiotic exposure, signs and symptoms of infection, sites of positive cultures, co-morbidities, and mortality.
All CRE isolates obtained are multidrug resistant with very limited therapeutic options, and are widespread throughout the extended care facilities (ECF) in the Chicago metropolitan area. With a mortality rate of 40%, CRE may pose a real challenge unless appropriately addressed.
Horizontal dissemination appears to have an important role in the emergence of CRE infections. This is supported by the fact that most patients resided in an ECF prior to admission. Furthermore, only one patient had previous exposure to a carbapenem, and all infections were acquired prior to admission except for one.
Chronic illnesses and indwelling supportive devices also appear to increase the risk of acquiring CRE infections. This might be related to a decreased functional status, or possibly some degree of immunosupression, both of which have been reported as risk factors for CRE infections.
A larger sample size is needed for more accurate calculations.
RESULTS
CONCLUSIONS
Represents the location of our institution
Represents the residence locations of CRE positive cases
There were a total of 20 patients with 32 CRE positive cultures in our institution during the study period.
19/20 (95%) were infected, only 1 (5%) was colonized.
Only one patient (5%) had previous carbapenem exposure.
40% had two sites of infection with CRE.
Infection sites included urine (60%), blood (25%), wounds (15%), sputum (15%), and PEG tubes (5%).
2/5 of bacteremic patients died (40%).
95% had at least one type of chronic indwelling supportive device (PEG tube, urinary catheter, tracheostomy, PICC line).
90% had at least one chronic co-morbidity.
80% of patients with chronic indwelling urinary catheter presented with CRE in the urine. 
30/32 CRE cultures (93.7%) were identified as K. pneumoniae while the other two isolates were E. coli and P. mirabilis.
Patients in extended care facilities are at risk for acquiring CRE.
Use of contact precautions, hand hygiene, and other infection control measures may limit the spread of CRE.
Screening for CRE should be considered in areas of high CRE endemicity.
Development of new antimicrobial agents is needed.
REFERENCES
1. Rapid Spread of Carbapenem-Resistant K pneumoniae in New York City. S Bratu, MD et al. Arch Intern Med. 2005;165:
2. Carbapenemase-producing Enterobacteriaceae, U.S. rivers. Aubron, C., L. Poirel, R. J. Ash, and P. Nordmann Emerg. Infect. Dis. 11:
3. Carbapenem resistance in Klebsiella pneumoniae not detected by automated susceptibility testing. Tenover FC. Kalsi RK. Williams PP. Carey RB. Stocker S. Lonsway D. Rasheed JK. Biddle JW. McGowan JE Jr. Hanna B. Emerging Infectious Diseases. 12(8): , 2006 Aug.
4. Carbapenem-resistant Enterobacteriaceae: a potential threat. JAMA 300:
5. Tigecycline for the treatment of multidrug-resistant Enterobacteriaceae: a systematic review of the evidence from microbiological and clinical studies. Journal of Antimicrobial Chemotherapy 62:
6. Guidance for control of infections with carbapenem-resistant or carbapenemase-producing Enterobacteriaceae in acute care facilities. Centers for Disease Control and Prevention (CDC). Morbidity & Mortality Weekly Report. 58(10):256-60, 2009 Mar 20.
7. Ventilator-associated pneumonia caused by carbapenem-resistant Enterobacteriaceae carrying multiple metallo-beta-lactamase genes. Dwivedi M. Mishra A. Azim A. Singh RK. Baronia AK. Prasad KN. Dhole TN. Dwivedi UN. Indian Journal of Pathology & Microbiology. 52(3):339-42, 2009 Jul-Sep.
8. Potential role of active surveillance in the control of a hospital-wide outbreak of carbapenem-resistant Klebsiella pneumoniae infection. Infection Control & Hospital Epidemiology 31:
9. Risk Factors and Outcomes Associated with Acquisition of Colistin-Resistant KPC-Producing K pneumoniae: a Matched Case-Control Study. Zarkotou et al. J. Clin. Microbiol. 2010;48:

39. 150/3206 = 4.7%
Chicago
area
53/3040 = 1.7%
2/2408=0.08%

40. Figure 1. A) Worldwide geographic distribution of Klebsiella pneumoniae carbapenemase (KPC) producers. Gray shading indicates regions shown separately: B) distribution in the United States; C) distribution in Europe; D) distribution in China.
EID, Oct. 2011

41. Current tests for carbapenemase producers
AST patterns (ACL - all carbapenems in Gram negative panels)
Gram negative panels must include doripenem, ertapenem, imipenem, and meropenem for optimal sensitivity
Modified Hodge test ( ACL - Screen if carbapenems are NS)
Lacks sensitivity (does not detect all NDM, VIM, IMI producers) and specificity (hyper AmpC producers)
Takes too long, an additional hours
E Tests
MBL for verification of a metallo-lactamase - carbapenem +EDTA/carbapenem
Cefotetan/Cefotetan+ cloxacillin for AmpC expression
Takes too long
Rosco Disks (ACL - Classify carbapenemases)
Differentiates MBLs, from KPCs, from hyper AmpC
Low sensitivity for Oxa-48
Amplified molecular methods (ACL – KPC only, so far)
Rapid
Sensitivity dependent on variation of sequences of carbapenem resistance genes
Costly?

42. Positive for KPC
Modified
Hodge test
ROSCO
Disks

43. Class b carbapenemase VIM, IMP, and NDM most common
NDM more common in E. coli than KPC
Require zinc at active site for hydrolysis of the beta-lactam ring
Resistant to all beta-lactams except for aztreonam
May not be modified Hodge Test positive

44. Class b carbapenemase Recent Case - Patient History
70 year old male. Visiting relatives.
History – diabetes and chronic kidney failure, on dialysis
Admitted 9/23/2012 to CMC for shortness of breath.
Cardiac surgery - Triple bypass
Complicated recovery, discharged 10/22 to Long Term Acute Care Hospital (LTACH)

45. Laboratory Data
Treated with Pip/tazo and fluconazole

46. Laboratory Data
Repeat urine culture on 10/3 was negative

47. Fosfomycin = S

50. Colistin
Sample is MHT +
Tigecycline
AmpC
MBL
IMI +
EDTA
IMI

51. NDM 2/17/2013 K. Pneumoniae 10/8/2012 MHT negative K. Pneumoniae
MHT positive
Meropenem +
cloxacillin
Meropenem
Meropenem +
Boronic acid
Meropenem +
Dipicolinic acid
Temocillin
Positive =
> 5 mm difference

52. Case Review Patient not isolated prior to MBL report on 10/8
Did treatment (Pip-tazo) select for MBL?
Rectal swabs taken on all patients in Adult Surgical Heart Unit. All were negative for MBL
Rectal swabs preincubated in 2 μg/ml ertapenem in TSB for 18 hours and then plated on gram negative selective media with meropenem disks.
Gown and glove precautions on entire unit.
Patient discharged to Kindred (LTACH)

53. Current Metallo β-Lactamase Outbreak
Pt. MM. 68F 4/ LGH
Abd. Wound- E. coli, NDM (CDC Confirmed)
Present on admission to LGH
Risk factors: unknown, new pt.
Pt.SQ. 70M 9/ CMC
Indian national
Urine - K. Pneumoniae x 2
NDM-1 confirmed by CDC
Pt. In LTACH
Pt. CK 68F 1/ LGH
Urine – E. coli NDM-1 (CDC
Confirmed) x 2
Undermined acquisition
LGH - Seen in ER and admitted
Risk factors: close relative
Recent Travel to Asia/Canada
At LTACH at same time
PFGE Results
Pt. MR. 88F 3/ LGH
Urine – E. coli NDM (CDC
Confirmed)
Present on admission to LGH
Risk factors: multiple AB for frequent UTIs, recent nursing home stay (G), Dementia
Pt. FR. 85M 4/ Nursing Home
Rectal swab – E. coli NDM (CDC Confirmed)
Risk factors: Ventilator dependent, roommate to Pt. KK at nursing home B, multiple MDRs
= highly related
= pending
Follow-up Actions
Each case reported to CCPH and IDPH by LGH Infection Prevention
Communicated to LGH and Advocate Senior leadership
Education provided to physicians and associates
There are no relationships among these cases with locations and time at LGH
CCDP and IDPH conducting active surveillance of CRE in LTACH and 2 Nursing Homes
LTACH screen 25% KPC+
Active surveillance for CRE on LGH Rehab Unit negative
Beginning 4/29 all admits to LGH Rehab Unit will be screened for CRE
~20% KPC+
55% P. aeruginosa carbapenem resistant
Pt. KK. 73M 3/ LGH
Sputum - E. coli NDM-1 (CDC Confirmed)
Present on admission to LGH
Risk factors: ventilator dependent , feeding tube, LTACH and Nursing home stays
Pt. expired 3/28/13

54. National Resistance Alert 3 ADDENDUM Carbapenemase-producing Enterobacteriaceae in the UK: NDM (New Delhi Metallo-) β-lactamase: repeated importation from Indian subcontinent
Numbers of carbapenemase-producing Enterobacteriaceae continue to increase sharply
Many recently referred carbapenemase producers have NDM (New Delhi Metallo)-β-lactamase
Most producers are resistant to ALL antibiotics except polymyxins and tigecycline and may pose a serious treatment challenge in severe infections
· Vigilance and good infection control are essential to minimize transmission and accumulation in the UK
NDM-1 +
E. coli
K. pneumoniae
K. oxytoca
Enterobacter spp.
Proteus spp.
C. freundii
M. morganii
Providencia spp.
Medical
Tourism
Detection of Enterobacteriaceae Isolates Carrying Metallo-Beta-Lactamase — United States, 2010 – MMWR. June 25, 2010

55. Metallo β-Lactamases, Next Wave
NDM, Current Wave
IMP = imipenem hydrolyzing metallo β-lactamase
NDM = New Delhi Metallo carbapenemase
VIM = Verona Integron-encoded Metallo-β-lactamase
Emerging Infectious Disease, Oct. 2011

56. The Carbapenemase Threat Class D - Oxacillin hydrolyzing β-lactamase
First identified in Turkey in 2003,
Originated from Shewanella spp.
Confers resistance or reduced susceptibility to carbapenems and penicillin-inhibitor combinations, but producers only show slight resistance to oxyiminocephalosporins (Ceftriaxone, Ceftazidime) unless they have co-resident mechanisms such as ESBLs or AmpC.
High-level resistance to both piperacillin-tazobactam and temocillin may be useful indicators of OXA-48 production in enterobacteriae
Found in Acinetobacter baumanii, Pseudomonas aeruginosa, and Enterobacteriaceae.
Not confirmed in Midwest???

57. Oxa-48
EID,
Oct. 2011

58. Why Care About Mechanisms of Resistance?
Carbapenemases
Chromosomal Vs. plasmid based
Chromosomal – Not an Infection Control Emergency
SME, NMC
See more with lower carbapenem breakpoints
Plasmid – Infection Control Emergency!
KPC, NDM, GES, VIM, Oxa-48
Need to isolate all patients??
A commercially available, standardized, and reproducible amplified molecular assay will make CRE detection/identification faster, more sensitive, and consistent

59. Nanosphere - Gram Negative Blood Culture ID
Pathogens detected
Escherichia coli/Shigella spp., Klebsiella pneumonaie, Klebsiella oxytoca, Serratia marcescens, Pseudomonas aeruginosa, Citrobacter spp., Enterobacter Spp., Proteus spp., Acinetobacter spp.
Resistance genes
KPC
NDM
CTX-M
VIM
IMP
Oxa-48

60. In Summary Clinical Cases Asymptomatic Carriage
New resistance mechanisms, new challenges
Lines blurring between HAI and community acquired infections
MRSA, CREs, ESBLs, etc.
ESBLs are not just HAI’s anymore
Team approach absolutely required
Lab, Pharmacy, and ICPs
Antibiotic stewardship
Lab needs to be more responsive and less conservative
Do you need to double check your results prior to reporting?
Patient to patient transmission can be limited by strict infection control measures
Laboratory identification of infection or carriage must be paired with rapid implementation of infection control measures
Group effort required
Screening – who pays?
Ongoing surveillance is essential
Surveillance must include extended care facilities and cooperation between healthcare systems
Moving target
Rapid detection and reporting essential
Asymptomatic
Carriage