Clostridium difficile infection (CDI)- what’s new in diagnosis and treatment; target of antibiotic

stewardship• Changing strains; selection for

more virulent strains, aging population = higher cost for health care.

• The cause of transmissible nosocomial diarrhea, due 99% to antibiotic induction

• Changingepidemiology…• ~700,000 cases in USA/year,

+30000 in Canada, Ontario Today

• Worldwide, ? Asia?

Thomas J. Louie, MD, FRCPCMedical Director, IP&C, Calgary Health Region; Professor of Medicine, Dept. Medicine and Microbiology, Univ. of Calgary

Disclosures. Tom Louie, Dept.Medicine and Microbiology-Immunol-Infect Dis, Univ Calgary

Investigator for Cubist [CB 183,315], Actelion [Cadazolid], Optimer [Fidaxomicin]. Advisory panels: MicrobEX [fecal transplant], Merck: Monoclonal Antibodies; Pfizer [vaccines].

C. difficile infection.. update

• Local epidemiology• National epidemiology• Strain type 027 is

important, we are not up to speed.

• Current therapy: metro and vanco: strengths and weaknesses

• testing

• What is the microbiome? And C. difficile as the arch type model of disturbed microbiome.

• Narrow agents: better but need formulary decision for Alberta

• Infection control bundle for C.difficile infection.

Emergence of multiple C. difficile infection (CDI)treatment modalities

CDI

“standard antibiotics”• metronidazole• vancomycin• [bacitracin,

teichoplanin, fucidin]• nitazoxanide

“ narrow spectrum antimicrobials”

• Fidaxomicin (OPT-80)• Rifaximin• CB-183,315 (Cubist)• Cadazolid (Actelion)

Passive AB• humanized mouse

monoclonal AB. Merck, phase 3

NEJM Jan.2010

Vaccines to induce antibodies to toxins• Sanofi-Aventis

Probiotics• Non-toxigenic C. difficile• Lactobacillus

Bifidobacterium• S. boulardii

Prebiotics

Fecal Microbiome Transplantation

Clostridium difficile counts of 106-8 CFU/ml diarrheal effluent. Spores 1/104 to 1/10

C. difficile cytotoxin B titers 0-32,000-1 mean 2000-1

Clostridium difficile counts of 106-8 CFU/ml diarrheal effluent. Spores 1/104 to 1/10

C. difficile cytotoxin B titers 0-32,000-1 mean 2000-1

Death within 30 days: 1.5% 1999 6% 2008

Toxic Megacolon

Colitis Pseudomembranous Colitis

Fever, Leucocytosis

Creatinine , Albumin

Diarrhea : mean 8 movements/day range (4-15) in clinical trials

Canadian Nosocomial Infection Surveillance Program. Health Canada and hospitals across Canada. Surveillance of CDI rates per 1,000 admissions. 2011. Mark Miller et al

C.Difficile incidence by AGE. AHRQ HCUP data 2009

13%

52%46%

10%

39%

48%

57%

NAP 1/ ribo027/rea:BI strains from trials “07-‘08

Gerding, icaac 2009

2010, 50% NAP1 in west Canada

3 fold increase of CDI rates in USA over decade

Our plan in AB: CDI bundle

• 1600 primary cases/year• 400 est recurrent disease

in hospital, causing multiple encounters with health care

• 400-800cases in the community, not HA or HCA

• 5% death rate, 30 day mortality 2012

• Better diagnositics• Better infection control

environmental sanitation,HH, isolation

• Rate/disease/outcomes• Medical control: better

primary therapies,• Arrest recurrent

disease,UA/UC N/S clinic• Save on est. 30-40M

budgetary impact on AHS

Ribotype 027/NAP1/BI strain type: importance

• Quinolone resistant• Hypertoxin producer• Hyper spore producer• Cause of death rate

increase from 1.5% to 5-15% over last 10 yrs

• Hyper-spreader? Dominates in hospitals; 80% of strains ONT,PQ

• 2 clades antibiotic resistant clades developed in PQ and pittsburgh circa 2002, spread UK,Europe,Au based on SNP analysis of 400 strains [Nature Genetics, in press]

• 10% less response, doubles recurrence rate

Pathogenesis

Antibiotic therapy

Altered colonic flora (loss of colonization resistance)

C. difficile exposure and colonization

Toxin production

Protective immune response No protective immune response

Asymptomatic carriage Diarrhea and colitis

(Adapted from Kyne GI Clinics N. Am 2001)

C. difficile Pathogenicity Locus (PaLoc)

tcdA codes for toxin A tcdB toxin B tcdC negative regulator of toxin productiontcdD positive regulator of toxin production (Geric J Clin Microbiol 2003)

Toxin A & B protein structure

Toxins A & B are monoglucosyl transferases that target Rho GTPases Toxin A = 308 kDa Toxin B = 270 kDa 50% amino acid homology

Toxin production varies with culture conditions/nutrients Clinical isolates typically produce < 200 ng/mL (McFarland Inf & Immunity 1991)

25% of C. difficile isolates are toxin A-/B- (Fekety JAMA 1993)

Enzyme Immuno assay

[EIA]

C.difficile common antigen

[Glutamic Dehydrogenase = “GDH”] plus EIA

GDH followed by PCR for cytotoxin B gene [gene

xpert]

PCR every sample for cytotoxin B gene [gene

Xpert]

Sensitivity(n=72) 58.3% 83.1% 86.1% 94.4%

Specificity(n=360) 94.7% 96.7% 97.8% 96.3%

Tests for C.difficile infection using toxigenic culture i.e growth of C.difficile and proof bug makes toxin as gold standard. J.Clin Micro 2010. 48: 889-93, Novak-Weekley et al.

Points on C.difficile testing.

• Specificity is good for all tests, but EIA used in most places lacks sensitivity, more in 70% range. If negative repeat. Switch over to PCR should be coming. Endoscopy, special requests for PCR should be established.

• Often, patients on metro or vanco become test negative for varying durations; test before you treat.

• Do not ask for test for cure. They still have the bug 80% of the time [more likely all the time]

Treatment of C.difficile infectionMild -moderate severe disease: [4-10 diarrheal bowel motions (BM)/day, no fever, leucocytosis or abdominal pain]

Metronidazole 500 mg TID for 10-14 days [ not approved by US Food and Drug Administration]

Severe disease Unresponsive to metronidazole, fever, leucocytosis, abdominal pain, hypoalbuminemia elevated serum creatinine

Vancomycin 125 mg QID for 10-14 days [250-500 mg QID x 10-14 days occasionally required for some patients][vancomycin tapering dosage for recurrent disease]

Mild, moderate and severe disease Fidaxomicin 200 mg BID x 10 days

Comparison of metronidazole vs vancomycin in 2 trials [Genzyme 301 and 302) S.Johnson et al, IDSA, San Diego, Oct 19, 2012

81.1%

210/259

Vanco

% Response

to treatment

Recurrence of CDI as a function of age category, Metronidazole vs Vancomycin

% r

ecu

rren

ce b

y d

ay 4

0

Johnson et al, IDSA, Oct 19, 2012

121 130

Increasing risk of recurrence of CDI after repeated recurrences; by -product of dependence on vancomycin

McFarland et al, ICHE 1999; 20: 43, Gerding, Curr Top Microbiol Immunol 2000; 250: 127Louie, 2011 NEJM Feb 3.Kuijper 2011, personal communication

Serial damage to microbiome? VS increased adherence/persistence, biofilm?

Impact of Metro, Vanco treatment of CDI

Metronidazole C. difficile effect : 106-7 103-4 /g @ 10d Suspected/expected

damage to normal microbiota

VRE selection, less well quantified

Spores, low numbers, persist

~ 7-8 ug/ml peak, via serum. MIC=0.5 (up to 2-4 for ribotype 027).

Vancomycin C. difficile effect: 106-7 <102 /g @ 10d Proven damage to normal

microbiota by 2-4 log10 CFU/g

VRE very strong selection Spores, low numbers persist High gut concentrations

600-1000 ug/ml fecal filtrate, MIC =2

Advancing the concept of ‘sustained response’ for chemotherapy of CDI

2 major endpoints for CDI therapy: resolution of diarrheal illness & absence of recurrent disease = “sustained response”, “global cure”

treatment cure recurrence Sustained response

Vancomycin (003)

88% (485/563) 24% 64%

Metronidazole (Genzyme)

72% (103/143) 20% 52%

Tolevamer (Genzyme)

47% ( 124/266) 4% 43%

Quantitative C.difficile CFUs in patients randomized to Vanco, Metro or Tolevamer, Genzyme 301 (n=43)

Louie TJ , 48th ICAAC/46th IDSA. October 2008; Washington, DC. Abstract K-520.

0

1

2

3

4

5

6

7

8

Day 0 Day 4 Day 10 Day 14 Day 21 Day 28 Day 42

log1

0 CF

U/g

Wet

Wt F

eces

Van Mtz Tol

P=0.04 V vs T, day 42,

P= 0.028V vs M

P=0.0001V or M vs T

Clindamycin deodorizes stool

Fast findings about gut normal flora• ~ 1000 species • 1/3 cultivable• ½ are live, 20% injured,

30% dead• C. coccoides, C. leptum,

Bacteroides groups most numerous, old folks have less

• Host genetics govern make up, likely every person has a unique microbial composition

• genetically linked persons have more similar flora [spouses are different]

• Few data about which microbes might confer colonization resistance against C. difficile

• Diagnosis of C.diff with stools, yet disease is mucosal

Bacteroidetes predominate on the mucosal surface.

Firmacutes (major groupings: Clostridium coccoides and Clostridium leptum)

Ecklund, Bernstein, Relman. Science 2005.

Multiple colonic biopsies and feces examined by 16S rRNA sequencing of 3 patients.

1011 /g

HEALTHY CONTROLS

CLOSTRIDIUM DIFFICILE INFECTIONC. difficile

Proteobacter coliforms

CDI occurs in association with a • 10-1 to -3 CFU/g reduction of Firmacutes• 10-2 to -6 reduction of Bacteroidetes• 102 to 3 increase in coliforms

Antibiotic, C.difficile spore

Clinical predictors of recurrent CDI based on 999 patients, 794 pts with recurrence, in 2 recent RCTs

variable comparison OR P-value

Age category > 65 years / < 65 1.34 0.048

Concomitant antibiotic exposure

Yes / No 1.46 0.130

Strain type 027 vs non-027 1.61 0.036

Renal insufficiency Yes / No 1.34 0.020

Treatment group Fidaxo vs Vanco 0.41 <0.001

33

Fidaxomicin (OPT-80)New Class of Antibacterial

- New class for CDI: Macrocyclic antibiotic- Targets bacterial RNA polymerase - No cross resistance with known antibacterials- Evidence of low rate of C. difficile resistance development

Potent compound against C. difficile, including BI (NAP1/027)- MIC90 vs. C. difficile, 0.125 µg/mL- Bactericidal activity against C. difficile - Long post-antibiotic affect (>24h)

Narrower spectrum (?)- No activity vs. Gram-- Moderate vs. some Gram+

Low systemic absorption- ng/mL plasma concentrations- High fecal concentrations

>10,000 x the MIC90

HO Cl

OH

Cl

O

O

O

OHH3COO

O

OH

HO

O

O O

O

O

OH

HO

2011; 364: 422-31

Lancet Infectious Disease 2012; 12 (4) 281-289.

O

OHHO

O

O

OH

O

O

OO

HO

HO Cl

OH

Cl

O

OO

OHH3CO

OPT-80 50 mg bid

0

2

4

6

8

10

Day 0 Day 10

Log1

0 C

FU/ g

m

OPT-80 100 mg bid

0

2

4

6

8

10

Day 0 Day 10

Lo

g 1

0 C

FU

/ g

m

OPT-80 200 mg bid

0

2

4

6

8

10

12

Day 0 Day 10

Lo

g 1

0 C

FU

/gm

Vanco 125 mg QID

0

2

4

6

8

10

Day 0 Day 10

Lo

g10

CF

U/g

m

Quantitative reduction of C. difficile counts in the OPT-80 phase 2A study. Louie et al, AAC 2009

0

1

2

3

4

5

6

7

8

9

50 mg bid 100 mg bid 200 mg bid vancomycin

Mean Counts of B. fragilis grp Day 0Day 10

OPT-80 treatment

Log 10 CFU/gm Bacteroides group organisms by increasing doses of OPT-80 BID or vancomycin 125 mg qid; Phase 2a study (Louie, AAC Jan’09) [ recurrence: 2/41 ]

Response: 12/14 13/15 16/16

Results of FISH/FLOW study of OPT-80 or Vancomycin treatment of CDI, Phase 2, Tannock et al. Microbiology 2010

Cure of CDI by Fidaxomicin or Vancomycin, Two DB-RCTs, involving 999 per protocol patients

Fidaxomicin(200 mg bid)

Oral Vancomycin(125 mg qid)

003 (NA) study92.1%

(244/265)89.8%

(254/283)

004 (Int’l) study91.7%

(198/216)90.6%

(213/235)

Per Protocol: Patient group with CDI confirmed by diarrhea with a positive toxin assay, protocol compliant, and received at least 3 days of therapy if failure and at least 8 days of therapy for cure

NEJM 2011; 364: 422-31 (Feb 3, 2011) and Lancet Infect Dis 2012; 12 (4) : 281-89 (April 4, 2012).

Recurrence within 4 weeks post treatmentFidaxomicin had a 47% lower recurrence rate

Fidaxomicin(200 mg bid)

Vancomycin(125 mg qid)

P value(95% CI)

003 (NA) study 13.3%(28/211)

24.0%(53/221)

0.004(–17.9, –3.3)

004 (Int’l) study 12.8%(23/180)

25.3%(46/182)

0.002(-20.3, -4.4)

Louie T et al. Presented at: 19th ECCMID. May 17, 2009; Helsinki, Finland. Abstract.Miller M et al. Gastroenterology. 2009;136 (Suppl 1):Abstract 751a.

Golan Y et al. Presented at: 49th ICAAC. Sept. 14, 2009; San Francisco, CA. Abstract L1-1639.Crook, D et al, LB2401, ECCMID 2010, Vienna, Austria, April 2010

Time to Recurrence (003 trial)

Louie T et al. Presented at: 19th ECCMID. May 17, 2009; Helsinki, Finland. Abstract.Miller M et al. Gastroenterology. 2009;136 (Suppl 1):Abstract 751a.

Golan Y et al. Presented at: 49th ICAAC. Sept. 14, 2009; San Francisco, CA. Abstract L1-1639.

Number of Days From Treatment Completion0 5 10 15 20 25 30 35 40

Prop

ortio

n of

Pati

ents

With

out R

ecur

renc

e

1.0

0.9

0.8

0.7

VancomycinFidaxomicin

Log rank: P value <0.01Generalized Wilcoxon: P value <0.01

Vancomycin Fidaxomicinn=221 n=211

Recurrence within 10d 30/221 (14%) 7/211 (3%)Recurrence within 20d 45/221 (20%) 18/211 (9%)

2.00

3.00

4.00

5.00

6.00

7.00

8.00

9.00

10.00

11.00

12.00

0 4 10 14 21 28 42

Log C

FU

Day

Bacteroides CFU's over 7 time points in 10 patients on Vancomycin

001-005

001-019

001-011

001-048

001-052

001-004

001-033

001-031

001-044

001-062

Day 42 Mean

Day 42 Vanco Mean

Day 42 Fidaxomicin Mean

Normal Control Mean (N=10)

2.00

3.00

4.00

5.00

6.00

7.00

8.00

9.00

10.00

11.00

12.00

0 4 10 14 21 28 42

Log C

FU

Day

Bacteroides CFU's over 7 time points in 10 patients on Fidaxomicin

001-008

001-088

001-010

001-030

001-017

001-012

001-037

001-022

001-042

001-024

Day 42 Mean

Day 42 Vanco Mean

Day 42 Fidaxomicin Mean

Normal Control Mean (N=10)

qPCR:Vancomycin kills major components of the normal flora thought to prevent

C. difficile disease. CID 2012

Vanco

Fidaxo

2.00

3.00

4.00

5.00

6.00

7.00

8.00

9.00

10.00

11.00

0 4 10 14 21 28 42

Log C

FU

Day

C.coccoides group CFU's over 7 time points in 10 patients on Vancomycin

001-005

001-019

001-011

001-048

001-052

001-004

001-033

001-031

001-044

001-062

Day 42 Mean

Day 42 Vanco Mean

Day 42 Fidaxomicin Mean

Normal Control Mean

2.00

3.00

4.00

5.00

6.00

7.00

8.00

9.00

10.00

0 4 10 14 21 28 42

Log C

FU

Day

C.coccoides group CFU's over 7 time points in 10 patients on Fidaxomicin

001-008

001-088

001-010

001-030

001-017

001-012

001-037

001-022

001-042

001-024

Day 42 Mean

Day 42 Vanco Mean

Day 42 Fidaxomicin Mean

Normal Control Mean

Vanco

Fidaxo

0.00

1.00

2.00

3.00

4.00

5.00

6.00

7.00

8.00

9.00

10.00

0 4 10 14 21 28 42

Log C

FU

Day

C.leptum group CFU's over 7 time points in 10 patients on Vancomycin

001-005

001-019

001-011

001-048

001-052

001-004

001-033

001-031

001-044

001-062

Day 42 Mean

Day 42 Vanco Mean

Day 42 Fidaxomicin Mean

Normal Control Mean

0.00

1.00

2.00

3.00

4.00

5.00

6.00

7.00

8.00

9.00

0 4 10 14 21 28 42

Log C

FU

Day

C.leptum group CFU's over 7 time points in 10 patients on Fidaxomicin

001-008

001-088

001-010

001-030

001-017

001-012

001-037

001-022

001-042

001-024

Day 42 Mean

Day 42 Vanco Mean

Day 42 Fidaxomicin Mean

Normal Control Mean

Vanco

Fidaxo

2.00

3.00

4.00

5.00

6.00

7.00

8.00

9.00

10.00

11.00

0 4 10 14 21 28 42

Log C

FU

Day

Prevotella CFU's over 7 time points in 10 patients on Vancomycin

001-005

001-019

001-011

001-048

001-052

001-004

001-033

001-031

001-044

001-062

Day 42 Mean

Day 42 Vanco Mean

Day 42 Fidaxomicin Mean

Normal Control Mean

2.00

3.00

4.00

5.00

6.00

7.00

8.00

9.00

10.00

11.00

0 4 10 14 21 28 42

Log C

FU

Day

Prevotella CFU's over 7 time points in 10 patients on Fidaxomicin

001-008

001-088

001-010

001-030

001-017

001-012

001-037

001-022

001-042

001-024

Day 42 Mean

Day 42 Vanco Mean

Day 42 Fidaxomicin Mean

Normal Control Mean

Vanco

Fidaxo

Day 0

T. Louie, ECCMID 2010, Vienna, Austria April 2010, IDSA Vancouver Oct 2010 and in press, Clin Infect Dis April 2012.

10

9

8

7

6

5

4

3

2

1

0Day 10 Day 14 Day 21 Day 28

FDX VAN

P=0.0001 0.0001 0.03 0.04

Bacteroides/Prevotella group

Day 0

10

8

6

4

2

0Day 10 Day 14 Day 21 Day 28

P=0.001 P<0.03

C. coccoides group

Day 0

7

5

3210

Day 10 Day 14 Day 21 Day 28

P<0.03

C. leptum group

6

4

Log10 CFU/gm Feces of Major Cultivable and Noncultivable Genera of the Normal Fecal Microbiota; n=20

(Fidaxomicin phase 3 [003] protocol)

Vancomycin vs Fidaxomicin: C. Difficile colony forming units (CFU) and [toxin] in 89 pts at FMC

Day 0 Day 4 Day 10

Day 14

Day 21

Day 28

Day 42

log 10 CFU/g + SD

Van 6.2 + 2.6

2.2 + 0.9

2.0 + 0.0

3.1 + 2.2

4.4 + 2.6

3.9 + 2.2

4.5 + 2.4

Fdx 5.8

+ 2.8

2.1

+ 0.9

2.6 + 3.1

2.8 + 3.1

4.4

+ 2.4

3.8

+2.1

3.1

+2.0

Toxin B titer + SEM(pos/total)

Van 2800+1250

neg neg 7/30 15/30 3/22 1/12

(26/94) 1260 + 350

Fdx 2250+600

neg neg 1/23 6/27 5/20 1/21

(13/91) 2400 + 1400 , one value 16,000

Treatment period

No difference in C. diff effect, toxin re-expression halved, recurrence 10 Vanco vs 5 Fidaxomicin

Ribotype 027/ NAP1/BI: 10% reduced response and higher recurrence.

Strain type

vancomycin fidaxomicin

cure BI/NAP1 84.7% (61/72) 86.2% (56/65)

Other 94.4% (119/126) 96.6% (115/119)

recurrence BI/NAP1 23.6% (13/55) 24.4% (11/45)

Other 25.5% (27/106) 7.8% (8/103)

Lawley et al, Plos Pathogens, October 2012. Ribotype 027 persists post infection in C57BL mice, whereas ribotype 012 [630], and 017 [toxAneg] clear spontaneously. 027 is a special strain type. All strains were clindamycin R/ermB pos.

Bacte

roide

s

Prevo

tella

C.coc

coide

s

C.lept

um

Lact

obac

illus

Enter

ococ

cus/

Lact

o

Bifidob

acte

rium

Veillon

ella

Enter

obac

teria

ceae

Desulf

ovibr

io

C.diff

icile

0.00

1.00

2.00

3.00

4.00

5.00

6.00

7.00

8.00

9.00

10.00GC, 46yo Female: Fecal Transplant Gut Microflora Profile

Pre

Post

Donor

LO

G (

CF

U/g

wet

sto

ol)

Comparison of microbial group changes pre- and post fecal microflora transplantation, by enema. Fecal transplantation appears better accepted today. IDSA and AmerGastroenterolAssociation working group 2012.

Bacte

roide

s

Prevo

tella

C.coc

coide

s

C.lept

um

Lact

obac

illus

Enter

ococ

cus/

Lact

o

Bifidob

acte

rium

Veillon

ella

Enter

obac

teria

ceae

Desulf

ovibr

io

C.diff

icile

0.00

1.00

2.00

3.00

4.00

5.00

6.00

7.00

8.00

9.00

10.00BL, 83yo Female: Oral Transplant Gut Microflora Profile

Pre

Post 5 days

Post 1 week

Post 1 month

Donor

Group

LOG

(CFU

/g w

et st

ool)

This patient failed enema x2 and was successfully treated with concentrated fecal microbes by serial high speed centrifugation; 5 cc daily x 4 consecutive days.

Microbe groups that appear to restore colonization resistance against recurrent C.

difficile infection: analysis of 25 patient-donor pairs by qPCR (T. Louie, unpublished).

• Bacteroidetes• Prevotella spp.• Firmacutes : C. coccoides and C. leptum groups• Bifidobacteria spp• Desulfovibrio spp

Achieved by FMT or by narrower spectrum therapy

My parting shots on CDI

• Stop excess antibiotic use• Culprits selecting for C

diff: cephs, quinolones.• Only SXT,

aminoglycosides, aztreonam ‘safe’

• Monitor daily..can turn on you toxic megacolon

• Colonization by week 3 is 20%, 30% by week 4.

• Allow up to a week for response, but if worsens change therapy

• C.diff clinic North/South being entertained

• Reduce recurrent disease will reduce hospital transmission. We need to be like the netherlands, rates 0.4/10000 pt days.

• Hands!!!

• Interplay of host, gut microbiota, pathogen & therapeutics• How damaged is the normal gut flora in CDI patients?• What do metro & vanco do to C. diff and to normal flora? • Which microbial groups break the cycle of CDI recurrence?

Lessons learned from antimicrobial agent effects during treatment of CDI and from fecal microbiota transplantation*

* The ultimate probiotic?

Some departing concepts today:

…then you don’t!

Wash your hands!

First you see them…

NOTE: The hand print on the left was touched to a sheep blood agar plate after performing patient care and before hand hygiene; the yellow spots are bacterial colonies. The hand print on the right was touched to a sheep blood agar plate after

patient care and after hand hygiene with chlorhexidine soap or alcohol-based hand rub.