Case study created by : Robert Patrick Fredal II

I C. Diff-iculty Ahead

PATIENT HISTORY

A 67 year old female presented to the hospital because of ongoing

watery diarrhea that occurred up to 7 times a day for the past five

days. Signs of dehydration were noted and she has also been

complaining of moderate to severe abdominal pain, fever, nausea,

and loss of appetite. Upon further investigation this patient was

treated with antibiotics a week prior due to a nosocomial urinary tract

infection acquired after her lengthy hospital stay for a broken hip.

LAB RESULTS

Because of the patients prior antibiotic history an anaerobic culture was added to

the routine stool culture

The anaerobically incubated media grew gram positive spore producing bacilli

Occult blood was detected in the specimen along with a small amount of pus

Upon microscopic examination many white blood cells were noted

A colonoscopy was performed and revealed areas of inflammation and pus along

with necrosis of the colon wall

www.gihealth.com

What is the possible diagnosis of this patient?

What organism could be causing this?

She was diagnosed with pseudomembranous colitis,

confirmatory tests were done and came up positive for

Clostridium difficile

Other pathogenic species of the Clostridium genus

include: C. botulinium (botulism) this organism produces an

active neurotoxin and can have CNS involvement such

as blurred vision

C. perfringens ( gas gangrene) cause of amputations in

diabetics

Clostridium tetani (tetanus) which causes painful muscle

spasms that can often lead to respiratory complications

Clostridium difficile: the basics

It is One of the most serious nosocomial infections

worldwide

Associated with antibiotic associated diarrhea

(20-30% of all cases)

can range from self limiting diarrhea and flu-

like symptoms to life-threatening colitis

It can be a small part of an adults normal gut flora

More than half a million people become ill a year

because of this organism

In recent years C. difficile has because more

frequent than ever before, more severe, and

even more difficult to treat

The most virulent strain (BI/NAP1/027) has

increased toxin production and drug resistance

http://www.vancocin-us.com/healthcareprofessionals/aboutcdifficile

Cultural characteristics

Gram positive bacilli

They can look club shaped with a bulge at

each end

Forms endospores

Strict anaerobe

Grows well on SBA at 37 degrees celcius

Colony morphology; Glossy, gray/white , circular

colonies with a rough edge, fluoresce green-

yellow under UV light, non-hemolytic, and a

characteristic farmyard smell

peritrichous flagella

http://lancastria.net/blog/new-drug-to-treat-c-diff.html

http://depts.washington.edu/molmicdx/mdx/tests/cdiff.shtml

Culture media

Cycloserine Cefoxitine Fructose Agar (CCFA)

Selective medium used for C. difficile

D-cycloserine and cefoxitine antibiotics are added to inhibit most other

organisms

Colonies appear large, flat, yellow , ground glass look , and a filamentous

edge can be observed

Spores are absent when grown on artificial media along with reduced

motility

Has a characteristic “Farmyard” smell

http://www.cdc.gov/media/dpk/2014/dpk-hai.html

Biochemical reactions

Non hemolytic

Sachharolytic

Indole negative

Lecithinase negative

Hydrolyzes Aesculin

http://haveyroo.blogspot.com/2009/07/clostridium-

difficile-or-c-diff.html

Identification

Cell cytotoxicity assays are considered the gold standard

test for detection of C. difficile toxin by observing the

cytopathic effects of the toxin in cell culture

Enzyme ImmunoAssays (EIA) and Enzyme-Linked

Immunosorbent Assay (ELISA) tests are available for use

and can detect toxins A and B

PCR is also now starting to be used

Clinical Significance

Antibiotic associated diarrhea

Colitis

Pseudomembranous colitis

Perforated colon

Inflammatory bowel disease

Paralytic ileus

Toxic mega colon

Sepsis

Death

Virulence factors

Enterotoxin (Toxin A)

Stimulates chemotaxis and induces cytokine production that leads to

hyper secretion of fluids from the bowel

Cytotoxin ( Toxin B)

Causes depolymerization of actin accompanied by loss of the cellular

cytoskeleton (cytopathic effect)

Binary toxin

It is unclear the role of this toxin but it may synergistically increase the

virulence of toxins A & B

Adhesion factor

Aids in binding to cells in the colon

Hyaluronidase ( produces hydrolytic activity)

Spore formation

Allows for the organism to remain viable under harsh conditions and for

long periods of time

Pathogenic Mechanisms

Antibiotics reduce normal flora which allows for C. diff to start

to multiply and begin to overtake the normal gut bacteria

Toxins are produced and cause degradation of the cell

cytoskeleton

This causes loss of cell shape and decreased adherence

to eachother

Fluid leaks occur which leads to the watery diarrhea

The toxins can also erode away the colon membrane and

in severe cases can cause bowel perforation

http://www.cdiff-support.co.uk/about.htm

Susceptibility testing

susceptible to metronidazole and vancomycin

resistant to clindamycin , fusidic acid, and fluoroquinolone

http://www.eurosurveillance.org/ViewArticle.aspx?ArticleId=19000

Treatment

First you should discontinue taking antibiotics that likely caused the

infection

Keep thoroughly hydrated

Normally oral metronidazole is given(DOC), but in more complicated

infections oral vancomycin is administered

Human micro biota transplants (poo transplant)

Repopulates the gut and suppresses the growth of C. diff

Probiotics

Surgery may be needed depending on the damage to the bowel (

colectomy)

Prevention and disease control

WASH YOUR HANDS with soap and

water

Alcohol-based hand cleansers do

not kill C.diff spores

Patient is isolated in a room that includes

an attached bathroom

Contact precautions

Cleansing with bleach to disinfect any

potentially contaminated surfaces

http://www.nanobugs.com/shop/sposters.html