Clostridium difficile

MORPHOLOGY:
  • Clostridium difficile is a species of Gram-positive, rod-shaped, spore-forming bacteria.
  • C. difficile are anaerobic—lives in the absence of oxygen.
  • In the presence of oxygen, the vegetative form of C. difficile can survive up to 24 hours on an inanimate surface; whereas, C. difficile spores can survive up to 2 years on inanimate surfaces that are exposed to oxygen
  • Inhabits the microflora of intestines of humans
  • Spores are subterminal
  • Ideal condition for growth is around 37ºC (98.6 ºF); this explains why the human body plays the perfect host for C. difficile.
  • C. difficile moves via peritrichous flagella.
  • Shows fecal-oral transmission
RISK FACTORS:
  • Prolong antibiotic therapy
  • Pantoprazole increases the risk
  • Associated with use of rectal thermometer
TEST FOR IDENTIFICATION:
  • The cytotoxin assay is the standard test for identification
  • A fresh stool sample is needed and no prep is required.
  • Other tests include endoscopy and anaerobic cultures.
SIGNS & SYMPTOMS:
  • Clostridium difficile causes pseudomembranous colitis
  • Watery diarrhea (at least three bowel movements per day for two or more days), fever, loss of appetite, nausea, abdominal pain/tenderness .
  • 3 unformed stools per 24h for 2days ,Toxin A or B detected in the stool, Pseudo membranes in colonoscopy There is also a disctinct odor when the feces contains Clostridium difficile.
  • May cause crohn's disease
  • More severe cases of Clostiridium difficile infection present with ulcerative colitis which can be severe enough to result in the need for a bowel resection.
  • Signs and symptoms of colitis can include the above list as well as dehydration and bloody stool.
VIRULENCE :
  • In addition to the two major toxins of Clostridium difficile-toxins A and B, which represent the major virulence factors a number of other putative virulence factors have been described.
  • These factors include fimbriae and the ability to associate with gut cells/mucus, the production of a capsule, the secretion of a range of hydrolytic enzymes, the production of other toxins (such as an actin-specific ADP-ribosyltransferase by some strains), and the controversial possibility of the production of a second enterotoxin .
CONTROL & TREATMENT:
  • The first step that should be taken once a diagnosis is made is to stop administering currently prescribed antibiotics to the patient.
  • In mild cases of Clostridium difficile infection, Metronidazole is administered.
  • In severe cases, treatment can begin with the administration of Vancomycin but can also require surgical intervention.
Exam Question
  • Clostridium difficile causes pseudomembranous colitis
  • Clostridium difficile is a Gram positive,obligate anaerobic, Spore-forming bacillus
  • Most common manifestation of clostridium difficile infection is Diarrhea
  • 3 unformed stools per 24h for 2days ,Toxin A or B detected in the stool, Pseudo membranes in colonoscopy are included in the diagnostic criteria for clostridium difficile infection
  • Clostridium difficile shows subterminal spores
  • Prolong antibiotic therapy ,Pantoprazole use & use of rectal thermometer are the risk factors for cl. difficile infection
  • Clostridium difficile is a normal commensal of gut
  • Clostridium difficile infection is treated by vancomycin & metronidazole
  • Features of Abdominal pain, diarrhea get cured on Taking metronidazol suggest infection by cl. difficile
  • Crohn's disease may be caused by cl. difficile
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