Last updated on April 18, 2014 at 1:21 EDT

Clostridium difficile

Clostridium difficile, also known as “CDF/cdf”, or “C. diff”, is a Gram-positive bacteria of the genus Clostridium that causes severe diarrhea and other intestinal disease when competing bacteria in the gut flora are wiped out by antibiotics. They are anaerobic, spore-forming rods and is the most serious cause of antibiotic-associated diarrhea and potentially to pseudomembranous colitis.

C. difficile bacteria naturally resides in the gut of a small percentage of the adult population. Others can accidentally ingest spores while in a hospital, nursing home, or similar facility. When normal gut flora is destroyed in the colon C. difficile can overrun the gut. Overpopulation can cause bacteria to release toxins that cause bloating and diarrhea with abdominal pain. Infections from C. difficile are the most common cause of pseudomembranous colitis and can, in rare cases, can progress to toxic megacolon.

Symptoms often mimic flu-like symptoms and can mimic disease flare in patients with inflammatory bowel disease-associated colitis. Mild cases are cured by discontinuing the antibiotics responsible. Serious cases require metronidazole, and if that fails then vancomycin. C. difficile AAD relapses are reported in up to 20% of cases.

Significant diarrhea, antibiotic exposure, colitis, and fever have proven to be the best sign for clinical prediction. Most spores are resistant to routine cleaning methods used on surfaces. These spores can remain viable outside the human body for long periods of time. Very rigorous infection protocols are required in order to decrease or eliminate infection risk.

It can range in severity from asymptomatic to life-threatening. People are most often infected in hospitals, nursing homes, or other medical institutions. It is estimated that 13% of patients contract C. difficile when they stay for 2 weeks. Often diarrhea was associated with fluoroquinolones and the European Center for Disease Prevention and Control recommend that fluoroquinolones and the antibiotic clindamycin be avoided in clinical practice due to their high association with subsequent clostridium difficile infections.

Frequency and severity remains high and is associated with increased death rates. Delayed diagnosis and immunocompromised status result in elevated risk of death. Early intervention and aggressive management are key factors to recovery. In 2005 a highly toxic strain that was resistant to fluoroquinolone antibiotics was breaking out in North America. It’s possible that overuse of antibiotics in the raising of livestock has contributed to outbreaks.

Clostridia are ubiquitous in nature and are especially prevalent in soil. It appears as long, irregular shaped cells with a bulge at their terminal ends. The strains produce several toxins, the most well-characterized of those are enterotoxin and cytotoxin. Antibiotic treatment infections are difficult due to antibiotic resistance.

It is transmitted from person to person by fecal-oral route. Once ingested the bacteria pass through the stomach unscathed because of their acid-resistance. Then they germinate into vegetative cells in the colon. Bleach is effective in killing the organism. Sending in three samples is often needed to rule out the disease if initial tests are negative. If treatment is effective the toxin should clear from the stool of previously infected patients. Many hospitals test only for the prevalent toxin A although toxin B is now commonly tested for as well.

Preventing CDAD is most often done through proper antimicrobial prescribing. Approximately 50% of antimicrobial prescription is considered inappropriate. This number is consistent whether in the hospital, clinic, community, or academic setting. Britain tests patients over the age of 65 for C. difficile if they have diarrhea. Gloves, watching with soap, and bleach wipes are effective at limiting the spread of C. difficile.

Studies in treatments with oral supplements containing live bacteria have been done. A few studies have proven that there is no benefit of oral supplements of similar bacteria preventing CDAD. Immediate treatment is suggested in order to prevent sepsis or bowel perforation. Metronidazole, oral vancomycin, and linezolid are three antibiotics effective. Ramoplanin and fidaxomicin are newer drugs that are in clinical development. Often drugs used to treat diarrhea frequently worsen the course of C. difficile.

Clostridium difficile