• For starters, we're only looking at aerobic bacteria with these plates.
• For certain, he's got some anaerobic bugs we're not growing.
• Perhaps a virus, but still we don't see bacteria, normal or otherwise.
• The obvious question is, in the absence of normal flora what's taken over?
• You've probably scoped this out. Clostridium difficile has repopulated his colon.
• He killed off everything with the broad spectrum antibiotic.
• The C. difficile spores survived and hatched out when the coast was clear.

• C. difficile is making two toxins that are causing the problem.
• The picture to the right shows the results of an assay for both toxins.

• Anaerobic, gram positive organism. Very difficult (difficile) to isolate.
• Normally present in a number of people, but in low numbers.
• Transmission occurs via spores.
• Broad spectrum antibiotics kill off normal flora, selecting for spore forming bugs.
• Exotoxins do the damage and cause the symptoms.
• Toxin A: enterotoxin causing fluid loss through the mucosa.
• Toxin B: cytotoxic to the colonic epithelium.
• In conjunction, these result in pseudomembranous colitis.

I sure hope there's more.                                                                                  Back