What member of the human intestinal microbiota occasionally causes life-threatening disease?

Question

Quizplus · Accepted Answer

Clostridium difficile can sometimes overgrow and produce toxins that cause severe diarrhea, colon inflammation, and even life-threatening colitis. This bacterium is a member of the human intestinal microbiota, but it can cause harm under certain circumstances, such as prolonged antibiotic treatment or suppressed immune system. Escherichia coli O157:H7 and Salmonella enterica are also pathogenic bacteria that can cause serious foodborne infections, but they are not part of the normal gut microbiota. Giardia intestinalis is a protozoan parasite that can cause gastrointestinal illness, but it is not a bacterial member of the gut microbiota. Lactobacillus is a beneficial bacterium that can promote digestive health and prevent infections, but it is not known to cause any diseases in healthy individuals.

What Member of the Human Intestinal Microbiota Occasionally Causes Life-Threatening