A patient who is not a healthcare worker is diagnosed with C. difficile pseudomembranous colitis. What most likely led to this infection?
a. The patient was recently treated with a bacteriostatic drug.
b. The patient was recently treated with a broad-spectrum drug.
c. The patient was treated with a bactericidal drug.
d. The patient recently became immune compromised and therefore had an increased risk for infection.
e. The patient was recently exposed to someone with an active C. difficile infection.

Verified step by step guidance

1. Step 1: Understand the nature of Clostridioides difficile (C. difficile) infection, which commonly occurs when the normal gut flora is disrupted, allowing C. difficile to overgrow and produce toxins causing pseudomembranous colitis.
2. Step 2: Recognize that broad-spectrum antibiotics can kill a wide range of bacteria, including beneficial gut microbiota, which normally suppress C. difficile growth.
3. Step 3: Analyze the options to identify which factor most likely disrupts normal gut flora, focusing on antibiotic use rather than immune status or direct exposure.
4. Step 4: Note that bacteriostatic and bactericidal drugs refer to the mechanism of killing or inhibiting bacteria, but the key issue is the spectrum of activity affecting gut flora balance.
5. Step 5: Conclude that recent treatment with a broad-spectrum antibiotic is the most common cause of C. difficile infection in patients who are not healthcare workers, as it disrupts normal intestinal microbiota and allows C. difficile to proliferate.

Key Concepts

Clostridioides difficile Infection and Pseudomembranous Colitis

C. difficile is a spore-forming bacterium that causes pseudomembranous colitis, an inflammation of the colon characterized by toxin-mediated damage. It often occurs after disruption of normal gut flora, leading to overgrowth of C. difficile and toxin production, which damages the intestinal lining.

Impact of Broad-Spectrum Antibiotics on Gut Microbiota

Broad-spectrum antibiotics kill a wide range of bacteria, including beneficial gut flora. This disruption reduces microbial competition, allowing opportunistic pathogens like C. difficile to proliferate and cause infection, especially after antibiotic treatment.

Difference Between Bacteriostatic and Bactericidal Drugs

Bacteriostatic drugs inhibit bacterial growth without killing bacteria, while bactericidal drugs kill bacteria directly. Both can affect gut flora, but the key factor in C. difficile infection is the broad-spectrum nature of the antibiotic rather than whether it is bacteriostatic or bactericidal.