Which microorganism is the most common cause of peritonitis in patients undergoing peritoneal dialysis?

• A. Candida albicans
• B. Pseudomonas aeruginosa
• C. Staphylococcus aureus
• D. Escherichia coli

Answer: (D)

Verified step by step guidance

1. Understand the clinical context: Peritonitis is an infection of the peritoneal cavity, which can occur in patients undergoing peritoneal dialysis due to contamination or introduction of microorganisms.
2. Identify common causative agents: The most frequent pathogens causing peritonitis in peritoneal dialysis patients are typically skin flora such as Staphylococcus aureus, gram-negative bacteria like Escherichia coli, and sometimes fungi like Candida albicans.
3. Consider the source of infection: Since peritoneal dialysis involves a catheter that passes through the skin, skin flora such as Staphylococcus aureus are common, but contamination from the gastrointestinal tract can introduce gram-negative bacteria such as Escherichia coli.
4. Review epidemiological data: Studies show that Escherichia coli is one of the most common gram-negative bacteria causing peritonitis in these patients, often due to translocation from the gut or contamination during dialysis exchanges.
5. Conclude that among the options given, Escherichia coli is the most common cause of peritonitis in patients undergoing peritoneal dialysis, as it is a frequent gram-negative pathogen associated with this condition.