A 52-year-old man on peritoneal dialysis for 4 years presents with cloudy dialysate effluent, abdominal pain, and fever. Cell count of effluent shows 220 WBC/microliter with 80% neutrophils. Which organism is MOST likely responsible?
- A Coagulase-negative staphylococcus ✓
- B Escherichia coli
- C Staphylococcus aureus
- D Candida albicans
Correct answer: A. Coagulase-negative staphylococcus
Explanation
Coagulase-negative staphylococcus (especially Staphylococcus epidermidis) is the most common organism causing peritonitis in peritoneal dialysis patients, typically from touch contamination during exchanges. Staphylococcus aureus is also common but usually relates to exit-site or tunnel infection. Gram-negative organisms and fungi are less common but should be considered if empiric therapy fails.
Reference: Brenner and Rector's The Kidney, 11th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
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