Uncommon Occurrence of Methicillin-Resistant Staphylococcus aureus in a Biliary Sample

BACKGROUND: Acute cholecystitis is an acute inflammatory disease of the gall bladder that is rarely superimposed by bacterial infections and usually involves enteric bacteria. MRSA is commonly seen on skin, soft tissues, and nares, but MRSA has been rarely reported to cause cholecystitis, especially in the absence of bacteremia. We present here an uncommon case of acute acalculous cholecystitis caused by MRSA in the absence of bacteremia.
CASE REPORT: A 95-year-old man with several comorbidities, including a chronic indwelling Foley catheter, presented from a nursing home with right shoulder pain, diffuse abdominal pain, and low-grade fever. Physical examination was remarkable for tenderness with deep palpation in the right upper quadrant of the abdomen. Laboratory results showed leukocytosis. Blood cultures did not grow any organisms. Urine culture was positive for MRSA, which was thought to be due to chronic colonization. Imaging studies, including CT scan, ultrasound, and HIDA scan, revealed evidence of acute acalculous cholecystitis. A percutaneous cholecystostomy drain was placed. Bile culture grew MRSA. He was treated with Vancomycin and then Doxycycline, with clinical improvement.
CONCLUSIONS: Acute cholecystitis complicated with infection is usually caused by enteric organisms, and is very rarely caused by MRSA, usually in the setting of concurrent bacteremia. We present a very unique case of MRSA cholecystitis in the absence of bacteremia. This case also suggests that even though initial empiric antibiotic coverage is usually not tailored toward MRSA, suspicion should remain high in cases that are not clinically improving, and addition of anti-MRSA antibiotics should be considered.

Keywords: Acalculous Cholecystitis, Biliary Tract Diseases, Cholecystitis, Acute, Methicillin-resistant Staphylococcus aureus