Abstract
Micrococcus lylae, a Gram-positive bacterium of the Micrococcaceae family, is considered an opportunistic microorganism with only a few reported cases of infection. In this report, we present a case of cholangitis caused by Micrococcus lylae in a 69-year-old woman with a medical history of type 2 diabetes and a cholecystectomy performed a decade ago. She was admitted to the gastroenterology department with symptoms indicative of acute cholangitis. Abdominal computed tomography and endoscopic ultrasound showed a consistent and symmetrical dilatation and thickening of the main bile duct, containing micro stones and a macro stone in the cystic duct stump. The patient received empirical antibiotic therapy based on ceftriaxone and metronidazole. She underwent ERCP with biliary endoscopic sphincterotomy and marginal biopsy, followed by balloon-assisted manipulation to facilitate bile release and collection of an intraoperative bile fluid sample for microbiological examination to identify the pathogen and guide the treatment adjustments. The microbiological examination demonstrated the exclusive presence of Micrococcus lylae. The patient's condition notably improved, marked by the normalization of inflammatory indicators. After three days, the patient was discharged in a stable condition, continuing the antibiotic regimen with the oral administration of ciprofloxacin and metronidazole. Jaundice resolved after one week, and liver function tests were completely normalized on follow-up at one month.