[Anaerobes in biliary tract infection].

Area of Science:

• Microbiology
• Gastroenterology
• Surgical Infections

Context:

• Bile infection is a significant complication following biliary tract surgery and percutaneous transhepatic cholangiography (PTC).
• Hepatolithiasis and cholecystolithiasis present different risks and microbial profiles in bile.
• Biliary tract tumors are associated with sterile bile, unlike stone-related conditions.

Purpose:

• To investigate the prevalence and types of anaerobic and aerobic bacterial infections in bile from patients undergoing biliary procedures.
• To compare bacterial infection rates in hepatolithiasis versus cholecystolithiasis.
• To identify the most common bacterial species and determine the optimal antimicrobial treatment for anaerobic bile infections.

Summary:

• Bacteriological study of bile from 69 patients revealed high rates of anaerobic (74.0%) and aerobic (98.0%) infections in hepatolithiasis cases.
• Cholelithiasis showed lower infection rates (27.3% anaerobes, 36.4% aerobes), while biliary duct tumors had sterile bile.
• Bacteroides species were the most common anaerobes; mixed infections were universal. Bacterial infection was more frequent in pigmented calcium stones than cholesterol stones.
• Metronidazole is identified as the preferred treatment for anaerobic bile infections.

Impact:

• This research highlights the critical role of anaerobic bacteria in biliary tract infections, particularly in hepatolithiasis.
• Findings guide the selection of appropriate antibiotic therapy, emphasizing metronidazole for anaerobic coverage.
• The study underscores the association between stone composition and bacterial infection incidence, informing clinical management strategies.