Antimicrobial agents	Community‐acquired biliary infection			HeaIthcare‐associated biliary infection
	Grade I Cholecystitis and cholangitis	Grade II Cholecystitis and cholangitis	Grade III Cholecystitis and cholangitis	Cholecystitis and cholangitis
Penicillin‐based therapy	Ampicillin/sulbactam	Piperacillin/tazobactam	Piperacillin/tazobactam	Piperacillin/tazobactam
Cephalosporin‐based therapy	Cefazolin, or cefuroxime, or ceftriaxone, or cefotaxime ± metronidazole, cefmetatole, cefoxitin flomoxef, cefoperazone/sulbactam	Ceftriaxone, or cefotaxime, or cefepime, or cefozopran, or ceftazidime, ± metronidazole, cefoperazone/sulbactam	Cefepime, or ceftazidime, or cefoperazon ± metronidazole	Cefepime, or ceftazidime, or cefoperazon ± metronidazole
Carbapenem‐based therapy	Ertapenem	Ertapenem	Imipenem/cilastatin, meropenem, doripenem, ertapenem	Imipenem/cilastatin, meropenem, doripenem, ertapenem
Monobactam‐based therapy	—	—	Aztreonam ± metronidazole	Aztreonam ± metronidazole
Fluoroquinolone‐based therapy	Ciprofloxacin, levofloxacin, pazufloxacin ± metronidazole, moxifloxacin	Ciprofloxacin, levofloxacin, pazufloxacin ± metronidazole, moxifloxacin	—	—