Unusual cholangitis Unusual bacterial cholangitis Unusual susceptibility to bacterial cholangitis Increased susceptibility to bacterial cholangitis, as manifested by recurrent or severe infection of the biliary tract, or by cholangitis occurring in an unusual clinical context such as absence of cholelithiasis or biliary obstruction. Principal causative agents include Escherichia coli, Klebsiella pneumoniae, and Enterococcus species. Unusual ascending cholangitis Recurrent bacterial cholangitis