Enterococcal bactibilia in patients with malignant biliary obstruction.

Biliary obstruction due to pancreaticobiliary malignancy is often accompanied by bactibilia. The aims of this study were to clarify the impact of preoperative antibiotic use on bile bacterial flora and to identify the bile bacteria responsible for postoperative septic complications in patients with malignant biliary obstruction. Eighty-four patients with malignant biliary obstruction underwent a biliary decompression procedure before definitive surgery. In 63 patients (75%), preoperative bile culture was positive, with nine species being detected. Only the incidence of enterococcal bactibilia increased after antibiotic use (P = 0.0009), with a 16% incidence before and 63% after antibiotic use. When analyzing the correlation between preoperative bile bacteria and postoperative complications, only the Enterococcus species was associated with the occurrence of complications (P = 0.037). In conclusion, bile bacterial flora changes after preoperative antibiotic use, with a significant increase in the incidence of enterococcal bactibilia. The Enterococcus species is most responsible for postoperative septic complications in patients with malignant biliary obstruction.