Bacterial flora in the bile: Clinical implications and sensitivity pattern from a tertiary care centre

Background: Though preoperative biliary drainage (PBD) has been suggested to be linked with increased perioperative morbidity it is still practiced commonly. We studied the association of PBD and positive biliary culture with surgical site infection and also analysed the common pathogens and their antibiotic sensitivity spectrum.

Methods: Prospectively maintained data of patients who underwent various pancreatobiliary surgeries from 2017 to 2019 was analysed. Patients whose intraoperative bile culture reports were available were included in the study. Various factors associated with surgical site infection (SSI), microbial spectrum of bile culture and their sensitivity pattern were analysed.

Results: Out of 68 patients whose bile culture report were available, PBD was done in 65% (n = 44). Among patients with infected bile (n = 51), biliary stent was present in 78.4% (n = 40). On univariate analysis, the factors associated with SSI were low albumin level (<3.5 mg%), long operative time (>6 h), duration of abdominal drain (>4 days), length of hospital stay, intraoperative bile spillage and infected bile. However, on multivariate analysis, only presence of drain for >4 days (p = 0.04) and positive bile culture (p = 0.02) was linked with increased risk of SSI. Most common organism isolated was E coli (73.2%), with 100% sensitivity to Colistin and Tigecycline shown by gram negative isolates.

Conclusion: Preoperative biliary stenting alone did not increase the risk of SSI, but the positive bile culture correlated with SSI irrespective of PBD. Most biliary pathogens were resistant to commonly used antibiotics and intraoperative bile culture will aid in providing appropriate antibiotic coverage.