Bacteriological Analysis and Antibiotic Sensitivity Patterns of Biliary Stent Cultures in Post op laparotomy patients in a tertiary care hospital of Peshawar. A cross sectional study

Abstract

Background: Biliary stenting is done in the management of obstructive biliary tract diseases. However, disruption of the sphincter of Oddi by stenting predisposes to bacterial colonization of bile and stents, increasing the risk of postoperative infectious complications. The presence of multidrug-resistant organisms further complicates antimicrobial management. Local data on the bacteriological profile and antibiotic sensitivity patterns of biliary stent cultures in post-operative laparotomy patients remain limited. Objectives: To identify the spectrum and frequency of bacterial isolates from biliary stent cultures in post-operative laparotomy patients, to determine their antibiotic sensitivity patterns, and to compare bacteriological profiles across different biliary pathologies. Results: Eighty patients were included, with a mean age of 54.2 ± 13.6 years. Bacterial growth was observed in 85% of biliary stent samples. Gram-negative organisms predominated (73.8%), with Escherichia coli (33.3%) and Klebsiella pneumoniae (21.4%) being the most common isolates, followed by Enterococcus spp. (19%). Malignant biliary obstruction was significantly associated with Enterococcus isolation (p = 0.03). Gram-negative isolates showed high sensitivity to colistin (92%), tigecycline (88%), and carbapenems (85%), while resistance to third-generation cephalosporins and fluoroquinolones was common. ESBL production was identified in 38% of Enterobacteriaceae, and vancomycin-resistant Enterococcus was detected in 12.5% of isolates. Postoperative infections occurred in 27.5% of patients and were significantly higher in culture-positive cases (p < 0.01). Conclusion: Biliary stent colonization is highly prevalent in post-operative laparotomy patients, with frequent multidrug-resistant organisms. Routine intraoperative culture and sensitivity testing can guide targeted antimicrobial therapy and may reduce postoperative infectious morbidity.