Microbial Profile in Bile from Cholecystectomised Patients by Culture and Multiplex PCR

Objectives Bile in the biliary tract is normally sterile but presence of gallstones, ascending infection from duodenum or bacterial translocation from portal vein leads to microfloral colonization. Therefore, this study was aimed to evaluate the microbiological profile of bile for determination of the appropriate antimicrobials in cholecystectomised patients. Design This was a descriptive type of cross sectional study from July, 2013 to December, 2014 Setting In a tertiary medical college hospital, Dhaka, Bangladesh Participants This study included 246 patients irrespective of age and sex who underwent laparoscopic or open cholecystectomy for various indications in a tertiary hospital, Dhaka, Bangladesh. Primary and secondary outcome measures Similar secondary outcome as in protocol Methods The intraoperative bile samples were collected and cultured in Blood agar and MacConkey’s agar media aerobically in the laboratory of Microbiology Department, Dhaka Medical College. The isolates were then tested for antibiotic sensitivity pattern. To detect anaerobic bacteria ( Bacteroides fragilis, Clostridium perfringens and Fusobacterium nucleatum ), multiplex polymerase chain reaction (PCR) was used with specific primers. Results Out of 246 bile samples, organisms were identified in 69.51% cases where 48.37% were aerobic bacteria identified by culture and 21.14% were anaerobic bacteria identified by multiplex PCR. Escherichia coli (26.61%) were found predominantly followed by Staphylococcus aureus (19.35%), Citrobacter freundii (14.52%), Clostridium perfringens (13.82%), Pseudomonas spp. (11.29%), Salmonella enterica serovar Typhi 8 (3.45%), and Acinetobacter spp. (3.23%). Gram negative bacteria showed resistance to amoxiclav, ceftriaxone and ceftazidime while meropenem, piperacillin-tazobactam and colistin were found more effective antimicrobials. Conclusions A great proportion of aerobic and anaerobic bacterial infection associated with gallstones or biliary tract obstruction may warrants serious health risk to cholecystectomised patients in this region. Regular surveillance of bile culture from gallbladder should be done after cholecystectomy. Strength The antimicrobial susceptibility pattern of aerobic bacteria was assessed to find out multidrug resistant bacteria Multiplex PCR was done to detect important biliary anaerobic bacteria Limitations Isolation by culture and the antimicrobial susceptibility pattern of anaerobic bacteria was not assessed Due to lack of primers, PCR could not be done for other biliary anaerobic bacteria, virulence genes and drug resistance genes Source(s) of funding for work This research received no specific grant from any funding agency in the public, commercial or not-for-profit sectors. Competing interests None Conflict of interests None