Bile cultures are poor predictors of antibiotic resistance in postoperative infections following pancreaticoduodenectomy

Relationship between Intraoperative Bile Culture Outcomes and Subsequent Postoperative Infectious Complications: A Retrospective Cohort Study

The presence of positive bile culture during intraoperative procedures has been associated with elevated morbidity and mortality rates in hepatobiliopancreatic surgeries, contributing to increased healthcare expenditures. However, the precise impact of bactobilia on the development of postoperative complications remains uncertain due to existing disparities in the published literature. In this retrospective cohort study, we assessed 137 patients who underwent major hepatobiliopancreatic surgery to examine the relationship between intraoperative bile culture outcomes and subsequent postoperative infectious complications. Among patients with bactobilia, a significant 35.1% exhibited systemic or local infectious complications, whereas only 11.1% of those with negative culture results experienced any infectious complications (p = 0.002). Similarly, a notable difference was observed in the incidence of surgical site infections, with 24.3% in the bactobilia group compared to 7.9% in the negative culture group (p = 0.01). A total of 74 monomicrobial cultures with microbiological growth were isolated, predominantly featuring Gram-negative microorganisms, primarily Enterobacteriaceae in 49 cultures. Escherichia coli was identified in 37.8% of positive cultures, while Klebsiella pneumoniae was evident in 21.6%. Gram-positive microorganisms were present in 10 cultures, with Enterococcus emerging as the prevailing species. The logistic regression model identified a positive bile culture as an independent factor significantly associated with infection development (OR: 2.26; 95% confidence interval: 1.23-11; p = 0.02). Considering the limitations of the study, these findings underscore the critical importance of conducting bile cultures during the intraoperative phase to enable vigilant monitoring and prompt management of infectious complications.

Association of cephalosporin resistance in intraoperative biliary cultures with surgical site infections in patients undergoing pancreaticoduodenectomy. A retrospective cohort study

BACKGROUND

The aim of this study was to assess the incidence of bacterobilia at the time of a pancreaticoduodenectomy (PD) and the association of resistant bacteria in bile to surgical site infections (SSI).

METHODS

This was a retrospective cohort study including patients undergoing PD in a single center between May 2016 and October 2020. Data of preoperative biliary drainage (PBD), intraoperative biliary cultures (IBC) and postoperative complications were analysed to assess the risk factors for resistant bacteria in IBC and SSIs.

RESULTS

Of 361 patients included, 254 (70%) had undergone PBD. Second-generation cephalosporin resistant bacteria were found in IBC of 183 (64%) of all the patients. PBD was the only risk factor for second-generation cephalosporin resistance. The risk for second-generation cephalosporin resistance was more than 20-fold in patients with PBD [n = 170/254 (67%) (OR 22.58 (95% CI, 9.61-53.01), p < 0.001)] compared to patients who did not have PBD (n = 13/107 (12%)). Also, if the time between PBD and surgery was 2 months or more the second-generation cephalosporin resistance in IBC increased the risk for SSIs (OR 4.14 (95% CI, 1.18-14.51), p = 0.027).

CONCLUSION

The second-generation cephalosporin resistance in IBC is common in patients who have undergone PBD. Broad-spectrum antibiotics in prophylaxis may be beneficial for these patients.

Extended antibiotic therapy is associated with a lower rate of clinically relevant postoperative pancreatic fistula after pancreatoduodenectomy in intermediate- and high-risk patients: A single-institution analysis

BACKGROUND

Clinically relevant postoperative pancreatic fistula remains a common complication after pancreatoduodenectomy. The fistula risk score is a validated tool to predict the risk of clinically relevant postoperative pancreatic fistula. To mitigate complications, we have implemented an extended antibiotic pathway for patients at increased risk of clinically relevant postoperative pancreatic fistula (fistula risk score ≥3). We report outcomes after pancreatoduodenectomy in patients at increased risk for clinically relevant postoperative pancreatic fistula who received extended antibiotic therapy compared to those who received standard perioperative antibiotics (single dose before incision).

METHODS

Single-institution analysis of 87 patients who underwent elective pancreatoduodenectomy (2018-2022) with soft gland texture and fistula risk score ≥3 and were treated with (n = 34) or without (n = 53) 10 days of broad-spectrum antibiotics (piperacillin/tazobactam converted to amoxicillin/clavulanic acid at discharge) after surgery. Associations between extended antibiotics and postoperative outcomes were analyzed.

RESULTS

Baseline clinicodemographic factors were similar between cohorts. Patients who received extended antibiotics had shorter index days (6 vs 8 days, P = .004) and 90-day composite length of stay (8.5 vs 12 days, P = .018). Patients who received extended antibiotics had lower rates of clinically relevant postoperative pancreatic fistula (11.8% vs 37.7%; odds ratio = 0.17, 95% confidence interval: 0.04-0.68), wound infections (8.8% vs 30.2%; odds ratio = 0.08, 95% confidence interval: 0.01-0.50), organ space infections (14.7% vs 43.4%; odds ratio = 0.15, 95% confidence interval: 0.04-0.52), and image-guided drain placement (8.8% vs 34.0%; odds ratio = 0.15, 95% confidence interval: 0.04-0.62). There were no Clostridium difficile infections in the extended antibiotic group.

CONCLUSION

Extended antibiotic therapy is associated with a lower rate of clinically relevant postoperative pancreatic fistula and associated complications after pancreatoduodenectomy in patients with a fistula risk score ≥3. These results form the basis of a randomized controlled trial (NCT05753735).

Tailored Pre-Operative Antibiotic Prophylaxis to Prevent Post-Operative Surgical Site Infections in General Surgery

The average American today undergoes three inpatient and two outpatient surgical procedures during one's life, each of which carries with it a risk of post-operative infection. It has long been known that post-operative infections cause significant morbidity in the immediate peri-operative period, but recent evidence suggests that they can have long-term consequences as well, increasing a patient's risk of infectious complications in unrelated surgeries performed months or even years later. While there are several theories on the origin of this association, including bacterial colonization of a post-operative infectious wound site, antimicrobial resistance from curative courses of antibiotics, subclinical immunosuppression, or the creation of an inflammatory "pathobiome" following an infectious insult, it is ultimately still unclear why patients who experience a single post-operative infection seem to be at a significantly higher risk of experiencing subsequent ones. Regardless, this association has significant implications for the routine use of pre-operative antibiotic prophylaxis. Indeed, while the prescription of antibiotics pre-operatively has dramatically reduced the rate of post-operative infections, the chosen prophylaxis regimens are typically standardized according to national guidelines, are facing increasing antimicrobial resistance patterns, and have been unable to reduce the risk of post-operative infection to acceptably low levels for certain surgeries. As a result, some clinicians have speculated that tailoring pre-operative antibiotic prophylaxis according to a patient's prior infectious and operative history could improve efficacy and further reduce the rate of post-operative infections. The purpose of this review is to describe the evidence for the link between multiple post-operative infections and explore the efficacy of individualized pre-operative prophylaxis.

Prolonged antibiotic prophylaxis after pancreatoduodenectomy: systematic review and meta-analysis

BACKGROUND

Previous studies have reported conflicting results of prolonged antibiotic prophylaxis on infectious complications after pancreatoduodenectomy. This study evaluated the effect of prolonged antibiotics on surgical-site infections (SSIs) after pancreatoduodenectomy.

METHODS

A systematic review and meta-analysis was undertaken of SSIs in patients with perioperative (within 24 h) versus prolonged antibiotic (over 24 h) prophylaxis after pancreatoduodenectomy. SSIs were classified as organ/space infections or superficial SSI within 30 days after surgery. ORs were calculated using a Mantel-Haenszel fixed-effect model.

RESULTS

Ten studies were included in the qualitative analysis, of which 8 reporting on 1170 patients were included in the quantitative analysis. The duration of prolonged antibiotic prophylaxis varied between 2 and 10 days after surgery. Four studies reporting on 782 patients showed comparable organ/space infection rates in patients receiving perioperative and prolonged antibiotics (OR 1.35, 95 per cent c.i. 0.94 to 1.93). However, among patients with preoperative biliary drainage (5 studies reporting on 577 patients), organ/space infection rates were lower with prolonged compared with perioperative antibiotics (OR 2.09, 1.43 to 3.07). Three studies (633 patients) demonstrated comparable superficial SSI rates between patients receiving perioperative versus prolonged prophylaxis (OR 1.54, 0.97 to 2.44), as well as in patients with preoperative biliary drainage in 4 studies reporting on 431 patients (OR 1.60, 0.89 to 2.88).

CONCLUSION

Prolonged antibiotic prophylaxis is associated with fewer organ/space infection in patients who undergo preoperative biliary drainage. However, the optimal duration of antibiotic prophylaxis after pancreatoduodenectomy remains to be determined and warrants confirmation in an RCT.

Clinico-epidemiological characteristics of the biliary samples and their antibiotic susceptibility pattern at a teaching hospital in Northern India

Introduction

Bile is deemed a sterile fluid, with the presence of clinical conditions like cholelithiasis, cholecystitis, previous biliary interventions, biliary strictures, and so on, leading to bile stasis, and increases the chances of bacteriobilia. In this study, we recognize the bacterial spectrum of microorganisms isolated from bile samples, diagnostic parameters, and antibiotic sensitivity patterns.

Methods

A retrospective observational study was carried out by compiling data from the hospital information system of a tertiary care center from 2021 to 2022 to evaluate biliary infections in patients who underwent surgical procedures related to the biliary tract and associated organs.

Results

A total of 234 patients' bile samples were included in our study. The mean age of patients was 48.04 ± 14.74 years, with more patients below the age of 65 years among those with infected bile samples. One hundred and sixty-three (163/234, 69.66%) patients infected by 209 pathogenic microorganisms were recognized. The most common microorganism isolated was Escherichia coli (83/209, 39.71%), followed by Pseudomonas aeruginosa (37/209, 17.7%). Acinetobacter baumannii and Klebsiella pneumoniae isolate owed to more than 90% penicillin, extended-spectrum beta-lactamase, carbapenem, and fluoroquinolone resistance among all isolates. Length of hospital stay, malignant obstruction, and chronic kidney disease were identified as statistically significant risk factors that lead to the isolation of multi-drug-resistant isolates from bile culture.

Conclusion

We recognized the spectrum of pathogens causing biliary tract infections at our center along with the antibiotic resistance pattern to guide and facilitate prompt and appropriate treatment by primary health care professionals and family medicine practitioners.

Multifactorial Analysis of Biliary Infection in Patients with Hepato-pancreatico-biliary and Associated Intraabdominal Malignancies Admitted to a Teaching Hospital in Northern India

Background

Blockage of the biliary tract is commonly caused by malignant tumors leading to deranged liver function, responsible for poor prognosis and a high rate of bacteriobilia leading to mortality.

Material and methods

We collected retrospective data from the hospital information system and laboratory registers in our department from 2021 to 2022 to evaluate biliary infections in patients with hepato-pancreatico-biliary and associated intraabdominal malignancies.

Result

A total of 118 (118/234, 50.43%) patients' bile samples were estimated in this study. Patients' average age was 53.02 ± 13.49 years, with more patients below the age of 65 years among those with infected bile samples. Eight patients were infected by 102 pathogenic microorganisms. The most common pathogenic microorganism responsible for biliary infection in patients with abdominal malignancies was Escherichia coli (38/102, 37.25%) followed by Klebsiella pneumoniae (21/102, 20.59%) and Enterococcus spp. (18/102, 17.65%). Underlying comorbidities like diabetes mellitus, hypothyroidism, hypoproteinemia, chronic liver disease, immunosuppression, chronic kidney disease, increased hospital stay, admission to the intensive care unit (ICU), and presence of percutaneous transhepatic biliary drain were statistically significant risk factors for isolation of multidrug-resistant pathogenic bacteria.

Conclusion

Our study guided physicians in identifying the associated demographic characteristics, risk factors, and the spectrum of pathogens responsible for bacteriobilia in abdominal cancer patients along with the antibiotic resistance pattern among these isolates and better selection of antibiotics and antibiotic prophylaxis for patients at risk of developing biliary tract infections with multidrug-resistant pathogens.

How to cite this article

Kar M, Dubey A, Patel SS, et al. Multifactorial Analysis of Biliary Infection in Patients with Hepato-pancreatico-biliary and Associated Intraabdominal Malignancies Admitted to a Teaching Hospital in Northern India. Euroasian J Hepato-Gastroenterol 2023;13(1):10-17.

A Retrospective Study on Bile Culture and Antibiotic Susceptibility Patterns of Patients with Biliary Tract Infections

Aim

This study aimed to provide profiles of microorganisms isolated from bile and antibiotic susceptibility patterns of biliary tract infections (BTIs) in our center.

Methods

A total of 277 patients diagnosed with BTIs at the Second Affiliated Hospital of Harbin Medical University from 2011 to 2018 were included in this study. Medical records were reviewed to obtain clinical and demographic data. Bile specimens were prepared through endoscopic retrograde cholangiopancreatography (ERCP), percutaneous transhepatic cholangiodrainage (PTCD), and percutaneous transhepatic gallbladder drainage (PTGD) under aseptic conditions. In those with positive bile culture results, blood cultures were concurrently conducted. The concordance of the results between bile culture and blood culture were also analysed.

Results

Two hundred and sixty-seven bile cultures were positive, while 280 strains of micro-organisms were isolated. Among these, 76.8% were Gram-negative, 22.5% were Gram-positive and 0.7% were fungi. The most common microorganisms were Escherichia coli, Klebsiella pneumoniae, and Enterococcus faecalis. Gram-negative bacteria we tested were highly sensitive to ertapenem, imipenem, tigecycline, and amikacin. Gram-positive bacteria we tested were highly sensitive to tigecycline, teicoplanin, linezolid, vancomycin, and chloramphenicol. For the 44 patients with positive bile cultures, a blood culture was also performed. Among them, 29 cases yielded positive blood culture results. Among those cases with positive blood culture, 48.3% showed complete agreement with bile culture, 3.4% showed partial agreement, and 48.3% showed disagreement. The most common microorganisms in blood culture were the same as in bile culture. Additionally, the proportion of Staphylococcus epidermidis was significantly higher in blood culture (P < 0.05).

Conclusion

Our study provided a comprehensive analysis of the bacteria distribution and drug resistance profiles in patients with BTIs in northern China. Further studies should be conducted to validate our findings.

Association of Intra-Operative Bile Culture with Post-Operative Complications after Pancreaticoduodenectomy

Background: Infectious complications after pancreaticoduodenectomy (PD) are a major cause of morbidity. The association of bactibilia with the occurrence of surgical site infection (SSI) is debatable. Patients and Methods: Consecutive patients who underwent PD between July 2019 and December 2020 were included. All patients underwent standard pre-operative preparation and imaging. Pre-operative biliary drainage (PBD) was done as clinically indicated. A bile sample was collected just before the transection of common bile duct (CBD). Post-operative outcomes including SSI were analyzed. Results: Fifty-four patients were assessed for enrollment; 50 were found to be resectable during surgery and were included. The incidence of bactibilia was 46%. Nineteen (38%) patients developed SSIs and the occurrence was higher in patients who had positive bile culture (14 [60.8%] vs. 5 [18.5%]; p = 0.002). A similar organism between bile culture and SSI was seen in nine (64.2%) of 14 patients. Patients who had positive bile culture had more frequent change of antibiotic (16 [69%] vs. 8 [29.6%]; p = 0.005) and required prolonged duration of postoperative antibiotic agents (12 days [IQR, 8-14] vs. 8 days [IQR, 6-10]; p = 0.003). There was no association between bile culture growth and development of post-operative pancreatic fistula, delayed gastric emptying, and post-operative pancreatic hemorrhage. Patients with bactibilia had prolonged post-operative stay (17 days [IQR, 11-20] vs. 11 days [IQR, 8-14]; p = 0.010) and severe post-operative complications (8 [34.7%] vs. 2 [7.4%]; p = 0.008). Conclusions: Bactibilia is associated with the development of SSI and may provide a guide in selection of antibiotics.

Optimizing Nanopore Sequencing for Rapid Detection of Microbial Species and Antimicrobial Resistance in Patients at Risk of Surgical Site Infections

Surgical site infections (SSI) are a significant burden to patients and health care systems. We evaluated the use of Nanopore sequencing (NS) to rapidly detect microbial species and antimicrobial resistance (AMR) genes present in intraoperative bile aspirates. Bile aspirates from 42 patients undergoing pancreatic head resection were included. Three methods of DNA extraction using mechanical cell lysis or protease cell lysis were compared to determine the optimum method of DNA extraction. The impact of host DNA depletion, sequence run duration, and use of different AMR gene databases was also assessed. To determine clinical value, NS results were compared to standard culture (SC) results. NS identified microbial species in all culture positive samples. Mechanical lysis improved NS detection of cultured species from 60% to 76%, enabled detection of fungal species, and increased AMR predictions. Host DNA depletion improved detection of streptococcal species and AMR correlation with SC. Selection of AMR database influenced the number of AMR hits and resistance profile of 13 antibiotics. AMR prediction using CARD and ResFinder 4.1 correctly predicted 79% and 81% of the bile antibiogram, respectively. Sequence run duration positively correlated with detection of AMR genes. A minimum of 6 h was required to characterize the biliary microbes, resulting in a turnaround time of 14 h. Rapid identification of microbial species and AMR genes can be achieved by NS. NS results correlated with SC, suggesting that NS may be useful in guiding early antimicrobial therapy postsurgery. IMPORTANCE Surgical site infections (SSI) are a significant burden to patients and health care systems. They increase mortality rates, length of hospital stays, and associated health care costs. To reduce the risk of SSI, surgical patients are administered broad-spectrum antibiotics that are later adapted to target microbial species detected at the site of surgical incision. Use of broad-spectrum antibiotics can be harmful to the patient. We wanted to develop a rapid method of detecting microbial species and their antimicrobial resistance phenotypes. We developed a method of detecting microbial species and predicting resistance phenotypes using Nanopore sequencing. Results generated using Nanopore sequencing were similar to current methods of detection but were obtained in a significantly shorter amount of time. This suggests that Nanopore sequencing could be used to tailor antibiotics in surgical patients and reduce use of broad-spectrum antibiotics.