Changes in causative pathogens of acute cholangitis and their antimicrobial susceptibility over a period of 6 years

Development and derivation of bacteremia prediction model in patients with hepatobiliary infection

INTRODUCTION

Hepatobiliary infections are common in the emergency department (ED), and the mortality rate for this condition is high. A suitable bacteremia prediction model would support prompt identification of bacteremia and appropriate management of hepatobiliary infections in the ED. Therefore, we attempted to produce a bacteremia prediction model with both internal and external validation for hepatobiliary infections in the ED.

METHODS

Patients with hepatobiliary infection were extracted from retrospective cohort databases of two tertiary hospitals from January 2018 to December 2019 and from January 2016 to December 2019, respectively. Independent risk factors were determined using multivariable logistic regression in a developmental cohort. We assigned a weighted value to predictive factors and developed a prediction model, which was validated both internally and externally. We assessed discrimination using the area under the receiver operating characteristics curve (AUC).

RESULTS

One hospital cohort of 1568 patients was randomly divided into a developmental group of 927 patients (60%) and an internal validation group of 641 patients (40%), and 736 people from the other hospital cohort were used for external validation. Bacteremia rates were 20.5%, 18.1%, and 23.1% in the developmental, internal, and external validation cohorts, respectively. Nine significant factors were used for predicting bacteremia, including age, three vital signs, and five laboratory tests. After applying our bacteremia prediction rule to the validation cohort, 56.5% and 53.8% of the internal and external validation groups were classified as low-risk bacteremia groups (bacteremia rates: 8.6% and 13.9%, respectively). The AUCs were 0.727 (95% confidence interval [CI]: 0.686-0.767), 0.730 (95% CI: 0.679-0.781), and 0.715 (95% CI: 0.672-0.758) for the developmental, internal, and external validation cohorts, respectively. The sensitivity and specificity for internal validation/external validation was 73.2%/67.6% and 63.0%/60.2%, respectively.

CONCLUSION

A bacteremia prediction model for hepatobiliary infection might be useful to predict the risk of bacteremia. It might also reduce the need for blood culture in low-risk patients.

Korean Guidelines for Use of Antibiotics for Intra-abdominal Infections in Adults

The guidelines are intended to provide practical information for the correct use of antibiotics for intra-abdominal infections in Korea. With the aim of realizing evidence-based treatment, these guidelines for the use of antibiotics were written to help clinicians find answers to key clinical questions that arise in the course of patient care, using the latest research results based on systematic literature review. The guidelines were prepared in consideration of the data on the causative pathogens of intra-abdominal infections in Korea, the antibiotic susceptibility of the causative pathogens, and the antibiotics available in Korea.

A Multipathogen Bile Sample-based PCR Assay Can Guide Empirical Antimicrobial Strategies in Cholestatic Liver Diseases

BACKGROUND AND OBJECTIVES

Polymerase chain reaction (PCR) techniques provide rapid detection of pathogens. This pilot study evaluated the diagnostic utility and clinical impact of multiplex real-time PCR (mRT-PCR, SeptiFast) vs. conventional microbial culture (CMC) in bile samples of patients with chronic cholestatic liver diseases (cCLDs), endoscopic retrograde cholangio-pancreatography (ERCP), and peri-interventional-antimicrobial-prophylaxis (pAP).

METHODS

We prospectively collected bile samples from 26 patients for microbiological analysis by CMC and mRT-PCR. Concordance of the results of both methods was determined by Krippendorff's alpha (α) for inter-rater reliability and the Jaccard index of similarity.

RESULTS

mRT-PCR_bile and CMC_bile results were concordant for only Candida albicans (α=0.8406; Jaccard index=0.8181). mRT-PCR_bile detected pathogens in 8/8 cases (100%), CMC_bile in 7/8 (87.5%), and CMC_blood in 5/8 (62.5%) with clinical signs of infection. mRT-PCR_bile, CMC_bile, and CMC_blood had identical detection results in 3/8 (37.5%) with clinical signs of infection (two Klebsiella spp. and one Enterococcus faecium). The total pathogen count was significantly higher with mRT-PCR_bile than with CMC_bile (62 vs. 31; χ²=30.031, p<0.001). However, pathogens detected by mRT-PCR_bile were more often susceptible to pAP according to the patient infection/colonization history (PI/CH) and surveillance data for antibiotic resistance in our clinic (DARC). Pathogens identified by mRT-PCR_bile and resistant to pAP by PI/CH and DARC were likely to be clinically relevant.

CONCLUSIONS

mRT-PCR in conjunction with CMCs for bile analysis increased diagnostic sensitivity and may benefit infection management in patients with cholestatic diseases. Implementation of mRT-PCR in a bile sample-based diagnostic routine can support more rapid and targeted use of antimicrobial agents in cCLD-patients undergoing ERCP and reduce the rate/length of unnecessary administration of broad-spectrum antibiotics.

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.

ROLE OF CHANGE IN THE LEVELS OF INFLAMMATORY MARKERS POST DRAINAGE IN PREDICTING OUTCOME IN ACUTE CHOLANGITIS

BACKGROUND

Acute cholangitis (AC) is a gastro-intestinal emergency associated with significant mortality. Role of change in the levels of inflammatory markers post drainage in predicting outcome in acute cholangitis is uncertain.

OBJECTIVE

To evaluate the predictive value of changes in C-reactive protein (CRP) and procalcitonin levels after biliary drainage in relation to outcomes (survival or mortality) at 1 month.

METHODS

A prospective observational study of consecutive adults presenting with AC was performed. At admission and at 48 hours post biliary drainage, procalcitonin and CRP were sent.

RESULTS

Between August 2020 till December 2020 we recruited 72 consecutive patients of AC. The median age of the patients was 55 years (range 43-62 years) and 42 (58.33%) were females. Although the delta change in serum procalcitonin (P value<0.001) and CRP (P value<0.001) was significant, it had no bearing on the outcome. Altered sensorium and INR were independently associated with mortality at 1 month. The 30-day mortality prediction of day 0 procalcitonin was measured by receiver operating characteristic analysis which resulted in an area under the curve of 0.697 with a 95% confidence interval (95%CI) of 0.545-0.849. The optimal cut-off of procalcitonin would be 0.57ng/mL with a sensitivity and specificity of 80% and 60% respectively to predict mortality.

CONCLUSION

Change in serum procalcitonin and CRP levels at 48 hours post drainage although significant, had no impact on the outcome of acute cholangitis.

Quick detection of causative bacteria in cases of acute cholangitis and cholecystitis using a multichannel gene autoanalyzer

PURPOSES

Acute cholangitis and cholecystitis can become severe conditions as a result of inappropriate therapeutic administration and thereafter become increasingly resistant to antimicrobial treatment. The simultaneous detection of the bacterial nucleic acid and antimicrobial resistance gene is covered by the national health insurance program in Japan for sepsis. In this study, we evaluate the use of a multichannel gene autoanalyzer (Verigene system) for the quick detection of causative bacteria in cases of acute cholangitis and cholecystitis.

METHODS

This study included 108 patients diagnosed with acute cholangitis or cholecystitis between June 2015 and November 2018. A bacterial culture test and Verigene assay were used to evaluate the bile samples.

RESULTS

The most commonly isolated bacteria were Escherichia coli, which includes six extended-spectrum beta-lactamase (ESBL)-producing E. coli. Among the patients with positive bile cultures, bacteria were detected in 35.7% of cases via the Verigene system. The detection rates of the Verigene system significantly increased when the number of bacterial colonies was ≥ 10⁶ colony-forming unit (CFU)/mL (58.1%). Cases with a maximum colony quantity of ≥ 10⁶ CFU/mL exhibited higher inflammation, suggesting the presence of a bacterial infection.

CONCLUSIONS

The Verigene system might be a new method for the quick detection of causative bacteria in patients with infectious acute cholangitis and cholecystitis.

Antibiotic prophylaxis in acute cholecystectomy revisited: results of a double-blind randomised controlled trial

Purpose

Evidence supporting the value of preoperative antibiotic prophylaxis (PAP) in surgery for acute cholecystitis is lacking. This study aimed to shed light on whether PAP in acute cholecystectomy for cholecystitis reduces the postoperative infectious complication (PIC) rate. Secondary outcomes were the prevalence of bacteriobilia, CRP values and leucocyte counts.

Methods

The study was performed as a single-centre, double-blinded, placebo-controlled, randomised study. Patients with acute cholecystitis amenable for acute laparoscopic cholecystectomy were randomly assigned to either PAP (piperacillin/ tazobactam) or placebo, and the subsequent clinical course was followed.

Results

A total of 106 patients were enrolled, 16 of whom were excluded due to protocol violation. PIC developed in 22 of the 90 patients included with no significant difference between the PAP and placebo groups (8 patients in the PAP group and 14 in the placebo arm, p = 0.193). The PIC rate was significantly higher in patients with a raised CRP at randomisation and on the day of surgery and in cases of conversion to an open procedure (p = 0.008, 0.004 and 0.017, respectively) but with no differences between the study groups.

Conclusion

PAP does not affect the risk for PIC in patients with acute cholecystitis. The major risk factors determining PIC in these patients need defining, in particular, the impact of bacteriobilia.

Trial registration

The study was registered at clinicaltrials.gov (NCT02619149) December 2, 2015.

Developing a risk prediction model for multidrug-resistant bacterial infection in patients with biliary tract infection

BACKGROUND/AIMS

The aim of this study was to develop a tool to predict multidrug-resistant bacteria infections among patients with biliary tract infection for targeted therapy.

PATIENTS AND METHODS

We conducted a single-center retrospective descriptive study from January 2016 to December 2018. Univariate and multivariable logistic regression analysis were used to identify independent risk factors of multidrug-resistant bacterial infections. A nomogram was constructed according to multivariable regression model. Moreover, the clinical usefulness of the nomogram was estimated by decision curve analysis.

RESULTS

121 inpatients were randomly divided into a training cohort (n = 79) and validation cohort (n = 42). In multivariate analysis, 5 factors were associated with biliary tract infections caused by multidrug-resistant bacterial infections: aspartate aminotransferase (Odds ratio (OR), 13.771; 95% confidence interval (CI), 3.747-64.958; P < 0.001), previous antibiotic use within 90 days (OR, 4.130; 95% CI, 1.192-16.471; P = 0.032), absolute neutrophil count (OR, 3.491; 95% CI, 1.066-12.851; P = 0.046), previous biliary surgery (OR, 3.303; 95% CI, 0.910-13.614; P = 0.079), and hemoglobin (OR, 0.146; 95% CI, 0.030-0.576; P = 0.009). The nomogram model was constructed based on these variables, and showed good calibration and discrimination in the training set [area under the curve (AUC), 0.86] and in the validation set (AUC, 0.799). The decision curve analysis demonstrated the clinical usefulness of our nomogram. Using the nomogram score, high risk and low risk patients with multidrug-resistant bacterial infection could be differentiated.

CONCLUSIONS

This simple bedside prediction tool to predict multidrug-resistant bacterial infection can help clinicians identify low versus high risk patients as well as choose appropriate, timely initial empirical antibiotics therapy. This model should be validated before it is widely applied in clinical settings.

Antibiotics for adults with acute cholecystitis or acute cholangitis or both

This is a protocol for a Cochrane Review (intervention). The objectives are as follows:

To assess the benefits and harms of antibiotics treatment versus placebo, no intervention, or another antibiotic for people with cholecystitis or cholangitis, or both.

Clinical and microbiological characteristics of patients with biliary disease

BACKGROUND

Biliary diseases are common digestive system disorders which may combine with biliary tract infection such as cholecystitis or cholangitis. Thus, rapid identification of the bacteria and their antibiotic susceptibility profiles are crucial for reducing the mortality of patients with biliary tract infection.

AIM

To identify bacterial species and antibiotic susceptibility for antibacterial therapy and analyze bile cultivation risk factors for increasing detection rates.

METHODS

This retrospective study was conducted from July 2008 to July 2017. In total, 1339 bile samples which were collected during therapeutic endoscopic retrograde cholangiopan-creatography or percutaneous transhepatic cholangiodrainage or other biliary surgeries or biliary drainage were obtained to characterize pathogen spectra, antibiotic susceptibility, and clinical features. Clinical data including age, sex, comorbidities, clinical symptoms, protopathies, and history of biliary tract diseases and surgeries were collated from hospital medical records. Species identification and initial drug susceptibility were further identified by biochemical characterization using the VITEK 2 Compact test.

RESULTS

Positive microbiological findings were observed in 738 samples. The most frequently encountered strains were gram-negative bacteria (74.94%), including Escherichia coli (37.78%), Pseudomonas aeruginosa (8.96%), and Klebsiella pneumoniae (10.29%). Bile bacteria were largely sensitive to carbapenems, piperacillin/tazobactam, and gentamicin. Gram-negative strains had low susceptibility to ceftriaxone, quinolones and ampicillin. Almost the same micro-organisms were present in patients with malignant and benign diseases. The number of samples with Klebsiella pneumoniae in the bile culture were significantly different between patients with malignant and benign diseases (55 vs 30; P = 0.019). Age (P < 0.001), fever (P < 0.001), history of biliary tract diseases and surgeries (both P < 0.001), benign disease (P = 0.002), and the comorbidity chronic renal insufficiency (P = 0.007) affected the positive rates of the bile samples.

CONCLUSION

Gram-negative bacteria were the most commonly isolated biliary bacteria. We determined the major factors associated with positive detection rates. Microbiological analysis of bile samples allowed accurate antibiotic treatments.

Increasing burden of biliary tract infection caused by extended-spectrum beta-lactamase-producing organisms in Korea: A nationwide population-based study

BACKGROUND AND AIM

Biliary tract infections (BTIs) are a major cause of bacteremia. The prevalence of antibiotic-resistant pathogens in BTI patients is reported to be increasing. We used a nationwide database to evaluate the prevalence of, and risk factors for, BTIs caused by extended-spectrum beta-lactamase-producing organisms (ESBL-PO) in Korea.

METHODS

Patients with a BTI diagnosis, an admission history, a history of a BTI-related procedure, and antibiotic use for ≥ 4 days between 2007 and 2016 were identified from the Health Insurance Review and Assessment Service database. A BTI treated with carbapenems (BTI-TC) was used as the surrogate for a BTI caused by ESBL-PO. We conducted a multivariate logistic regression analysis to determine the risk factors for BTI-TC.

RESULTS

In total, 341 002 patients were enrolled. The overall percentage of BTI-TC among BTIs was 2.4%, with an increasing annual trend (P < 0.0001). The risk of acute cholangitis caused by ESBL-PO increased significantly in men, older patients, patients with comorbidities, patients with a history of a biliary procedure within the previous year, and patients with a history of antibiotic use within the previous 90 days. Regarding antibiotic use, the patients at highest risk were those previously prescribed carbapenems (adjusted odds ratio, 4.77; P < 0.0001).

CONCLUSIONS

The prevalence of BTIs caused by ESBL-PO has increased during the last 10 years. Initial carbapenem therapy should be considered for elderly patients with acute cholangitis if they have had a previous biliary procedure and/or a history of carbapenem administration within the previous 90 days.

Changes in Microbial Profiles and Antibiotic Resistance Patterns in Patients with Biliary Tract Infection over a Six-Year Period

Background: Biliary tract infection (BTI) is a common complication in patients with biliary obstruction caused by various biliary tract disorders. To improve the management of patients with BTI, microbial profiles from bile cultures and antibiotic resistance patterns were evaluated in this six-year retrospective study. Methods: A total of 709 patients with various biliary tract disorders from January 2012 to December 2017 were enrolled in this study. Bile specimens were taken from intra-operative puncture or post-operative drainage for microbial culture under sterile conditions. Microbial culture, identification, and antibiotic resistance test were performed according to a standard routine. Results: Cultures were positive in 574 of 789 bile specimens (73%). Of all isolates, 386 were gram-negative bacilli (67%), 170 were gram-positive cocci (30%), and 18 were fungi (3%). The two most common micro-organisms were Escherichia coli (29%) and Klebsiella pneumoniae (16%), the extended-spectrum β-lactamases (ESBL) positivity rates of which were 52% and 21%, respectively. Both bacteria were highly resistant to commonly used antibiotic agents (penicillins, cephalosporins, and quinolones), and highly susceptible to carbapenems, amikacin, and piperacillin-tazobactam. Enterococcus (19%) was the next most common bacteria isolated from bile samples, mainly including Enterococcus faecium (8%) and Enterococcus faecalis (6%). These two bacteria were resistant to cefazolin and clindamycin but sensitive to teicoplanin, tigecycline, and vancomycin. Enterococcus faecium was more resistant than Enterococcus faecalis to most of the tested antibiotic agents. Annual statistical analysis showed that the frequency of gram-negative enteric bacteria was decreasing slowly, but that of gram-positive enterococci was increasing slowly. Moreover, the overall antibiotic resistance rates of the most common strains have been decreasing slowly over the past six years. Conclusions: Enterobacteriaceae (Enterococcus coli and Klebsiella pneumoniae) and Enterococcus (Enterococcus faecium and Enterococcus faecalis) were the common pathogenic bacteria causing BTI, which exhibited high resistance to routinely used antibiotic agents and were highly sensitive to piperacillin-tazobactam, carbapenem, amikacin, and vancomycin. The microbial profiles from bile and its antibiotic resistance patterns have changed, which will help in the empirical treatment of BTI.

Tokyo Guidelines 2018: antimicrobial therapy for acute cholangitis and cholecystitis

Antimicrobial therapy is a mainstay of the management for patients with acute cholangitis and/or cholecystitis. The Tokyo Guidelines 2018 (TG18) provides recommendations for the appropriate use of antimicrobials for community-acquired and healthcare-associated infections. The listed agents are for empirical therapy provided before the infecting isolates are identified. Antimicrobial agents are listed by class-definitions and TG18 severity grade I, II, and III subcategorized by clinical settings. In the era of emerging and increasing antimicrobial resistance, monitoring and updating local antibiograms is underscored. Prudent antimicrobial usage and early de-escalation or termination of antimicrobial therapy are now important parts of decision-making. What is new in TG18 is that the duration of antimicrobial therapy for both acute cholangitis and cholecystitis is systematically reviewed. Prophylactic antimicrobial usage for elective endoscopic retrograde cholangiopancreatography is no longer recommended and the section was deleted in TG18. Free full articles and mobile app of TG18 are available at: http://www.jshbps.jp/modules/en/index.php?content_id=47. Related clinical questions and references are also included.

Risk Factors for Multi-Drug Resistant Pathogens and Failure of Empiric First-Line Therapy in Acute Cholangitis

Background

Acute cholangitis (AC) requires the immediate initiation of antibiotic therapy in addition to treatment for biliary obstruction. Against a background of an increasing prevalence of multi-drug resistant (MDR) bacteria, the risk factors for the failure of empiric therapy must be defined.

Methods

Using a pathogen-based approach, 1764 isolates from positive bile duct cultures were retrospectively analyzed to characterize the respective pathogen spectra in two German tertiary centers. Using a patient-based approach, the clinical and laboratory data for 83 patients with AC were assessed to identify risk factors for AC with pathogens resistant to the applied empiric therapy.

Results

Bile cultures were predominantly polymicrobial, and empiric antibiotic therapies did not cover the full biliary pathogen spectrum in 78% of cases. MDR bacteria were isolated from the bile of 24/83 (29%) patients. The univariate risk factors for biliary MDR bacteria were male sex, nosocomial AC, prior antibiotic exposure and prior biliary stenting, of which biliary stenting was the only independent risk factor according to multivariate analysis (OR = 3.8; 95% CI 1.3–11.0, P = 0.013). Although there were no significant differences in survival or hospital stay in AC patients with and without detected biliary MDR pathogens, the former more often had a concomitant bloodstream infection (58% vs. 24%; P = 0.019), including those involving MDR pathogens or fungi (21% vs. 2%; P = 0.007).

Conclusion

Patients with biliary stents who develop AC should receive empiric therapy covering enterococci and extended-spectrum beta-lactamase (ESBL)-producing Enterobacteriaceae. These patients are at an increased risk for bloodstream infections by MDR pathogens or fungi.

Risk Factors for Multi-Drug Resistant Pathogens and Failure of Empiric First-Line Therapy in Acute Cholangitis

BACKGROUND

Acute cholangitis (AC) requires the immediate initiation of antibiotic therapy in addition to treatment for biliary obstruction. Against a background of an increasing prevalence of multi-drug resistant (MDR) bacteria, the risk factors for the failure of empiric therapy must be defined.

METHODS

Using a pathogen-based approach, 1764 isolates from positive bile duct cultures were retrospectively analyzed to characterize the respective pathogen spectra in two German tertiary centers. Using a patient-based approach, the clinical and laboratory data for 83 patients with AC were assessed to identify risk factors for AC with pathogens resistant to the applied empiric therapy.

RESULTS

Bile cultures were predominantly polymicrobial, and empiric antibiotic therapies did not cover the full biliary pathogen spectrum in 78% of cases. MDR bacteria were isolated from the bile of 24/83 (29%) patients. The univariate risk factors for biliary MDR bacteria were male sex, nosocomial AC, prior antibiotic exposure and prior biliary stenting, of which biliary stenting was the only independent risk factor according to multivariate analysis (OR = 3.8; 95% CI 1.3-11.0, P = 0.013). Although there were no significant differences in survival or hospital stay in AC patients with and without detected biliary MDR pathogens, the former more often had a concomitant bloodstream infection (58% vs. 24%; P = 0.019), including those involving MDR pathogens or fungi (21% vs. 2%; P = 0.007).

CONCLUSION

Patients with biliary stents who develop AC should receive empiric therapy covering enterococci and extended-spectrum beta-lactamase (ESBL)-producing Enterobacteriaceae. These patients are at an increased risk for bloodstream infections by MDR pathogens or fungi.