Clinical impact of extended-spectrum β-lactamase-producing Enterobacteriaceae in patients with biliary tract infection

Risk factors for cefmetazole-non-susceptible bacteremia in acute cholangitis

INTRODUCTION

Cefmetazole (CMZ), an antibiotic with limited international distribution, is recommended by the Tokyo Guidelines 2018 (TG18) for non-severe cases of acute cholangitis (AC). However, the risk factors for CMZ-non-susceptible (CMZ-NS) bacteremia in AC remain unclear. Here, we aimed to investigate the risk factors for CMZ-NS bacteremia and evaluate mortality in patients with AC.

METHODS

This single-center, retrospective, observational study included all patients diagnosed with definite bacteremic AC, based on TG18, from April 2019 to March 2023. Risk factors for CMZ-NS bacteremia were analyzed by univariate, and age- and sex-adjusted, logistic regression analyses. Mortality was compared by cause of obstruction, CMZ-susceptible/CMZ-NS bacteremia, and initial treatment.

RESULTS

In total, 165 patients were enrolled. CMZ-NS bacteremia was diagnosed in 46 (27.9 %) patients. Histories of diabetes mellitus, hepato-biliary-pancreatic cancer, malignant biliary obstruction, and endoscopic sphincterotomy were identified as significant factors associated with the risk of CMZ-NS bacteremia. Thirteen patients died within 30 days of hospital admission. The mortality of patients with AC and malignant biliary obstruction was statistically higher than that of patients with bile duct stones. No patients with AC and bile duct stones died in the group with CMZ-NS bacteremia and inappropriate initial antibiotics.

CONCLUSIONS

In AC, a history of diabetes mellitus, hepato-biliary-pancreatic cancer, malignant biliary obstruction, and endoscopic sphincterotomy are associated with an increased risk of CMZ-NS bacteremia. Therefore, the choice of empiric therapy for AC should be based on the etiology and patient background, rather than on the severity.

Effect of Antibiotic Resistance of Pathogens on Initial Antibiotic Therapy for Patients With Cholangitis

Objectives

Considering that pathogens resistant to initial antibiotic therapies for cholangitis can affect mortality rates, appropriate initial empiric antibiotic therapy is important. However, evidence regarding the influence of pathogens resistant to initial antibiotics in patients with cholangitis who have undergone early endoscopic retrograde cholangiopancreatography (ERCP) is limited, and the conditions in several cases can improve with early ERCP even when pathogens resistant to initial antibiotics are detected on time. Therefore, this study aimed to assess the influence of pathogens resistant to initial antibiotics on the course of cholangitis in patients undergoing early ERCP.

Materials and methods

Patients (n=266) with positive blood or bile culture results treated with early ERCP were divided into those with cultures that were resistant to the initial antibiotics (antibiotic-resistant group; n=66; 24.8%) and those with cultures that were sensitive to the initial antibiotics (antibiotic-sensitive group; n=200; 75.2%). The duration of hospitalization, in-hospital mortality rates due to cholangitis, rates of increased disease severity, and complications during hospitalization were studied.

Results

Enterococcus, Enterobacter, Citrobacter, and Pseudomonas species showed high resistance to several antibiotics. No significant between-group differences were found in the duration of hospitalization, in-hospital mortality rates due to cholangitis, and rates of increased disease severity. However, the rate of post-ERCP cholecystitis was significantly higher in the antibiotic-resistant group than in the antibiotic-sensitive group (p=0.0245).

Conclusions

Even if the initial antibiotics were ineffective, the rate of fatal outcomes did not increase among patients with cholangitis who had undergone early ERCP. However, when initial antibiotics were ineffective, the frequency of post-ERCP cholecystitis increased even after early bile duct decompression.

The Great ESKAPE: Exploring the Crossroads of Bile and Antibiotic Resistance in Bacterial Pathogens

Throughout the course of infection, many pathogens encounter bactericidal conditions that threaten the viability of the bacteria and impede the establishment of infection. Bile is one of the most innately bactericidal compounds present in humans, functioning to reduce the bacterial burden in the gastrointestinal tract while also aiding in digestion. It is becoming increasingly apparent that pathogens successfully resist the bactericidal conditions of bile, including bacteria that do not normally cause gastrointestinal infections. This review highlights the ability of Enterococcus, Staphylococcus, Klebsiella, Acinetobacter, Pseudomonas, Enterobacter (ESKAPE), and other enteric pathogens to resist bile and how these interactions can impact the sensitivity of bacteria to various antimicrobial agents. Given that pathogen exposure to bile is an essential component to gastrointestinal transit that cannot be avoided, understanding how bile resistance mechanisms align with antimicrobial resistance is vital to our ability to develop new, successful therapeutics in an age of widespread and increasing antimicrobial resistance.

Variation of effect estimates in the analysis of mortality and length of hospital stay in patients with infections caused by bacteria-producing extended-spectrum beta-lactamases: a systematic review and meta-analysis

OBJECTIVE

To assess the variation of effect estimates in the analysis of mortality and length of stay (LOS) in patients with infections caused by extended-spectrum beta-lactamase (ESBL)-producing Enterobacteriaceae.

DESIGN

Systematic review and meta-analysis METHODS: Literature search for clinical studies from 1 January 1960 to 1 October 2018 was conducted in PubMed. Primary outcomes were risk ratios (RRs) of all-cause and attributable mortality and weighted mean differences (WMDs) in LOS in patients with bloodstream infections (BSIs) and non-invasive infections. Any change in the effect estimates was assessed by grouping studies according to design, setting, economy-based country classification, reporting period, microbiological aetiology, infection type and adjustment for appropriateness of empirical treatment. The impact of ESBL production was calculated using random-effect meta-analysis and heterogeneity was evaluated by I² statistics and metaregression.

RESULTS

Eighty-four studies including 22 030 patients and 149 outcome measures were included in the meta-analysis. Most studies were retrospective cohorts from high-income countries, providing unadjusted estimates. ESBL production in patients with BSIs (56 studies) increased the RR for all-cause mortality by a factor of 1.70 (95% CI 1.52 to 1.90; p<0.001), attributable mortality (16 studies) by 1.75 (95% CI 1.448 to 2.108; p<0.001) and WMD in the intensive care unit by 3.07 days (95% CI 1.61 to 4.54; p<0.001). WMD in hospital LOS was significantly higher in BSIs (4.41 days; 95% CI 3.37 to 5.46; p<0.001) and non-invasive (2.19 days; 95% CI 1.56 to 2.81; p<0.001). Subgroup analyses showed variation of estimates by study design, population, strain and assessment of appropriateness of empiric treatment. High heterogeneity was observed in all analyses.

CONCLUSIONS

Current evidence of the clinical burden of infections caused by ESBL-producing bacteria is highly heterogeneous and based mainly on unadjusted estimates derived from retrospective studies. Despite these limitations, ESBL production in strains causing BSIs seems associated with higher all-cause and attributable mortality and longer hospitalisation.

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.

Clinical epidemiology and outcomes of biliary tract infections caused by Klebsiella pneumoniae

Background

Biliary tract infection (BTI) is a common cause of bacteremia, and is associated with high morbidity and mortality. The clinical epidemiology and outcomes of BTI caused by Klebsiella pneumoniae (KP) have not been well investigated.

Methods

This was a retrospective study performed at a university teaching hospital in China from May 2012 to June 2017 that analyzed data for 119 patients with BTI caused by KP. We identified KP from bile cultures obtained before endoscopic or surgical treatment. Patients' demographic characteristics and clinical outcomes were also recorded.

Results

Forty-seven KP strains (39.5%) were positive for the extended spectrum beta-lactamase (ESBL) phenotype. The ESBL-positive group had a higher rate of stay in ICU [12.8% vs. 1.4% (ESBL-negative group); P=0.015] and a significantly longer hospital stay (30.79±31.512 vs. 20.06±23.945 days, respectively; P=0.037). There were no significant differences for 30-day mortality between the two groups; 112 (94.1%) patients survived and 7 (5.9%) died within 30-days of onset. Univariate analysis showed that nonsurvivors were significantly more likely to be older (66.46±22.34 vs. 46±14.84 years, respectively; P=0.001), and have hypoproteinemia (5/7, 71.4% vs. 21/112, 18.8%; P=0.006), immunosuppression (3/7, 42.9% vs. 4/112, 3.6%; P=0.004), solid tumors (5/7, 71.4% vs. 20/112, 17.9%; P=0.004), bloodstream infections (6/7, 85.7% vs. 22/112, 19.6%; P=0.001), and lower surgery rates (1/7, 14.3% vs. 66/112, 58.9%; P=0.042) compared with survivors, respectively. However, we found no significant independent risk factor for mortality. The malignant biliary obstruction group was significantly more likely to have chronic liver disease (P=0.035) than the benign biliary obstruction group, and mortality was higher for the malignant biliary obstruction group (5/25, 20% vs. 2/94, 2.1%, respectively; P=0.05). The malignant biliary group also had higher alkaline phosphatase, and direct and total bilirubin direct levels. Multivariate analysis showed that chronic liver disease was an independent risk factor in patients with malignant biliary disease [odds ratio (OR), 2.431; 95% confidence interval, 1.834-4.031; P=0.001].

Conclusions

Patients with BTI caused by KP were more likely to have the ESBL phenotype, and antibiotic resistance was not associated with overall survival. Patients with malignant biliary obstruction had higher mortality, and chronic liver disease was an independent risk factor.

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.

Clinical outcomes of spontaneous bacterial peritonitis due to extended-spectrum beta-lactamase-producing Escherichia coli or Klebsiella pneumoniae: a retrospective cohort study

PURPOSE

The aim of this study was to (1) evaluate the clinical outcomes of spontaneous bacterial peritonitis (SBP) due to extended-spectrum beta-lactamase (ESBL)-producing Escherichia coli or Klebsiella pneumoniae (EK) and (2) investigate the relationship between the adequacy of initial antibiotic treatments and patient outcomes.

METHODS

We conducted a retrospective cohort study of cirrhotic patients with SBP caused by EK. We evaluated the 30-day mortality rate and used Cox proportional hazard models to identify risk factors for mortality.

RESULTS

Between January 2006 and December 2012, a total of 231 episodes of SBP due to EK were recorded. Among them, 52 were caused by ESBL-producing EK (ESBL-EK). The 30-day mortality rate was significantly higher in patients with SBP due to ESBL-EK than in those with non-ESBL-producing EK (non-ESBL-EK) (34.6 vs. 18.4 %, respectively; p = 0.013). Multivariate analysis revealed that ESBL production [adjusted HR (aHR) 1.82, 95 % confidence interval (CI) 1.00-3.31], nosocomial infection (aHR 2.24, 95 % CI 1.26-3.95), septic shock (aHR 4.84, 95 % CI 2.70-8.65), higher Child-Pugh score (aHR 1.57, 95 % CI 1.28-1.92), and higher Charlson comorbidity index (aHR 1.37, 95 % CI 1.15-1.64) were independent risk factors for 30-day mortality in the total cohort. When we analyzed patients with SBP due to ESBL-EK separately, septic shock (aHR 3.64, 95 % CI 1.40-9.77), accompanying bacteremia (aHR 3.71, 95 % CI 1.37-10.08), and hepatocellular carcinoma (aHR 3.21, 95 % CI 1.20-8.56) were independent risk factors.

CONCLUSIONS

Both 7- and 30-day mortalities for SBP due to ESBL-EK were significantly higher than for SBP due to non-ESBL-EK. Initial antibiotic choice was not associated with poor clinical outcomes in patients with SBP due to ESBL-EK.