Risk factors for mortality in liver transplant recipients with ESKAPE infection

Risk Factors for E2SKAPE Infections and Mortality Among Liver Transplant Recipients

PURPOSE

Infections caused by Enterococcus faecium, Staphylococcus aureus, Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa, and Enterobacter spp (ESKAPE) plus Escherichia coli (E2SKAPE), in particular multidrug-resistant (MDR) E2SKAPE infections, occur frequently and pose a life-threatening to liver transplant (LT) recipients. To prevent E2SKAPE infections and improve the prognosis of LT recipients, the identification of risk factors for E2SKAPE infections and mortality is necessary.

METHODS

E2SKAPE pathogens were isolated and identified from clinical samples following standard microbiological procedures. All episodes of E2SKAPE infections and mortality documented among LT recipients were analyzed.

FINDINGS

A total of 83 episodes of E2SKAPE infections, including 75 (90.4%) episodes of MDR-E2SKAPE infections, occurred in 23.1% (53/229) of LT recipients. E. faecium was the dominant causative bacterium (37/83; 44.6%). The most common site of infections was the urinary tract (14/53; 26.4%). Sixteen (7%) patients died within 2 months after LT, and 7 deaths were E2SKAPE infections-related. Multivariate logistic regression analysis revealed that female sex [odds ratio (OR) = 3.665, 95% confidence interval (CI): 1.614-8.321, P = 0.002], duration of surgery ≥ 400 min [OR = 2.328, 95%CI: 1.151-4.707, P = 0.019], intraoperative red blood cell (RBC) transfusion ≥ 12U [OR = 2.542, 95%CI: 1.218-5.306, P = 0.013] and indwelling urethral catheter use ≥ 3 days [OR = 3.96, 95%CI: 1.309-11.981, P = 0.015] were independent risk factors for E2SKAPE infections after LT, and that only exposure to more than 2 intravenous antibiotics post-LT [OR = 0.318, 95%CI: 0.15-0.674, P = 0.003] was negatively associated with acquisition of E2SKAPE infections. The predictors of crude mortality included female sex [OR = 4.822, 95%CI: 1.299-17.904, P = 0.019], creatinine on day 3 post-LT > 1.5 mg/dL [OR = 11.014, 95%CI: 2.985-40.637, P < 0.001], mechanical ventilation post-LT [OR = 10.724, 95%CI: 2.695-42.676, P = 0.001] and recipients with E2SKAPE infections [OR = 4.112, 95%CI: 1.169-14.47, P = 0.028].

IMPLICATIONS

A high incidence of E2SKAPE infections was noted in the early post-LT period. The most common infection site was the urinary tract, and the dominant pathogenic bacterium was E. faecium. Female sex, prolonged surgery time, massive RBC transfusion, or delayed urethral catheter removal were associated with E2SKAPE infections. Only exposure to more than 2 intravenous antibiotics post-LT was negatively related to the acquisition of E2SKAPE infections. The predictors of mortality included female sex, creatinine on day 3 post-LT>1.5 mg/dL, mechanical ventilation post-LT, and recipients with E2SKAPE infections.

Penicillin-Binding Protein 5/6 Acting as a Decoy Target in Pseudomonas aeruginosa Identified by Whole-Cell Receptor Binding and Quantitative Systems Pharmacology

The β-lactam antibiotics have been successfully used for decades to combat susceptible Pseudomonas aeruginosa, which has a notoriously difficult to penetrate outer membrane (OM). However, there is a dearth of data on target site penetration and covalent binding of penicillin-binding proteins (PBP) for β-lactams and β-lactamase inhibitors in intact bacteria. We aimed to determine the time course of PBP binding in intact and lysed cells and estimate the target site penetration and PBP access for 15 compounds in P. aeruginosa PAO1. All β-lactams (at 2 × MIC) considerably bound PBPs 1 to 4 in lysed bacteria. However, PBP binding in intact bacteria was substantially attenuated for slow but not for rapid penetrating β-lactams. Imipenem yielded 1.5 ± 0.11 log10 killing at 1h compared to <0.5 log10 killing for all other drugs. Relative to imipenem, the rate of net influx and PBP access was ~ 2-fold slower for doripenem and meropenem, 7.6-fold for avibactam, 14-fold for ceftazidime, 45-fold for cefepime, 50-fold for sulbactam, 72-fold for ertapenem, ~ 249-fold for piperacillin and aztreonam, 358-fold for tazobactam, ~547-fold for carbenicillin and ticarcillin, and 1,019-fold for cefoxitin. At 2 × MIC, the extent of PBP5/6 binding was highly correlated (r2 = 0.96) with the rate of net influx and PBP access, suggesting that PBP5/6 acted as a decoy target that should be avoided by slowly penetrating, future β-lactams. This first comprehensive assessment of the time course of PBP binding in intact and lysed P. aeruginosa explained why only imipenem killed rapidly. The developed novel covalent binding assay in intact bacteria accounts for all expressed resistance mechanisms.

Multi-drug resistant ESKAPE pathogens and the uses of plants as their antimicrobial agents

Infections by ESKAPE (Enterococcus sp., Staphylococcus aureus, Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa, and Enterobacter spp.) pathogens cause major concern due to their multi-drug resistance (MDR). The ESKAPE pathogens are frequently linked to greater mortality, diseases, and economic burden in healthcare worldwide. Therefore, the use of plants as a natural source of antimicrobial agents provide a solution as they are easily available and safe to use. These natural drugs can also be enhanced by incorporating silver nanoparticles and combining them with existing antibiotics. By focussing the attention on the ESKAPE organisms, the MDR issue can be addressed much better.

Antibiotic-Resistant Infections and Treatment Challenges in the Immunocompromised Host: An Update

This article reviews antibiotic resistance and treatment of bacterial infections in the growing number of patients who are immunocompromised: solid organ transplant recipients, the neutropenic host, and persons with human immunodeficiency virus and AIDS. Specific mechanisms of resistance in both gram-negative and gram-positive bacteria, as well as newer treatment options are addressed elsewhere and are only briefly discussed in the context of the immunocompromised host.

Epidemiology, risk factors and outcomes of bloodstream infection caused by ESKAPEEc pathogens among hospitalized children

Background

Bloodstream infection (BSI) resulting from ESKAPEEc pathogens (Enterococcus faecium, Staphylococcus aureus, Klebsiella pneumoniae, Escherichia coli, Acinetobacter baumannii, Pseudomonas aeruginosa and Enterobacter spp) is relevant to high mortality and economic cost. Data concerning the impact of BSI due to ESKAPEEc in pediatric population was virtually scant. Our purpose was to summarize the epidemiology, risk factors and outcomes of ESKAPEEc BSI among hospitalized children.

Methods

Inpatients diagnosed with BSI with definite etiology between January 2016 and December 2018 were enrolled retrospectively at the West China Second University Hospital. Data were systematically reviewed on patients’ clinical characteristics and laboratory findings to ascertain independent predictors, clinical features and outcomes.

Results

Of the 228 patients with BSI, 174 (76.3%) were caused by ESKAPEEc (124 MDR-ESKAPEEc). Multivariate analysis demonstrated that premature and/ or low birth weight (odds ratio [OR] = 2.981, P = 0.036), previous surgery and/or trauma (OR = 5.71, P = 0.029) and source of urinary tract infection (OR = 10.60, P = 0.004) were independently associated with ESKAPEEc BSI. The independent risk factor for MRD-ESKAPEEc BSI was nosocomial infection (OR = 3.314, P = 0.037). The overall mortality rate in patients with ESKAPEEc BSI was 14.4% (25/174), and no significant difference was ascertained in mortality between MRD-ESKAPEEc and non-MRD ESKAPEEc BSI groups (13.7% vs. 11.4%, P = 0.692). In addition, previous surgery and/or trauma, thrombocytopenia, and mechanical ventilation were significant risk factors for mortality caused by ESKAPEEc BSI.

Conclusions

More than two-thirds of BSI among hospitalized children were caused by ESKAPEEc. Previous surgery and/or trauma, thrombocytopenia and mechanical ventilation increased the risk rate for mortality in ESKAPEEc BSI. The risk factors ascertained could assist physicians to early suspect ESKAPEEc BSI and MDR ESKAPEEc BSI.

Risk Factors for Acquisition of Carbapenem-Resistant Klebsiella pneumoniae and Mortality Among Abdominal Solid Organ Transplant Recipients with K. pneumoniae Infections

BACKGROUND For abdominal solid organ transplant (ASOT) recipients, infection with Klebsiella pneumoniae, particularly carbapenem-resistant K. pneumoniae (CRKP), can be life-threatening. The aims of this study were to characterize the risk factors associated with acquisition of CRKP and 90-day crude mortality among patients. MATERIAL AND METHODS In our cohort study, we retrospectively reviewed 68 K. pneumoniae-infected transplant recipients, studied their demographics, clinical manifestations, microbiology, and outcomes, and determined the risk factors associated with the occurrence of CRKP and crude mortality due to K. pneumoniae infections. RESULTS Sixty-eight ASOT recipients (5.4%) experienced 78 episodes of K. pneumoniae infection. Among these, 20 patients (29.4%) died. The independent risk factors associated with mortality were multiple infected organs or sites (odds ratio=22.034, 95% confidence intervals=4.348-111.653, P=0.001) and septic shock (odds ratio=27.090, 95% confidence intervals=1.841-398.512, P=0.016). Risk factors associated with acquisition of CRKP were multiple infected organs or sites (odds ratio=3.056, 95% confidence intervals=1.091-8.556, P=0.033). CONCLUSIONS K. pneumoniae infections, especially CRKP, frequently occurred among ASOT recipients, with a high mortality rate. Multiple infected organs or sites and septic shock were predictors of crude mortality caused by K. pneumoniae infections, while CRKP infections were associated with multiple infected organs or sites. Greater efforts are needed towards improved antibiotic administration, early diagnosis and precise treatment, recognition of septic shock, and reduced length of hospitalization.

Bacterial and Fungal Infections After Liver Transplantation: Microbial Epidemiology, Risk Factors for Infection and Death with Infection

Background

Infections, especially bacterial and fungal infections, are the leading cause of high mortality after liver transplantation (LT). This research investigated the pathogenic spectrum, antimicrobial susceptibility results, and risk factors of infection and death with infection to better control such infections.

Material/Methods

A retrospective cohort study was performed, and 433 liver transplant recipients between January 2010 and December 2016 were analyzed.

Results

We found 290 isolates of bacteria and fungi in 170 infected liver transplant patients. Significant independent risk factors for bacterial and fungal infections were prolonged hospital stay (OR 1.034, 95% CI 1.013~1.056, p=0.002), mechanical ventilation (OR 3.806, 95% CI 1.567~9.248, p=0.003), and liver failure (OR 2.659, 95% CI 1.019~6.940, p=0.046). Furthermore, postoperative MELD scores (OR 1.120, 95% CI 1.020~1.230, p=0.017) and septic shock (OR 12.000, 95% CI 1.124~128.066, p=0.003) were independent risk factors for death with infection. CRAB infection is the main pathogenic bacteria of septic shock in LT patients.

Conclusions

We found that 39.3% of recipients had at least 1 bacterial or fungal infection after LT. Shortening the length of hospital stay and early withdrawal of mechanical ventilation will reduce the risk of infection after LT. Patients with liver failure should be more vigilant against postoperative infection. Once an infection occurs, immediate assessment of the postoperative MELD score, early diagnosis of septic shock, and active search for pathogenic evidence for precise treatment will help improve patient prognosis. Routine screening for CRAB colonization before surgery will facilitate empirical use of effective antibiotics.

Prevalence, Risk Factors And Treatment Of The Most Common Gram-Negative Bacterial Infections In Liver Transplant Recipients: A Review

Advances in surgical techniques and immunosuppressive agents have made solid organ transplant (Tx) an important strategy for treatment of end-stage organ failures. However, the incidence of infections following Tx due to Gram-negative pathogens is on the rise. These infections are associated with increased mortality and morbidity in patients following transplantation, including liver Tx. Thus, managing infections in liver Tx recipients is a big challenge, requiring prompt medical attention. Considering the important effect of Gram-negative bacterial infections on the outcomes of liver Tx recipients, the most prevalent Gram-negative pathogens including Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa and Escherichia coli will be discussed in this review.

Effect of Intraoperative Single-Shot Application of Vancomycin in Liver Transplant Recipients on Postoperative Infections With Enterococcus faecium and Enterococcus faecalis

OBJECTIVES

Infections are major causes of morbidity and mortality in the early postoperative period after liver transplant. We observed a high rate of enterococcal infections at our center. Therefore, we added an intraoperative single shot of vancomycin to the standard regimen of meropenem given over 5 days. The aim of this study was to determine the prevalence of both Enterococcus faecium and Enterococcus faecalis infections during the first 28 days after surgery depending on the type of antibiotic prophylaxis and their implications on mortality and morbidity.

MATERIALS AND METHODS

Our retrospective cohort analysis included 179 patients: 93 patients received meropenem only and 86 patients were treated with meropenem plus vancomycin.

RESULTS

During the first 28 days after transplant, microbiological tests showed that 51 patients (28.5%) were positive for Enterococcus faecium and 25 patients (14.0%) were positive for Enterococcus faecalis. Enterococcus faecium infections appeared significantly more often in patients without vancomycin (P = .013). In the second week after transplant, there was a significant reduction in Enterococcus faecium infections in the meropenem plus vancomycin group (P = .015). Enterococcus faecalis infections occurred more often in the patients receiving meropenem alone, but results were not statistically significant (P = .194). There was a trend toward more frequent renal replacement therapy in the meropenem plus vancomycin group. We found no differences between the groups regarding survival after 1 and 2 years, length of hospital stay, or duration in the intensive care unit. Overall 1-year survival was 78.8% (141/179 patients).

CONCLUSIONS

Although postoperative Enterococcus species infections can be reduced after liver transplant by adding vancomycin to the intraoperative antibiotic regimen, it does not improve the long-term outcomes.

Epidemiology and management of healthcare-associated bloodstream infections in non-neutropenic immunosuppressed patients: a review of the literature

Advancements in medicine have led to a considerable increase in the proportion of patients living with severe chronic diseases, malignancies, and HIV infections. Most of these conditions are associated with acquired immune-deficient states and treatment-related immunosuppression. Although infections as a result of neutropenia have long been recognized and strategies for management were developed, non-neutropenic immunosuppression has been overlooked. Recently, community-acquired infections in patients with frequent, significant exposure to healthcare settings and procedures have been classified as 'healthcare-associated infections' since they are more similar to hospital-acquired infections. Most of the non-neutropenic immunosuppressed patients have frequent contact with the healthcare system due to their chronic and severe diseases. In this review, we focus on the healthcare-associated bloodstream infections in the most common non-neutropenic immunosuppressive states and provide an update of the recent evidence for the management of these infections.

Antibiotic-Resistant Infections and Treatment Challenges in the Immunocompromised Host

This article reviews antibiotic resistance and treatment of bacterial infections in the growing number of patients who are immunocompromised: solid organ transplant recipients, the neutropenic host, and persons with human immunodeficiency virus and AIDS. Specific mechanisms of resistance in both gram-negative and gram-positive bacteria, as well as newer treatment options are addressed elsewhere, and are only briefly discussed in the context of the immunocompromised host.

Mortality Predictors in Acute Respiratory Distress Syndrome Renal Transplant Recipients With ESKAPE/rESKAPE Pneumonia

BACKGROUND

A sustained immunosuppressive state in renal transplant recipients is a factor that can contribute to increased incidence of acute respiratory distress syndrome (ARDS) due to pneumonia. ARDS renal recipients with ESKAPE (E. faecium, S. aureus, K. pneumoniae, A. baumannii, P. aeruginosa, and Enterobacter spp.) pneumonia are probably related to high morbidity and mortality. We therefore sought to investigate the frequency of ESKAPE and resistant ESKAPE (rESKAPE) pathogens isolated from respiratory tract specimens of renal recipients with ARDS and determine the risk factors for mortality.

METHODS

A retrospective analysis of ARDS renal recipients with ESKAPE/rESKAPE pneumonia was reviewed. Multiple logistic regression analysis was conducted to identify the independent risk factors associated with infection-related mortality.

RESULTS

During the study period, 88 ESKAPE pathogens obtained from respiratory tract specimens of 54 ARDS renal recipients were documented including 33 A. baumannii, 24 P. aeruginosa, 17 S. aureus, 6 K. pneumoniae, 8 Enterobacter species, and 0 E. Faecium. Among these ESKAPE organisms, 61.4% (54/88) were antimicrobial resistant. The risk factors for mortality independently associated with ARDS renal recipients with ESKAPE pneumonia were severe ARDS (odds ratio [OR] 4.3 (95% confidence interval [CI] 1.1-16.4), P = .032), serum creatinine level >1.5 mg/dL (OR 4.2 95% CI (1.0-17.9), P = .05) and body temperature less than 38°C (OR 5.0 (95% CI 1.3-19.6), P = .02) at ARDS onset. The independent determinants of mortality were associated with ARDS renal recipients with rESKAPE pneumonia were serum creatinine level >1.5 mg/dL (OR 13.7, 95% CI 1.3-142.1, P = .028) and body temperature less than 38°C (OR 5.5 (95% CI 1.1-26.6) at ARDS onset, P = .035).

CONCLUSIONS

The majority of EPKAPE isolates were antimicrobial resistant. Mortality in ARDS renal recipients with ESKAPE/rESKAPE pneumonia was associated with the severity of ARDS, elevated serum creatinine level, or depressed febrile response at ARDS onset.