Bloodstream infections after solid-organ transplantation

Review of Association between Urinary Tract Infections and Immunosuppressive Drugs after Heart Transplantation

Management of infections in heart transplant recipients is complex and crucial. In this population, there is a need for a better understanding of immunosuppressive trough levels (C0), infectious complications, and urinary tract infections (UTIs). The purpose of this review was to understand the association between immunosuppressive trough levels and UTIs after heart transplantation. A review of scientific literature (n= 100) was conducted based on the topic of interest by searching PUBMED.Gov (https://pubmed.ncbi.nlm.nih.gov/), Web of Science, and Scopus. The analysis of bacterial pulmonary infection required the occurrence of new or deteriorating pulmonary infiltrates and the development of organisms in cultures of sputum specimens. The diagnosis of UTIs was based on the result of related signs, pyuria, and a positive urine culture. The incidence of UTIs was reported as 0.07 episodes/1000 regarding heart transplantation days. An eightfold increase in the rate of rejection was noted in heart transplant recipients with higher variability in tacrolimus C0. There are associations between C0 of immunosuppressive drugs and clinical presentation of infection complications. Recipients with a low metabolism of immunosuppressive drugs are more susceptible to infectious complications. Attention to the biology of herpes viruses, Escherichia coli, Enterococcus spp., Pseudomonas aeruginosa, and Staphylococcus saprophyticus after heart transplantation are important, in which some of them are the most common pathogens responsible for UTIs. Pneumocystis and cytomegalovirus affect all transplant recipients. Pneumonia due to bacterial, viral, protozoa, and fungal infections, in addition to UTIs, are more specific reported types of infections in heart transplant recipients. Bacterial infections produced by extensively drug-resistant Enterobacteriaceae, vancomycin-resistant enterococci, and non-fermenting gramnegative bacteria were reported to increase after transplantation.

The Effect of Enhanced Recovery After Surgery Protocol on Surgical Site Infections in Liver Transplantation

Background: Liver surgeries are treatment modalities that require careful pre- and postoperative follow-up for both the surgeon and the patient. Infections are the leading causes of morbidity and mortality after liver transplantation. Infections are the most frequent cause of death between 30 and 180 days after liver transplantation. We aimed to investigate the effect of the Enhanced Recovery After Surgery (ERAS) protocol on the prevention of infections in liver transplant patients. Patients and Methods: The study included patients who underwent liver transplantation in Ataturk University Organ Transplantation Center between 2017 and 2022. Two patient groups with and without ERAS were formed. Blood and urine cultures were collected retrospectively, and those with positive blood cultures for bacteremia were recorded as infection development. The development of infection between the two groups was statistically compared. Also, all patients' length of intensive care stay, length of hospital stay, and duration of antibiotic use were recorded. These parameters were compared between both groups. Results: There was a statistically significant difference between the two groups in terms of infection development (p: 0.01). There was a statistically significant difference between the two groups in terms of duration of antibiotic use and length of hospital stay (Mann-Whitney U test; p: 0.00, p: 0.04, respectively). There was no statistically significant difference between the two groups in terms of length of intensive care stay. Conclusion: We concluded that the introduction of an ERAS protocol was associated with fewer infections, thus shortening the duration of antibiotic therapy and length of hospital stay, although the standardization of the protocols is difficult, especially in liver transplants.

Multidrug-resistant organism bloodstream infections in solid organ transplant recipients and impact on mortality: a systematic review

Background

Bloodstream infections (BSIs) cause significant morbidity and mortality in solid organ transplant (SOT) recipients. There are few data regarding the contribution of MDR organisms (MDROs) to these infections. We evaluated the resistance percentage of MDRO BSIs in SOT recipients and the associated mortality.

Methods

A systematic review of MEDLINE and Embase databases up to January 2024, for studies of adult SOT recipients that quantified MDRO BSI resistance percentage and/or associated crude mortality. MDROs studied were carbapenem-resistant Enterobacterales (CRE), Acinetobacter baumannii (CRAB) and Pseudomonas aeruginosa (CRPA), third-generation cephalosporin-resistant Enterobacterales (3GCR-E), MRSA and VRE. Resistance percentage and mortality outcomes were reported as median (IQR) and crude mortality (%), respectively.

Results

Of 945 studies identified, 52 were included. Most were retrospective (41/52) and/or single centre (37/52), and liver transplantation was the most frequently studied SOT type (22/52). High resistance percentages of BSIs were noted, ranging from 13.6% CRE for Enterobacterales to 59.2% CRAB for A. baumannii. Resistance percentage trends decreased over time, but these changes were not statistically significant. Asia had the highest resistance percentages for MRSA [86.2% (IQR 77.3%-94.6%)], 3GCR-E [59.5% (IQR 40.5%-66.7%)] and CRE [35.7% (IQR 8.3%-63.1%)]. North America had the highest VRE resistance percentages [77.7% (IQR 54.6%-94.7%)]. Crude mortality was 15.4%-82.4% and was consistently higher than for non-MDRO BSIs.

Conclusions

MDRO BSI resistance percentages were high for all pathogens studied (IQR 24.6%-69.4%) but there was geographical and temporal heterogeneity. MDRO BSIs were associated with high mortality in SOT recipients. Microbiological and clinical data in this vulnerable population were incomplete, highlighting the need for robust international multicentre studies.

Immune response against bacterial infection in organ transplant recipients

This comprehensive review delves into the intricate dynamics between the immune system and bacterial infections in organ transplant recipients. Its primary objective is to fill existing knowledge gaps while critically assessing the strengths and weaknesses of current research. The paper accentuates the delicate balance that must be struck between preventing graft rejection through immunosuppression and maintaining robust immunity against bacterial threats. In this context, personalized medicine emerges as a transformative concept, offering the potential to revolutionize clinical outcomes by tailoring immunosuppressive regimens and vaccination strategies to the unique profiles of transplant recipients. By emphasizing the pivotal role of continuous monitoring, the review underscores the necessity for vigilant surveillance of transplant recipients to detect bacterial infections and associated immune responses early, thereby reducing the risk of severe infections and ultimately improving patient outcomes. Furthermore, the study highlights the significance of the host microbiome in shaping immune responses, suggesting that interventions targeting the microbiome hold promise for enhancing bacterial immunity in transplant recipients, both in research and clinical practice. In terms of future research directions, the review advocates for large-scale, longitudinal studies encompassing diverse patient cohorts to provide more comprehensive insights into post-transplant immune responses. It also advocates integrating multi-omics approaches, including genomics, transcriptomics, proteomics, and microbiome data, to understand immune responses and their underlying mechanisms. In conclusion, this review significantly enriches our understanding of immune responses in transplant recipients. It paves the way for more effective and personalized approaches to managing infections in this complex setting.

Incidence, causative organisms, and risk factors of bloodstream infections in pediatric liver transplant patients: a systematic review

Bacterial bloodstream infections (BSI) are the leading cause of mortality and morbidity in pediatric solid organ transplant recipients. This systematic review aimed to pool global data from leading transplant institutions and identify the overall incidence, risk factors, and causative organisms of BSI in pediatric liver transplant recipients. A systematic review of the PubMed and OVID databases was conducted from 2000 to 2022. The initial search yielded 252 unique articles, which were independently reviewed by 2 authors. Articles that reported pediatric-specific data on BSI in isolated liver transplant patients were included, including the incidence of BSI, isolated organisms, and involved risk factors involved. This systematic review was registered with PROSPERO (ID: CRD42023403206). Fourteen articles from the United States, France, Iran, Japan, Korea, South Africa, Thailand, and Turkey were included. A total of 4,812 liver transplants were included in the final analysis. The mean patient age was 25 months (age range, 0-18 years), and 50.9% were male. The overall incidence of BSI was 23.5% (range, 14.7%-55%). The most commonly reported organisms were Staphylococcus epidermidis, Enterococcus, Klebsiella spp., and Escherichia coli. Among the risk factors studied, postope rative biliary complications, a medical history of biliary atresia, and younger age were the risk factors most commonly associated with BSI. Bacterial BSI after pediatric liver transplantation occur at a high incidence, with a unique organism profile notable for a higher percentage of gram-negative organisms. Further studies are required to determine the most appropriate prophylactic and empirical antibiotic management strategies for this population.

Posttransplant complications: molecular mechanisms and therapeutic interventions

Posttransplantation complications pose a major challenge to the long-term survival and quality of life of organ transplant recipients. These complications encompass immune-mediated complications, infectious complications, metabolic complications, and malignancies, with each type influenced by various risk factors and pathological mechanisms. The molecular mechanisms underlying posttransplantation complications involve a complex interplay of immunological, metabolic, and oncogenic processes, including innate and adaptive immune activation, immunosuppressant side effects, and viral reactivation. Here, we provide a comprehensive overview of the clinical features, risk factors, and molecular mechanisms of major posttransplantation complications. We systematically summarize the current understanding of the immunological basis of allograft rejection and graft-versus-host disease, the metabolic dysregulation associated with immunosuppressive agents, and the role of oncogenic viruses in posttransplantation malignancies. Furthermore, we discuss potential prevention and intervention strategies based on these mechanistic insights, highlighting the importance of optimizing immunosuppressive regimens, enhancing infection prophylaxis, and implementing targeted therapies. We also emphasize the need for future research to develop individualized complication control strategies under the guidance of precision medicine, ultimately improving the prognosis and quality of life of transplant recipients.

Perioperative Use of IgM-Enriched Immunoglobulins in Liver Transplantation Recipients at High Risk for Infections: A Preliminary Study

Background: Infections frequently occur after orthotopic liver transplantation (OLT) and are associated with increased mortality. In 2018, we introduced perioperative administration of intravenous immunoglobulin enriched in IgM as an optional therapy in recipients at a high risk of infection. This preliminary study evaluated whether this preparation reduced infections in the early post-transplantation period. Methods: Adult patients with a high risk of postoperative infections who underwent OLT between January 2014 and December 2021 in our center were included in the study. The primary outcome was the occurrence of new postoperative bacterial and fungal infections within the first 30 days after OLT. Results: Ninety recipients at a high risk of postoperative infections who underwent OLT were included, of whom 51 (57%) received IgM preparation. Patients treated and not treated with IgM were similar in terms of demographics, model of end-stage liver disease score, and risk factors for postoperative infections. The occurrence of new infections was lower (absolute risk reduction (ARR) 21.2%; p = 0.038) in patients who received IgM than in those who did not. Multivariate analysis adjusted for confounders (OR 0.348; p = 0.033) and propensity score-based matching analysis (ARR 21.2%, p = 0.067) confirmed an association between IgM preparation and lower occurrence of postoperative infections. The 90-day mortality rate was lower (ARR 13.4%, p = 0.018) in patients who received IgM preparation. Conclusions: In OLT recipients at high risk for infections, perioperative administration of an IgM-enriched preparation seems to reduce the development of new infections within the first 30 days after OLT.

Clinical characteristics and risk factor analysis of recipients with multidrug-resistant bacterial bloodstream infections after liver transplantation: a single-centre retrospective study

Background

The clinical characteristics and associated risk factors for recipients who experience multidrug-resistant organism (MDRO) bloodstream infections after liver transplantation are poorly understood. This study aimed to analyse the clinical characteristics and epidemiology of pathogenic bacteria and identify associated risk factors in patients who underwent MDRO after liver transplantation.

Method

We retrospectively collected data on recipients who developed bloodstream infections after liver transplantation between 2018 and 2023. Recipients were divided into MDRO and non-MDRO groups based on blood culture results. We explored the risk factors for MDRO bloodstream infections post-transplantation and summarised the clinical features, pathogen epidemiology, and prognosis. A multivariate logistic regression analysis was conducted to identify significant risk factors.

Results

A total of 463 liver transplant recipients were studied, and 73 developed blood infections. There were 29 MDRO cases. The mean duration of the episodes was 26 days (range: 1-474 days). Among these patients, 22 (30.1%) developed blood infections without fever (temperature < 37.3°C), and 33 patients (45.2%) had a white blood cell count between 4 and 10 × 10⁹/L. Among the 108 positive blood cultures, 29 genera were detected, predominantly gram-negative bacilli (n = 64, 58.2%). The detection rate for multidrug-resistant bacilli was 31.8% (35/110), with the abdomen being the most common site of origin (21.3%). Factors such as a history of preoperative intensive care unit (ICU) hospitalisation (p < 0.001) and a preoperative international normalised ratio (INR) > 2 (p < 0.048) were identified as risk factors in multivariate regression analysis.

Conclusion

Multidrug-resistant bacterial bloodstream infections after liver transplantation tend to occur early in the postoperative period (<30 days) and are associated with high mortality and a lack of specific clinical manifestations. A history of preoperative intensive care unit (ICU) hospitalisation and an international normalised ratio (INR) > 2 may be risk factors for multidrug-resistant bacterial bloodstream infections after liver transplantation.

Can the pan-immune-inflammation value predict gram negative bloodstream infection-related 30-day mortality in solid organ transplant patients?

BACKGROUND

The recently used pan-immune-inflammation value (PIV) has not been adequately studied as a predictive marker for mortality in immunosuppressed patients. The aim of this study was to evaluate the usefulness of baseline PIV level as a predictor of 30-day mortality in solid organ transplant (SOT) recipients with gram negative bloodstream infections (GN-BSI).

METHODS

This retrospective, cross-sectional study was conducted between January 1, 2019, and December 31, 2022, in 1104 SOT recipients. During the study period, 118 GN-BSI were recorded in 113 patients. Clinical, epidemiological, and laboratory data were collected, and mortality rates (30-day and all-cause) were recorded.

RESULTS

The 113 recipients had a median age of 50 years [interquartile range (IQR) 37.5-61.5 years] with a male predominance (n = 72, 63.7%). The three most common microorganisms were as follows: 46 isolates (38.9%) of Escherichia coli, 41 (34.7%) of Klebsiella pneumoniae, and 12 (10.2%) of Acinetobacter baumannii. In 44.9% and 35.6% of the isolates, production of extended-spectrum beta-lactamases and carbapenem resistance were detected, respectively. The incidence of carbapenem-resistant GN-BSI was higher in liver recipients than in renal recipients (n = 27, 69.2% vs n = 13, 17.6%, p < 0.001). All-cause and 30-day mortality rates after GN-BSI were 26.5% (n = 30), and 16.8% (n = 19), respectively. In the group with GN-BSI-related 30-day mortality, the median PIV level was significantly lower (327.3, IQR 64.8-795.4 vs. 1049.6, IQR 338.6-2177.1; p = 0.002). The binary logistic regression analysis identified low PIV level [hazard ratio (HR) = 0.93, 95% confidence interval (CI) 0.86-0.99; p = 0.04], and increased age (HR = 1.05, 95% CI 1.01-1.09; p = 0.002) as factors associated with 30-day mortality. The receiver operating characteristic analysis revealed that PIV could determine the GN-BSI-related 30-day mortality with area under curve (AUC): 0.723, 95% CI 0.597-0.848, p = 0.0005.

CONCLUSIONS

PIV is a simple and inexpensive biomarker that can be used to estimate mortality in immunosuppressed patients, but the results need to be interpreted carefully.

Plant-Origin Components: New Players to Combat Antibiotic Resistance in Klebsiella pneumoniae

Klebsiella pneumoniae (Kpn) is an opportunistic pathogen that causes intrahospital complications such as pneumonia, liver abscesses, soft tissue infections, urinary infections, bacteraemia, and, in some cases, death. Since this bacterium has a higher frequency than other Gram-negative pathogens, it has become an important pathogen to the health sector. The adaptative genome of Kpn likely facilitates increased survival of the pathogen in diverse situations. Therefore, several studies have been focused on developing new molecules, synergistic formulations, and biomaterials that make it possible to combat and control infections with and dispersion of this pathogen. Note that the uncontrolled antibiotic administration that occurred during the pandemic led to the emergence of new multidrug-resistant strains, and scientists were challenged to overcome them. This review aims to compile the latest information on Kpn that generates intrahospital infections, specifically their pathogenicity-associated factors. Furthermore, it explains the natural-product-based treatments (extracts and essential oils) developed for Kpn infection and dispersion control.

Bloodstream infections after solid organ transplantation: clinical epidemiology and antimicrobial resistance (2016-21)

Background

Solid organ transplant (SOT) recipients are at risk of bloodstream infections (BSIs) with MDR organisms (MDROs).

Objectives

To describe the epidemiology of BSI in the year after several types of SOT, as well as the prevalence of MDRO infections in this population.

Methods

We conducted a single-centre, retrospective study of kidney, liver, heart, and multi-organ transplantation patients. We examined BSIs ≤1 year from SOT and classified MDRO phenotypes for Staphylococcus aureus, enterococci, Enterobacterales, Pseudomonas aeruginosa and Candida spp. We compared BSI characteristics between SOT types and determined risk factors for 90 day mortality.

Results

We included 2293 patients [1251 (54.6%) kidney, 663 (28.9%) liver, 219 (9.6%) heart and 160 (7.0%) multi-organ transplant]. Overall, 8.5% of patients developed a BSI. BSIs were most common after multi-organ (23.1%) and liver (11.3%) transplantation (P < 0.001). Among 196 patients with BSI, 323 unique isolates were recovered, 147 (45.5%) of which were MDROs. MDROs were most common after liver transplant (53.4%). The most frequent MDROs were VRE (69.8% of enterococci) and ESBL-producing and carbapenem-resistant Enterobacterales (29.2% and 27.2% of Enterobacterales, respectively). Mortality after BSI was 9.7%; VRE was independently associated with mortality (adjusted OR 6.0, 95% CI 1.7-21.3).

Conclusions

BSI incidence after SOT was 8.5%, with a high proportion of MDROs (45.5%), especially after liver transplantation. These data, in conjunction with local antimicrobial resistance patterns and prescribing practices, may help guide empirical antimicrobial selection and stewardship practices after SOT.

Approach to multidrug resistant infections in pediatric transplant recipients

Introduction

There is increasing recognition of infections due to multidrug-resistant Gram negative (MDRGN) bacterial infections among children undergoing solid organ and hematopoietic cell transplantation, which may be associated with morbidity and mortality.

Methods

We present two vignettes that highlight the clinical challenges of evaluation, management, and prevention of MDRGN bacterial infections in children prior to and after transplantation. The goal of this discussion is to provide a framework to help develop an approach to evaluation and management of these infections.

Results

Source control remains the utmost priority in management of MDR infections and is paired with antibiotic selection guided by in vitro susceptibilities, adverse effect profiles, and clinical response. Identification and confirmation of resistance can be challenging and often requires additional testing for recognition of complex mechanisms. Current antimicrobial approaches to MDRGN infections include use of novel agents, prolonged infusion, and/or combination therapy. We also discuss preventative efforts including infection control, antimicrobial stewardship, targeted pre-emptive or prophylactic treatment, and decolonization.

Discussion

The impact of MDRGN infections on patient and graft survival highlights the need to optimize treatment and prevention strategies.

Candidemia in thoracic solid organ transplant recipients: Characteristics and outcomes relative to matched uninfected and bacteremic thoracic organ transplant recipients

BACKGROUND

Little is understood about the risk factors and outcomes from candidemia in thoracic solid organ transplant recipients.

METHODS

This is a single-center retrospective cohort study of patients undergoing heart or lung transplant between January 1, 2013 and December 31, 2022. We performed two comparisons among heart and lung transplant recipients: (1) recipients with candidemia versus matched, uninfected recipients, and (2) recipients with candidemia versus recipients with bacteremia.

RESULTS

During the study 384 heart and 194 lung transplants were performed. Twenty-one (5.5%) heart and six (3.1%) lung recipients developed candidemia. Heart recipients with candidemia were more likely to have had delayed chest closure (38.1% vs. 0%, p < .0001), temporary mechanical circulatory support (57.1% vs. 11.9%, p = .0003), and repeat surgical chest exploration 76.2% vs. 16.7%, p < .0001) than uninfected controls. Heart and lung recipients who developed candidemia were more likely to have been on renal replacement therapy prior to infection relative to uninfected controls (57.1% vs. 11.9%, p = .0003 and 66.7% vs. 0%, p = .0041, respectively). Heart recipients with candidemia had significantly lower post-transplant survival and lower post-infection survival relative to matched uninfected controls and heart recipients with bacteremia, respectively (p < .0001 and p = .0002, respectively).

CONCLUSIONS

Candidemia following heart and lung transplantation is associated with significant morbidity and mortality. Further research is needed to understand if heart recipients with delayed chest closure, temporary mechanical circulatory support, renal replacement therapy, and repeat surgical chest exploration may benefit from targeted antifungal prophylaxis.

Risk factors of early bacterial infection and analysis of bacterial composition, distribution and drug susceptibility after cadaveric liver transplantation

BACKGROUND

This study provided a theoretical basis for the clinical diagnosis and treatment of bacterial infection after liver transplantation through analyzing the pathogenic distribution, drug sensitivity and risk factors of bacterial infection after liver transplantation.

METHODS

We collected clinical data from 207 recipients undergoing liver transplantation of graft from donation after citizens' death donors in the Third Xiangya Hospital of Central South University from January 2019 to December 2021 and analyzed the composition and distribution of bacterial pathogens, drug resistance and risk factors of infection.

RESULTS

A total of 90 bacterial infections occurred in 55 recipients within two months after liver transplantation, and the incidence of bacterial infection was 26.6% (55/207). The gram-negative bacteria (46/90, 51.1%) were more prevalent than gram-positive bacteria (44/90, 48.9%). Common sites of infection were the abdominal/biliary tract (26/90, 28.9%), lung (22/90, 22.4%) and urinary tract (22/90, 22.4%). Fourteen cases (6.8%) died after liver transplantation. Klebsiella pneumoniae (17/90, 18.9%) was the most frequent gram-negative bacteria causing infection in liver transplant recipients and 58.7%, 50%, 80.4% and 89.1% of gram-negative bacteria were sensitive to amikacin, minocycline, tigecycline and polymyxin B, respectively. The most common gram-positive bacteria was Enterococcus faecium (30/90, 33.3%) and 97.7%, 100%, 86.4%, 100% and 100% of gram-positive bacteria were sensitive to vancomycin, teicoplanin, daptomycin, tigecycline and linezolid, respectively. Univariate analysis revealed that bacterial infection was associated with female, age (≥ 50 years old), preoperative albumin (≤ 30 g/L), operation duration (≥ 400 min), intraoperative blood loss (≥ 3000 ml) and postoperative ventilator support. Binary Logistic regression analysis showed that female (OR = 3.149, 95% CI: 1.418-6.993, P = 0.005), operation duration (≥ 400 min) (OR = 2.393, 95% CI: 1.202-4.765, P = 0.013) and intraoperative blood loss (≥ 3000 ml) (OR = 2.052, 95% CI: 1.007-4.183, P = 0.048) were independent risk factors for bacterial infection after liver transplantation.

CONCLUSION

The incidence of early bacterial infection after liver transplantation was high, and the infection sites were mainly abdominal/biliary tract, respiratory tract and urinary tract. The most common pathogenic bacterium was gram-negative bacterium. Our study also identified several independent risk factors for bacterial infection after liver transplantation, including female gender, operation duration of 400 min or more, and intraoperative blood loss of 3000 ml or more. By addressing these risk factors, such as implementing strategies to optimize surgical procedures and minimize blood loss, healthcare professionals can work towards reducing the incidence of bacterial infections following liver transplantation.

Risk Factors and Outcome of Gram-Negative Bloodstream Infection in Living-Donor Renal Transplant Recipients: A Case-Control Study From Pakistan

OBJECTIVES

Gram-negative rods are the most common cause of bloodstream infection in renal transplant recipients. Acute rejection, urologic abnormalities, and ureteral stents are risk factors. Graft dysfunction is independently associated with gram-negative rod bloodstream infection. Our aim is to investigate the incidence, risk factors, and outcome among living donor renal transplant recipients from Pakistan.

MATERIALS AND METHODS

In this case-control study, we reviewed the medical records until June 2021 of renal transplant recipients seen from 2015 to 2019 for gram negative bacteremia. For every case, controls were matched by age, date of transplant, and sex. Demographics, risk factors, graft function, and mortality were compared. Clinical features, immunosuppression, source of blood stream infection, and microbiology were noted in cases.

RESULTS

Of 1677 renal transplant recipients, 44 developed gram negative bacteremia. The incidence was 5.9 per 1000 person-years. Median time since transplant was 5 months. The most common source was urinary tract infection. On univariate analysis, antithymocyte globulin, urinary tract infection, and recurrent urinary tract infections were associated with gram negative bacteremia. On multivariate analysis, urinary tract infection (adjusted odds ratio = 3.46; 95% CI, 1.27-9.37) and recurrent urinary tract infections (adjusted odds ratio = 4.03; 95% CI, 1.15-14.15) were significant risk factors. We found no difference in 30-day mortality and estimated glomerular filtration rate on last follow-up between cases and controls. Kaplan-Meier survival curves showed significant differences in graft survival in patients with gram negative bacteremia. Escherichia coli was the most common organism, with 75% ceftriaxone and 13% imipenem resistance.

CONCLUSIONS

The most significant risk factor for gram negative rod bloodstream infection was recurrent urinary tract infections. Timely treatment and prevention of recurrent urinary tract infections areimperative for prevention of gram negative bacteremia.

A, Sivaprasadan S, S. S. Immunosuppression in Liver Transplant Recipients in the Setting of Sepsis

Management of immunosuppression (IS) in liver transplant recipients in the setting of sepsis is an open stage for debate. The age-long practice of reduction or complete cessation of IS during sepsis has been followed by most centres across the world, although, their exact strategies are highly heterogeneous. On the other hand, the emergence of striking new evidence suggesting that there is, in fact, decreased mortality with the continuation of IS in sepsis, has raised doubts about our previously conceived intuitive notion that IS portends increased risk in sepsis. The theory postulated is that IS agents, perhaps reverse the state of dysregulated immune response in sepsis to that of an iatrogenically modulated immune response, thus dimming the inflammatory cascade and preventing its deleterious effects. Of note, none of these studies reported exaggerated rejection-related complications. These contrasting outlooks have made it rather onerous to formulate an evidence-based recommendation for liver transplant recipients afflicted with sepsis. Inclusion of transplanted patients in randomised controlled trials of sepsis-related interventions seems to be the need of the hour.

Bacteremia During the First Year After Solid Organ Transplantation: An Epidemiological Update

Background

There are limited contemporary data on the epidemiology and outcomes of bacteremia in solid organ transplant recipients (SOTr).

Methods

Using the Swiss Transplant Cohort Study registry from 2008 to 2019, we performed a retrospective nested multicenter cohort study to describe the epidemiology of bacteremia in SOTr during the first year post-transplant.

Results

Of 4383 patients, 415 (9.5%) with 557 cases of bacteremia due to 627 pathogens were identified. One-year incidence was 9.5%, 12.8%, 11.4%, 9.8%, 8.3%, and 5.9% for all, heart, liver, lung, kidney, and kidney-pancreas SOTr, respectively (P = .003). Incidence decreased during the study period (hazard ratio, 0.66; P < .001). One-year incidence due to gram-negative bacilli (GNB), gram-positive cocci (GPC), and gram-positive bacilli (GPB) was 5.62%, 2.81%, and 0.23%, respectively. Seven (of 28, 25%) Staphylococcus aureus isolates were methicillin-resistant, 2/67 (3%) enterococci were vancomycin-resistant, and 32/250 (12.8%) GNB produced extended-spectrum beta-lactamases. Risk factors for bacteremia within 1 year post-transplant included age, diabetes, cardiopulmonary diseases, surgical/medical post-transplant complications, rejection, and fungal infections. Predictors for bacteremia during the first 30 days post-transplant included surgical post-transplant complications, rejection, deceased donor, and liver and lung transplantation. Transplantation in 2014-2019, CMV donor-negative/recipient-negative serology, and cotrimoxazole Pneumocystis prophylaxis were protective against bacteremia. Thirty-day mortality in SOTr with bacteremia was 3% and did not differ by SOT type.

Conclusions

Almost 1/10 SOTr may develop bacteremia during the first year post-transplant associated with low mortality. Lower bacteremia rates have been observed since 2014 and in patients receiving cotrimoxazole prophylaxis. Variabilities in incidence, timing, and pathogen of bacteremia across different SOT types may be used to tailor prophylactic and clinical approaches.

Antibiotic stewardship implementation at the largest solid organ transplantation center in Asia: a retrospective cohort study

BACKGROUND

Using Antimicrobial stewardship programs (ASP) to monitor the use of antibiotics can lead to improved antibiotic use and reduced costs.

METHODS

This retrospective cohort study was done at Shiraz Organ Transplant Center, the largest transplant center in Asia. Antimicrobial use, cost, clinical outcomes, and antibiotic resistance pattern were evaluated before and after ASP.

RESULTS

This study included 2791 patients, 1154 of whom were related to the time before ASP and 1637 to the time after ASP. During the period of the research, a total of 4051 interventions were done. The use of all classes of antibiotics was significantly reduced by ASP, with 329 DDD/100PD before the intervention compared to 201 DDD/100PD after it (p = 0.04). In addition, the overall cost of antibiotics purchased was much lower after the ASP measures were implemented ($43.10 per PD) than before implementation of the ASP measures ($60.60 per PD) (p = 0.03). After the implementation of ASP, the number of MDR isolates was significantly reduced.

CONCLUSION

The results of our study showed that the implementation of ASP significantly reduced the number and costs of antibiotics and also the number of resistant pathogens, but did not affect the patients' length of stay.

Retrospective analysis of drug resistance characteristics and infection related risk factors of multidrug-resistant organisms (MDROs) isolated from the orthopedics department of a tertiary hospital

Patients infected with multidrug-resistant organisms (MDROs) are known to exhibit longer hospital stays and a significantly poorer prognosis. We performed a 6-year retrospective analysis of nosocomial infections reported in the orthopedics department of our institution, to gain valuable insights into antibiotic sensitivity and infectious characteristics of MDROs, in order to deduce effective measures to control the occurrence of multidrug-resistant infections in clinical practice. A retrospective, single center surveillance study (January 2012-December 2017) was performed on the nosocomial infections recorded in the department of orthopedics. A nosocomial infection is defined as one that develops when a patient is residing in a hospital but was not present at the time of admission. All relevant data, including basic patient information, cultivated bacterial strains, and antimicrobial resistance, was obtained from the hospital information system. A total of 1392 strains of pathogenic bacteria were isolated; 358 belonged to MDROs (detection rate = 25.7%). All the isolated strains of MDROs were mostly from secretions (52.2%). The number of cases infected with MDROs were 144 (40.2%) and 129 (36.0%) in the trauma and spinal wards, respectively. MRSA showed high resistance to β lactam antibiotics, but was sensitive to quinolone antibiotics, linezolid and cotrimoxazole. ESBL-positive strains showed more sensitivity to carbapenem antibiotics (resistance rate < 10%). MDR nonfermenters showed high resistance to most antibiotics. Logistic multivariate analysis revealed age, open injury, and central nervous system injury as independent risk factors for multidrug resistant infections. A high antibiotic resistance rate and an increasing prevalence of infections with MDROs was identified in the orthopedics department. Patients with open injury, central nervous system injury and those aged ≥ 60 years, were more prone to multidrug-resistant infections. Clinicians should pay more attention to such patients in order to actively prevent and control the occurrence of infections caused by MDROs.

Pseudomonas aeruginosa: Infections, Animal Modeling, and Therapeutics

Pseudomonas aeruginosa is an important Gram-negative opportunistic pathogen which causes many severe acute and chronic infections with high morbidity, and mortality rates as high as 40%. What makes P. aeruginosa a particularly challenging pathogen is its high intrinsic and acquired resistance to many of the available antibiotics. In this review, we review the important acute and chronic infections caused by this pathogen. We next discuss various animal models which have been developed to evaluate P. aeruginosa pathogenesis and assess therapeutics against this pathogen. Next, we review current treatments (antibiotics and vaccines) and provide an overview of their efficacies and their limitations. Finally, we highlight exciting literature on novel antibiotic-free strategies to control P. aeruginosa infections.

Bacteraemia Is Associated with Increased ICU Mortality in the Postoperative Course of Lung Transplantation

We aimed to describe the prevalence, risk factors, morbidity and mortality associated with the occurrence of bacteraemia during the postoperative ICU stay after lung transplantation (LT). We conducted a retrospective single-centre study that included all consecutive patients who underwent LT between January 2015 and October 2021. We analysed all the blood cultures drawn during the postoperative ICU stay, as well as samples from suspected infectious sources in case of bacteraemia. Forty-six bacteria were isolated from 45 bacteraemic patients in 33/303 (10.9%) patients during the postoperative ICU stay. Staphylococcus aureus (17.8%) was the most frequent bacteria, followed by Pseudomonas aeruginosa (15.6%) and Enterococcus faecium (15.6%). Multidrug-resistant bacteria accounted for 8/46 (17.8%) of the isolates. The most common source of bacteraemia was pneumonia (38.3%). No pre- or intraoperative risk factor for bacteraemia was identified. Recipients who experienced bacteraemia required more renal replacement therapy, invasive mechanical ventilation, norepinephrine support, tracheotomy and more days of hospitalization during the ICU stay. After adjustment for age, sex, type of LT procedure and the need for intraoperative ECMO, the occurrence of bacteraemia was associated with a higher mortality rate in the ICU (aOR = 3.55, 95% CI [1.56–8.08], p = 0.003). Bacteraemia is a major source of concern for lung transplant recipients.

A retrospective observational study of the treatment with polymyxin B for liver transplantation recipients infected by multidrug-resistant gram-negative bacteria

WHAT IS KNOWN AND OBJECTIVE

Only a few studies about polymyxin B (PMB) against multidrug-resistant gram-negative bacteria (MDR GNB) infection were conducted in liver transplantation recipients (LTRs). The purpose of this study was to investigate the efficacy and safety of PMB in the treatment of MDR-GNB in liver transplant recipients and to determine the risk factors affecting clinical cure and 30-day all-cause mortality.

METHODS

Data of LTRs receiving PMB from January 2016 to February 2020 were collected. Clinical cure and 30-day all-cause mortality were the main efficacy outcomes, while the incidence of nephrotoxicity, neurotoxicity, and hyperpigmentation of PMB was the main safety outcome.

RESULTS AND DISCUSSION

Data of 42 LTRs were included. Clinical cure with PMB was observed in 27 recipients (64.3%), and the 30-day all-cause mortality rate was 31.0% (13/42). The incidence of acute kidney injury (AKI), neurotoxicity, and hyperpigmentation was 57.1% (16/28), 4.8% (2/42), and 16.7% (7/42), respectively. Logistic regression analysis showed that Acute Physiology and Chronic Health Evaluation (APACHE) II score (OR, 1.203; 95% CI, 1.016-1.423, p = 0.032) was an independent risk factor for 30-day all-cause mortality, whereas renal replacement therapy (OR, 0.128; 95% CI, 0.019-0.860, p = 0.034) was an independent risk factor for clinical cure with PMB.

WHAT IS NEW AND CONCLUSIONS

This is the first study to evaluate the application of PMB in LTRs. If there were no better therapeutic options left for LTRs other than PMB, it can be used against MDR GNB infection in LTRs. We should closely observe adverse events or reactions, and adjust the dose based on the balance of efficacy and safety.

Risk Factors and Outcomes of Acute Graft Pyelonephritis with Bacteremia Due to Multidrug-Resistant Gram-Negative Bacilli among Kidney Transplant Recipients

Acute graft pyelonephritis (AGP) is the leading cause of bloodstream infection in kidney transplant (KT) recipients. The prevalence of urinary tract infections caused by multidrug-resistant (MDR) Gram-negative bacilli is increasing. This 14-year prospective observational study sought to determine the clinical characteristics, risk factors, and outcomes of AGP with bacteremia due to MDR Gram-negative bacilli. Overall, 278 episodes of AGP with bacteremia due to MDR Gram-negative and non-MDR Gram-negative bacilli were identified and compared in 214 KT recipients; MDR Gram-negative bacilli were the cause in 28.4%. Overall 30-day mortality was low (1.1%). Risk factors independently associated with AGP due to MDR Gram-negative bacilli were male sex (OR 3.08; 95%CI 1.60–5.93), previous episode of bacteremic AGP (OR 2.11, 95%CI 1.09–4.09), prior antibiotic therapy in the preceding month (OR 2.47, 95%CI 1.33–4.57), and nosocomial acquisition (OR 2.03, 95%CI 1.14–3.62). Forty-three percent of MDR Gram-negative episodes received inappropriate empirical antibiotic therapy. The risk factors identified in this study may help physicians when selecting empirical antibiotic treatment for AGP. Previous antibiotic use was the main modifiable factor. Its presence highlights the importance of avoiding unnecessary antibiotics in order to bring down the high rates of MDR Gram-negative bacilli infections in this population.

In-hospital mortality and length of stay among patients with infective endocarditis and solid organ transplant: A study from National Inpatient Sample 2016-2019

Infective endocarditis (IE) is a rare but serious complication following a Solid Organ Transplant (SOT). Due to the lack of sufficient studies, we aimed to compare in-hospital mortality and length of stay (LOS) of patients primarily admitted for IE (index or principal hospitalization) with history of SOT, including the subgroup of heart or lung transplant (HLT), to those without a history of SOT (non-SOT) or HLT (non-HLT). We used the 2016–2019 National Inpatient Sample, the largest all-payer inpatient hospital data from Healthcare Cost and Utilization Project (HCUP), including patients 18 years or older with IE, as a principal diagnosis for hospitalization. From 2016 to 2019, there were 56,330 principal or index hospitalizations for IE. Among them, 0.6 % (n = 327) were SOT recipients, 0.1% (n = 68) were HLT recipients, and 41.4% were females. The mean age was 51.9 ± 19.2 years. Compared to non-SOT controls, SOT recipients were older (mean age 59.3 vs. 51.8 years; P = 0.002) and had higher Charlson-comorbidity-index (CCI) of 3 or more (87.7% vs. 33.2%; p < 0.001). SOT status was not statistically significant for a higher or lower odds of in-hospital mortality (adjusted odds ratio (aOR) 0.7; 95% confidence interval (CI): 0.2, 2.4; p = 0.60) or increased or decreased LOS (coefficient: -0.1, 95% CI: -0.4, 0.1; p = 0.23) among index IE hospitalizations after controlling for age, sex, race, hospital-region, hospital-teaching status, income, insurance status, and CCI. HLT status was also not associated with higher or lower odds of in-hospital mortality (aOR 1.4; 95% CI: 0.2, 13.1; p = 0.77) or increased or decreased LOS (coefficient: -0.1, 95% CI: -0.3, 0.5; p = 0.59). From 2016 to 2019, the rate of index IE hospitalization trends from 37.8 to 41.4 per 100,000 overall hospitalizations (p = 0.001). We found the rate of index IE hospitalizations increasing with time. Among index IE hospitalizations, SOT, including a subgroup of HLT recipients, have similar in-hospital mortality and LOS compared to non-SOT or non-HLT groups. We need a larger sample size to comment on outcomes of IE hospitalizations with the HLT subgroup.

The Role of Peritoneal Dialysis in Different Phases of Kidney Transplantation

The utilization of peritoneal dialysis (PD) has been increasing in the past decade owing to various government initiatives and recognition of benefits such as better preservation of residual renal function, quality of life, and lower cost. The Advancing American Kidney Health initiative aims to increase the utilization of home therapies such as PD and kidney transplantation to treat end stage kidney disease (ESKD). A natural consequence of this development is that more patients will receive PD, and many will eventually undergo kidney transplantation. Therefore, it is important to understand the effect of pretransplant PD on posttransplant outcomes such as delayed graft function (DGF), rejection, thrombosis, graft, and patient survival. Furthermore, some of these patients may develop DGF, which raises the question of the utility of PD during DGF and its risks. Although transplant is the best renal replacement therapy option, it is not everlasting, and many transplant recipients must go on dialysis after allograft failure. Can PD be a good option for these patients? This is another critical question. Furthermore, a significant proportion of nonrenal solid organ transplant recipients develop ESKD. Is PD feasible in this group? In this review, we try to address all of these questions in the light of available evidence.

Infection with Two Multi-Drug-Resistant Organisms in Solid Organ Transplant Patients Is Associated with Increased Mortality and Prolonged Hospitalization

Background: Solid organ transplant recipients have several risk factors for peri-operative multi-drug-resistant infection: their immune system is dampened as a result of critical illness and surgical stress that may be further impaired by induction immunotherapy and broad-spectrum antibiotic prophylaxis promotes selection for resistant pathogens. Infection with multi-drug-resistant organisms (MDRO) results in morbidity and mortality for solid organ transplant recipients. Patients and Methods: To assess in-hospital mortality and hospitalization duration associated with these infections, we analyzed cross-sectional, retrospective data from the 2016 Agency for Healthcare and Quality, Healthcare Cost and Utilization Project's National Inpatient Sample. Our analysis included 31,105 index admissions records for liver, kidney, heart, lung, and pancreas transplant recipients in the United States. Outcomes were assessed by multivariable regression analysis adjusting for covariables. Results: One percent (355/29,451) of patients with diagnosis of no MDRO infections died, 3% (40/1491) with diagnosis of one MDRO infection died, and 15% (25/166) with diagnosis of two MDRO infections died. Diagnosis of one MDRO infection was associated with a 20-day increase in hospitalization duration (95% confidence interval [CI], 17-22) but not increased odds of death (odds ratio [OR], 1.2; 95% CI, 0.5-2.5). Diagnosis of two MDRO infections was associated with an increased odds of death (OR, 9.6' 95% CI, 3.3-27.9) and a 41-day increase in hospitalization duration (95% CI, 34-49). Conclusions: Strategies to decrease peri-operative MDRO infection may improve survival and decrease duration of hospitalization for solid organ transplant patients.

Pseudomonas aeruginosa Pneumonia: Evolution of Antimicrobial Resistance and Implications for Therapy

Pseudomonas aeruginosa (PA), a non-lactose-fermenting gram-negative bacillus, is a common cause of nosocomial infections in critically ill or debilitated patients, particularly ventilator-associated pneumonia (VAP), and infections of urinary tract, intra-abdominal, wounds, skin/soft tissue, and bloodstream. PA rarely affects healthy individuals, but may cause serious infections in patients with chronic structural lung disease, comorbidities, advanced age, impaired immune defenses, or with medical devices (e.g., urinary or intravascular catheters, foreign bodies). Treatment of pseudomonal infections is difficult, as PA is intrinsically resistant to multiple antimicrobials, and may acquire new resistance determinants even while on antimicrobial therapy. Mortality associated with pseudomonal VAP or bacteremias is high (> 35%) and optimal therapy is controversial. Over the past three decades, antimicrobial resistance (AMR) among PA has escalated globally, via dissemination of several international multidrug resistant "epidemic" clones. We discuss the importance of PA as a cause of pneumonia including health care-associated pneumonia, hospital-acquired pneumonia, VAP, the emergence of AMR to this pathogen, and approaches to therapy (both empirical and definitive).

Incidencia de infecciones en el postrasplante renal inmediato

Introducción: El receptor de un trasplante renal es un paciente de alto riesgo para sufrir infección debido a las potenciales complicaciones quirúrgicas y al tratamiento inmunosupresor que reciben.El desarrollo de infecciones supone un riesgo aumentado de pérdida del injerto y de la mortalidad. Objetivos: El objetivo principal fue conocer la incidencia de las infecciones más frecuentes en el paciente con un trasplante renal, durante el periodo postrasplante inmediato.Los objetivos secundarios fueron describir los gérmenes responsables de las infecciones más frecuentes y analizar la relación entre los tipos de infección estudiados y sus posibles factores de riesgo. Metodología: Estudio observacional retrospectivo en pacientes trasplantados renales entre enero de 2018 y diciembre de 2019 durante el periodo del postrasplante inmediato.Resultados: La incidencia de infección fue 69,4%, los síndromes descritos fueron infección del tracto urinario (48%), bacteriemia (9,2%), infección relacionada con catéter (8,2%) e infección por citomegalovirus (4,1%). Los microorganimos más frecuentemente implicados, en estos procesos infecciosos fueron Escherichia coli (16,3%), Enterococus faecium (12,2%) y Enterobacter cloacae (8,1%).Se ha encontrado relación significativa entre la aparición de infección y la duración del ingreso, así como con la presencia o no del antecedente personal de hipertensión arterial. También entre la incidencia de infección relacionada con el catéter venoso central y el tiempo que permaneció insertado. Conclusiones: La infección más frecuente encontrada en el postrasplante renal inmediato fue la infección del tracto urinario, mientras que el microorganismo más presente habitualmente en los procesos infecciosos fue la Escherichia coli.

Carbapenemase-Producing Klebsiella pneumoniae Colonization and Infection in Solid Organ Transplant Recipients: A Single-Center, Retrospective Study

Carbapenemase-KPC producing Klebsiella pneumoniae (CP-Kp) infection represents a serious threat to solid organ transplant (SOT). All patients admitted between 1 May 2011 and 31 August 2014 undergoing SOT were included in the retrospective study. The primary outcomes included a description of the association of enteric colonization and invasive infections by CP-Kp with one-year mortality. Secondary outcomes were the study of risk factors for colonization and invasive infections by CP-Kp. Results: A total of 5.4% (45/828) of SOT recipients had at least one positive rectal swab for CP-Kp, with most (88.9%) occurring after transplantation. 4.5% (35/828) of patients developed a CP-Kp-related invasive infection, with 68.6% (24/35) being previously colonized. The 1-year mortality was 31.1% in patients with enteric colonization with CP-Kp and, it was 51.4% among patients with CP-Kp-related invasive infections. At univariate analysis, colonization, invasive infections, sepsis, severe sepsis, and septic shock were significantly associated with 1-year mortality. At multivariate analysis, only invasive infections and the combination of sepsis, severe sepsis, or septic shock were significantly associated with 1-year mortality, whereas gastrointestinal colonization was significantly associated with survival. In this population, the 1-year mortality was significantly associated with invasive infections; otherwise, gastrointestinal colonization was not associated with increased 1-year mortality.

Clonality, virulence genes, and antibiotic resistance of Staphylococcus aureus isolated from blood in Shandong, China

BACKGROUND

Bloodstream infection (BSI) caused by Staphylococcus aureus (S. aureus) can be life-threatening and pose a great challenge to infection control and clinical treatment. However, little information exists regarding the characterization of S. aureus in BSI patients in Shandong, China. To identify the clonality, virulence genes, and antibiotic resistance of S. aureus in blood, a total of 101 nonrepetitive blood isolates were collected. The antibiotic resistance phenotypes were determined, and virulence genes were analyzed with polymerase chain reaction (PCR). Finally, the genetic relatedness was investigated with Staphylococcus chromosomal cassette mec (SCCmec) typing for methicillin-resistant S. aureus (MRSA) isolates, Staphylococcal protein A (spa), and multilocus sequence typing (MLST) for all of 101 isolates.

RESULTS

Of the 101 S. aureus isolates, 24 MRSA isolates and 77 methicillin-susceptible S. aureus (MSSA) isolates were identified. Overall, MRSA isolates had higher resistance rates than MSSA isolates when exposed to any of the 15 antibiotics tested in this study except for trimethoprim/sulfamethoxazole. Among the 17 virulence genes tested in this study, hla, hld, and hlg could be detected in all isolates. MRSA isolates were more likely to carry seb and hlb genes, while MSSA isolates were more likely to carry seg and sei genes. Thirty-five sequence types (STs) and 49 spa types were identified, of which ST59-t437 and ST398-t571 were the most abundant. These two genotypes were also the most abundant ST-spa types in MRSA and MSSA isolates, but their abundances shifted over time, with ST398-t571 being the predominant genotype from 2016 to 2017, and ST59-t437 from 2018 to 2020. Besides, all the ST59-t437 isolates harbored hlgb gene, whereas most (88.9%) ST398-t571 did not. In addition, twenty-four MRSA isolates were subject to SCCmec typing. SCCmec IVa was the most prevalent SCCmec type, and all the ST59-t437 MRSA isolates were SCCmec IVa. We also observed 15 new STs, and some of them were MRSA.

CONCLUSION

These findings provide additional observations and epidemiological data for blood S. aureus isolates, which can improve future infection-control measures and aid in potential clinical treatments in hospitals and other clinical settings.

Enterococcal Infections the First Year after Liver Transplantation-A Prospective Cohort Study

This study aimed to investigate the incidence of enterococcal infections and determine risk factors associated with enterococcal bloodstream infection (BSI) within the first year post-liver transplantation (LTx). We included 321 adult liver transplant recipients transplanted from 2011 to 2019 in a prospective cohort study. Cumulative incidence of enterococcal infections and risk factors associated with BSI were investigated in a competing risk model and time-updated Cox models, respectively. A total of 223 enterococcal infections were identified in 89 recipients. The cumulative incidences of first enterococcal infection and first enterococcal BSI were 28% (95% CI (23-33)) and 11% (CI (7-14)), respectively. Risk factors associated with enterococcal BSI were previous infections in the biliary tract (HR, 33; CI (15-74); p < 0.001), peritoneum (HR, 8.1; CI (3-23); p < 0.001) or surgical site (HR, 5.5; CI (1.4-22); p = 0.02), recipient age (HR per 10 years increase, 1.2; CI (1.03-1.6); p = 0.03), and cold ischemia time (HR per one hour increase, 1.2; CI (1.1-1.3); p < 0.01). Enterococcal infections are highly prevalent the first year post-LTx, and recipients with enterococcal infections in the biliary tract, peritoneum, or surgical site are at increased risk of BSI. These findings may have implications for the choice of empiric antibiotics early post-LTx.

New drugs for difficult bugs: management of multidrug-resistant gram-negative infections in solid organ transplant recipients

PURPOSE OF REVIEW

Multidrug-resistant Gram-negative bacteria remain a significant threat to patient and allograft survival. Management of these infections in solid organ transplant (SOT) recipients remains challenging due to a limited antimicrobial pipeline and reliance on novel agents, which have not been systematically evaluated in the transplant population.

RECENT FINDINGS

Novel antimicrobials, including the second-generation β-lactam/β-lactamase inhibitors, cefiderocol, plazomicin and eravacycline, have been developed to combat infections due to multidrug-resistant Gram-negative infections, but each has microbiologic and therapeutic niches and warrant further study in SOT recipients.

SUMMARY

This review summarizes therapeutic options for extended-spectrum β-lactamase-producing Enterobacterales, carbapenem-resistant Enterobacterales and Pseudomonas aeruginosa with difficult-to-treat resistance in SOT recipients and emphasizes recently approved antimicrobial agents.

Bacterial and fungal bloodstream infections in solid organ transplant recipients: results from a Danish cohort with nationwide follow-up

OBJECTIVES

Bloodstream infections (BSI) are prevalent after solid organ transplantation (SOT). In this study, we aimed to investigate the incidence and risk factors for BSI in the first 5 years post-transplantation.

METHODS

The study included 1322 SOT (kidney, liver, lung and heart) recipients transplanted from 2010 to 2017 with a total of 5616 years of follow-up. Clinical characteristics and microbiology were obtained from the Centre of Excellence for Personalized Medicine of Infectious Complications in Immune Deficiency (PERSIMUNE) data repository with nationwide follow-up. Incidence was investigated in the different SOT groups. Risk factors associated with BSI were assed in the combined group in time-updated multivariable Cox regressions.

RESULTS

The cumulative incidence of first BSI in the first 5 years post-transplantation differed in the SOT groups with a lower incidence in heart transplant recipients than in the other SOT groups (heart: 4.4%, CI 0.0-9.7%, vs. kidney: 24.6%, CI 20.9-28.2%, liver: 24.7%, CI 19.4-29.9%, and lung: 19.6%, CI 14.5-24.8%, p <0.001). Age above 55 years (HR 1.71, CI 1.2-2.4, p=0.002) and higher Charlson comorbidity index score (HR per unit increase: 1.25, CI 1.1-1.4, p<0.001) at transplantation, current cytomegalovirus (CMV) infection (HR 4.5, CI 2.6-7.9, p<0.001) and current leucopenia (HR 13.3, CI 3.7-47.9, p<0.001) were all associated with an increased risk of BSI.

CONCLUSION

In SOT recipients, the incidence of BSI differed with the type of transplanted organ. Risk of BSI was higher in older recipients and in recipients with comorbidity, current CMV infection or leucopenia. Thus, increased attention towards BSI in recipients with these characteristics is warranted.

The Impact of Timing of Stent Removal on the Incidence of UTI, Recurrence, Symptomatology, Resistance, and Hospitalization in Renal Transplant Recipients

Purpose

To evaluate the impact of early (<3 weeks) versus late (>3 weeks) urinary stent removal on urinary tract infections (UTIs) post renal transplantation.

Methods

A retrospective study was performed including all adult renal transplants who were transplanted between January 2017 and May 2020 with a minimum of 6-month follow-up at King Abdulaziz Medical City, Riyadh, Saudi Arabia.

Results

A total of 279 kidney recipients included in the study were stratified into 114 in the early stent removal group (ESR) and 165 in the late stent removal group (LSR). Mean age was 43.4 ± 15.8; women: n: 114, 40.90%; and deceased donor transplant: n: 55, 19.70%. Mean stent removal time was 35.3 ± 28.0 days posttransplant (14.1 ± 4.6 days in the ESR versus 49.9 ± 28.1 days in LSR, p < 0.001). Seventy-four UTIs were diagnosed while the stents were in vivo or up to two weeks after the stent removal “UTIs related to the stent” (n = 20, 17.5% in ESR versus n = 54, 32.7% in LSR; p=0.006). By six months after transplantation, there were 97 UTIs (n = 36, 31.6% UTIs in ESR versus n = 61, 37% in LSR; p=0.373). Compared with UTIs diagnosed after stent removal, UTIs diagnosed while the stent was still in vivo tended to be complicated (17.9% versus 4.9%, p: 0.019), recurrent (66.1% versus 46.3%; p: 0.063), associated with bacteremia (10.7% versus 0%; p: 0.019), and requiring hospitalization (61% versus 24%, p: 0.024). Early stent removal decreased the need for expedited stent removal due to UTI reasons (rate of UTIs before stent removal) (n = 11, 9% in the early group versus n = 45, 27% in the late group; p=0.001). The effect on the rate of multidrug-resistant organisms (MDRO) was less clear (33% versus 47%, p: 0.205). Early stent removal was associated with a statistically significant reduction in the incidence of UTIs related to the stent (HR = 0.505, 95% CI: 0.302-0.844, p=0.009) without increasing the incidence of urological complications. Removing the stent before 21 days posttransplantation decreased UTIs related to stent (aOR: 0.403, CI: 0.218-0.744). Removing the stent before 14 days may even further decrease the risk of UTIs (aOR: 0.311, CI: 0.035- 2.726).

Conclusion

Early ureteric stent removal defined as less than 21 days post renal transplantation reduced the incidence of UTIs related to stent without increasing the incidence of urological complications. UTIs occurring while the ureteric stent still in vivo were notably associated with bacteremia and hospitalization. A randomized trial will be required to further determine the best timing for stent removal.

Pre-transplant Psoas Muscle Density as a Ready-to-Use and Low-cost Predictor of Patient Survival After Liver Transplant

Background: Sarcopenia, defined as low muscle mass with reduced function, is frequently encountered in cirrhotic patients and is a major predictor of adverse events, including post-liver transplant (LT) outcome. Objectives: This study assessed the impact of sarcopenia using computed tomography (CT)-based measurements on post-LT mortality and complications. Methods: From January 2008 to June 2016, 646 adult patients underwent 613 LTs at our institution. We analyzed the postoperative outcome of 287 patients who had pathologically proven cirrhosis on the explanted liver and who had performed a CT examination three months before LT. Psoas muscle density (PMD) was detected for every patient using standard instruments present in the radiological workstation and was related to postoperative survival rates and complications. Statistical analysis was carried out using the appropriate tests. Results: Postoperative mortality was 6.3%. At least one grade III-IV postoperative complication was experienced by 121 patients. Respiratory and infective complications occurred in 30 and 32 patients, respectively. Also, PMD was an independent predictor of postoperative mortality (P = 0.021), respiratory complications (P = 0.015), and infections (P = 0.010). The ROC analysis identified a PMD ≤ 43.72 HU as the best cutoff value for predicting 90-day mortality after LT. Conclusions: Psoas muscle density accurately predicted post-LT mortality and complications. Its ease and low-cost determination can allow widespread use of this parameter to improve clinical care and help with the decision to give these patients some priority on the transplant waiting list.

Continuation of Peritoneal Dialysis in Adult Kidney Transplant Recipients With Delayed Graft Function

INTRODUCTION

Peritoneal dialysis (PD) has been used increasingly in past decade. Many of these patients undergo transplantation and may require dialysis for delayed graft function (DGF). The outcomes of DGF based on the post-transplantation dialysis modality are not well known.

METHODS

We retrospectively reviewed all adult kidney transplant recipients (KTRs) from the University of Wisconsin School of Medicine and Public Health who developed DGF between November 2015 and April 2019. Patients were divided into those who received hemodialysis (HD) or PD during the DGF period. Immediate graft explant, DGF among living donor KTRs, or those requiring just a single dialysis treatment were excluded.

RESULTS

Of 224 KTRs with DGF during the study period, 167 fulfilled our selection criteria. There were 16 patients in the PD and 151 in the HD group. Baseline characteristics were similar between the two groups, except diabetes was more prevalent in the HD group. Five of 16 PD patients had to be transitioned to HD. There was no difference in DGF duration, hospital length of stay, infectious or surgical complications, rejection at various time periods, graft function at last follow-up, or graft failure. In multivariate analysis, only rejection within the first year of transplantation (hazard ratio [HR]: 4.26; 95% confidence interval [CI]: 1.20-15.08; P = 0.02) and post-surgical complications (HR: 3.79; 95% CI: 1.03- 13.91; P = 0.04) were associated with death-censored graft failure (DCGF). The use of PD for treatment of DGF was not associated with DCGF.

CONCLUSIONS

In carefully selected patients, PD can be continued safely for DGF without any effect on short-term or long-term transplant outcomes.

Investigation and Analysis of the Colonization and Prevalence of Carbapenem-Resistant Enterobacteriaceae in Pediatric Liver Transplant Recipients

OBJECTIVE

This study aimed to investigate the colonization and prevalence of carbapenem-resistant Enterobacteriaceae (CRE) in pediatric liver transplant recipients and analyze the high-risk factors and prognosis of CRE infection.

METHODS

A prospective study involving 152 pediatric patients undergoing liver transplantation was carried out. Anal swab bacteria cultures were collected when the patients entered the intensive care unit (ICU) and when they left in order to screen for intestinal CRE colonization. The results were grouped according to the occurrence of CRE infection following surgery, and the patients were divided into two groups: a CRE infection group and a non-CRE infection group. Univariate analysis and multiple logistic regression analysis were conducted to determine the independent risk factors of CRE infection and analyze the survival rate.

RESULTS

Of the 152 pediatric liver transplant recipients enrolled in the study, there were 13 cases of postoperative CRE infection and 139 cases of non-CRE infection. The incidence of preoperative CRE infection, preoperative cytomegalovirus (CMV) infection, and preoperative sepsis in the CRE infection group was significantly higher than in the non-CRE infection group (P < 0.005). Intraoperative bleeding volume and operation times in the CRE infection group were also significantly higher than in the non-CRE infection group (P < 0.05). Furthermore, postoperative ICU treatment time, postoperative occurrence of unplanned surgery, postoperative mechanical ventilation of more than 24 hours, and the incidence of pre-ICU CRE colonization in the CRE infection group were significantly higher than in the non-CRE infection group (P < 0.05). Finally, the difference between the CRE infection group and the non-CRE infection group in six-month survival rate following surgery was significant (P < 0.001).

CONCLUSION

The independent risk factors of CRE infection following pediatric liver transplantation include preoperative CRE infection and pre-ICU CRE colonization. CRE infection progresses quickly, with a poor prognosis and a high mortality rate. The CRE screening of anal swabs is crucial for the early detection of CRE infection.

Infective endocarditis in patients with solid organ transplantation. A nationwide descriptive study

BACKGROUND

Solid organ transplantation (SOT) implies immunosuppression and frequent health care contact. Our aim was to compare the characteristics of patients with infective endocarditis (IE) and SOT against those without SOT.

METHODS

We used data from the Spanish Collaboration on Endocarditis during the period 2008-2018.

RESULTS

We identified 4794 cases of IE, 85 (1.8%) in SOT (56 kidney, 18 liver, 8 heart, 3 lung). Thirteen patients with other transplantation types (bone marrow, hematopoietic precursors, and cornea) were excluded from the analysis. Compared with patients without SOT, patients with SOT had lower median age (61 vs. 69 years, p<0.001), more comorbidities (mean age-adjusted Charlson index 5.7±2.9 vs. 4.9±2.9, p=0.004), a lower prevalence of native valvular heart disease (29.4 vs. 45.4%, p=0.003), more in-hospital and healthcare-related IE (70.5% vs. 36.3%, p<0.001) and staphylococcal etiology (57.7% vs. 39.7%, p=0.001). Patients with SOT had more frequent kidney function worsening (47.1% vs. 34.6%, p=0.02), septic shock (25.9% vs. 12.1 %, p<0.001), sepsis (27.1% vs. 17.2%, p=0.02), and less surgery indication (54.1% vs 66.3%, p=0.02) and surgery (32.9% vs. 46.3%, p=0.01) than patients without SOT. There were no significant differences in mortality: inhospital (30.6% SOT vs. 25.6% without SOT, p=0.31), 1-year (38.8% SOT vs. 31.9% without SOT, p=0.18).

CONCLUSIONS

Most IE in SOT recipients are nosocomial and over 70% are health care-related. Half have previously normal heart valves and almost 60% are due to Staphylococcus spp. infections. Mortality seems to be similar to non-SOT counterparts.

Recent Trends of Infectious Complications Following Heart Transplantation

BACKGROUND

Heart transplantation is a life-saving procedure that has seen improvements in transplant and patient outcomes due to advances in immunosuppression and prevention of posttransplantation infectious episodes (IEps). This study systematically evaluates IEps in the modern era of heart transplantation at Stanford University Medical Center.

METHODS

This is a single-center retrospective review that includes 279 consecutive adult heart transplantation recipients from January 2008 to September 2017. Baseline demographic, clinical, serological, and outcomes information were collected. Kaplan-Meier estimator was used to assess survival stratified by IEp occurrence within the first year.

RESULTS

A total of 600 IEps occurred in 279 patients (2.15 IEps per patient) during a median follow-up period of 3 years. Overall survival was 83.3% (95% confidence interval [CI], 76.2-88.4) at 1 year posttransplantation for those with any IEp compared with 93.0% (95% CI, 87.2-96.4) in those without IEp (P = 0.07). Bacterial IEps were the most common (n = 375; 62.5%), followed by viral (n = 180; 30.0%), fungal (n = 40; 6.7%), and parasitic (n = 5; 0.8%). IEps by Gram-negative bacteria (n = 210) outnumbered those by Gram-positive bacteria (n = 142). Compared with prior studies from our center, there was a decreased proportion of viral (including cytomegalovirus), fungal (including Aspergillus spp. and non-Aspergillus spp. molds), and Nocardia infections. There were no IEps due to Mycobacterium tuberculosis, Pneumocystis jirovecii, or Toxoplasma gondii.

CONCLUSIONS

A significant reduction in viral, fungal, and Nocardia IEps after heart transplantation was observed, most likely due to advancements in immunosuppression and preventive strategies, including pretransplant infectious diseases screening and antimicrobial prophylaxis.

Does oral health-related quality of life of patients after solid organ transplantation indicate a response shift? Results of a systematic review

BACKGROUND

The physical oral health and dental behaviour of patients after solid organ transplantation (SOT) has repeatedly been reported as insufficient. The objective of this systematic review was to detect whether the oral health-related quality of life (OHRQoL) of patients after SOT is reduced compared to that of healthy individuals.

METHODS

A systematic literature search was performed by two independent individuals based on the PubMed, Web of Science and Scopus databases by using the following search terms: "transplantation" AND "oral health-related quality of life". The findings were checked to determine eligibility, whereby publication prior to 31 October 2020, examination of adult patients (age at least 18 years) with SOT, reporting of an OHRQoL outcome and full text in English language were the prerequisites for inclusion in the qualitative analysis. Quality appraisal of the included studies was performed using the Agency for Healthcare Research and Quality methodology checklist.

RESULTS

Seven of 25 studies that examined patients after kidney (3), heart (2), liver (1) and lung transplantation (1) were included. Four studies included healthy controls, and five studies included a cohort of patients before transplantation for comparison. Clinical oral health examinations were heterogeneous between groups. The majority of studies (5/7) applied the short form of the "Oral Health Impact Profile" (OHIP 14) to assess OHRQoL. The OHIP 14 values ranged between 1.7 and 8.9 across studies, indicating an unaffected or just slightly reduced OHRQoL. Only one study found better OHRQoL in patients after SOT compared to a group before SOT, and one study confirmed worse OHRQoL of SOT recipients compared to a healthy control. Only two studies revealed an association between OHRQoL and oral health parameters. Furthermore, two studies each found a relationship between OHRQoL and general health-related quality of life or disease-related parameters.

CONCLUSIONS

Patients after SOT show an unaffected or only slightly reduced OHRQoL, which was mainly independent of the insufficient oral status. This might indicate a shift in the perception threshold for oral diseases and conditions caused by the general health burden related to the SOT.

Poor outcomes of early recurrent post-transplant bloodstream infection in living-donor liver transplant recipients

Bloodstream infection (BSI) is a common complication after living-donor liver transplantation (LDLT). Some patients develop recurrent BSIs. We evaluated the impacts of early recurrent BSIs (ER-BSIs) on outcomes in LDLT recipients. LDLT cases between 2008 and 2016 were included. Early BSI (E-BSI) was defined as a BSI event that occurred within 2 months after LDLT. ER-BSIs were defined as new-onset BSIs within 2 months due to another pathogen at a ≥ 48-h interval or a relapse of BSIs by the same pathogen at a ≥ 1-week interval, with negative cultures in between. The primary objective was evaluating the all-cause mortality of each group of LDLT recipients (90 days and 1 year). The secondary objectives were analyzing associated factors of each all-cause mortality and risk factors for early single BSI and ER-BSI. Among 727 LDLT recipients, 108 patients experienced 149 events of E-BSI with 170 isolated pathogens. Twenty-eight patients (25.9%, 28/108) experienced ER-BSI. The 1-year survival rates of patients without BSI, with early single BSI event, and with ER-BSIs were 92.4%, 81.3%, and 28.6%, respectively. ER-BSI was the most significant risk factor for 1-year mortality (adjusted HR = 5.31; 95% CI = 2.27–12.40). Intra-abdominal and/or biliary complications and early allograft dysfunction were risk factors for both early single BSI and ER-BSI. Interestingly, longer cold ischemic time and recipient operative time were associated with ER-BSI. LDLT recipients with ER-BSI showed very low survival rates accompanied by intra-abdominal complications. Clinicians should prevent BSI recurrence by being aware of intra-abdominal complications.

Dental Implant Failure Rate and Marginal Bone Loss in Transplanted Patients: A Systematic Review and Meta-Analysis

This systematic review investigates the failure rate and marginal bone loss (MBL) of dental implants placed in patients undergoing solid-organ transplant (SOT) compared to healthy controls. Three databases (PubMed, Web of Sciences, and the Cochrane Library) were searched up to June 2020 (PROSPERO CRD42019124896). Case-control and cohort studies reporting data failure rate and marginal bone loss (MBL) of dental implants placed in SOT patients were included. The risk of bias of observational studies was assessed through the Newcastle-Ottawa Scale (NOS). Four case-control studies fulfilled the inclusion criteria; all had low risk of bias. Meta-analyses revealed consistently lower implant failure rate than control populations at patient and implant levels. SOT patients had a significant difference of −18% (p-value < 0.001) MBL compared to healthy patients. SOT status poses no serious threat to implant survival. Overall, this group of patients presented lower levels of dental implant failure rate and marginal bone loss compared to otherwise healthy patients. Further intervention trials with larger sample size and longer follow-ups are necessary to confirm these summarized results.

Treatment of multidrug-resistant gram-negative bacilli after solid organ transplant: Outcomes and complications

BACKGROUND

Infections caused by multidrug-resistant gram-negative bacilli (GNB) cause significant morbidity and mortality in solid organ transplant (SOT) recipients.

METHODS

We retrospectively collected data from all SOT recipients at a single center from 1 January 2007 to 15 April 2017 treated for infections caused by multi-drug-resistant GNB. This study examined the effects of specific antibiotics on nephrotoxicity, neurotoxicity, 30-day mortality, and length of stay in the hospital and intensive care unit.

RESULTS

A total of 225 infections were identified among 143 patients. Carbapenem-sensitive organisms were present in 112 (49.8%) infections and were associated with decreased 30-day mortality (OR 0.35, 95% CI 0.16-0.75). Neurotoxicity was associated with polymyxin use with an 8% increase in odds of neurotoxicity per day of exposure (P=.03). There was no relationship between nephrotoxicity and any individual antibiotic class. Increased hospital length-of-stay occurred among patients exposed to aminoglycosides (β-statistic = 0.48 (0.23); P = .04), while there was no relationship between antibiotic class and intensive care unit (ICU) length-of-stay. Mortality at 30 days occurred in 37 infections (16%). Carbapenem exposure was associated with decreased 30-day mortality (OR 0.93; 95% CI 0.90-0.98; P = .02). No other antibiotic class had a significant impact on 30-day mortality.

CONCLUSIONS

Carbapenems appear to be a safe and effective treatment for solid-organ transplant recipients with infections caused by carbapenem-sensitive multidrug-resistant GNB; treatment of carbapenem-resistant gram-negatives remains challenging.

Bloodstream infections by gram-negative bacteria in kidney transplant patients: Incidence, risk factors, and outcome

BACKGROUND

Kidney transplant recipients (KTRs) are at increased risk of infections.

METHODS

The aims of this study were to describe the incidence of bloodstream infections (BSIs) by gram-negative bacteria in a cohort of KTRs, the risk factors for BSI due to multi-drug-resistant (MDR) gram-negative bacteria, and the predictors for unfavorable outcome, defined as death or nephrectomy or return to dialysis, within 30 days from BSI. We conducted a retrospective cohort study at the renal transplant unit of a tertiary care hospital in Athens, Greece.

RESULTS

In a total of 1962 KTRs, we recorded 195 BSI episodes in 182 single patients (male/female = 97/85), with a median (interquartile range) age of 57.2 (44-64.9) years. The incidence was 1.393/100 patient-years. The most common source of infection was urinary tract (70.9%), and Escherichia coli (63.7%) was the most common pathogen. 19.2% of the infecting organisms were MDR; previous antibiotic use (OR 8.2; CI 2.1-32.9) and previous stay in the intensive care unit (OR 34.2; CI 1.6-730.2) were associated with MDR BSIs. 6% of patients died, and 2.2% underwent nephrectomy, while no patients had to return to dialysis. Diabetes mellitus (OR 8.1; 95% CI 1.3-50.3), Pseudomonas aeruginosa BSI (OR 46.1; 95% CI 3.9-552.3), and septic shock (OR 46.7; 95% CI 1.7-1304.9) were independent predictors of unfavorable outcome.

CONCLUSION

Bloodstream infections in KTRs have a significant impact on allograft and patients outcome.

Periodontitis Impact in Interleukin-6 Serum Levels in Solid Organ Transplanted Patients: A Systematic Review and Meta-Analysis

This systematic review aimed to investigate the influence of periodontitis on post-transplant IL-6 serum levels of solid organ transplanted patients as compared to healthy subjects. Four databases (PubMed, Scholar, EMBASE, and CENTRAL) were searched up to February 2020 (PROSPERO CRD42018107817). Case-control and cohort studies on the association of IL-6 serum levels with a periodontal status of patients after solid organ transplantation were included. The risk of bias of observational studies was assessed through the Newcastle-Ottawa Scale (NOS). Random effects meta-analyses were thoroughly conducted. GRADE assessment provided quality evidence. Four case-control studies fulfilled the inclusion criteria (274 transplant recipients and 146 healthy controls), all of low risk of bias. Meta-analyses revealed significantly higher IL-6 levels in transplanted patients than healthy individuals with low-quality evidence (Mean Difference (MD): 2.55 (95% confidence interval (CI): 2.07, 3.03)). Transplanted patients with periodontitis have higher serum IL-6 levels than transplanted patients without periodontitis with moderate quality evidence (MD: 2.20 (95% CI: 1.00, 3.39)). We found low-quality evidence of higher IL-6 levels than healthy patients in patients with heart and kidney transplant. In these transplanted patients, there was moderate quality evidence that periodontitis is associated with higher IL-6 serum levels. Future research should consider the impact of such a difference in organ failure and systemic complications.

Tinospora cordifolia Aqueous Extract Alleviates Cyclophosphamide- Induced Immune Suppression, Toxicity and Systemic Candidiasis in Immunosuppressed Mice: In vivo Study in Comparison to Antifungal Drug Fluconazole

OBJECTIVE

The present study was aimed to evaluate the effect of the aqueous extract of Tinospora cordifolia (AETC) against cyclophosphamide-induced immunosuppression and systemic Candida albicans infection in a murine model.

METHODS

The protective effect of AETC against cyclophosphamide-induced leukopenia was evaluated by quantitative and qualitative analysis of the leukocytes. The immune-stimulating potential of AETC on macrophages was assessed by determining the levels of secreted cytokines. To determine the direct antifungal activity, AETC or fluconazole was administered to C. albicans infected mice. The efficacy of treatment was assessed by determining the survival rate, kidney fungal burden, the organ index and liver inflammation parameters.

RESULTS

Cyclophosphamide administration resulted in substantial depletion of leukocytes, whereas AETC treatment induced the recovery of leukocytes in cyclophosphamide-injected mice. Moreover, AETC treatment of macrophages resulted in enhanced secretion of IFN-γ, TNF-α and IL-1β. C. albicans infected mice treated with AETC at the doses of 50 and 100 mg/kg exhibited 40% and 60% survival rate, whereas the mice treated with fluconazole at a dose of 50 mg/kg showed 20% survival rate. Like survival data, the fungal load was found to be the lowest in the kidney tissues of mice treated with AETC at a dose of 100 mg/kg. Interestingly, mice infected with C. albicans demonstrated improvement in the organ indices and liver functioning after AETC treatment.

CONCLUSION

These results suggest that AETC may potentially be used to rejuvenate the weakened immune system and eliminate systemic candidiasis in mice.

Efficacy and safety of a comprehensive educational antimicrobial stewardship program focused on antifungal use

OBJECTIVE

Few data exist regarding the impact of antimicrobial stewardship programs on antifungal use. We evaluated the efficacy and safety of a comprehensive long-term antimicrobial stewardship program (ASP) focused on antifungal use.

METHODS

During a 9-year period, we quarterly assessed antifungal consumption, incidence density of hospital-acquired candidemia, Candida spp. distribution, antifungal resistance, and crude death rate per 1000 occupied bed days (OBDs) of hospital-acquired candidemia. We performed segmented regression analysis of interrupted time series.

RESULTS

A significant change in trend was observed for antifungal consumption, with a sustained reduction of -0.87% per quarter (95% confidence interval [CI], -1.36 -0.38, p < 0.001), accounting for a final reduction of -38.4%. The main reduction was produced in fluconazole, with a sustained reduction of -1.37% per quarter (95%CI, -1.96 -0.68, p<0.001). The incidence density of hospital-acquired candidemia decreased, with a change in slope of -5.06% cases per 1000 OBDs per year (95%CI, -8.23 -1.77, p = 0.009). The 14-day crude death rate per 1000 OBDs dropped from 0.044 to 0.017 (-6.36% deaths per 1000 OBDs per year; 95%CI, -13.45 -1.31, p = 0.09).

CONCLUSIONS

This ASP has succeeded in optimizing the use of antifungal with a long-lasting reduction without increasing the incidence, neither the mortality, of hospital-acquired candidemia.

Sepsis outcomes in solid organ transplant recipients

BACKGROUND

We present data on a cohort of patients diagnosed with sepsis over a 10-year period comparing outcomes in solid organ transplant (SOT) and non-solid organ transplant (non-SOT) recipients.

METHODS

This is a retrospective single-center study of patients with diagnosis of sepsis from 1/1/06 to 6/30/16. Cases and controls were matched by year of sepsis diagnosis with propensity score matching. Conditional logistic regression and repeated measurement models were performed for binary outcomes. Trends over time for in-hospital mortality were determined using the Cochran-Armitage test. A gamma-distributed model was performed on the continuous variables.

RESULTS

Overall, there were 18 632 admission encounters with a discharge diagnosis of sepsis in 14 780 unique patients. Of those admissions, 1689 were SOT recipients. After 1:1 matching by year, there were three thousand three hundred and forty patients (1670 cases; 1670 controls) diagnosed with sepsis. There was a decreasing trend for in-hospital mortality for sepsis over time in SOT patients and non-SOT patients (P < .05) due to early sepsis recognition and improved standard of care. Despite higher comorbidities in the SOT group, conditional logistic regression showed that in-hospital mortality for sepsis in SOT patients was similar compared with non-SOT patients (odds ratio [OR] =1.14 [95% confidence interval {CI}, 0.95-1.37], P = .161). However, heart and lung SOT subgroups had higher odds of dying compared with the non-SOT group (OR = 1.83 [95% CI, 1.30-2.57], P < .001 and OR = 1.77 [95% CI, 1.34-2.34], P < .001). On average, SOT patients had 2 days longer hospital length of stay compared with non-SOT admissions (17.00 ± 19.54 vs 15.23 ± 17.07, P < .05). Additionally, SOT patients had higher odds of hospital readmission within 30 days (OR = 1.25 [95% CI, 1.06-1.51], P = .020), and higher odds for DIC compared with non-SOT patients (OR = 1.76 [95% CI, 1.10-2.86], P = .021).

CONCLUSION

Sepsis in solid organ transplants and non-solid organ transplant patients have similar mortality; however, the subset of heart and lung transplant recipients with sepsis has a higher rate of mortality compared with the non-solid organ transplant recipients. SOT with sepsis as a group has a higher hospital readmission rate compared with non-transplant sepsis patients.