Risk factors for multidrug-resistant organisms among deceased organ donors

Real-time, random-access organ screening for carbapenem-resistant organisms (CRO) reduces CRO-associated, donor-derived infection mortality in lung transplant recipients

PURPOSE

Donor-derived infection (DDI) has become an important factor affecting the prognosis of lung transplantation patients. The risks versus benefits of using donor organs infected with multidrug-resistant organisms (MDRO), especially carbapenem-resistant organisms (CRO), are frequently debated. Traditional microbial culture and antimicrobial susceptibility testing at present fail to meet the needs of quick CRO determination for donor lungs before acquisition. In this study, we explored a novel screening method by using Xpert® Carba-R assay for CRO in donor lungs in a real-time manner to reduce CRO-associated DDI mortality.

METHODS

This study was registered on chictr.org.cn (ChiCTR2100053687) on November 2021. In the Xpert Carba-R screening group, donor lungs were screened for CRO infection by the Xpert Carba-R test on bronchoalveolar fluid (BALF) before acquisition. If the result was negative, donor lung acquisition and subsequent lung transplantation were performed. In the thirty-five potential donors, nine (25.71%) with positive Xpert Carba-R results in BALF were declined for lung transplantation. Twenty-six recipients and the matching CRO-negative donor lungs (74.29%) were included in the Xpert Carba-R screening group. In the control group, nineteen recipients underwent lung transplants without Xpert Carba-R screening. The incidence and mortality of CRO-associated DDI were collected and contrasted between the two groups.

RESULTS

Multivariate analysis showed that CRO-related death due to DDI within 60 days was significantly lower in the Xpert Carba-R screening group than that in the control group (OR = 0.05, 95% CI 0.003-0.74, p = 0.03).

CONCLUSION

Real-time CRO screening of donor lungs before transplantation at the point of care by the Xpert Carba-R helps clinicians formulate lung transplantation strategies quickly and reduces the risk of subsequent CRO infection improving the prognosis of lung transplantation.

Impact of the Five-Year Intervention of an Antimicrobial Stewardship Program on the Optimal Selection of Surgical Prophylaxis in a Hospital without Antibiotic Prescription Restrictions in Costa Rica: A Retrospective Study

This study aims to characterize the impact of the implementation of an antimicrobial stewardship program (AMS) on the optimal selection of surgical antibiotic prophylaxis in adult patients. This is a retrospective quasi-experimental study that compared the selection and duration of antibiotics for all surgical prophylaxis prescriptions over six months, both before (pre-AMS) and after a five-year intervention of AMS (post-AMS). In addition, data related to the consumption of antibiotics, adverse drug reactions, and surgical site infections throughout the years of the intervention were analyzed. The rate of appropriate selection of antibiotic prophylaxis in surgical procedures improved to 80% during the post-AMS period. The percentage of optimal duration increased from 69.1% (N = 1598) in the pre-AMS period to 78.0% (N = 841) in the post-AMS period (p < 0.001). The consumption of ceftriaxone significantly decreased, while the use of cefazolin increased more than nine times. No severe adverse reactions or increases in surgical site infections were detected after the intervention. The implementation of an AMS in the surgical ward demonstrated a trend towards a positive overall impact on the selection and duration of prophylactic antibiotics for surgery, with positive results also observed in other variables associated with the prescription of these antibiotics.

The Next Generation: Mentoring and Diversity in the Antibacterial Resistance Leadership Group

The Antibacterial Resistance Leadership Group (ARLG) Mentoring Program was established to develop and prepare the next generation of clinician-scientists for a career in antibacterial resistance research. The ARLG Diversity, Equity, and Inclusion Working Group partners with the Mentoring Committee to help ensure diversity and excellence in the clinician-scientist workforce of the future. To advance the field of antibacterial research while fostering inclusion and diversity, the Mentoring Program has developed a number of fellowships, awards, and programs, which are described in detail in this article.

Optimal Perioperative Antimicrobial Management Strategies of Kidney Transplant Recipients Guided by Metagenomic Next-Generation Sequencing of Deceased Donors' Microbiology Samples

Background

There is no consensus on the optimal use of perioperative antibiotics prophylaxis after kidney transplantation, but there is a common trend to limit the duration of antibiotic use worldwide. Metagenomic next-generation sequencing (mNGS) has emerged as a novel technology for pathogen detection in clinical practice due to its noninvasive, rapid, precise and high susceptibility to detect infectious pathogens. However, data are lacking on whether mNGS analyses could be used to detect pathogens and guide anti-infection regimens in kidney transplant donors and recipients.

Methods

We conducted a retrospective study to review all clinic data of mNGS and traditional laboratory methods (TMs) for pathogen detection in kidney transplant recipients and their corresponding deceased donors from August 1, 2021 to October 30, 2022 in our center.

Results

A total of 57 donors and 112 of their corresponding recipients were included. The antimicrobial strategy mainly depended on mNGS results combined with traditional pathogen culture and clinical conditions. The percentages of positive pathogen detected by mNGS in blood, urine, bronchoalveolar lavage fluid (BALF) and preservation fluids (PFs) were 50.9% (29/57), 35.1% (20/57), 84.2% (48/57) and 54.4% (31/57) respectively, and were 24.6% (14/57), 15.8% (9/57), 57.9% (33/57) and 14.1% (8/57) respectively when using TMs. mNGS could detected all of pathogens which were detected by TMs. However, samples with negative TMs testing can be additionally detected as positive by mNGS (15/43 in blood, 11/48 in urine, 15/24 in BALF and 23/49 in PFs). Drug resistance genes were detected in 9 donors by mNGS,which were consistent with 6 donors by TMs. There was only one case of donor-derived infection in this study.

Conclusion

This study showed that it is effective to combine mNGS with traditional pathogen detection methods and clinical features to develop optimal perioperative antimicrobial management strategies for deceased donor kidney transplantation.

Epidemiology and Prevention of Early Infections by Multi-Drug-Resistant Organisms in Adults Undergoing Liver Transplant: A Narrative Review

Invasive bacterial infections are a leading cause of morbidity and mortality after liver transplant (LT), especially during the first months after LT, and infections due to multi-drug-resistant organisms (MDRO) are increasing in this setting. Most of the infections in patients in intensive care unit arise from the endogenous microflora and, for this reason, pre-LT MDRO rectal colonization is a risk factor for developing MDRO infections in the post-LT. Moreover, the transplanted liver may carry an increased risk of MDRO infections due to organ transportation and preservation, to donor intensive care unit stay and previous antibiotic exposure. To date, little evidence is available about how MDRO pre-LT colonization in donors and recipients should address LT preventive and antibiotic prophylactic strategies, in order to reduce MDRO infections in the post-LT period. The present review provided an extensive overview of the recent literature on these topics, with the aim to offer a comprehensive insight about the epidemiology of MDRO colonization and infections in adult LT recipients, donor-derived MDRO infections, possible surveillance, and prophylactic strategies to reduce post-LT MDRO infections.

Minimizing the Risk of Donor-Derived Events and Maximizing Organ Utilization Through Education and Policy Development

Herein, we review the current knowledge of donor-derived disease and current US Organ Procurement and Transplantation Network policies to minimize the risk. During the process, we also consider actions to further mitigate the risk of donor-derived disease. The overarching goal is to provide an infectious disease perspective on the complex decision of organ acceptance for transplant programs and candidates.

Evaluation of donor-derived bacterial infections in lung transplant recipients

Background

This study aims to evaluate the etiology and outcomes of donor-derived bacterial infections in patients undergoing lung transplantation.

Methods

Between January 2013 and December 2017, a total of 71 lung transplant recipients (56 males, 15 females; median age: 43.3 years) were retrospectively analyzed. The diagnosis of donor-derived bacterial infection was defined as the isolation of the same bacteria with the same antibiotic susceptibility patterns in a lung sample of donor and in one sample obtained from patients after transplantation and the presence of clinical evidence of infection.

Results

Ten (14%) patients were found to have donor-derived bacterial infection. Acinetobacter baumannii was found in three, Pseudomonas aeruginosa in three, Klebsiella pneumoniae in one, Enterobacter cloacae in one, Staphylococcus aureus in one, and both Klebsiella pneumoniae and Acinetobacter baumannii in one patient. Twenty-four of lung-transplant recipients and four patients with donor-derived infection died.

Conclusion

Lung transplants are usually performed in hospitalized patients or in those admitted to the intensive care unit. These patients commonly experience infection and colonization with resistant microorganisms.

Utility of deceased donor cultures in solid organ transplantation in preventing donor-derived bacterial and fungal infectious diseases transmission

Deceased donor and organ perfusion fluid cultures are obtained in order to inform recipient antimicrobial management and therefore reduce the risk of donor-derived bacterial and fungal infections. However, important heterogeneity exists in laboratory practice across organ procurement organizations and clinical management of culture results across transplant centers. While not standardized, the clinical approach to donors with positive bacterial and/or fungal cultures should be informed by the risk of donor-derived infection (DDI) and the consequence of organ non-utilization and account for potential unintended effects of antimicrobial use in the recipient. In this review, we summarize the literature on bacterial and fungal DDIs, describe the significance of positive cultures by anatomic site, and summarize current guidance on the management of positive cultures from donors or preservation fluids.

Prevention, diagnosis, and management of donor derived infections in pediatric kidney transplant recipients

Donor derived infections (DDIs) in pediatric kidney transplant recipients remain challenging to diagnose and can result in serious morbidity and mortality. This review summarizes the current guidelines and recommendations for prevention, diagnosis, and treatment of unexpected DDIs in pediatric kidney transplant recipients. We provide a contemporary overview of DDI terminology, surveillance, epidemiology, and recommended approaches for assessing these rare events with an emphasis on the pediatric recipient. To address prevention and risk mitigation, important aspects of donor and pediatric candidate evaluations are reviewed, including current Organ Procurement and Transplantation Network (OPTN) and American Society of Transplantation (AST) recommendations. Common unexpected DDI encountered by pediatric transplant teams including multi-drug resistant organisms, tuberculosis, syphilis, West Nile Virus, toxoplasmosis, Chagas disease, strongyloidiasis, candidiasis, histoplasmosis, coccidioidomycosis, and emerging infections such as COVID-19 are discussed in detail. Finally, we consider the general challenges with management of DDIs and share our experience with a novel application of next generation sequencing (NGS) of microbial cell-free DNA that will likely define a future direction in this field.

Deceased donors with multidrug-resistant organisms: implications and future directions

PURPOSE OF REVIEW

Organ utilization from donors infected or colonized with multidrug-resistant organisms (MDROs) remains inconsistent, and hesitancy to accept organs from these donors may relate to poor outcomes among solid organ transplant recipients with MDRO donor-derived infections (DDIs). An improved understanding of the risk factors for donor MDRO colonization or infection and the risk of MDRO DDI is needed to safely expand the donor pool while minimizing unnecessary organ discard.

RECENT FINDINGS

Recent studies have begun to delineate risk factors for MDRO acquisition among deceased donors and the epidemiology of MDRO DDIs, but additional efforts are warranted to inform optimal approaches to donor evaluation, risk stratification, management, interfacility and interagency data sharing, and approaches to recipient management.

SUMMARY

This review summaries recent data regarding risk factors for MDRO colonization and infection in deceased donors, epidemiology of MDRO DDIs, and current approaches to donors harboring MDROs and provides a framework for future research and collaboration.

Shorter durations of antibiotic therapy in organ transplant

PURPOSE OF REVIEW

Recent evidence supports shorter courses of antibiotics for several common infections and prophylactic indications. Unfortunately, solid organ transplant patients are often underrepresented or excluded from these studies. As a result, prolonged antibiotic durations are often used in clinical practice despite a lack of demonstrable benefit. This paper reviews recent publications addressing antibiotic duration of therapy in SOT recipients.

RECENT FINDINGS

Although largely limited to observational studies, longer courses of antibiotics for surgical prophylaxis, urinary tract infections, and bloodstream infections have not demonstrated benefit compared to shorter courses. In some instances, longer courses of therapy have been associated with harm (i.e., adverse drug events and development of resistance).

SUMMARY

Although the data remains limited, findings from retrospective studies evaluating shorter courses of antibiotics in SOT patients is encouraging. More robust research is desperately needed to define the optimal duration of antibiotics for common infections in SOT patients.

Machine perfusion combined with antibiotics prevents donor-derived infections caused by multidrug-resistant bacteria

Donor infection affects organ utilization, especially the infections by multidrug-resistant bacteria, which may have disastrous outcomes. We established a rat model, inoculated with Escherichia coli or carbapenem-resistant Klebsiella pneumoniae (CRKP), to investigate whether hypothermic machine perfusion (HMP), normothermic machine perfusion (NMP), or static cold storage (SCS) combined with antibiotic (AB) could eliminate the bacteria. E. coli or CRKP-infected kidneys were treated with cefoperazone-sulbactam and tigecycline, respectively. The HMP+AB and NMP+AB treatments had significant therapeutic effects on E. coli or CRKP infection compared with the SCS+AB treatment. The bacterial load of CRKP-infected kidneys in the HMP+AB (22 050 ± 2884 CFU/g vs. 1900 ± 400 CFU/g, p = .007) and NMP+AB groups (25 433 ± 2059 CFU/g vs. 500 ± 458 CFU/g, p = .002) were significantly reduced, with no statistically significant difference between both groups. Subsequently, the CRKP-infected kidneys of the HMP+AB and SCS+AB groups were transplanted. The rats in the SCS+AB group were severe infected and euthanized on day 4 post-transplant. By contrast, the rats in the HMP+AB group were in good condition. In conclusion, HMP and NMP combined with AB seems to be efficient approaches to decrease bacterial load of infected kidneys. This might lead to higher utilization rates of donors with active infection.

Challenges of Antimicrobial Resistance and Stewardship in Solid Organ Transplant Patients

Purpose of Review

Without effective antimicrobials, patients cannot undergo transplant surgery safely or sustain immunosuppressive therapy. This review examines the burden of antimicrobial resistance in solid organ transplant recipients and identifies opportunities for antimicrobial stewardship.

Recent Findings

Antimicrobial resistance has been identified to be the leading cause of death globally. Multidrug-resistant pathogens are associated with significant morbidity and mortality in transplant recipients. Methicillin-resistant S. aureus affects liver and lung recipients, causing bacteremia, pneumonia, and surgical site infections. Vancomycin-resistant enterococci is a nosocomial pathogen primarily causing bacteremia in liver recipients. Multidrug-resistant Gram-negative pathogens present urgent and serious threats to transplant recipients. Extended-spectrum beta-lactamase-producing E. coli and K. pneumoniae commonly cause bacteremia and intra-abdominal infections in liver and kidney recipients. Carbapenemase-producing Enterobacterales, mainly K. pneumoniae, are responsible for infections early-post transplant in liver, lung, kidney, and heart recipients. P. aeruginosa and A. baumannii continue to be critical threats. While there are new antimicrobial agents targeting resistant pathogens, judicious prescribing is crucial to minimize emerging resistance. The full implications of the COVID-19 global pandemic on antimicrobial resistance in transplant recipients remain to be understood. Currently, there are no established standards on the implementation of antimicrobial stewardship interventions, but strategies that leverage existing antimicrobial stewardship program structure while tailoring to the needs of transplant recipients may help to optimize antimicrobial use.

Summary

Clinicians caring for transplant recipients face unique challenges tackling emerging antimcirobial resistance. Coordinated antimicrobial stewardship interventions in collaboration with appropriate expertise in transplant and infectious diseases may mitigate against such threats.

Impact of donor multidrug-resistant organisms on solid organ transplant recipient outcomes

BACKGROUND

The impact of donor colonization or infection with multidrug-resistant organisms (MDROs) on solid organ transplant (SOT) recipient outcomes remains uncertain. We thus evaluated the association between donor MDROs and risk of posttransplant infection, graft failure, and mortality.

METHODS

A multicenter retrospective cohort study was performed. All SOT recipients with a local deceased donor were included. The cohort was divided into three exposure groups: recipients whose donors had (1) an MDRO, (2) a non-MDRO bacterial or candidal organism, or (3) no growth on cultures. The primary outcomes were (1) bacterial or invasive candidal infection within 3 months and (2) graft failure or death within 12 months posttransplant. Mixed effect multivariable frailty models were developed to evaluate each association.

RESULTS

Of 658 total SOT recipients, 93 (14%) had a donor with an MDRO, 477 (73%) had a donor with a non-MDRO organism, and 88 (13%) had a donor with no organisms on culture. On multivariable analyses, donor MDROs were associated with a significantly increased hazard of infection compared to those with negative donor cultures (adjust hazard ratio [aHR] 1.63, 95% CI 1.01-2.62, p = .04) but were not associated with graft failure or death (aHR 0.45, 95% CI 0.15-1.36, p = .16).

CONCLUSIONS

MDROs on donor culture increase the risk of early posttransplant infection but do not appear to affect long-term graft or recipient survival, suggesting organ donors with MDROs on culture may be safely utilized. Future studies aimed at reducing early posttransplant infections associated with donor MDROs are needed.

Daptomycin-Resistant Enterococcus Bacteremia Is Associated with Prior Daptomycin Use and Increased Mortality after Liver Transplantation

Background

Risk factors for acquisition of vancomycin-resistant Enterococcus (VRE) include immunosuppression, antibiotic exposure, indwelling catheters, and manipulation of the gastrointestinal tract, all of which occur in liver transplant recipients. VRE infections are documented in liver transplantation (LT); however, only one single center study has assessed the impact of daptomycin-resistant Enterococcus (DRE) in this patient population.

Methods

We conducted a retrospective multicenter cohort study comparing liver transplant recipients with either VRE or DRE bacteremia. The primary outcome was death within 1 year of transplantation. Multivariable logistic regression analyses were performed to calculate adjusted odds ratios for outcomes of interest.

Results

We identified 139 cases of Enterococcus bacteremia following LT, of which 78% were VRE and 22% were DRE. When adjusted for total intensive care unit days in the first transplant year, liver-kidney transplantation, and calcineurin inhibitor use, patients with DRE bacteremia were 2.65 times more likely to die within 1 year of transplantation (adjusted odds ratio [aOR], 2.648; 95% CI, 1.025–6.840; P = .044). Prior daptomycin exposure was found to be an independent predictor of DRE bacteremia (aOR, 30.62; 95% CI, 10.087–92.955; P < .001).

Conclusions

In this multicenter study of LT recipients with Enterococcus bacteremia, DRE bacteremia was associated with higher 1-year mortality rates when compared with VRE bacteremia. Our data provide strong support for dedicated infection prevention and antimicrobial stewardship efforts for transplant patients. Further research is needed to support the development of better antibiotics for DRE and practical guidance focusing on identification and prevention of colonization and subsequent infection in liver transplant recipients at high risk for DRE bacteremia.

The time is now: antimicrobial stewardship in solid organ transplantation

PURPOSE OF REVIEW

To provide a summary of complications of antimicrobials and opportunities for antimicrobial stewardship (AS) in solid organ transplant (SOT) patient care.

RECENT FINDINGS

Personalized, precision antimicrobial prescribing in SOT aiming to avoid negative consequences of antimicrobials is essential to improving patient outcomes. The positive impact AS efforts in transplant care has been recognized and bespoke activities tailored to special interests of transplant patients and providers are evolving. Strategies to optimize stewardship interventions targeting antibacterial, antiviral, and antifungal drug selection and dosing in the transplant population have been recently published though clinical integration using a 'handshake' stewardship model is an optimal starting point in transplant care. Other recent studies involving transplant recipients have identified opportunities to shorten duration or avoid antimicrobials for certain commonly encountered clinical syndromes. This literature, informing recent consensus clinical practice guidelines, may help support institutional practice guidelines and protocols. Proposals to track and report stewardship process and outcome measures as a routine facet of programmatic transplant quality reporting have been published. However, developing novel metrics accounting for nuances of transplant patients and programs is critical. Important studies are needed to evaluate organizational transplant prescribing cultures and optimal behavioral science-based interventions relevant to antimicrobial use in this population.

SUMMARY

Consequences of antimicrobial use, such as drug toxicities, and Clostridiodes difficile (CDI) and multidrug-resistant organisms colonization and infection disproportionately affect SOT recipients and are associated with poor allograft and patient outcomes. Stewardship programs encompassing transplant patients aim to personalize antimicrobial prescribing and optimize outcomes. Further studies are needed to better understand optimal intervention strategies in SOT.

Multi-Drug Resistant Organisms Infection Impact on Patients Length of Stay in Respiratory Care Ward

This study aimed to investigate the effects of multi-drug-resistant organism (MDRO) infection and other factors on the length of hospital stay (LOS) of patients in the respiratory care ward (RCW) of a regional hospital in Taiwan. In this retrospective study, we collected cases from MDRO-infected patients in the RCW from January 2016 to March 2020. The RCW comprises 13 beds in total. There were 106 infected patients, of which 42 were in the case group (infected with MDROs) and 64 were in the control group (not infected with MDROs). Clinical specimens were inoculated in a selective medium to isolate the pathogenic bacteria by standard procedures. The results showed the main factors affecting the LOS were: patients with MDRO infection, patients discharged from the RCW, and patients who underwent catheterization. The LOS of patients infected with MDROs was significantly longer than that of patients without MDRO infection (β = 0.55, 95% CI = 0.02–1.09), with the case group and the control group being 479.8 ± 546.5 and 307.3 ± 436.2 days, respectively. Infection with carbapenem-resistant Pseudomonas aeruginosa (CRPA) was associated with a longer LOS than other MDRO strains. These findings have important implications for infection control in RCW and in better tracking the health of patients.

Antibiotic utilization in deceased organ donors

Antibiotic use in deceased organ donors has not been previously described. In a retrospective cohort of 440 donors, we found 427 (97%) received at least one antibiotic course, 312 (71%) received broad-spectrum antibiotics, and 61 (14%) received potentially redundant antibiotics during their terminal hospitalization, suggesting a need for stewardship.

Ten years of donor-derived disease: A report of the disease transmission advisory committee

Despite clinical and laboratory screening of potential donors for transmissible disease, unexpected transmission of disease from donor to recipient remains an inherent risk of organ transplantation. The Disease Transmission Advisory Committee (DTAC) was created to review and classify reports of potential disease transmission and use this information to inform national policy and improve patient safety. From January 1, 2008 to December 31, 2017, the DTAC received 2185 reports; 335 (15%) were classified as a proven/probable donor transmission event. Infections were transmitted most commonly (67%), followed by malignancies (29%), and other disease processes (6%). Forty-six percent of recipients receiving organs from a donor that transmitted disease to at least 1 recipient developed a donor-derived disease (DDD). Sixty-seven percent of recipients developed symptoms of DDD within 30 days of transplantation, and all bacterial infections were recognized within 45 days. Graft loss or death occurred in about one third of recipients with DDD, with higher rates associated with malignancy transmission and parasitic and fungal diseases. Unexpected DDD was rare, occurring in 0.18% of all transplant recipients. These findings will help focus future efforts to recognize and prevent DDD.

Collaborative Antimicrobial Stewardship for Surgeons

Antimicrobial stewardship efforts that include surgeons rely on healthy and open communications between surgeons, infectious diseases specialists, and pharmacists. These efforts most frequently are related to surgical prophylaxis, the management of surgical infections, and surgical critical care. Policy should be based on best evidence and timely interactions to develop consensus on how to develop appropriate guidelines and protocols. Flexibility on all sides leads to increasingly strong relationships over time.