Comparison in outcome with tailored antibiotic prophylaxis postoperatively in pediatric intestinal transplant population

A metagenomic prospective cohort study on gut microbiome composition and clinical infection in small bowel transplantation

Two-thirds of small-bowel transplantation (SBT) recipients develop bacteremia, with the majority of infections occurring within 3 months post-transplant. Sepsis-related mortality occurs in 31% of patients and is commonly caused by bacteria of gut origin, which are thought to translocate across the implanted organ. Serial post-transplant surveillance endoscopies provide an opportunity to study whether the composition of the ileal and colonic microbiota can predict the emergence as well as the pathogen of subsequent clinical infections in the SBT patient population. Five participants serially underwent aspiration of ileal and colonic bowel effluents at transplantation and during follow-up endoscopy either until death or for up to 3 months post-SBT. We performed whole-metagenome sequencing (WMS) of 40 bowel effluent samples and compared the results with clinical infection episodes. Microbiome composition was concordant between participants and timepoint-matched ileal and colonic samples. Four out of five (4/5) participants had clinically significant infections thought to be of gut origin. Bacterial translocation from the gut was observed in 3/5 patients with bacterial infectious etiologies. In all three cases, the pathogens had demonstrably colonized the gut between 1-10 days prior to invasive clinical infection. Recipients with better outcomes received donor grafts with higher alpha diversity. There was an increase in the number of antimicrobial resistance genes associated with longer hospital stay for all participants. This metagenomic study provides preliminary evidence to support the pathogen translocation hypothesis of gut-origin sepsis in the SBT cohort. Ileal and colonic microbiome compositions were concordant; therefore, fecal metagenomic analysis could be a useful surveillance tool for impeding infection with specific gut-residing pathogens.

Multidrug-resistant organisms: A significant cause of severe sepsis in pediatric intestinal and multi-visceral transplantation

Severe sepsis in immunocompromised children is associated with increased mortality. This paper describes the epidemiology landscape, clinical acuity, and outcomes for severe sepsis in pediatric intestinal (ITx) and multi-visceral (MVTx) transplant recipients requiring admission to the pediatric intensive care unit (PICU). Severe sepsis episodes were retrospectively reviewed in 51 ITx and MVTx patients receiving organs between 2009 and 2015. Twenty-nine (56.8%) patients had at least one sepsis episode (total of 63 episodes) through December 2016. Bacterial etiologies accounted for 66.7% of all episodes (n = 42), occurring a median of 122.5 days following transplant (IQR 59-211.8 days). Multidrug-resistant organisms (MDROs) accounted for 73.8% of bacterial infections; extended spectrum beta-lactamase producers, vancomycin-resistant enterococcus, and highly-resistant Pseudomonas aeruginosa were the most commonly identified. Increased mechanical ventilation and vasoactive requirements were noted in MDRO episodes (OR 3.03, 95% CI 1.09-8.46 and OR 3.07, 95% CI 1.09-8.61, respectively; p < .05) compared to non-MDRO episodes. PICU length of stay was significantly increased for MDRO episodes (7 vs. 3 days, p = .02). Graft loss was 24.1% (n = 7) and mortality was 24.1% (n = 7) in patients who experienced severe sepsis. Further attention is needed for MDRO risk mitigation and modification of sepsis treatment guidelines to ensure MDRO coverage for this population.

Carbapenemase-producing Enterobacteriaceae in transplant patients

Carbapenemase-producing Enterobacteriaceae (CPE) are a serious public health concern and represent a major threat to immunocompromised hosts, including solid organ (SOT) and stem cell transplant (HSCT) recipients. Transplant patients are at particular risk of developing CPE colonization and/or infection due to their frequent exposure to prolonged courses of broad-spectrum antibiotics, altered immunocompetence and exposure to invasive procedures and immunosuppressive drugs. Gut colonization with CPE, in particular carbapenem-resistant Klebsiella pneumoniae, may occur before or after SOT in 2%-27% of patients and among 2%-9% of HSCT and has been associated with increased risk of developing CPE infections. In endemic areas, CPE infections occur in up to 18% of SOT, and HSCT patients can account for 5%-18% of all patients with CPE bacteraemia. Mortality rates up to 70% have been associated with CPE infections in both patient populations. The rapid initiation of an active therapy against CPE is advocated in these infections. Therapeutic options, however, are limited by the paucity of novel compounds that are currently available and by potential antibiotic-associated toxicities. Therefore, a multidisciplinary approach involving infection control and antimicrobial stewardship programmes still represents the mainstay for the management of CPE infections among transplant patients. The evidence for the use of prevention strategies such as CPE-targeted perioperative prophylaxis or gut decolonization is still scarce. Large, multicentre trials are required to better define prevention strategies and to guide the management of CPE infections in the transplant setting.

Care of Pediatric Solid Organ Transplant Recipients: An Overview for Primary Care Providers

As the number of living pediatric solid organ transplant (SOT) recipients continues to grow, there is an increased likelihood that primary care providers (PCPs) will encounter pediatric SOT recipients in their practices. In addition, as end-stage organ failure is replaced with chronic medical conditions in transplant recipients, there is a need for a comprehensive approach to their management. PCPs can significantly enhance the care of immunosuppressed hosts by advising parents of safety considerations and avoiding adverse drug interactions. Together with subspecialty providers, PCPs are responsible for ensuring that appropriate vaccinations are given and can play an important role in the diagnosis of infections. Through early recognition of rejection and posttransplant complications, PCPs can minimize morbidity. Growth and development can be optimized through frequent assessments and timely referrals. Adherence to immunosuppressive regimens can be greatly improved through reinforcement at every encounter, particularly among adolescents. PCPs can also improve long-term outcomes by easing the transition of pediatric SOT recipients to adult providers. Although guidelines exist for the primary care management of adult SOT recipients, comprehensive guidance is lacking for pediatric providers. In this evidence-based overview, we outline the main issues affecting pediatric SOT recipients and provide guidance for PCPs regarding their management from the first encounter after the transplant to the main challenges that arise in childhood and adolescence. Overall, PCPs can and should use their expertise and serve as an additional layer of support in conjunction with the transplant center for families that are caring for a pediatric SOT recipient.

Surgical site infections: Guidelines from the American Society of Transplantation Infectious Diseases Community of Practice

These guidelines from the Infectious Diseases Community of Practice of the American Society of Transplantation review the diagnosis, prevention, and management of post-operative surgical site infections (SSIs) in solid organ transplantation. SSIs are a significant cause of morbidity and mortality in SOT recipients. Depending on the organ transplanted, SSIs occur in 3%-53% of patients, with the highest rates observed in small bowel/multivisceral, liver, and pancreas transplant recipients. These infections are classified by increasing invasiveness as superficial incisional, deep incisional, or organ/space SSIs. The spectrum of organisms implicated in SSIs in SOT recipients is more diverse than the general population due to other important factors such as the underlying end-stage organ failure, immunosuppression, prolonged hospitalizations, organ transportation/preservation, and previous exposures to antibiotics in donors and recipients that could predispose to infections with multidrug-resistant organisms. In this guideline, we describe the epidemiology, clinical presentation, differential diagnosis, potential pathogens, and management. We also provide recommendations for the selection, dosing, and duration of peri-operative antibiotic prophylaxis to minimize post-operative SSIs.