Citations

Abstract Objectives Whipple’s disease (WD) results from infection of the bacteria Tropheryma whipplei (TW). This disease is characterized by macrophage infiltration of intestinal mucosa and primarily affects Caucasian males. Genetic studies of host susceptibility are scarce. Nucleotide-binding oligomerization domain containing protein 2 (NOD2) is an innate immune sensor, resides mainly in monocytes/macrophages and contributes to defence against infection and inflammatory regulation. NOD2 mutations are associated with autoinflammatory diseases. We report the association of NOD2 mutations with TW and WD for the first time. Methods A multicentre, retrospective study of three patients with WD was conducted. Patients received extensive multidisciplinary evaluations and were cared for by the authors. NOD2 and its association with infection and inflammation were schematically represented. Results All patients were Caucasian men and presented with years of autoinflammatory phenotypes, including recurrent fever, rash, inflammatory arthritis, gastrointestinal symptoms and elevated inflammatory markers. All patients underwent molecular testing using a gene panel for periodic fever syndromes and were identified to carry NOD2 mutations associated with NOD2-associated autoinflammatory disease. Despite initially negative gastrointestinal evaluations, repeat endoscopy with duodenal tissue biopsy ultimately confirmed WD. After initial ceftriaxone and maintenance with doxycycline and/or HCQ, symptoms were largely controlled, though mild relapses occurred in follow-up. Conclusion Both NOD2 and TW/WD are intensively involved in monocytes/macrophages. WD is regarded as a macrophage disease. NOD2 leucin-rich repeat–associated mutations in monocytes/macrophages cause functional impairment of these cells and consequently may make the host susceptible for TW infection and WD, especially in the setting of immunosuppression.

The literature regarding Clostridioides difficile infection (CDI) in left ventricular assist devices (LVADs) patients is limited. Therefore, we aimed to characterize the clinical course, risk factors, management, and outcomes of LVAD patients who developed CDI. Adult patients who underwent LVAD placement during 2010–2022 and developed CDI were included. To determine risk factors and outcomes, we matched CDI patients with LVAD patients who did not develop CDI. Each CDI case was matched with up to two control subjects by age, sex, and time from LVAD implantation. Forty-seven of 393 LVAD patients (12.0%) developed CDI. The median time from LVAD implantation to CDI was 147 days (interquartile range 22.5–647.0). The most common CDI treatment was oral vancomycin (n = 26, 55.3%). Thirteen patients (27.7%) required treatment extension because of a lack of clinical response. Three patients (6.4%) developed recurrent CDI. When 42 cases were matched to 79 control subjects, antibiotic exposure within 90 days was significantly associated with CDI (adjusted odds ratio 5.77; 95% confidence interval, 1.87–17.74; p = 0.002). Moreover, CDI was associated with 1 year mortality (adjusted hazard ratio 2.62; 95% confidence interval, 1.18–5.82; p = 0.018). This infection occurs most often within the first year after LVAD implantation and was associated with 1 year mortality. Antibiotic exposure is an important risk for CDI.

AbstractBackgroundIn the management of Gram‐negative bloodstream infection (GN‐BSI), short antimicrobial courses have been increasingly demonstrated to be non‐inferior to prolonged therapy, with lower risk of Clostridioides difficile infection (CDI) and emergence of multi‐drug resistant (MDR) organisms. However, immunocompromised hosts were excluded from these studies. We investigated outcomes of short (≤10 days), intermediate (11–14 days), and prolonged (≥15 days) antimicrobial durations for GN‐BSI in neutropenic patients.MethodsA retrospective cohort study was conducted on neutropenic patients with monomicrobial GN‐BSI between 2018 and 2022. The primary outcome was a composite of all‐cause mortality and microbiologic relapse within 90 days after therapy completion. The secondary outcome was a composite of 90‐day CDI and development of MDR‐GN bacteria. Cox regression analysis with propensity score (PS) adjustment was used to compare outcomes between the three groups.ResultsA total of 206 patients were classified into short (n = 67), intermediate (n = 81), or prolonged (n = 58) duration. Neutropenia was predominantly secondary to hematopoietic stem cell transplantation (48%) or hematologic malignancy (35%). The primary sources of infection included intra‐abdominal (51%), vascular catheter (27%), and urinary (8%). Most patients received definitive therapy with cefepime or carbapenem. No significant difference in the primary composite endpoint was observed for intermediate versus short (PS‐adjusted hazard ratio [aHR] 0.89; 95% confidence interval [95% CI] 0.39–2.03) or prolonged versus short therapy (PS‐aHR 1.20; 95% CI 0.52–2.74). There was no significant difference in the secondary composite endpoint of CDI or MDR‐GN emergence.ConclusionOur data suggest that short antimicrobial courses had comparable 90‐day outcomes as intermediate and prolonged regimens for GN‐BSI among immunocompromised patients with neutropenia. image

Leptotrichia species are anaerobic, Gram-negative bacilli increasingly recognized as pathogens capable of causing invasive infections such as bloodstream infection (BSI), particularly among immunocompromised patients. However, there is a paucity of data regarding epidemiology, antimicrobial susceptibility, optimal treatment, and clinical outcomes among patients with Leptotrichia bacteremia.

Abstract Background Leptotrichia spp. are anaerobic, gram-negative bacilli that are part of the normal oral and intestinal microbiota. Although traditionally considered non-pathogenic, these bacteria can result in invasive infections including bacteremia in immunosuppressed patients, particularly those with neutropenia. There are limited published data to inform best management strategies in those with Leptotrichia bacteremia. Methods All cases of Leptotrichia spp. bacteremia between January 2012 and 2022 at our tertiary academic medical center were retrospectively reviewed to determine patient risk factors, clinical outcomes, and antimicrobial susceptibilities. Descriptive statistical methods were used. Antimicrobial susceptibilities were performed by agar dilution. Results 26 cases of Leptotrichia spp. bacteremia were identified (Figure 1). The mean patient age was 55 years (SD 17), with 9 female patients (35%). All 26 patients were immunocompromised, predominantly due to hematologic malignancy (69%) or hematopoietic stem cell transplant (23%) (HSCT). 25 of 26 patients were actively neutropenic, with a median duration of neutropenia of 21 days (13-26) (Table 1). The most frequent sources of Leptotrichia bacteremia were gastrointestinal translocation (60%), followed by catheter-related infection (35%). 10 patients had polymicrobial bacteremia (38.5%). The primary antibiotics utilized to treat Leptotrichia bacteremia included metronidazole (42%), piperacillin-tazobactam (27%), and carbapenems (19%). Overall, the mean duration of treatment was 11 days, with a 60-day all-cause mortality of 19% (Table 1) with no cases of microbiologic relapse. In the 22 clinical isolates evaluated for susceptibility, Leptotrichia spp. were largely susceptible to metronidazole, penicillin, ertapenem, and piperacillin-tazobactam, but uniformly resistant to moxifloxacin (Table 2). Figure 1:Leptotrichia spp. identified as cause of bacteremia in 26 patientsTable 1:Baseline characteristics of patients with Leptotrichia bacteremia (n=26) between January 2012 to January 2022Table 2:Antimicrobial susceptibility profile of the Leptotrichia spp. (n=22) Conclusion Leptotrichia spp. may be a rare cause of bacteremia in neutropenic hosts, particularly those with underlying hematologic malignancies and HSCT. The pathogen has a favorable susceptibility profile to penicillins and carbapenems, but has high degree of resistance to fluoroquinolones. Disclosures All Authors: No reported disclosures.

Abstract Background The incidence of end-stage heart failure necessitating advanced cardiac therapy continues to increase in the United states. Implantable left ventricular assist devices (LVADs) represent an important modality that is utilized both as a bridge to heart transplant or as destination therapy. LVAD-associated infections, ranging from driveline exit site or pocket infections to endovascular infections, are a major complication with high mortality. Antibiotic prophylaxis at time of LVAD implantation is therefore an important strategy to mitigate infections. However, a clear surgical infection prophylaxis regimen and associated outcomes have not been reported. Methods We performed a single center, retrospective cohort study evaluating the impact of antimicrobial prophylaxis on risk of infection in patients who underwent LVAD implantation between February 2007 and June 2019 at Mayo Clinic. LVAD-specific and related infections were defined according to the International Society of Heart Lung Transplantation criteria. Single drug prophylaxis (SDP) included cefazolin only, vancomycin only, or cefazolin and vancomycin; multidrug (MDP) regimen includes either of the SDP regimens plus another antibiotic. We compared incidence of infection within 90-day and within one-year of implantation, as well as risk of C. difficile infections between the SDP and MDP cohorts. Results We reviewed 403 patients who received LVAD implantation (Table 1), 402 of had information on surgical prophylaxis. 307 (76%) patients received SDP and 95 patients (24%) received MDP. 14 patients developed an infection within 1 year of implantation (Table 2). There was no difference in the incidence of infections between SDP and MDP arms both at 90 days and 1-year post-implantation (p=0.11). The median time of infection since LVAD implantation was similar between SDP and MDP (p=0.37) arms. Incidence of C. difficile infection was not different between groups (p=0.10) (Table 3). Conclusion There was no significant difference in incidence or time to first infection, within 90-day and 1-year of implantation, between single- and multidrug antibiotic surgical prophylaxis regimens administered at the time of LVAD implantation. Future prospective trials are needed to develop a clear LVAD antibiotic prophylaxis protocol. Disclosures John C. O'Horo, Sr., MD, MPH, Bates college: Advisor/Consultant|MITRE corporation: Grant/Research Support|nferenec, Inc: Grant/Research Support.