Garrigos, Zerelda Esquer

Background: Preventing infections associated with cardiac implantable electronic devices (CIED) and neurostimulators is essential to optimizing patient outcomes. This study aimed to evaluate the antimicrobial performance of a biologic CIED envelope incorporating a bioabsorbable disc infused with rifampin and minocycline. Methods: The antimicrobial activity was evaluated in a rabbit model and in vitro elution tests. Based on in vivo–in vitro correlation studies, a modified AATCC-100 method was used to quantitatively assess antibacterial activity across seven bacterial strains relevant to CIED infections. Results: Pharmacokinetic analysis showed a biphasic elution profile, with rapid initial release followed by more gradual elution over 14 days. The AATCC results showed no bacterial recovery for any tested species, with complete eradication in all replicates. Conclusions: These results support the use of antibiotic-eluting bioenvelopes as an effective strategy for preventing bacterial infections associated with CIED. The modified AATCC-100 test and in vivo–in vitro correlation studies provide new tools for the evaluation of the antibiotic activity of implantable biomaterials.

Abstract Based on expert consensus, the American Society of Transplantation recommends 7–14 days of preventive antibiotic therapy for solid organ transplant recipients from donors with positive blood cultures. We evaluated management and outcomes of kidney transplant recipients from these donors.

Summary We describe a case of culture-negative infective endocarditis due to Neisseria gonorrhoeae, where the application of metagenomics shotgun sequencing in blood played a pivotal role in elucidating the underlying aetiology, guiding targeted therapy and ultimately resulting in the patient’s complete recovery. Beyond its immediate clinical impact, prompt treatment bears significant implications for public health. The utilisation of molecular testing emerges as a valuable strategy to enhance diagnostic accuracy, particularly in cases involving fastidious organisms that are infrequently associated with infective endocarditis.

Abstract Background Fungal infections following pancreas transplantation carry significant morbidity and mortality with an estimated incidence of 3 to 28%. The American Society of Transplantation (AST) suggests considering fluconazole prophylaxis in pancreas transplant recipients (PTR) at high-risk of invasive candidiasis (IC). However, optimal dosage and duration of prophylaxis is unclear. Weekly fluconazole for prevention of IC has been previously reported in liver and bone marrow transplant recipients. We analyzed outcomes of once weekly fluconazole prophylaxis in PTR. Methods We retrospectively reviewed all pancreas transplants performed at our institution from January 2017 through September 2021. PTR at high-risk for IC were defined per AST criteria as those with enteric drainage, vascular thrombosis, and post-perfusion pancreatitis. Patients received once weekly oral fluconazole 200 mg for 12 weeks post-transplant for IC prophylaxis. We analyzed incidence of breakthrough IC within the first 6 months post-transplant. Results We identified a total of 22 PTR, all of whom received simultaneous kidney transplantation from deceased donors. Of these, 12/22 (55%) were male and 11/22 (50%) were African American. Median age at the time of transplantation was 39 years (IQR 34-46). The most common indication for transplantation was type 1 diabetes mellitus (17/22, 21%) with associated nephropathy. No donor organ cultures were positive for fungi and all pancreas transplants were performed using enteric drainage. Notably, one patient developed pancreas allograft thrombosis while another developed pancreatitis. No patients required early discontinuation of fluconazole due to intolerance or side effects and none developed breakthrough IC within 6 months post-transplant (Table 1). Table 1. Conclusion Weekly fluconazole prophylaxis has not been previously studied in PTR. In our cohort, this approach was well tolerated, with no cases of IC at 6 months post-transplantation in patients at high-risk. Randomized controlled clinical trials are needed to define the optimal strategy in this population. Disclosures M. Rizwan Sohail, MD, Aziyo Biologics: Honoraria|Boston Scientific Corporation: Honoraria|Medtronic: Grant/Research Support|TRYX: Grant/Research Support.

Abstract Background Mycoplasma hominis, Ureaplasma urealyticum, and Ureaplasma parvum may cause post-transplant infections in lung transplant recipients. We evaluated routine pretransplant screening for these Mollicutes. Methods We retrospectively reviewed records of lung transplant recipients at our tri-site institution from 01/01/2015 to 11/15/2019. M. hominis and/or Ureaplasma polymerase chain reaction (PCR) was performed on pretransplant recipient urine specimens and donor bronchial swabs at the time of transplantation. Development of Mollicute infection and hyperammonemia syndrome (HS) was recorded. Results A total of 268 patients underwent lung transplantation during the study period, of whom 105 were screened with at least 1 Mollicute PCR. Twelve (11%) screened positive; 10 donors, 1 recipient, and 1 both. Among positive donors, 3 were positive for M. hominis, 5 for U. urealyticum, and 4 for U. parvum. Preemptive therapy included doxycycline, levofloxacin, and/or azithromycin administered for 1–12 weeks. Despite therapy, 1 case of M. hominis mediastinitis and 1 case of HS associated with Ureaplasma infection occurred, both donor-derived. Of those screened before transplant, cases with positive screening were more likely (P < 0.05) to develop Mollicute infection despite treatment (2/12, 17%) than those who screened negative (1/93, 1%). Conclusions Pretransplant recipient urine screening had a low yield and was not correlated with post-transplant Mollicute infection, likely because most M. hominis and U. parvum/urealyticum infections in lung transplant recipients are donor-derived. Routine donor bronchus swab PCR for M. hominis, U. urealyticum, and U. parvum followed by preemptive therapy did not obviously impact the overall incidence of Mollicute infection or HS in this cohort.

Abstract Background Based on expert opinion, solid organ transplant recipients from donors with bacteremia are treated with 7-14 days of pre-emptive antibiotic therapy (PAT). However, studies addressing necessity, optimal duration of therapy, and outcomes in kidney transplant recipients (KTR) are lacking. Methods We retrospectively reviewed all kidney transplants performed at our institution from 01/01/2015-01/01/2021 to identify those cases where matched deceased donors had positive blood cultures. Bacteremia was defined per CDC criteria. We analyzed rate of infection in the KTR with the same organism identified in the donor blood culture within 30 days of transplantation. Results A total of 56 KTRs with donor positive blood cultures were identified. Demographic data are summarized in Table 1. Twenty of 56 cases (35.8%) had bacteremia and 36 (64.2%) had organisms classified as common commensals. The most common organisms in the bacteremia group were Gram-negative bacteria (12/20) and Staphylococcus aureus (6/20). Most common commensals were coagulase-negative staphylococci (26/36) (Table 2). All KTR received preoperative antibiotics at the time of transplantation, primarily cefazolin (15/20), and vast majority received TMP/SMX prophylaxis, for Pneumocystis jirovecii, post-transplant (19/20). PAT was administered in 70% (14/20) cases of bacteremia for a median of 8.5 days (IQR 7-14), while six cases were left untreated (Table 2). In contrast, majority of cases with common commensals were not treated (75%, 27/36). Of the cases treated (9/36), median duration of therapy was 7 days (IQR 5-14). No cases of infection with the same organism identified in the donor blood culture were reported in KTR within 30 days of transplantation. Conclusion KTR donors with bacteremia who were treated received a median of 8.5 days of PAT with no instances of breakthrough infection. In contrast, majority of donor blood cultures with organisms classified as common commensals were not treated and did well. Future studies are needed to assess whether perioperative antibiotics coupled with TMP/SMX prophylaxis post-transplantation are sufficient in select cases of transplantation from donors with bacteremia. Disclosures All Authors: No reported disclosures

Introduction: Cardiovascular implantable electronic devices (CIED) infections are frequently complicated with bloodstream infection (BSI). Complete device removal and prolonged antimicrobial therapy is essential for cure. The frequency of persistent BSI after source control (device extraction) is not well described. This study aims to assess the utility of repeat blood cultures (BC) after device extraction as recommended by the American Heart Association (AHA) guidelines. Methods: We selected patients who presented with BSI in the setting of CIED infection and underwent device removal at Mayo Clinic Rochester between 2012 and 2017. Cases where BC were not drawn prior to extraction, or repeated within 72 hours of device extraction, or met criteria for contamination were excluded. Results: Of 656 patients who underwent CIED extraction for device infection, 190 with post-extraction BC met study criteria. Among the final study cohort (Table 1), 159 patients had negative BC, while 31 had positive BC following CIED extraction. Pre-extraction, the most common causative organism was Staphylococcus aureus (91/190, 48%) (Figure 1a). Post-extraction, 22 of the 31 (71%) cases of persistent BSI were due to S. aureus (Fig 1b). The median duration of BSI was not significantly different between negative and positive BC groups (3 versus 4 days, p=0.92). Conclusions: Majority of patients had resolution of BSI after CIED extraction. S. aureus was the most common cause of persistent BSI post-extraction. Our findings support the AHA guidelines of repeating BC after device extraction, especially for S aureus .

Abstract Background Conventional blood cultures were compared to plasma cell-free DNA–based 16S ribosomal RNA (rRNA) gene polymerase chain reaction (PCR)/next-generation sequencing (NGS) for detection and identification of potential pathogens in patients with sepsis. Methods Plasma was prospectively collected from 60 adult patients with sepsis presenting to the Mayo Clinic (Minnesota) Emergency Department from March through August 2019. Results of routine clinical blood cultures were compared to those of 16S rRNA gene NGS. Results Nineteen (32%) subjects had positive blood cultures, of which 13 yielded gram-negative bacilli, 5 gram-positive cocci, and 1 both gram-negative bacilli and gram-positive cocci. 16S rRNA gene NGS findings were concordant in 11. For the remaining 8, 16S rRNA gene NGS results yielded discordant detections (n = 5) or were negative (n = 3). Interestingly, Clostridium species were additionally detected by 16S rRNA gene NGS in 3 of the 6 subjects with gastrointestinal sources of gram-negative bacteremia and none of the 3 subjects with urinary sources of gram-negative bacteremia. In the 41 remaining subjects, 16S rRNA gene NGS detected at least 1 potentially pathogenic organism in 17. In 15, the detected microorganism clinically correlated with the patient’s syndrome. In 17 subjects with a clinically defined infectious syndrome, neither test was positive; in the remaining 7 subjects, a noninfectious cause of clinical presentation was identified. Conclusions 16S rRNA gene NGS may be useful for detecting bacteria in plasma of septic patients. In some cases of gram-negative sepsis, it may be possible to pinpoint a gastrointestinal or urinary source of sepsis based on the profile of bacteria detected in plasma.

Lawsonella clevelandensis, an emerging pathogen, was first described in 2016, and has been implicated in abdominal, breast and spinal abscesses in a limited number of cases. Being a fastidious organism, it is primarily identified with molecular methods. With the incorporation of broad-range PCR testing in clinical diagnostics, L. clevelandensis has been increasingly reported in the literature. We describe a case of a 65-year-old man who presented with bilateral psoas abscesses secondary to aorto-bi-iliac vascular graft infection with L. clevelandensis identified using 16S rRNA/PCR sequencing. The patient underwent surgical resection and replacement of infected graft, followed by 6 weeks of intravenous antibiotic therapy and then chronic suppression with doxycycline and cefadroxil. He was infection-free at last follow-up.

AbstractBackgroundNeutropenia is a risk factor for development of infections; however, the direct effect of neutropenia on development of bloodstream infection (BSI) is not known. D‐index, which is area between the neutrophil time curve and a neutrophil count of 0.5 × 109/L, incorporates the combined effect of severity and duration of neutropenia. We aimed to evaluate whether D‐index can be used as a marker for BSI in patients with allogeneic stem cell transplantation.MethodWe conducted a retrospective cohort study of patients undergoing allogeneic stem cell transplantation between January 1, 2005, and September 30, 2015. The primary outcome measure was the development of BSI within 30 days of transplantation.ResultsA total of 714 patients were included in the study of whom 101 developed BSI. Patients with BSI had a significantly higher median D‐index value compared with patients who did not have BSI (4990 vs. 3570, P < .001). As a marker, the performance of the D‐index was similar to that of the duration of profound neutropenia (P = .18) and significantly better than the total duration of neutropenia (P = .001).ConclusionThe D‐index performed better than the total duration of neutropenia as a marker for BSI in patients with allogeneic stem cell transplantation. There was no difference between D‐index and, a more easily calculable indicator, duration of profound neutropenia.