Campioli, Cristina Corsini

Abstract Background Increasing use of deep brain stimulation (DBS) over the past 20 years is paralleled by a rise in DBS infections. There is a paucity of data on the diagnosis, management, and outcomes in such infections. We describe our center’s experience with DBS infections. Methods Adults ( >18 years) diagnosed with DBS associated infection between January 1, 2000 and May 1, 2020 were retrospectively reviewed. Data on patient demographics, clinical presentation, microbiology, and management was collected. Results Seventy cases were identified (table 1). The mean age at diagnosis was 58.9 ± 16.5 years. The bulk were free of comorbidities. Parkinson’s disease and essential tremors were the most common indications for DBS placement. The median time from implantation to infection was 4 months [IQR 1,24]. The neurotransmitter and extension wires were the most frequently infected parts. A microbiological diagnosis was made in 89% of cases, 47% of which were polymicrobial. The most commonly identified organisms were Staphylococcus aureus, Cutibacterium acnes, and coagulase-negative staphylococci. For patients with deep infection, 71% had complete device extraction, 20% partial extraction, and 9% device retention; clinical cure at 3 months occurred in 97%, 64% and 100%, respectively (figure 1). On the other hand, 93% of patients with superficial infection had device retention; cure at 3 months was seen in 64% (figure 2). Suppressive oral antibiotics were rarely used, 45% of patients with partial extraction and 26% with device retention. DBS was reimplanted in 71% of patients after complete extraction and led to reinfection in 30% at 1 year follow up. Median time to reimplantation was 2.7 months. All patients who failed at 3 months in the partial extraction and device retention cohorts subsequently underwent complete device removal leading to clinical cure sustained at 1 year follow up. Conclusion All patients who had complete extraction achieved clinical cure at 3-months follow-up, while high failure rates occurred in those with device retention. Most infections were polymicrobial and predominantly caused by gram-positive pathogens. Thirty percent of patients with re-implantation after complete device extraction developed re-infection within 1 year. Disclosures All Authors: No reported disclosures

Abstract Background Staphylococcus aureus bacteremia (SAB) is common and is characterized by high rates of morbidity and mortality. The clinical importance of a single positive blood culture bottle (SPBCB), however, is poorly defined despite it being a frequent laboratory finding. We therefore examined patients with SPBCB to determine its clinical significance and to understand the rationale of current practice. Methods We performed a retrospective, multicenter study of patients with a SPBCB for S. aureus in initial cultures from January 2019 to December 2019 using data collected from both electronic health records and the clinical microbiology laboratory. Results Overall, 534 patients with SAB were identified, and 118 (22.1%) had a SPBCB. Among SPBCB cases, 106 (89.3%) were classified as clinically significant while 12 were considered contaminated or of unclear clinical significance. Baseline characteristics were similar between the groups (Table 1). A majority (92.4%) received antibiotic therapy, but patients with clinically significant bacteremia were treated with a longer antibiotic course (25.9 vs 5.7 days, p< 0.001). Outcomes between those with SPBCB (contaminant vs clinically significant) were similar (Table 2). Of note, while there was no difference in use of echocardiography based on PREDICT criteria between the clinically significant SPBCB vs. the multiple positive blood culture bottles (MPBC) cohorts (Table 3), significant differences were seen in both frequency of echocardiography (65.1% vs. 84.6%, P< 0.001) and IE diagnosis (3.8% vs. 14.2%, P=0.002) for patients in the SPBCB vs. MPBC groups, respectively. In addition, those with MPBC had higher 90-day, 6-month and 1-year mortality rates. Conclusion SPBCB was documented in almost one-quarter of SAB cases and should trigger a thorough investigation as its associated mortality was high and complications, including IE, occurred. Although some SPBCB cases may represent contamination, antibiotic treatment of SPBCB was commonplace. Patients with clinically significant SPBCB were less likely to undergo echocardiography and had a reduced prevalence of an IE diagnosis as compared to those with MPBC. Patients with SPBCB may have a more favorable long-term prognosis as compared to that in patients with MPBC. Disclosures Muhammad R. Sohail, MD, Medtronic (Consultant)Philips (Consultant) Larry M. Baddour, MD, Boston Scientific (Individual(s) Involved: Self): Consultant; Botanix Pharmaceuticals (Individual(s) Involved: Self): Consultant; Roivant Sciences (Individual(s) Involved: Self): Consultant

A 78-year-old man with an implantable cardioverter-defibrillator (ICD) presented with chills and malaise. His history was significant for heart failure with reduced ejection fraction and complete heart block. He had undergone permanent pacemaker placement that was later upgraded to an ICD 5 years before his presentation. Physical examination revealed an open wound with surrounding erythema overlying the device site. Blood cultures obtained on admission were negative. Transesophageal echocardiogram did not show valve or lead vegetations. He underwent a prolonged extraction procedure. Postoperatively, he developed septic shock and cultures from the device, and repeat peripheral blood cultures grew Staphylococcus simulans and Staphylococcus epidermidis. He was treated with intravenous vancomycin but had refractory hypotension, leading to multiorgan failure. He later expired after being transitioned to comfort care. The patient may have acquired S. simulans by feeding cows on a nearby farm, and the prolonged extraction procedure may have precipitated the bacteraemia.

Abstract Background Nocardial brain abscesses are rare, and published literature describing brain abscesses due to Nocardia species is limited to individual case reports or small series. We report one of the largest contemporary retrospective studies describing risk factors, diagnostic evaluation, management, and outcomes of nocardial brain abscess. Methods Retrospective review of all adults with brain abscess due to culture-confirmed Nocardia species at our institution between January 1, 2009, and June 30, 2020. Results Overall, 24 patients had nocardial brain abscesses during the study period. The median age at presentation was 64 years, and 62.5% were immunocompromised. Pulmonary and cutaneous infections were the most common primary sites of nocardial infection. All 24 patients had magnetic resonance imaging performed, and the frontal lobe was the most commonly involved. The most common organism isolated was Nocardia farcinica, followed by Nocardia wallacei and Nocardia cyriacigeorgica. Thirteen patients were managed with antimicrobial therapy alone, while 11 had both medical and surgical management. In all patients, dual therapy was recommended for the initial 6 weeks of treatment, and 22 patients received at least 1 oral agent as part of their final antibiotic regimen, predominantly trimethoprim-sulfamethoxazole and linezolid. Fourteen patients achieved complete clinical and radiographic resolution of infection. Conclusions Nocardia is an important cause of brain abscess in the immunocompromised host. Early diagnostic and therapeutic aspiration may help health care providers confirm the diagnosis, choose an appropriate antimicrobial regimen, and achieve source control.

Abstract Cefazolin is commonly used as an alternative to antistaphylococcal penicillins (ASPs) in treating methicillin-susceptible Staphylococcus aureus (MSSA) infections; however, no study has compared these agents in MSSA spinal epidural abscess (SEA). We describe our experience in managing MSSA SEA and compare the clinical efficacy of cefazolin with ASPs. This retrospective multicenter study reviewed 79 adult patients diagnosed with SEA between January 2006 and July 2020 using data collected from electronic health records and clinical microbiology laboratory databases. Forty-five patients received cefazolin, while 34 received ASPs. The total antibiotic duration was longer in the ASPs group but not statistically significant. There were no significant differences in treatment failure at week 6 vs week 12, 30-day vs overall mortality, or in 90-day recurrence rates between the treatment groups. Cefazolin was equally as effective as ASPs, and our findings suggest that it can be an alternative to ASPs in the treatment of MSSA SEA.

Abstract Background Brain abscess and cerebritis are diseases associated with high-risk morbidity and mortality despite the advancement of imaging technologies and antimicrobial therapy for the past 30 years. We aimed to describe the demographics of patients with brain abscess and cerebritis at Mayo Clinic. Methods We retrospectively reviewed the demographics of all adult patients with the diagnosis of intracranial brain abscess, cerebritis, or both at our institution from January 1, 2009, through December 31, 2019. All analyses were performed using JMP software (Cary, NC). Results A total of 666 patients with brain abscess and cerebritis were identified during the study period. The median patient age was 59.7 years, and the majority were males (64.8%; P=0.0001). A total of 587 (88.1%) patients self-identified as Whites (P=< 0.0001) and 608 (91.2%) as Non-Hispanic or Latino (P=< 0.0001). A total of 453 (68.01%) patients were from the Midwest, with Minnesota and Wisconsin being the two most common States with 243 (36.4%; P=< 0.0001) and 101 (15.1%; P=0.01) patients respectively. The majority of patients (69.2%) had coronary artery disease and peripheral vascular disease with a median Charlson comorbidity index of 7 (P= < 0.0001) and an estimated 10-year survival of 0%. Conclusion Male, White Non-Hispanics, and elderly patients seem to be the most prevalent patient population at risk for brain abscess or cerebritis. This investigation provides clinicians the demographic data needed to identify potentially complex patients with brain abscesses. Disclosures M. Rizwan Sohail, MD, Aziyo Biologics (Consultant)Medtronic Inc (Consultant, Research Grant or Support)

Abstract Background Mycobacterium septicum is a rapidly growing non-tuberculous mycobacterium. It is a ubiquitous organism capable of causing infections in both healthy and immunocompromised individuals. Only a few cases have been reported to date, and standard therapeutic regimens, and optimal treatment duration have not been defined. Methods We conducted a retrospective chart review of all patients seen at Mayo Clinic in Rochester, MN from July 2014 to March 2020 from whom Mycobacterium septicum was isolated in culture by our clinical microbiology laboratory. Results There were 12 patients identified with M. septicum infection – 7 males and 5 females. The average age was 67 years, with an age range of 48 to 80 years. Seven of 12 isolates obtained were from sputum samples. Only one patient was on immunosuppressive medication. Three cases were considered clinically significant infections for which directed anti-mycobacterial therapy was instituted. In two of these three cases, co-infection with Mycobacterium avium complex (MAC) was seen. Underlying structural lung disease was present in the two cases of pulmonary infections. Peritoneal dialysis catheter-related peritonitis was seen in the third case. All the isolates were susceptible to amikacin, ciprofloxacin, imipenem, linezolid, moxifloxacin, and trimethoprim-sulfamethoxazole (TMP-SMX). The isolates were resistant to clarithromycin and doxycycline. Patient Characteristics, Associated M. septicum Illness, and Therapy Provided Antimicrobial Susceptibility Profiles of the Mycobacterium septicum Isolates, MIC (mcg/mL) and Interpretation Patient Demographics and Specimen Source of Mycobacerium septicum Isolates Conclusion M. septicum is an unusual cause of non-tuberculous mycobacterial infection. The presence of a foreign body may increase the risk of infection. Individuals with underlying structural lung disease are also likely to be at increased risk of developing pulmonary infection. Generalized treatment recommendations are limited by the lack of prospective controlled trials; hence, optimal antibiotic regimen and treatment duration have not been firmly established. Susceptibility testing should be performed to guide treatment selection, but the use of combination therapy with potentially empiric agents like amikacin, ciprofloxacin, imipenem, linezolid, moxifloxacin, and TMP-SMX as demonstrated in this small study, can be considered. A high rate of macrolide resistance was noted in our study. Disclosures All Authors: No reported disclosures

AbstractBackgroundAscertaining involvement of left ventricular assist device (LVAD) in a patient presenting with bloodstream infection (BSI) can be challenging, frequently leading to use of chronic antimicrobial suppressive (CAS) therapy. We aimed to assess the efficacy of CAS therapy to prevent relapse of BSI from LVAD and non-LVAD sources.MethodsWe retrospectively screened adults receiving LVAD support from 2010 through 2018, to identify cases of BSI. Bloodstream infection events were classified into LVAD-related, LVAD-associated, and non-LVAD BSIs.ResultsA total of 121 episodes of BSI were identified in 80 patients. Of these, 35 cases in the LVAD-related, 14 in the LVAD-associated, and 46 in the non-LVAD BSI groups completed the recommended initial course of therapy and were evaluated for CAS therapy. Chronic antimicrobial suppressive therapy was prescribed in most of the LVAD-related BSI cases (32 of 35, 91.4%) and 12 (37.5%) experienced relapse. Chronic antimicrobial suppressive therapy was not prescribed in a majority of non-LVAD BSI cases (33, 58.9%), and most (31, 93.9%) did not experience relapse. Chronic antimicrobial suppressive therapy was prescribed in 9 of 14 (64.2%) cases of LVAD-associated BSI and none experienced relapse. Of the 5 cases in this group that were managed without CAS, 2 had relapse.ConclusionsPatients presenting with LVAD-related BSI are at high risk of relapse. Consequently, CAS therapy may be a reasonable approach in the management of these cases. In contrast, routine use of CAS therapy may be unnecessary for non-LVAD BSIs.

Mycobacterium septicum is a rarely identified nontuberculous mycobacterium capable of causing infections in both healthy and immunocompromised individuals. Only a few cases of M. septicum infections have been reported, which makes recognizing corresponding clinical disease more challenging for clinicians. Antimicrobial susceptibility profiles for this organism are not well described, and corresponding optimal therapeutic regimens have not been established. We report a tertiary care center’s experience with M. septicum from 2014 to 2020.

Abstract Background Post-operative management of patients undergoing cardiac transplantation with an infected left ventricular assist device (LVAD) is unclear. Methods We retrospectively screened all adults with an LVAD who underwent cardiac transplantation at our institution from 2010 through 2018. We selected all cases of LVAD-specific and LVAD-related infections who were receiving antimicrobial therapy as initial treatment course or chronic suppression at the time of cardiac transplantation. Non-LVAD infections, superficial driveline-infection, or concurrent use of right ventricular assist device or extracorporeal membrane oxygenation device were excluded. Results A total of 54 cases met study criteria with 18/54 (33.6%) classified as LVAD- specific or related infections and 36/54 (66.6%) as non-infected. Cases of LVAD-infection had a higher median Charlson Comorbidity Index score at the time of transplantation compared to non-infected cases (P=.005). Of the 18 cases of infection, 13/18 (72.2%) were classified as LVAD-specific and 5/18 (27.8%) as LVAD-related. A total of 9/13 (69.2%) cases had proven LVAD-specific infections. Antimicrobial therapy was extended post-transplant to treat preceding LVAD-specific infection in all nine cases (9/13, 69.2%) with a median duration of 14 days (IQR 14-28). Following LVAD removal, antimicrobial treatment was not continued for preceding LVAD-related infections. Conclusions Patients with an LVAD-specific infection were treated with two weeks of pathogen-directed therapy post heart transplant without any relapses. For those without LVAD-specific infection or uncomplicated LVAD-related bacteremia who had completed antimicrobial therapy pre-transplant, antibiotics were discontinued after standard peri-operative prophylaxis and no relapses were observed.