bluuebunny/crossref_metadata_2025 huggingface dataset:
1167. Got Micafungin? The Incidence of Fungemia in Patients with Septic Shock
Authors: Piche Mackenzie , Campion Maureen , Adeel Alina
Published: January 2021

Background

Timely administration of antibiotics in patients presenting with sepsis decreases mortality, however evidence evaluating empiric antifungal coverage has been inconclusive. Recent data have shown no mortality benefit of empiric antifungal therapy in patients with ICU-acquired sepsis. Despite the lack of data, the Surviving Sepsis Campaign recommends empiric coverage for all suspected pathogens, including fungi. The purpose of this study is to determine the frequency of concomitant septic shock and fungemia at UMass Memorial Medical Center, a large tertiary care center.

Methods

This was a retrospective cohort study that included adult patients with a discharge diagnosis of severe sepsis or septic shock and/or fungemia admitted to UMMMC between October 2017 and October 2019. Patients with positive fungal blood cultures were further reviewed to identify if septic shock was present within 24 hours of blood culture collection. Additionally, risk factors for fungemia and 30-day mortality were assessed. Exclusion criteria included pregnancy, cultures from outside hospitals, incarceration, and hospice care.

Results

In the analysis period, 4,253 patients had a discharge diagnosis of severe sepsis or septic shock. There were 68 cases of fungemia. In total, 54 patients with fungemia were included after applying exclusion criteria. Of the 54 patients with fungemia, 8 patients (15.1%) met criteria for septic shock at the time of positive blood culture, while 81% met SIRS criteria. Of the 4,253 total patients, 0.19% had coexisting fungemia and septic shock. At 30 days, four patients (7.4%) with both septic shock and fungemia had expired out of 12 total deaths. Three of the four deaths had multiple risk factors for fungemia including central line in place for greater than 48 hours, parenteral nutrition, and prolonged antibiotic therapy.

Conclusion

Septic shock is a rare presentation of fungemia. Most patients with septic shock and fungemia have known risk factors. Despite recommendations by the Surviving Sepsis Campaign to initiate therapy for all likely pathogens, including fungal species, the incidence of fungemia presenting as septic shock at our academic medical center was very low and does not appear to warrant empiric coverage.

Disclosures

All Authors: No reported disclosures
1168. Higher Glycosylated Hemoglobin (A1c) Levels are Associated with Increased Mortality from Cryptococcus Infection
Authors: Archuleta Solana , Sillau Stefan , Franco-Paredes Carlos , Henao-Martinez Andres
Published: January 2021

Background

Diabetes mellitus is a well-established risk factor for the development of bacterial infections. However, the role of diabetes mellitus as a risk factor in the occurrence of Cryptococcosis is unknown. The aim of the study was to determine whether diabetes and A1c levels were independent risk factors for infection and mortality in Cryptococcus infection.

Methods

A retrospective hospital-based case-control study matched by age and gender (96 cases and 125 controls) was performed in patients tested for Cryptococcus infection at University of Colorado Hospital from 2001-2019 (n=221). Data was extracted through RedCap. A multivariable logistic regression model was used to identify predictors of infection and mortality.

Results

Diabetes mellitus was present in 24 cases (25.0%) and 24 controls (19.2%). In cases, the mean age was 54 years, 79% were men, and diabetes was the only known risk factor in 6 cases (6.3%) and accompanied additional risk factor in 18 cases (18.8%). Other common risk factors included: HIV (39.9%), steroid use (24.7%), malignancy (23.2%), solid organ transplant recipients (18.1%), and cirrhosis (5.2%). Cryptococcal meningitis (49.0%) followed by pulmonary infection (36.5%) were the most common sites of infection. The mean A1c value for cases vs. controls was 6.5 ± 1.5 vs. 6.2 ± 1.8 mmol/L, p=0.43. Overall mortality was 27.3% vs. 26.9% among cases and controls, respectively. Among cases, the risk of death was higher for patients with diabetes, although not significantly (39.1% vs 23.1%, p= 0.137). Adjusted for gender, age and case/control; for every 1-point increase in A1c levels, the odds of mortality increased by 40% (OR = 1.4, CI: 1.0-1.9, p= 0.045).

Conclusion

Diabetes mellitus alone is an uncommon risk factor for acquiring Cryptococcus infection. However, uncontrolled diabetes in Cryptococcosis may worsen outcomes from infection, including increased mortality. Glucose control interventions may improve clinical outcomes in patients with cryptococcal infection.

Disclosures

All Authors: No reported disclosures
1170. Invasive Fungal Infections and Colonization in Critically Ill Patients: Impact of Diagnosis and Management on Outcomes
Authors: Siudela Anthony , Khan Afshin , Bateman Marjorie E
Published: January 2021

Background

Invasive fungal infections (IFIs), though uncommon, are on the rise and have a high mortality rate. Fungal colonization is common, but its clinical significance is unclear. Our study aims to characterize the impact of these diagnoses and their management on outcomes in a large ICU population.

Methods

We utilized the Multiparameter Intelligent Monitoring in Intensive Care III database for this retrospective cohort study. Adults with positive fungal cultures were classified as colonized or infected using definitions from the EORTC/MSG guidelines and the Blot protocol for Aspergillus. Outcomes were compared between groups matched by age, SOFA score, admission diagnosis, culture results, and comorbidities.

Results

There were 595 hospital admissions with IFI (11.7/1000 admissions) and 5789 with colonization (114/1000 admissions). In-hospital mortality was 52% in patients with IFIs and 36% in colonized patients. Mortality post-discharge remained high and was not significantly different in the two groups.

67% of patients with IFIs had the diagnosis documented. 24% of patients with IFIs and 8% of colonized patients received antifungal therapy. Treatment did not significantly impact mortality in infected or colonized patients but was associated with increased length of hospital and ICU stay. Infectious disease (ID) consultation was performed in 39.8% of patients with IFIs and 20% of patients with colonization. In the group of IFI patients with ID consultation, in-hospital mortality was higher, but survival post-discharge increased significantly. There was a significant increase in diagnosis of IFI in the ID group and a trend toward increased treatment. In colonized patients with ID consultation, in-hospital mortality and survival post-discharge improved. Hospital and ICU length of stay were longer for patients with ID consultation.

Conclusion

Critically ill patients with IFIs have high mortality rates, which were not reduced by treatment. The prevalence of colonization was high, and colonized patients experienced significant in-hospital and post-discharge mortality. This study supports the need for additional investigation into ID consultation, which may improve outcomes in critically ill patients with fungal infection and colonization.

Disclosures

All Authors: No reported disclosures
1173. Ocular Candidiasis in Patients with Candidemia Diagnosed by Blood Culture Versus T2Candida® Assay
Authors: White Cameron , Pappas Peter , McCarty Todd P
Published: January 2021

Background

Ocular candidiasis (OC) is a serious complication of candidemia. Current guidelines recommend dilated fundoscopic exam (DFE) in all patients with candidemia. In this study, we examined characteristics and outcomes of patients at UAB Medical Center with candidemia diagnosed by blood culture (BC) or T2Candida® rapid diagnostic assay (T2C) who were found to have evidence of fungal disease on ophthalmologic exam.

Methods

Patients from 2016-2019 with either 1) at least one positive BC for Candida species or 2) positive T2C assay and negative or no paired BC were identified and retrospectively reviewed. Patients with additional positive BC or T2C within 60 days were excluded from the analysis. Data collected included risk factors for candidemia, causative Candida species, and whether DFE was performed after diagnosis. Patients with evidence of OC by exam were compared by type of ocular involvement (chorioretinitis vs. vitritis), whether visual symptoms were present, and whether intravitreal injection was performed.

Results

A total of 360 episodes of candidemia diagnosed by BC and 288 by T2C alone were included. Of those who underwent DFE, 33 BC patients (12.9%) had findings concerning for OC compared to 18 (8.9%) T2C patients (p=0.177) (Table 2). T2C patients with OC were younger, were more likely to have a prolonged ICU stay and to be mechanically ventilated, and were less likely to be on TPN compared to the BC group. Identification of C. parapsilosis was significantly more common in T2C patients (Table 1). There were no significant differences in presence of visual symptoms, type of ocular involvement, need for intravitreal injection, or 30-day mortality (Table 3).

Table 1. Demographics and risk factors

Table 2. Episodes of candidemia and ocular candidiasis by year

Table 3. Ocular findings and outcomes

Conclusion

The frequency of ocular disease was similar between groups. Significantly more T2C patients had candidemia due to C. parapsilosis, and the groups differed in terms of risk factors for candidemia. There were no differences in frequency of intravitreal injection, severity of eye disease, or mortality. Despite recent concerns about the necessity of DFE in asymptomatic patients with candidemia, we believe these results emphasize the importance of performing DFE in candidemic patients and also support the practice of doing so in patients with positive T2C even in the absence of positive blood cultures.

Disclosures

Peter Pappas, MD, SCYNEXIS, Inc. (Consultant, Advisor or Review Panel member, Research Grant or Support) Todd P. McCarty, MD, Amplyx (Scientific Research Study Investigator)Cidara (Scientific Research Study Investigator)
1175. Pulmonary Aspergillosis in Critically Ill Patients with COVID-19: A Case Series
Authors: Mitaka Hayato , Perlman David C , Javaid Waleed , Salomon Nadim
Published: January 2021

Background

Invasive pulmonary aspergillosis (IPA) has been reported in critically ill patients without pre-existing immunocompromising conditions. However, there are scant data on pulmonary aspergillosis in patients with COVID-19.

Methods

We performed a retrospective review of pharmacy records of antifungal use during 3/21-4/22, 2020, and collect longitudinal clinical data. Cases were then classified by the clinical algorithm for IPA in the ICU (AspICU).

Results

7 out of 18 (39%) patients who received antifungal therapy had Aspergillus fumigatus in tracheal aspirate specimens while mechanically ventilated in the ICU. None of the patients had EORTC/MSG host factors. Median time from admission to the date of positive respiratory culture was 9 days (range: 2-15). High-dose glucocorticoids were started a mean of 5.6 days (range 3-8) before the positive respiratory culture in 5 and on the day of the culture in 2. Six received 583-1000 mg equivalent of prednisone. Two received Tocilizumab. By AspICU criteria, 4 had putative IPA. Radiographic abnormalities included cavitary pneumonia, opacities with dense consolidation, worsening infiltrates, and diffuse interstitial and patchy hazy opacities. Compatible signs included worsening respiratory failure in 3 and fever after 3 days of antibacterial agents in 1. Associated findings were leukocytosis in 4, > 1 positive cultures in 3, high procalcitonin in 2, and positive serum galactomannan in 1. The remaining three were classified as colonization as they lacked compatible signs. One had concomitant Klebsiella aerogenes pneumonia with bacteremia, and two later developed Candidemia and Stenotrophomonas maltophilia pneumonia, respectively. All 3 had fever with leukocytosis. One had elevated procalcitonin. Six received antifungal therapy; one did not due to goals of care. All 7 patients expired despite ICU care.

Conclusion

The critically ill patients with severe COVID-19 in whom respiratory culture grew Aspergillus fumigatus showed very high mortality despite antifungal treatment. By AspICU algorithm, 4 patients had putative IPA. Further data on risk factors and clinical predictors of IPA in COVID-19 are needed.

Disclosures

All Authors: No reported disclosures
1177. Rapid, Non-invasive Detection of Invasive Mucormycosis Caused by Syncephalastrum monosporum Using Next-Generation Sequencing of Circulating Microbial Cell-free DNA in Plasma
Authors: Sanacore Melissa , Solh Melhem M , Holland H Kent , Bashey Asad , Webster Samuel , Morris Lawrence , Solomon Scott , de Vries Christiaan R
Published: January 2021

Background

Improving diagnostics have led to newly identified causes of invasive fungal infection (IFI) in immunocompromised hosts. Syncephalastrum spp. are Zygomycetes more commonly associated with skin infections and have only rarely been implicated as a cause of IFI(1). Next generation sequencing (NGS) for circulating microbial cell-free DNA (mcfDNA) in plasma offers a unique tool to diagnose rare causes of IFI (2,3).

Methods

Karius results were reviewed for Syncephalastrum detections with 2 identified at the same institution. McfDNA was extracted from plasma and NGS was performed by Karius, Inc. (Redwood City, California). Human sequences were removed and remaining sequences were aligned to a database of over 1,400 pathogens. Organisms present above a predefined statistical significance threshold were quantified in DNA molecules per microliter (MPM). Chart review was performed for clinical correlation.

Results

A 66 y/o male one month out of induction therapy for acute myeloblastic leukemia (AML) developed pneumonia. Although BAL was negative for mold and despite empiric antifungals, plasma NGS for mcfDNA showed S. monosporum at 562 MPM; the reference range is 0 MPM. Amphotericin was added to empiric posaconazole. The patient was discharged 10 days later and serial CT scans showed improvement. Repeat NGS mcfDNA 11 days later was negative. He underwent stem cell transplant (SCT) 4 months later.

In a second case, a 66 y/o female with acute prolymphocytic leukemia was admitted for fever with neutropenia. A CT chest showed new multifocal, bilateral, nodular opacities. Despite negative BAL fungal culture and pretreatment with fluconazole, plasma NGS mcfDNA revealed S. monosporum at 575 MPM. She was treated with micafungin, amphotericin, and posaconazole with clinical improvement. Repeat NGS mcfDNA 8 weeks later was negative. Serial CT scans showed improvement over 5 months. She proceeded to SCT.

Conclusion

Plasma-based NGS for mcfDNA enabled rapid, non-invasive detection of pulmonary mucormycosis caused by S. monosporum despite antifungal pretreatment and unrevealing invasive procedures in 2 patients with leukemia. The rapid identification of the specific etiology of IFI enabled targeted anti-fungal therapy and resumption of definitive oncological care including SCT.

Table 1: Clinical Parameters

Disclosures

Christiaan R. de Vries, MD, PhD, Karius (Consultant, Independent Contractor)Stanford University (Employee)
1178. Risk factors for death among patients with Candida endocarditis: An observational study in US academic medical centers
Authors: Huggins Jonathan , David Michael Z , Hohmann Samuel F
Published: January 2021

Background

Candida endocarditis is a rare, sometimes fatal complication candidemia. Our understanding of this condition is limited to findings from case series and small observational studies. Using the Vizient clinical database, a repository for clinical and administrative data from 117 academic medical centers and more than 300 affiliated hospitals, we assembled the largest cohort of Candida endocarditis patients to date, reporting patient characteristics and risk factors for death.

Methods

Using ICD-10 code B37.6 (Candidal Endocarditis) we identified 703 inpatients at 179 United States hospitals from October 2015 through April 2019. We examined demographic, diagnostic, and procedural data from each patient’s initial encounter. With univariate and multivariate logistic regression analyses we identified predictors of in-hospital mortality.

Results

Of 703 patients, 402 (57.2%) were male, 421 (59.9%) used tobacco, 213 (30.3%) had documented opiate abuse, 128 (18.2%) had other illicit drug abuse documented, and 190 (27.0%) had documented hepatitis C infection. Among the 703 patients, 114 (16.2%) died during the index encounter. On multivariate analysis, liver failure was the strongest predictor of death (OR 8.4, 95% CI 4.4 – 15.9), and female sex (OR 1.8, 95% CI 1.1 – 2.9), transfer from an outside facility (OR 1.7, 95% CI 1.1 – 2.7), underlying aortic valve pathology (OR 2.8, 95% CI 1.5 – 4.9), hemodialysis (OR 2.0, 95% CI 1.0 – 3.8), cerebrovascular disease (OR 2.2, 95% CI 1.2 – 3.8), neutropenia (OR 2.5, 95% CI 1.3 – 4.7) and alcohol abuse (OR 2.9, 95% CI 1.3 – 6.7) were also associated with higher odds of in-hospital death. In the same analysis, opiate abuse was associated with a lower odds of in-hospital death (OR 0.4, 95% CI 0.2 – 0.8).

Table 1. Characteristics of 703 patients with Candida endocarditis

Table 2. Factors associated with in-hospital death in multivariate regression analysis

Conclusion

We found that for patients Candida endocarditis inpatient mortality was 16.2% and liver failure was associated with a high risk of death while opiate abuse was protective. Further investigation is necessary to better understand these associations.

Disclosures

Michael Z. David, MD PhD, GSK (Consultant)
1179. Septic shock in Coccidioides immitis Infection
Authors: Wisniewski Piotr , Ewers Evan C , Maves Ryan C
Published: January 2021

Background

Coccidiodes can cause severe or disseminated disease in a minority of patients, but coccidioidomycosis resulting in septic shock is rare. We describe a case of fulminant C. immitis infection whose diagnosis was delayed by a markedly elevated serum procalcitonin. We review the published literature of coccidioidomycosis complicated by septic shock.

Case Report

A 74-year-old man presented with cough, fever, and three weeks of progressive decline. He was febrile at 39.1°C, tachycardic, and tachypneic with crackles in the left lung; an initial procalcitonin (PCT) was 1.73 ng/mL. Broad-spectrum antibacterials were administered. His condition worsened on the 2nd day, requiring vasopressors, endotracheal intubation, and hemodialysis. PCT rose to > 400 ng/mL. Respiratory cultures grew fungi consistent with Coccidioides. Liposomal amphotericin B (AmB) was initiated. His shock progressed, and he died on hospital day 6.

Methods

We performed a MEDLINE and Google Scholar search using the terms “coccidioidomycosis”, “Coccidioides”, “sepsis”, and “septic shock”. Indexed articles and conference abstracts were included if the patient had confirmed coccidioidomycosis and vasopressor-dependent shock with no alternate cause. Data on age, sex, ethnicity, comorbidities, antifungal therapy, and outcome were tabulated.

Results

We identified 18 reports describing 31 patients with vasopressor-dependent septic shock due to Coccidioides since 1993 (table 1). Of these cases, 23/31 (74.2%) died. Of those with reported race/ethnicity, 20/23 were Latino, 4/23 of African descent, 5/23 Asian-Pacific Islander, and 3/23 white. 27/31 (87.1%) were male. All but two were adults (median age 51.5 years). 21/31 (67.7%) had reported comorbid conditions. 20/31 patients (64.5%) and all of the survivors received AmB-based therapy.

Table 1 - Published cases of coccidioidomycosis complicated by septic shock. All ages are in years. Abbreviations: HIV/AIDS = human immunodeficiency virus/acquired immunodeficiency syndrome; CAD = coronary artery disease; COPD = chronic obstructive pulmonary disease; ESRD = End stage renal disease; SLE = Systemic Lupus Erythematosus; APC = recombinant human activated protein C (drotrecogin alfa).

Conclusion

Coccidioidomycosis is an elusive diagnosis in critically-ill patients due to its rarity, the lack of rapid diagnostics, and its propensity to mimic other infections. Mortality is high, potentially due to delays in diagnosis. The marked elevation in PCT has not been previously noted in coccidioidomycosis and may further confound diagnosis. Improved diagnostics and the rapid institution of AmB may reduce mortality in patients with coccidioidal sepsis.

Disclosures

All Authors: No reported disclosures
1184. Activity of anti-pseudomonal antibiotics among all Pseudomonas aeruginosa (PSA) at an academic medical health system, including β-lactam, multi-drug (MDR) and extensively drug resistant (XDR) strains
Authors: Rose Warren , Heikkinen Benjamin , Radaatz Janet , Puzniak Laura A , Dillon Ryan J , Schulz Lucas
Published: January 2021

Background

PSA with MDR and XDR are a growing threat, and appropriate initial treatment of this organism is critical. C/T is a novel antibiotic with broad gram-negative in vitro susceptibility among surveillance studies. However comprehensive susceptibility analyses of C/T among PSA clinical isolates in comparison with other anti-PSA antibiotics remain limited, since routine clinical C/T susceptibility testing is not typically performed.

Methods

This study assessed all adult inpatient cultures positive for PSA from 32 months at an academic health system. Antimicrobial susceptibility was prospectively performed using Kirby Bower disk diffusion and interpreted by BIOMIC V3 during routine clinical care. Initial susceptibility testing included C/T along with amikacin, aztreonam, cefepime, ciprofloxacin, doripenem, gentamicin, imipenem, meropenem, piperacillin/tazobactam, and tobramycin. MDR and XDR isolates were identified using established definitions. The primary outcome was to quantify C/T resistant PSA (includes intermediate and resistant strains). Secondary outcomes were to determine resistance to other anti-PSA antibiotics and to identify C/T activity among isolates with MDR, XDR and pan-β-lactam resistance (PBLR = all β-lactams except C/T).

Results

A total of 2990 PSA isolates from 2339 cultures in 1311 individual patients were collected. Most cultures were from the lung (45%), followed by urine (30%), and body fluids (10%). For the primary outcome, 121/2990 (4%) of PSA isolates were C/T resistant. All PSA blood cultures were susceptible to C/T. Table 1 summarizes in vitro activity of all anti-PSA agents evaluated. C/T had the greatest percent susceptibility across all culture locations including MDR/XDR PSA isolates with median MICs of 8 µg/mL. For PBLR strains 35/66 (53%) were susceptible to C/T with a median MIC of 8 µg/mL.

Table 1

Conclusion

C/T susceptibility testing during routine care over a 2.5-year period revealed 96% susceptibility among PSA. C/T showed the highest susceptibility among all anti-PSA antibiotics for all culture locations and for MDR and XDR isolates. Given the high rates of resistance to traditional anti-PSA agents, the value of new agents with high rates of in vitro susceptibility in the gram-negative armamentarium is high.

Disclosures

Warren Rose, PharmD, MPH, Merck (Grant/Research Support)Paratek (Grant/Research Support) Janet Radaatz, PharmD, Merck (Employee) Laura A. Puzniak, PhD, Merck (Employee) Ryan J. Dillon, MSc, Merck & Co., Inc., (Employee)
1186. Cefazolin inoculum effect predicts reduced susceptibility to other antibiotics and patient outcomes in MSSA endovascular infections
Authors: Smelter Dan , McCrone Sue , Rose Warren
Published: January 2021

Background

MSSA Infective endocarditis (IE) is inherently a high-burden infection with up to a 30% mortality rate. Cefazolin is an appealing treatment option for IE with low toxicity and a favorable dosing scheme. However, cefazolin has been associated with treatment failure in IE, attributed to an inoculum effect. The specific mechanism underlying the cefazolin inoculum effect (CIE) remains undetermined, but CIE has been linked to both blaZ expression and agr dysfunction. This study aims to determine whether CIE is linked to reduced susceptibility to other antibiotics and worse outcomes regardless of therapy in MSSA endovascular infections.

Methods

Sixty-four MSSA strains were collected from patients with endovascular infections not treated with cefazolin. To determine CIE phenotype, strains were cultured and MICs assayed for cefazolin, nafcillin, and vancomycin at 107 CFU/mL for high-inocula (HI) and 105 CFU/mL for standard-inocula (SI). This study defined CIE as a ≥ 4-fold increase in MIC at HI compared to SI, with at least an MIC of 4 mg/L at HI. Nitrocefin disks identified blaZ expression, and beta lysin disks were used to determine hemolysin type and agr function. Patient outcomes of mortality and bacteremia duration were assessed across cohorts.

Results

Twenty-four strains exhibit a CIE (38%), with 10 strains having an MIC of ≥ 32mg/L at HI. Nafcillin and vancomycin also had an inoculum effect, uncoupled from the CIE and occurring at a lower frequency and amplitude at HI. Presence of CIE had a greater association with blaZ expression (71% vs 25%) than agr dysfunction (38% vs 20%). 50% (9/18) of CIE infections were cleared within 48 hours while 77% (20/26) of CIE-negative infections were cleared within 48 hours (P=0.106). However, presence of CIE was not associated with increased mortality (25% CIE-positive vs 35%; P=0.578)

Conclusion

Previous studies for CIE failed to enrich for isolates from endovascular sources, where inocula are known to be high. This study presents one of the largest endovascular source cohorts for CIE evaluation. It identifies that CIE prevalence (38%) is higher than reports from diverse infection sources (10-36%). CIE appears to predict bacteremia duration with other MSSA treatment options, suggesting mechanisms independent of blaZ and agr function for this phenomenon.

Disclosures

Warren Rose, PharmD, MPH, Merck (Grant/Research Support)Paratek (Grant/Research Support)
1189. Correlation of BK polyomavirus (BKPyV)-specific Immunity and BKPyV Viruria within 6 months after Kidney Transplantation: A Prospective Cohort Study
Authors: Siripoon Tanaya , Kantachuvesiri Surasak , Apiwattanakul Nopporn , Bruminhent Jackrapong
Published: January 2021

Background

Since viral-specific immunity has been shown to be correlated with viral containment in solid organ transplant recipients, we investigated an association of BK polyomavirus (BKPyV)-specific immunity and BKPyV viruria in kidney transplant (KT) recipients.

Methods

A prospective cohort study of all adult KT recipients between January and August 2019 was conducted. High-level BKPyV viruria was defined as the presence of BKPyV viral load in urine > 7log10 copies/mL. BKPyV-specific immunity was measured by an intracellular cytokine assay measuring the percentage of IFN-γ-producing CD4+, CD8+, NK, and NKT cells, after stimulation with large-T antigen (LT) and viral capsid protein 1 (VP1). The incidence of high-level BKPyV viruria within 6 months after KT was estimated by the Kaplan-Meier method. Clinical and immunological factors were analyzed using Cox proportional hazard model. BKPyV-specific immune responses prior to and at 1 month after KT were compared using a mixed-linear regression test.

Results

Among 90 evaluable patients, 37% were female with a mean age + SD of 42 + 12 years. Sixty-four and 68 % received deceased-donor KT and induction immunosuppressive therapy, respectively. The cumulative incidence of BKPyV viruria within 6 months was 20%. In multivariate analysis, pre-transplant factors which were independently associated with BKPyV viruria were panel-reactive antibody of 11-50 % (HR 13.35; 95%CI, 1.926-92.590; P = 0.009), %natural killer (NK) cells (HR 1.26; 95%CI, 1.077-1.469; P = 0.004), and %VP1-specific NK cells (HR 1.25; 95%CI, 1.088-1.433; P = 0.002). Among those with BKPyV viruria, the mean %NK, %VP1-specific NK cells and %NKT cells at 1-month post-KT were significantly increased over time as compared to pre-KT (coefficient: 1.202; 95%CI, 0.033-2.371; P = 0.04), (coefficient: 2.602; 95%CI, 1.083-4.121; P = 0.001), and (coefficient: 0.199; 95%CI, 0.051-0.348; P = 0.008), respectively.

Conclusion

A presence and increasing proportion of NK, VP1-specific NK and NKT cells were observed among KT recipients who developed early and clinically significant BKPyV viruria in our cohort. Quantification of BKPyV-specific NK and NKT cell immune monitoring could potentially stratify those at risk of BKPyV viruria among KT recipients.

Disclosures

All Authors: No reported disclosures
1191. Evolution of Hepatitis C Virus Points to Postpartum Recovery of CD8+ T-Cell Selection Pressure
Authors: Smith Stephanie , Xu Zhaohui , Walker Christopher , Honegger Jonathan
Published: January 2021

Background

In acute persisting hepatitis C virus (HCV) infection, brief control of viral replication can occur with onset of a cellular immune response but is eventually lost due to selection of viral variants with escape mutations in CD8 T cell epitopes or development of T cell exhaustion. In chronic infection, the CD8s targeting remaining intact epitopes are exhausted, viral levels are stable, and selection of new escape mutations is rare. Postpartum (PP), some chronically infected women experience a drop in viremia which we hypothesize is due to recovery of the CD8 response and will be associated with selection of de novo escape mutations as seen in acute persisting infection.

Methods

HCV genomic evolution was assessed in 2 women with different patterns of PP viral control through consecutive pregnancies. Subject M016 experienced > 2.5 log10 drops in viral loads after each pregnancy while M062 had stable viral levels (Table 1). Longitudinal viral genomes were assessed by Illumina sequencing of near full length PCR products of viral cDNA. Reads were initially aligned to a genotype reference and then iterative consensus sequences until deep coverage was achieved across the entire PCR amplicon. To identify potential CD8 escape mutations, amino acid substitutions were counted if their frequency increased from < 10% of reads peripartum to > 90% at follow up. We focused on the nonstructural region to avoid substitutions related to antibody selection pressure.

Viral Load Levels

Results

M016 developed 3 nonsynonomous (NS) mutations after her 1st pregnancy and 1 more after her 2nd. Of these, 3 were directed away from the consensus amino acid sequence, and one differed from consensus at baseline and changed tangentially. M062 developed 1 NS mutation within a known class I epitope following her second pregnancy which was directed toward consensus for her genotype (Fig 1). All mutations occurred within predicted class I epitopes.

Nonsynonomous Substitutions in Nonstructural Region

Conclusion

While these pilot data require verification in additional subjects, the observed emergence of non-synonymous mutations directed away from genotype consensus in viral class I epitopes of a woman with postpartum viral control but not in a women with stable viral levels support our hypothesis enhanced CD8 T cell selection pressure contribute to enhanced control of HCV replication after childbirth.

Disclosures

All Authors: No reported disclosures
1192. H-NS-like Proteins in Pseudomonas aeruginosa Coordinately Silence Intragenic and Antisense Transcription
Authors: Lippa Andrew M , Gebhardt Michael J , Dove Simon L
Published: January 2021

Background

The H-NS-like proteins MvaT and MvaU act coordinately as global repressors in Pseudomonas aeruginosa by binding to AT-rich regions of the chromosome, which include horizontally acquired genes and numerous virulence factors. Although cells can tolerate the loss of either protein, identifying their combined regulatory effects has been challenging because the loss of both proteins is lethal due to induction of the prophage Pf4 and subsequent superinfection of the cell. Although in other bacteria, H-NS promotes cellular fitness by inhibiting intragenic transcription from AT-rich target regions, preventing them from sequestering RNA polymerase, a role for MvaT and MvaU in repressing transcription from intragenic promoters has not been demonstrated.

Methods

Here we utilize a parental strain that cannot be infected by Pf4 phage to identify the combined MvaT and MvaU regulon. RNA-seq was utilized to identify genes differentially expressed in cells lacking MvaU or both MvaU and MvaT. ChIP-seq was utilized to identify genes directly regulated by MvaT and MvaU in wild-type cells. Further, ChIP-seq was performed in cells of the parental strain and cells lacking both MvaT and MvaU to map genome-wide σ 70-dependent promoters that were active in the presence or absence of both H-NS-like proteins.

Results

We demonstrate that the loss of both MvaT and MvaU, but not MvaU alone, leads to increased sense, antisense, and intragenic transcription from loci directly controlled by these proteins. We further show that the loss of MvaT and MvaU leads to a striking redistribution of RNA polymerase containing σ 70 to those genomic regions vacated by these proteins.

Loss of MvaT and MvaU causes global changes in gene expression

Loss of MvaT and MvaU results in increased sense and antisense transcription

Loss of both MvaT and MvaU results in genome-wide redistribution of RNA polymerase

Conclusion

Our findings suggest that the ability of H-NS-like proteins to repress intragenic transcription is a universal function of these proteins and describe a second mechanism by which MvaT and MvaU may contribute to the growth of P. aeruginosa.

Disclosures

All Authors: No reported disclosures
1194. Identification and Characterization of Extracellular Inducers of Persistence in Staphylococcus epidermidis and Staphylococcus aureus
Authors: Habtu Danni Y , Chamberlain Neal , Curry Elyse , Hart Ryan
Published: January 2021

Background

This study describes the identification and partial characterization of persistence inducing factors (PIF) from Staphylococcus aureus (S. aureus) and Staphylococcus epidermidis (S. epidermidis). Persistence is an epigenetic process that results in tolerance of bacterial cells to antibiotic treatment, which can result in chronic human infections.

Methods

Others have demonstrated a significant increase in persister numbers during mid-log phase. Inducers of this mid-log increase have yet to be identified in staphylococci. Optical density at 600 nm (OD600) was used instead of time to determine when persister numbers increased during logarithmic growth. Concentrated culture filtrates (CCF) from S. epidermidis RP62A and S. aureus SH1000 were obtained at various OD600’s and following incubation at 16 h. The CCF’s were used to develop a persistence inducing factor (PIF) assay. The PIF assay was used to partially characterize PIF from S. epidermidis RP62A and S. aureus SH1000 for relative molecular weight, temperature and protease sensitivity and inter-species communications.

Results

Optimal OD600’s for the S. epidermidis RP62A and S. aureus SH1000 PIF assays were 2.0 and 0.5, respectively. The highest PIF activity for both species was from CCF following incubation overnight (16 h). S. epidermidis RP62A’s PIF activity was decreased by storage at 4o C (2 weeks or longer) but not following incubation at 20o C (16 h), 37o C (1 h) or 100o C (15 min). S. aureus SH1000’s PIF activity was decreased following storage at 4o C (2 week or longer) and after boiling at 100oC for 5 min but not after incubation at 37o C (1 h). PIF activity from both species was less than 3,000 Mrr. Proteinase-K treatment of S. aureus SH1000 PIF decreased activity but did not decrease PIF activity of S. epidermidis RP62A. PIF from S. epidermidis RP62A did not increase persister numbers when used to treat S. aureus SH1000 cells nor did PIF from S. aureus SH1000 increase persister numbers in S. epidermidis RP62A cells.

Conclusion

Previous attempts to discover PIF’s for staphylococcal species were unsuccessful due to the time-based means used to identify mid-log. Both staphylococcal species appear to produce unique, extracellular, low-molecular-weight inducers of persistence (PIF) when assayed using an OD600-based PIF assay.

Disclosures

All Authors: No reported disclosures
93. A Diagnostic Stewardship Intervention to Improve Utilization of 1,3-β-D-glucan Testing
Authors: Kendall Jonathan A , Colson Jordan , Saeed Lyla , Mizusawa Masako , Yamamoto Takeru
Published: January 2021

Background

1,3-β-D-glucan (BDG) is a cell wall component of fungi such as Aspergillus spp., Candida spp., and Pneumocystis jirovecii. BDG assay is used as a screening test to aid early diagnosis of invasive fungal infections (IFI) that are associated with significant morbidity and mortality in immunocompromised patients. The diagnostic performance varies depending on IFI risks among study populations, thus it is important to appropriately select patients with risk factors for IFI to optimize utilization of the BDG test.

Figure 1.

Figure 2.

Methods

An intervention to improve BDG test utilization was initiated at Truman Medical Center on November 28, 2018. The BDG test order was replaced by a BDG test request. The request was sent to the inbox of an on-call pathology team. Patient information was reviewed and the on-call pathology team called the ordering physician to discuss the case based on the approval algorithm chart. The criteria for BDG test approval were 1) immunocompromised or ICU patient, and 2) on empiric antifungal therapy, or inability to perform specific diagnostic tests such as bronchoscopy. If approved, a BDG test order was immediately processed. Retrospective chart review was conducted for 1 year pre- and post- intervention to obtain demographic, clinical, and laboratory data for 4 patient groups. Group 1 included patients who had BDG tests during pre-intervention period. Group 2 was composed of all patients who had BDG test requests during post-intervention period. Group 2a and 2b were the post-intervention patients with approved and rejected BDG test requests, respectively.

Figure 3.

Results

The number of BDG tests performed per year decreased from 156 pre-intervention to 24 post-intervention. The number of test requests was 65 and 41 of them were rejected which led to $7,380 direct cost savings. There was no significant difference in age or the proportion of immunocompromised and ICU patients between Group 1 and 2. The test positivity rate was significantly higher in Group 2-a compared to Group 1 (45.8 % vs. 25.3%, p=0.038). There was no delay in IFI diagnosis or IFI-related mortality in patients for whom BDG test requests were rejected.

Conclusion

We successfully and safely implemented a diagnostic stewardship intervention for BDG testing and improved test utilization.

Disclosures

All Authors: No reported disclosures
1199. Phylogenomic analysis of Campylobacter jejuni isolated from gastroenteritis cases in Michigan
Authors: Rodrigues Jose A , Blankenship Heather M , Cha Wonhee , Mosci Rebekah , Manning Shannon D
Published: January 2021

Background

C. jejuni is the leading cause of bacterial gastroenteritis worldwide. It has been classified as a serious antibiotic resistant threat, causing 13,000 hospitalizations and 120 deaths annually. Our goal was to describe the diversity of clinical C. jejuni using phylogenomics and classify resistance mechanisms.

Methods

Isolates were collected via sentinel surveillance at four hospitals, and demographic and clinical data were obtained. DNA was extracted and sequenced. Raw reads were processed with Trimmomatic and quality checked with FastQC. De novo genome assembly was performed in Spades. Assembled genomes were filtered for quality and completeness; samples of 1.4-2.1MB were annotated in Prokka followed by pangenome and phylogenetic analyses. Multilocus sequence typing loci and virulence and antibiotic resistance genes were extracted from each genome.

Results

Among the 214 C. jejuni isolates recovered, 86 unique sequence types (STs) were identified; five were novel STs with unique allele combinations. ST353 (8.3%: n=18), ST982 (7.4%: n=16), ST50 (5.1 %: n=11) and ST48 (5.1%: n=11) were the most prevalent STs identified, while the majority (50.1%: n=50) of STs were singletons. The pangenome analysis identified 8781, 615, and 1169 total, core, and shell core genes, respectively, which grouped the isolates into three major clades. Most isolates belonged to clade 1. A neighbor-net analysis detected significant recombination among all 86 STs (pairwise homoplasy index p=< 0.00001) and evidence of horizontal gene transfer across clades. The beta-lactamase gene, blaOXA-605, was the most common resistance gene identified (58.8%: n=125) followed by tet(O) (56.0%: n=121), which mediate resistance to beta-lactams and tetracyclines, respectively. Resistance phenotypes were confirmed using microbroth dilution.

Conclusion: Together, these data demonstrate that the C. jejuni population is highly diverse and carries important resistance determinants. The phylogenomic analyses also provide insight into the evolution of this major foodborne pathogen. Future work will focus on identifying molecular and epidemiological factors associated with specific strain types and resistance and virulence profiles circulating in Michigan.

Disclosures

All Authors: No reported disclosures
1200. Risk of group A streptococcal Transmission Among the Pediatric Population in the Houston Area
Authors: Alamarat zain I , Sommer Lauren , McNeil Jonathon C , Flores Anthony R
Published: January 2021

Background

Disease due to group A Streptococcus (GAS) occurs frequently in children and usually manifests as pharyngitis or superficial skin infections. However, invasive disease (iGAS) such as necrotizing fasciitis or streptococcal toxic shock syndrome is responsible for significant morbidity and mortality. National-level surveillance at the Centers for Disease Control and Prevention (CDC) estimates >10,000 cases and ~1,500 deaths due to iGAS occur annually in the US. Much interest revolves around the ability to detect potential transmission events (PTEs) of GAS disease using surveillance data as such information may change recommendations for chemoprophylaxis of close contacts. Studies by the CDC have shown a secondary attack rate from 66.1 to 102 /100,000, primarily occurring among older adults with co-morbidities. However, previous studies were limited in that the GAS surveillance was limited to iGAS disease.

Methods

Retrospective study using a comprehensive GAS passive surveillance system. GAS isolates and associated metadata were obtained from 2 hospital systems in the Texas Medical Center from 2017-2019. Molecular emm typing of GAS isolates was performed using the CDC protocol. PTEs were defined based on GAS disease isolates originating from the same zip code, occurring within 30 days of each other, and of the same emm type.

Results

A total of 1291 isolates were included in the study – 94 PTEs were identified representing 168 individual GAS isolates of which 74 were defined as index cases. The 4 most common GAS emm types identified among PTEs were emm1 (43/94, 45.7%), emm12 (30/94, 31.9%), emm4 (6/94, 6.4%), and emm6 (5/94, 5.3%). Index cases most frequently resulted in a single PTE (n=74) with an average number of PTEs per index case of 1.3 (range 1 to 3 PTEs). From index cases, 10 GAS isolates were derived from invasive disease (10/74, 13.5%) and 6 from skin and soft tissue infections (SSTI; 6/74, 8.1%). A substantial proportion of PTEs resulted in iGAS (9/94, 9.5%) and SSTI (10/94, 10.6%).

Conclusion

Using comprehensive local surveillance, we were able to identify several potential GAS transmission events. Further analysis – including whole genome sequencing on index and PTE isolates – is needed to better define transmission events.

Disclosures

Jonathon C. McNeil, MD, Nabriva (Research Grant or Support, I serve as the site investigator on a multicenter clinical trial sponsored by Nabriva)
1201. Sarcoidosis Candidate Microbes Identified by Next Generation Sequencing
Authors: Kriesel John D , Eckman Emily , Emerson Lyska , Scholand Marybeth , Hoidal John , Fischer Kael
Published: January 2021

Background

Sarcoidosis is an autoimmune disease characterized by granulomatous lung disease with very prominent mediastinal adenopathy. Acid-fast bacteria, fungi, and viruses have been considered as possible causes of sarcoidosis. We used next-generation or deep sequencing to characterize the microbial content of diseased mediastinal lymph nodes from 10 sarcoidosis patients compared to a set of 10 negative-controls.

Methods

RNA was extracted from fixed paraffinized mediastinal lymph nodes (MLN) from 12 diseased specimens taken from 10 sarcoidosis patients and 2 positive control subjects (TB, MAI), and normal appearing MLN from 10 negative-control subjects (mostly cancer patients). The extracted RNA was sequenced on the Illumina 2500, yielding 125-bp paired-end reads. These reads were aligned to the human genome, human transcriptome, and a nonredundant panmicrobial database. Each experimental sample were compared against the set of 10 negative-controls using the false discovery rate method (q-value). Directed qPCR was performed on all the samples.

Results

100-153 million read-pairs were obtained from the 24 sequenced samples (12 sarcoidosis, 10 negative-control, 2 positive-control). Among these, 0.01-1.32% of the reads were microbial, with a trend towards fewer microbial reads in the sarcoidosis group compared to controls (means 66K vs. 457K, p=0.09). Mycobacterial sequence was significantly enriched (q< 0.05) in the MAI but not the TB sample compared to the negative-controls. Among the 12 sarcoidosis samples, sequence mappings were significantly enriched (q< 0.05) for the following genera: fungal, Magnaporthe (N=4 samples) and Debaromyces (1); bacteria, Odoribacter (1) and Granulicella (1); and viral, Roseolovirus (6) and Mardivirus (6). Further metagenomic analysis eliminated Magnaporthe as a candidate. qPCR confirmed the presence of Odoribacter in 2 specimens and Debaromyces in 1. Roseolovirus (HHV6) could not be detected by qPCR in any of the samples.

Conclusion

We conclude that sequencing is a feasible method for identifying candidate microbes that might trigger sarcoidosis in human subjects. Further research is required to establish or refute the pathogenicity of these organisms in patients with sarcoidosis.

Disclosures

All Authors: No reported disclosures