scholarly journals 645. Absence of Toxemia in Clostridioides difficile infection: Results from Ultrasensitive Toxin Assay of Serum

2020 ◽  
Vol 7 (Supplement_1) ◽  
pp. S381-S382
Author(s):  
Rebecca Sprague ◽  
Karolyne Warny ◽  
Nira Pollock ◽  
Kaitlyn Daugherty ◽  
Qianyun Lin ◽  
...  
Keyword(s):  
Clinical Outcomes ◽  
Single Molecule ◽  
Limit Of Detection ◽  
High Serum ◽  
Serum Samples ◽  
Systemic Complications ◽  
Clostridioides Difficile ◽  
Number Of Patients ◽  
Wide Range ◽  
Clostridioides Difficile Infection

Abstract Background Clostridioides difficile infection (CDI) is the major cause of hospital-acquired bacterial infectious diarrheacaused by Toxin A (TcdA) and Toxin B (Tcd B), secreted from pathogenic strains of C.difficle bacteria. This infection can vary greatly in symptom severity and presentation. In fulminant CDI, these toxins lead to systemic complications such as toxemia, however, identification of toxemia in CDI patients is extremely rare. We hypothesized that this rarity of detection may be due to low concentrations of circulating toxins in the blood, below the limit of detection of commercially available assays. Methods The previously developed Single Molecule Array (Simoa) assay, capable of detecting TcdA and TcdB in stool, was modified for the detection of toxins in serum and applied to a panel of serum samples from patients with confirmed CDI. Results Our cohort included 169 patients with a median age of 68 years (IQR 54-78), most with severe CDI and many with severe clinical outcomes attributed to CDI (Table 1). We found no detectable TcdA or TcdB in the serum of our patient cohort despite a wide range of toxin concentrations in paired stool (Figure 1). The detection of toxin may be limited by the interference of anti-toxin anti-bodies circulating in serum. When serum samples were spiked with TcdA and/or TcdBvarying amounts of IgA, IgG or IgM anti-toxin, high serum anti-toxin antibody concentrations were associated with loss of Simoa signal, suggesting substantial inhibition of toxin measurements. Table 1. Demographics, Baseline Laboratory Values, and Clinical Outcomes for the cohort Figure 1. Comparison of TcdA and TcdB concentrations, as measured by Simoa, in serum and stool. Clinical cutoffs are shown: stool, 20 pg/ml for TcdA and for TcdB; serum 15.0 pg/ml for TcdA and is 26.7 pg/ml for TcdB. Signals below these cut-offs are below backgrounds and so negative. Conclusion In contrast to earlier published findings which reported on the presence of detectable toxin in the serum of a small number of patients with CDI, our work did not support this observation. Although Simoa is highly sensitive for detection of picogram quantities of TcdA or TcdB it was unable to detect either toxin in serum during CDI. This result does not support the hypothesis that toxemia develops even in severe C. difficile infection. Disclosures Alice Banz, Ph.D, BioMerieux (Employee) Kevin W. Garey, PharmD, MS, FASHP, Merck & Co. (Grant/Research Support, Scientific Research Study Investigator) Carolyn D. Alonso, MD, FIDSA, Alnylam Pharmaceuticals (Employee)Merck (Research Grant or Support) Ciarán Kelly, MD, Artugen (Consultant)Facile Therapeutics (Consultant)Finch (Consultant)First Light Biosciences (Consultant)Matrivax (Consultant)Merck (Consultant)Vedanta (Consultant)

scholarly journals High Serum Levels of Toxin A Correlate with Disease Severity in Patients with Clostridioides difficile Infection

Antibiotics ◽  
2021 ◽  
Vol 10 (9) ◽  
pp. 1093
Author(s):  
Guido Granata ◽  
Davide Mariotti ◽  
Paolo Ascenzi ◽  
Nicola Petrosillo ◽  
Alessandra di Masi
Keyword(s):  
Disease Severity ◽  
Limit Of Detection ◽  
Serum Levels ◽  
High Serum ◽  
Public Healthcare ◽  
Healthcare Associated Infection ◽  
Dot Blot ◽  
Toxin A ◽  
Systemic Complications ◽  
Clostridioides Difficile

Cloistridioides difficile (CD) represents a major public healthcare-associated infection causing significant morbidity and mortality. The pathogenic effects of CD are mainly caused by the release of two exotoxins into the intestine: toxin A (TcdA) and toxin B (TcdB). CD infection (CDI) can also cause toxemia, explaining the systemic complications of life-threatening cases. Currently, there is a lack of sensitive assays to detect exotoxins circulating in the blood. Here, we report a new semi-quantitative diagnostic method to measure CD toxins serum levels. The dot-blot assay was modified to separately detect TcdA and TcdB in human serum with a limit of detection at the pg/mL levels. TcdA and TcdB concentrations in the plasma of 35 CDI patients were measured at the time of CDI diagnosis and at the fourth and tenth day after CDI diagnosis and initiation of anti-CDI treatment. TcdA and TcdB levels were compared to those determined in nine healthy blood donors. Toxemia was detected in the plasma of 33 out of the 35 CDI cases. We also assessed the relationship between TcdA serum levels and CDI severity, reporting that at the time of CDI diagnosis the proportion of severe CDI cases with a TcdA serum level > 60 pg/µL was higher than in mild CDI cases (29.4% versus 66.6%, p = 0.04). In conclusion, data reported here demonstrate for the first time that toxemia is much more frequent than expected in CDI patients, and specifically that high serum levels of TcdA correlate with disease severity in patients with CDI.

scholarly journals 2356. Increased Clinical Specificity with Ultrasensitive Detection of Clostridioides difficile Toxins: Reduction of Overdiagnosis Compared with Nucleic Acid Amplification Tests

2019 ◽  
Vol 6 (Supplement_2) ◽  
pp. S811-S812 ◽  
Author(s):  
Johanna Sandlund ◽  
Joel Estis ◽  
Phoebe Katzenbach ◽  
Niamh Nolan ◽  
Kirstie Hinson ◽  
...  
Keyword(s):  
Nucleic Acid ◽  
Disease Severity ◽  
Single Molecule ◽  
Clinical Performance ◽  
Neutralization Assay ◽  
Nucleic Acid Amplification ◽  
Clostridioides Difficile ◽  
Percent Agreement ◽  
Clostridioides Difficile Infection ◽  
Healthcare Associated

Abstract Background Clostridioides difficile infection (CDI) is one of the most common healthcare-associated infections, resulting in significant morbidity, mortality, and economic burden. Diagnosis of CDI relies on the assessment of clinical presentation and laboratory tests. We have evaluated the clinical performance of ultrasensitive Single Molecule Counting technology for detection of C. difficile toxins A and B. Methods Stool specimens from 298 patients with suspected CDI were tested with nucleic acid amplification test (NAAT; BD MAX™ Cdiff assay or Xpert® C. difficile assay) and Singulex Clarity® C. difficile toxins A/B assay. Specimens with discordant results were tested with cell cytotoxicity neutralization assay (CCNA), and results were correlated with disease severity and outcome. Results There were 64 NAAT-positive and 234 NAAT-negative samples. Of the 32 NAAT+/Clarity− and 4 NAAT-/Clarity+ samples, there were 26 CCNA− and 4 CCNA- samples, respectively. CDI relapse or overall death was more common in NAAT+/toxin+ patients than in NAAT+/toxin− and NAAT−/toxin− patients, and NAAT+/toxin+ patients were 3.7 times more likely to experience relapse or death (Figure 1). The clinical specificity of Clarity and NAAT was 97.4% and 89.0%, respectively, and overdiagnosis was over three times more common in NAAT+/toxin− than in NAAT+/toxin+ patients (Figure 2). Negative percent agreement between NAAT and Clarity was 98.3%, and positive percent agreement increased from 50.0% to effective 84.2% and 94.1% after CCNA testing and clinical assessment. Conclusion The Clarity assay was superior to NAATs in diagnosis of CDI, by reducing overdiagnosis and thereby increasing clinical specificity, and presence of toxins was associated with disease severity and outcome. Disclosures All authors: No reported disclosures.

scholarly journals Investigation of the effect of the adsorbent DAV131A on the propensity of moxifloxacin to induce simulated Clostridioides (Clostridium) difficile infection (CDI) in an in vitro human gut model

2020 ◽  
Vol 75 (6) ◽  
pp. 1458-1465
Author(s):  
C H Chilton ◽  
G S Crowther ◽  
C Miossec ◽  
J de Gunzburg ◽  
A Andremont ◽  
...  
Keyword(s):  
Limit Of Detection ◽  
Toxin Production ◽  
Human Gut ◽  
Antibiotic Resistant ◽  
Delayed Onset ◽  
Clostridioides Difficile ◽  
Clostridioides Difficile Infection ◽  
Clinical Benefits ◽  
Bacteroides Fragilis Group

Abstract Background Clostridioides difficile infection (CDI) remains a high burden worldwide. DAV131A, a novel adsorbent, reduces residual gut antimicrobial levels, reducing CDI risk in animal models. Objectives We used a validated human gut model to investigate the efficacy of DAV131A in preventing moxifloxacin-induced CDI. Methods C. difficile (CD) spores were inoculated into two models populated with pooled human faeces. Moxifloxacin was instilled (43 mg/L, once daily, 7 days) alongside DAV131A (5 g in 18 mL PBS, three times daily, 14 days, Model A), or PBS (18 mL, three times daily, 14 days, Model B). Selected gut microbiota populations, CD total counts, spore counts, cytotoxin titre and antimicrobial concentrations (HPLC) were monitored daily. We monitored for reduced susceptibility of CD to moxifloxacin. Growth of CD in faecal filtrate and medium in the presence/absence of DAV131A, or in medium pre-treated with DAV131A, was also investigated. Results DAV131A instillation reduced active moxifloxacin levels to below the limit of detection (50 ng/mL), and prevented microbiota disruption, excepting Bacteroides fragilis group populations, which declined by ∼3 log10 cfu/mL. DAV131A delayed onset of simulated CDI by ∼2 weeks, but did not prevent CD germination and toxin production. DAV131A prevented emergence of reduced susceptibility of CD to moxifloxacin. In batch culture, DAV131A had minor effects on CD vegetative growth, but significantly reduced toxin/spores (P < 0.005). Conclusions DAV131A reduced moxifloxacin-induced microbiota disruption and emergence of antibiotic-resistant CD. Delayed onset of CD germination and toxin production indicates further investigations are warranted to understand the clinical benefits of DAV131A in CDI prevention.

scholarly journals Characterization of the Immune Response during Infection Caused by Clostridioides difficile

2019 ◽  
Vol 7 (10) ◽  
pp. 435 ◽  
Author(s):  
Hamo ◽  
Azrad ◽  
Nitzan ◽  
Peretz
Keyword(s):  
Immune Response ◽  
Severe Disease ◽  
Interferon Α ◽  
T Helper 1 ◽  
Serum Samples ◽  
Mild Disease ◽  
Clostridioides Difficile ◽  
Cytokines And Chemokines ◽  
Clostridioides Difficile Infection ◽  
Macrophage Colony

The high risk of complications and death following Clostridioides difficile infection (CDI) requires identifying patients with severe disease and treating them accordingly. We characterized the immune response of CDI patients in relation to infection severity. Concentrations of 28 cytokines and chemokines were measured in serum samples, obtained from 54 CDI patients within a median timeframe of 24–48 h after laboratory confirmation of C. difficile infection. Demographic and clinical data were retrospectively collected from medical records. Disease severity score was determined by “Score indices for Clostridioides difficile infection severity”. Of 54 patients (mean age, 76.6 years, 61.1% female), 38 (70.4%) had mild disease and 16 (29.6%) had moderate disease. Seven cytokines were associated with a more severe CDI: granulocyte-macrophage colony-stimulating factor (p = 0.0106), interleukin (IL)-1β (p = 0.004), IL-8 (p = 0.0098), IL-12p70 (p = 0.0118), interferon-α (p = 0.0282), IL-15 (p = 0.0015), and IL-2 (p = 0.0031). Additionally, there was an increased T-helper 1 response in more severe cases of CDI. Cytokines may serve as biomarkers for early prediction of CDI severity. Better and earlier assessment of illness severity will contribute to the adjustment of medical treatment, including monitoring and follow-up.

scholarly journals Risk Factors for BI/NAP1/027 Clostridioides difficile Infections and Clinical Outcomes Compared With Non-NAP1 Strains

2019 ◽  
Vol 6 (12) ◽  
Author(s):  
Nandita S Mani ◽  
John B Lynch ◽  
Ferric C Fang ◽  
Jeannie D Chan
Keyword(s):  
Risk Factors ◽  
Proton Pump Inhibitor ◽  
Clinical Outcomes ◽  
Case Control ◽  
Nursing Facilities ◽  
Single Center ◽  
Retrospective Case ◽  
Skilled Nursing ◽  
Clostridioides Difficile ◽  
Clostridioides Difficile Infection

Abstract We aim to describe the characteristics, risk factors, and clinical outcomes associated with NAP1 strain Clostridioides difficile infection (CDI) in this single-center, retrospective, case–control (1:1) study. We found that the NAP1 strain accounted for 19.7% of CDI, and risk factors for acquisition included residence in skilled nursing facilities, previous CDI, and proton pump inhibitor use.

scholarly journals Clinical Outcomes Following the Use of Archived HIV-1 DNA Sequencing to Guide Antiretroviral Therapy Regimen Adjustment and Simplification

2017 ◽  
Vol 4 (suppl_1) ◽  
pp. S425-S425
Author(s):  
Kristen Ellis ◽  
George Nawas ◽  
Connie Chan ◽  
Lawrence York ◽  
Alexander Mar ◽  
...  
Keyword(s):  
Antiretroviral Therapy ◽  
Clinical Outcomes ◽  
Limit Of Detection ◽  
Medical Center ◽  
Categorical Variables ◽  
Continuous Variables ◽  
Therapy Regimen ◽  
Hiv Rna ◽  
Number Of Patients

Abstract Background While favorable new antiretroviral therapy (ART) options are available for HIV disease, the Department of Health and Human Services guidelines recommend against switching suppressive regimens unless there is evidence that the new regimen will be fully active. A new assay analyzes archived HIV pro-viral DNA and can detect resistance mutations when HIV RNA is below the limit of detection, when standard genotyping (GT) is not possible. Small studies have correlated archived DNA GT to historical plasma RNA GT, but there is minimal available data on treatment outcomes when using this assay to determine antiretroviral therapy switch strategies. We evaluated clinical outcomes following ART adjustment based upon results of archived DNA GT testing. Methods A retrospective review of electronic medical records was performed at our medical center from October 2014 to October 2016. Inclusion criteria included age ≥ 18 years, archived DNA GT result available, ART changed after archived GT result, and follow up HIV RNA available after ART switch. Data was collected prior to and after ART switching. McNemar’s test was used for categorical variables and paired t-test for continuous variables. Results A total of 38 patients were included. Most patients were male (89%), Caucasian (66%), had a history of AIDS diagnosis (45%), had HIV for >10 years (74%), and had baseline ART resistance (24% resistant to 1 class, 37% resistant to ≥ 2 classes). Median baseline CD4 was 532 cells/mm3. At baseline, 31 (82%) patients had HIV RNA < 50 copies/mL. Compared with baseline, 35 (92%) patients were undetectable at furthest follow up (P = 0.22). Median time to furthest follow up was 146.5 days (range 12–485). Overall, 36 (95%) patients had at least one undetectable HIV RNA after switching. None of the patients with an initial undetectable HIV RNA became detectable after switching ART. Average number of pills per day and administrations per day decreased from 3.84 to 1.97 (P < 0.001) and 1.47 to 1.05 (P < 0.001) respectively. The number of patients on protease inhibitors (PIs) decreased from 66% to 21% (P < 0.001). Conclusion The use of archived DNA GT to guide ART adjustment may result in maintained viral suppression while allowing for regimens with optimized long-term safety and decreased pill burden. Disclosures All authors: No reported disclosures.

An umbrella for the cytokine storm: Enabling precision detection of CRS in CAR-T therapy.

2019 ◽  
Vol 37 (15_suppl) ◽  
pp. e14223-e14223
Author(s):  
Qimin Quan
Keyword(s):  
Single Molecule ◽  
Biomarker Discovery ◽  
Dynamic Range ◽  
Limit Of Detection ◽  
Predictive Biomarkers ◽  
Small Sample ◽  
Detection Sensitivity ◽  
Patient Death ◽  
Wide Range ◽  
Car T

e14223 Background: Cytokine release syndrome (CRS), a systemic inflammatory response observed with monoclonal antibody drugs and adoptive T cell treatments, has become a major issue for CAR-T therapy. CRS can present as a mild reaction requiring minimally invasive supportive care up to a severe systemic response resulting in patient death. Monitoring this response during these therapeutic treatments is non-trivial due the wide range of biomarker concentrations, small sample volumes, and long assay times. Current analytical methods are unable to address these needs, limiting the precision of CAR-T therapy and effective management of its side effects. Methods: Emerging studies in this area have focused in establishing a panel of predictive biomarkers to manage dosing and early interventions, among them, IFNγ, IL6, TNFα, MIP1 have shown predicative powers in pediatric patients. Nevertheless, a significant improvement (100x) on the detection sensitivity is required to predict the CRS response with currently available methods. In addition, CRS-associated biomarkers including CRP and ferritin vary from 10ng/mL-10mg/mL while other predictive biomarkers (eg, IL6, IFNγ, etc.) vary from 1pg/mL-100ng/mL. At present, no analytical tool, known to us, can provide this large dynamic range ( > 9 logs), with the requisite lower limit of detection, in a rapid single test to predict and differentiate low, medium or high grade responses. Results: We present the NanoMosaic platform, the technology that has requisite sensitivity and breadth of dynamic range to enable precision detection based on precise quantitation of CRS-relevant biomarkers. NanoMosaic technology is enabled by single molecule nanoneedle sensors that are densely integrated on a silicon chip and manufactured with a CMOS-compatible process. Absolute quantitation is achieved by imaging the spectrum of nanoneedles, corresponding directly to the number of molecules. Conclusions: Direct comparison of different protein biomarkers with orders of magnitude concentration variations becomes possible in one platform and small sample sizes. We envision NanoMosaic technology will not only drive biomarker discovery, but also enable precise dosing management for CAR-T therapy.

scholarly journals 218. Evaluation of Clinical Outcomes with Shorter Vs. Longer Duration of Treatment for Common Inpatient Bacterial Infections Associated with Bacteremia

2019 ◽  
Vol 6 (Supplement_2) ◽  
pp. S128-S128
Author(s):  
Leila Hojat ◽  
Mary T Bessesen ◽  
Margaret Reid ◽  
Bryan C Knepper ◽  
Matthew A Miller ◽  
...  
Keyword(s):  
Clinical Outcomes ◽  
Antibiotic Treatment ◽  
Primary Outcome ◽  
Safety Net ◽  
Duration Of Treatment ◽  
Duration Of Therapy ◽  
Clostridioides Difficile ◽  
Short Course ◽  
Tertiary Center ◽  
Clostridioides Difficile Infection

Abstract Background Pneumonia (PNA), urinary tract infection (UTI), and acute bacterial skin and skin structure infection (ABSSSI) are the most common infections treated in the inpatient setting and often are associated with bacteremia. Though short courses of treatment are advocated for these infections in general, no established guidelines exist for cases involving bacteremia. We evaluated the clinical outcomes of patients receiving short (5–9 days) vs. long (10–15 days) duration of antibiotic treatment. Methods A retrospective study was conducted at 3 area hospitals comprising a university-based tertiary center, a public safety net hospital, and a Veterans’ Affairs hospital. We included hospitalized adult patients with transient bacteremia associated with uncomplicated cases of PNA, UTI, or ABSSSI. The primary outcome consisted of a composite of rehospitalization or resumption of antibiotic treatment attributed to the original infection or death due to any cause within 30 days of the antibiotic start date. Secondary outcomes included the individual composite components, Clostridioides difficile infection, and antibiotic-related adverse effects leading to change in antibiotic therapy. A propensity score weighted logistic regression model was used to mitigate factors which could bias a patient toward receiving a shorter or longer treatment duration. Results Of 411 patients included in the study, 123 (29.9%) received a short duration of therapy and 288 (70.1%) received a long duration of therapy. The median duration of treatment was 8 days in the short group and 13 days in the long group. In the propensity-weighted analysis, the probability of meeting the composite primary outcome was not statistically different between the short and long groups (Table 1). However, receiving a short course was associated with a higher probability of restarting antibiotics and Clostridioides difficile infection. Conclusion Shorter vs. longer courses of antibiotic treatment for bacteremia associated with PNA, UTI, and ABSSSI were not significantly different in a composite of readmission, restart of antibiotics, and mortality; however, further study is needed to evaluate the safety and effectiveness of short-course therapy. Disclosures All authors: No reported disclosures.

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