1
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Sandora TJ, Kociolek LK, Williams DN, Daugherty K, Geer C, Cuddemi C, Chen X, Xu H, Savage TJ, Banz A, Garey KW, Gonzales-Luna AJ, Kelly CP, Pollock NR. Baseline stool toxin concentration is associated with risk of recurrence in children with Clostridioides difficile infection. Infect Control Hosp Epidemiol 2023; 44:1403-1409. [PMID: 36624698 PMCID: PMC10330943 DOI: 10.1017/ice.2022.310] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
BACKGROUND In adults with Clostridioides difficile infection (CDI), higher stool concentrations of toxins A and B are associated with severe baseline disease, CDI-attributable severe outcomes, and recurrence. We evaluated whether toxin concentration predicts these presentations in children with CDI. METHODS We conducted a prospective cohort study of inpatients aged 2-17 years with CDI who received treatment. Patients were followed for 40 days after diagnosis for severe outcomes (intensive care unit admission, colectomy, or death, categorized as CDI primarily attributable, CDI contributed, or CDI not contributing) and recurrence. Baseline stool toxin A and B concentrations were measured using ultrasensitive single-molecule array assay, and 12 plasma cytokines were measured when blood was available. RESULTS We enrolled 187 pediatric patients (median age, 9.6 years). Patients with severe baseline disease by IDSA-SHEA criteria (n = 34) had nonsignificantly higher median stool toxin A+B concentration than those without severe disease (n = 122; 3,217.2 vs 473.3 pg/mL; P = .08). Median toxin A+B concentration was nonsignificantly higher in children with a primarily attributed severe outcome (n = 4) versus no severe outcome (n = 148; 19,472.6 vs 429.1 pg/mL; P = .301). Recurrence occurred in 17 (9.4%) of 180 patients. Baseline toxin A+B concentration was significantly higher in patients with versus without recurrence: 4,398.8 versus 280.8 pg/mL (P = .024). Plasma granulocyte colony-stimulating factor concentration was significantly higher in CDI patients versus non-CDI diarrhea controls: 165.5 versus 28.5 pg/mL (P < .001). CONCLUSIONS Higher baseline stool toxin concentrations are present in children with CDI recurrence. Toxin quantification should be included in CDI treatment trials to evaluate its use in severity assessment and outcome prediction.
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Affiliation(s)
- Thomas J. Sandora
- Division of Infectious Diseases, Department of Pediatrics, Boston Children’s Hospital and Harvard Medical School, Boston, MA, 02115, USA
| | - Larry K. Kociolek
- Division of Infectious Diseases, Department of Pediatrics, Ann & Robert H. Lurie Children’s Hospital of Chicago and Northwestern University Feinberg School of Medicine, Chicago, IL, 60611, USA
| | - David N. Williams
- Institutional Centers for Clinical and Translational Research, Boston Children’s Hospital, Boston, MA, 02115, USA
| | - Kaitlyn Daugherty
- Division of Gastroenterology (K.D., C.G., C.C., C.K) and Division of Infectious Diseases (N.R.P.), Department of Medicine, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, MA, 02115, USA
| | - Christine Geer
- Institutional Centers for Clinical and Translational Research, Boston Children’s Hospital, Boston, MA, 02115, USA
- Division of Gastroenterology (K.D., C.G., C.C., C.K) and Division of Infectious Diseases (N.R.P.), Department of Medicine, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, MA, 02115, USA
| | - Christine Cuddemi
- Division of Gastroenterology (K.D., C.G., C.C., C.K) and Division of Infectious Diseases (N.R.P.), Department of Medicine, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, MA, 02115, USA
| | - Xinhua Chen
- Division of Gastroenterology (K.D., C.G., C.C., C.K) and Division of Infectious Diseases (N.R.P.), Department of Medicine, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, MA, 02115, USA
| | - Hua Xu
- Division of Gastroenterology (K.D., C.G., C.C., C.K) and Division of Infectious Diseases (N.R.P.), Department of Medicine, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, MA, 02115, USA
| | - Timothy J. Savage
- Division of Infectious Diseases, Department of Pediatrics, Boston Children’s Hospital and Harvard Medical School, Boston, MA, 02115, USA
- Division of Pharmacoepidemiology and Pharmacoeconomics, Department of Medicine, Brigham and Women’s Hospital and Harvard Medical School, Boston, MA, 02120, USA
| | - Alice Banz
- bioMerieux, Marcy L’Etoile, 69280, France
| | - Kevin W. Garey
- Department of Pharmacy Practice and Translational Research, University of Houston College of Pharmacy, Houston, TX, 77204, USA
| | - Anne J. Gonzales-Luna
- Department of Pharmacy Practice and Translational Research, University of Houston College of Pharmacy, Houston, TX, 77204, USA
| | - Ciarán P. Kelly
- Division of Gastroenterology (K.D., C.G., C.C., C.K) and Division of Infectious Diseases (N.R.P.), Department of Medicine, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, MA, 02115, USA
| | - Nira R. Pollock
- Division of Gastroenterology (K.D., C.G., C.C., C.K) and Division of Infectious Diseases (N.R.P.), Department of Medicine, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, MA, 02115, USA
- Department of Laboratory Medicine, Boston Children’s Hospital and Harvard Medical School, Boston, MA, 02115, USA
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2
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Madden GR, Rigo I, Boone R, Abhyankar MM, Young MK, Basener W, Petri WA. Novel Biomarkers, Including tcdB PCR Cycle Threshold, for Predicting Recurrent Clostridioides difficile Infection. Infect Immun 2023; 91:e0009223. [PMID: 36975808 PMCID: PMC10112139 DOI: 10.1128/iai.00092-23] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2023] [Accepted: 03/09/2023] [Indexed: 03/29/2023] Open
Abstract
Traditional clinical models for predicting recurrent Clostridioides difficile infection do not perform well, likely owing to the complex host-pathogen interactions involved. Accurate risk stratification using novel biomarkers could help prevent recurrence by improving underutilization of effective therapies (i.e., fecal transplant, fidaxomicin, bezlotoxumab). We used a biorepository of 257 hospitalized patients with 24 features collected at diagnosis, including 17 plasma cytokines, total/neutralizing anti-toxin B IgG, stool toxins, and PCR cycle threshold (CT) (a proxy for stool organism burden). The best set of predictors for recurrent infection was selected by Bayesian model averaging for inclusion in a final Bayesian logistic regression model. We then used a large PCR-only data set to confirm the finding that PCR CT predicts recurrence-free survival using Cox proportional hazards regression. The top model-averaged features were (probabilities of >0.05, greatest to least): interleukin 6 (IL-6), PCR CT, endothelial growth factor, IL-8, eotaxin, IL-10, hepatocyte growth factor, and IL-4. The accuracy of the final model was 0.88. Among 1,660 cases with PCR-only data, cycle threshold was significantly associated with recurrence-free survival (hazard ratio, 0.95; P < 0.005). Certain biomarkers associated with C. difficile infection severity were especially important for predicting recurrence; PCR CT and markers of type 2 immunity (endothelial growth factor [EGF], eotaxin) emerged as positive predictors of recurrence, while type 17 immune markers (IL-6, IL-8) were negative predictors. In addition to novel serum biomarkers (particularly, IL-6, EGF, and IL-8), the readily available PCR CT may be critical to augment underperforming clinical models for C. difficile recurrence.
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Affiliation(s)
- Gregory R. Madden
- Division of Infectious Diseases & International Health, Department of Medicine, University of Virginia School of Medicine, Charlottesville, Virginia, USA
| | - Isaura Rigo
- Division of Infectious Diseases & International Health, Department of Medicine, University of Virginia School of Medicine, Charlottesville, Virginia, USA
| | - Rachel Boone
- Division of Infectious Diseases & International Health, Department of Medicine, University of Virginia School of Medicine, Charlottesville, Virginia, USA
| | - Mayuresh M. Abhyankar
- Division of Infectious Diseases & International Health, Department of Medicine, University of Virginia School of Medicine, Charlottesville, Virginia, USA
| | - Mary K. Young
- Division of Infectious Diseases & International Health, Department of Medicine, University of Virginia School of Medicine, Charlottesville, Virginia, USA
| | - William Basener
- School of Data Science, University of Virginia School of Medicine, Charlottesville, Virginia, USA
| | - William A. Petri
- Division of Infectious Diseases & International Health, Department of Medicine, University of Virginia School of Medicine, Charlottesville, Virginia, USA
- Department of Microbiology, Immunology, and Cancer Biology, University of Virginia, Charlottesville, Virginia, USA
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3
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Ok MT, Liu J, Bliton RJ, Hinesley CM, San Pedro EET, Breau KA, Gomez-Martinez I, Burclaff J, Magness ST. A leaky human colon model reveals uncoupled apical/basal cytotoxicity in early Clostridioides difficile toxin exposure. Am J Physiol Gastrointest Liver Physiol 2023; 324:G262-G280. [PMID: 36749911 PMCID: PMC10010926 DOI: 10.1152/ajpgi.00251.2022] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/25/2022] [Revised: 01/31/2023] [Accepted: 02/05/2023] [Indexed: 02/09/2023]
Abstract
Clostridioides difficile (C. difficile) toxins A (TcdA) and B (TcdB) cause antibiotic-associated colitis in part by disrupting epithelial barrier function. Accurate in vitro models are necessary to detect early toxicity kinetics, investigate disease etiology, and develop preclinical models for new therapies. Properties of cancer cell lines and organoids inherently limit these efforts. We developed adult stem cell-derived monolayers of differentiated human colonic epithelium (hCE) with barrier function, investigated the impact of toxins on apical/basal aspects of monolayers, and evaluated whether a leaky epithelial barrier enhances toxicity. Single-cell RNA-sequencing (scRNAseq) mapped C. difficile-relevant genes to human lineages. Transcriptomics compared hCE to Caco-2, informed timing of in vitro stem cell differentiation, and revealed transcriptional responses to TcdA. Transepithelial electrical resistance (TEER) and fluorescent permeability assays measured cytotoxicity. Contribution of TcdB toxicity was evaluated in a diclofenac-induced leaky gut model. scRNAseq demonstrated broad and variable toxin receptor expression. Absorptive colonocytes in vivo displayed increased toxin receptor, Rho GTPase, and cell junction gene expression. Advanced TcdA toxicity generally decreased cytokine/chemokine and increased tight junction and death receptor genes. Differentiated Caco-2 cells remained immature whereas hCE monolayers were similar to mature colonocytes in vivo. Basal exposure of TcdA/B caused greater toxicity and apoptosis than apical exposure. Apical exposure to toxins was enhanced by diclofenac. Apical/basal toxicities are uncoupled with more rapid onset and increased magnitude postbasal toxin exposure. Leaky junctions enhance toxicity of apical TcdB exposure. hCE monolayers represent a physiologically relevant and sensitive system to evaluate the impact of microbial toxins on gut epithelium.NEW & NOTEWORTHY Novel human colonocyte monolayer cultures, benchmarked by transcriptomics for physiological relevance, detect early cytopathic impacts of Clostridioides difficile toxins TcdA and TcdB. A fluorescent ZO-1 reporter in primary human colonocytes is used to track epithelial barrier disruption in response to TcdA. Basal TcdA/B exposure generally caused more rapid onset and cytotoxicity than apical exposure. Transcriptomics demonstrate changes in tight junction, chemokine, and cytokine receptor gene expression post-TcdA exposure. Diclofenac-induced leaky epithelium enhanced apical exposure toxicity.
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Affiliation(s)
- Meryem T Ok
- Joint Department of Biomedical Engineering, University of North Carolina at Chapel Hill and North Carolina State University, Chapel Hill, North Carolina, United States
| | - Jintong Liu
- Center for Gastrointestinal Biology and Disease, University of North Carolina at Chapel Hill and North Carolina State University, Chapel Hill, North Carolina, United States
| | - R Jarrett Bliton
- Joint Department of Biomedical Engineering, University of North Carolina at Chapel Hill and North Carolina State University, Chapel Hill, North Carolina, United States
| | - Caroline M Hinesley
- Center for Gastrointestinal Biology and Disease, University of North Carolina at Chapel Hill and North Carolina State University, Chapel Hill, North Carolina, United States
| | - Ekaterina Ellyce T San Pedro
- Center for Gastrointestinal Biology and Disease, University of North Carolina at Chapel Hill and North Carolina State University, Chapel Hill, North Carolina, United States
| | - Keith A Breau
- Department of Cell Biology and Physiology, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, United States
| | - Ismael Gomez-Martinez
- Department of Cell Biology and Physiology, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, United States
| | - Joseph Burclaff
- Joint Department of Biomedical Engineering, University of North Carolina at Chapel Hill and North Carolina State University, Chapel Hill, North Carolina, United States
- Center for Gastrointestinal Biology and Disease, University of North Carolina at Chapel Hill and North Carolina State University, Chapel Hill, North Carolina, United States
| | - Scott T Magness
- Joint Department of Biomedical Engineering, University of North Carolina at Chapel Hill and North Carolina State University, Chapel Hill, North Carolina, United States
- Center for Gastrointestinal Biology and Disease, University of North Carolina at Chapel Hill and North Carolina State University, Chapel Hill, North Carolina, United States
- Department of Cell Biology and Physiology, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, United States
- Department of Medicine, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, United States
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4
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Raeisi H, Azimirad M, Asadzadeh Aghdaei H, Yadegar A, Zali MR. Rapid-format recombinant antibody-based methods for the diagnosis of Clostridioides difficile infection: Recent advances and perspectives. Front Microbiol 2022; 13:1043214. [PMID: 36523835 PMCID: PMC9744969 DOI: 10.3389/fmicb.2022.1043214] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2022] [Accepted: 10/13/2022] [Indexed: 08/30/2023] Open
Abstract
Clostridioides difficile, the most common cause of nosocomial diarrhea, has been continuously reported as a worldwide problem in healthcare settings. Additionally, the emergence of hypervirulent strains of C. difficile has always been a critical concern and led to continuous efforts to develop more accurate diagnostic methods for detection of this recalcitrant pathogen. Currently, the diagnosis of C. difficile infection (CDI) is based on clinical manifestations and laboratory tests for detecting the bacterium and/or its toxins, which exhibit varied sensitivity and specificity. In this regard, development of rapid diagnostic techniques based on antibodies has demonstrated promising results in both research and clinical environments. Recently, application of recombinant antibody (rAb) technologies like phage display has provided a faster and more cost-effective approach for antibody production. The application of rAbs for developing ultrasensitive diagnostic tools ranging from immunoassays to immunosensors, has allowed the researchers to introduce new platforms with high sensitivity and specificity. Additionally, DNA encoding antibodies are directly accessible in these approaches, which enables the application of antibody engineering to increase their sensitivity and specificity. Here, we review the latest studies about the antibody-based ultrasensitive diagnostic platforms for detection of C. difficile bacteria, with an emphasis on rAb technologies.
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Affiliation(s)
- Hamideh Raeisi
- Foodborne and Waterborne Diseases Research Center, Research Institute for Gastroenterology and Liver Diseases, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Masoumeh Azimirad
- Foodborne and Waterborne Diseases Research Center, Research Institute for Gastroenterology and Liver Diseases, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Hamid Asadzadeh Aghdaei
- Basic and Molecular Epidemiology of Gastrointestinal Disorders Research Center, Research Institute for Gastroenterology and Liver Diseases, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Abbas Yadegar
- Foodborne and Waterborne Diseases Research Center, Research Institute for Gastroenterology and Liver Diseases, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Mohammad Reza Zali
- Gastroenterology and Liver Diseases Research Center, Research Institute for Gastroenterology and Liver Diseases, Shahid Beheshti University of Medical Sciences, Tehran, Iran
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5
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Sandora TJ, Williams DN, Daugherty K, Geer C, Cuddemi C, Kociolek LK, Chen X, Xu H, Savage TJ, Banz A, Garey KW, Gonzales-Luna AJ, Kelly CP, Pollock NR. Stool Toxin Concentration Does Not Distinguish Clostridioides difficile Infection from Colonization in Children Less Than 3 Years of Age. J Pediatric Infect Dis Soc 2022; 11:454-458. [PMID: 35801632 PMCID: PMC9595052 DOI: 10.1093/jpids/piac059] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/04/2021] [Accepted: 06/10/2022] [Indexed: 11/14/2022]
Abstract
In a prospective cohort study, stools from children <3 years with and without diarrhea who were Clostridioides difficile nucleic acid amplification test-positive underwent ultrasensitive and quantitative toxin measurement. Among 37 cases and 46 controls, toxin concentration distributions overlapped substantially. Toxin concentration alone does not distinguish C. difficile infection from colonization in young children.
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Affiliation(s)
- Thomas J Sandora
- Corresponding Author: Thomas J. Sandora, MD MPH, Boston Children’s Hospital, 300 Longwood Avenue, Boston, MA 02115, USA. E-mail:
| | - David N Williams
- Institutional Centers for Clinical and Translational Research, Boston Children’s Hospital, Boston, Massachusetts, USA
| | - Kaitlyn Daugherty
- Division of Gastroenterology, Department of Medicine, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, Massachusetts, USA
| | - Christine Geer
- Institutional Centers for Clinical and Translational Research, Boston Children’s Hospital, Boston, Massachusetts, USA,Division of Gastroenterology, Department of Medicine, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, Massachusetts, USA
| | - Christine Cuddemi
- Division of Gastroenterology, Department of Medicine, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, Massachusetts, USA
| | - Larry K Kociolek
- Division of Infectious Diseases, Department of Pediatrics, Ann & Robert H. Lurie Children’s Hospital of Chicago, Northwestern University Feinberg School of Medicine, Chicago, Illinois, USA
| | - Xinhua Chen
- Division of Gastroenterology, Department of Medicine, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, Massachusetts, USA
| | - Hua Xu
- Division of Gastroenterology, Department of Medicine, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, Massachusetts, USA
| | - Timothy J Savage
- Division of Infectious Diseases, Department of Pediatrics, Boston Children’s Hospital, Harvard Medical School, Boston, Massachusetts, USA
| | | | - Kevin W Garey
- Department of Pharmacy Practice and Translational Research, University of Houston College of Pharmacy, Houston, Texas, USA
| | - Anne J Gonzales-Luna
- Department of Pharmacy Practice and Translational Research, University of Houston College of Pharmacy, Houston, Texas, USA
| | - Ciarán P Kelly
- Division of Gastroenterology, Department of Medicine, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, Massachusetts, USA
| | - Nira R Pollock
- Department of Laboratory Medicine, Boston Children’s Hospital, Harvard Medical School, Boston, Massachusetts, USA,Division of Infectious Diseases, Department of Medicine, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, Massachusetts, USA
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6
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Adamson H, Ajayi MO, Gilroy KE, McPherson MJ, Tomlinson DC, Jeuken LJC. Rapid Quantification of C. difficile Glutamate Dehydrogenase and Toxin B (TcdB) with a NanoBiT Split-Luciferase Assay. Anal Chem 2022; 94:8156-8163. [PMID: 35634999 PMCID: PMC9201815 DOI: 10.1021/acs.analchem.1c05206] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
![]()
C. difficile infection (CDI) is a leading healthcare-associated
infection with a high morbidity and mortality and is a financial burden.
No current standalone point-of-care test (POCT) is sufficient for
the identification of true CDI over a disease-free carriage of C. difficile, so one is urgently required to ensure timely,
appropriate treatment. Here, two types of binding proteins, Affimers
and nanobodies, targeting two C. difficile biomarkers,
glutamate dehydrogenase (GDH) and toxin B (TcdB), are combined in
NanoBiT (NanoLuc Binary Technology) split-luciferase assays. The assays
were optimized and their performance controlling parameters were examined.
The 44 fM limit of detection (LoD), 4–5 log range and 1300-fold
signal gain of the TcdB assay in buffer is the best observed for a
NanoBiT assay to date. In the stool sample matrix, the GDH and TcdB
assay sensitivity (LoD = 4.5 and 2 pM, respectively) and time to result
(32 min) are similar to a current, commercial lateral flow POCT, but
the NanoBit assay has no wash steps, detects clinically relevant TcdB
over TcdA, and is quantitative. Development of the assay into a POCT
may drive sensitivity further and offer an urgently needed ultrasensitive
TcdB test for the rapid diagnosis of true CDI. The NanoBiTBiP (NanoBiT
with Binding Proteins) system offers advantages over NanoBiT assays
with antibodies as binding elements in terms of ease of production
and assay performance. We expect this methodology and approach to
be generally applicable to other biomarkers.
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Affiliation(s)
- Hope Adamson
- School of Biomedical Sciences and Astbury Centre for Structural Molecular Biology, University of Leeds, Leeds, LS2 9JT, United Kingdom
| | - Modupe O. Ajayi
- School of Molecular and Cellular Biology and Astbury Centre for Structural Molecular Biology, University of Leeds, Leeds, LS2 9JT, United Kingdom
| | - Kate E. Gilroy
- School of Molecular and Cellular Biology and Astbury Centre for Structural Molecular Biology, University of Leeds, Leeds, LS2 9JT, United Kingdom
| | - Michael J. McPherson
- School of Molecular and Cellular Biology and Astbury Centre for Structural Molecular Biology, University of Leeds, Leeds, LS2 9JT, United Kingdom
| | - Darren C. Tomlinson
- School of Molecular and Cellular Biology and Astbury Centre for Structural Molecular Biology, University of Leeds, Leeds, LS2 9JT, United Kingdom
| | - Lars J. C. Jeuken
- School of Biomedical Sciences and Astbury Centre for Structural Molecular Biology, University of Leeds, Leeds, LS2 9JT, United Kingdom
- Leiden Institute of Chemistry, Leiden University, PC Box 9502, 2300 RA, Leiden, The Netherlands
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7
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Decataldo F, Giovannini C, Grumiro L, Marino MM, Faccin F, Brandolini M, Dirani G, Taddei F, Lelli D, Tessarolo M, Calienni M, Cacciotto C, De Pascali AM, Lavazza A, Fraboni B, Sambri V, Scagliarini A. Organic Electrochemical Transistors as Versatile Tool for Real-Time and Automatized Viral Cytopathic Effect Evaluation. Viruses 2022; 14:1155. [PMID: 35746627 PMCID: PMC9227436 DOI: 10.3390/v14061155] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2022] [Revised: 05/24/2022] [Accepted: 05/25/2022] [Indexed: 02/01/2023] Open
Abstract
In-vitro viral studies are still fundamental for biomedical research since studying the virus kinetics on cells is crucial for the determination of the biological properties of viruses and for screening the inhibitors of infections. Moreover, testing potential viral contaminants is often mandatory for safety evaluation. Nowadays, viral cytopathic effects are mainly evaluated through end-point assays requiring dye-staining combined with optical evaluation. Recently, optical-based automatized equipment has been marketed, aimed at the real-time screening of cell-layer status and obtaining further insights, which are unavailable with end-point assays. However, these technologies present two huge limitations, namely, high costs and the possibility to study only cytopathic viruses, whose effects lead to plaque formation and layer disruption. Here, we employed poly(3,4-ethylenedioxythiophene):poly(styrene sulfonate) (Pedot:Pss) organic electrochemical transistors (OECTs) for the real-time, electrical monitoring of the infection of cytolytic viruses, i.e., encephalomyocarditis virus (EMCV), and non-cytolytic viruses, i.e., bovine coronavirus (B-CoV), on cells. OECT data on EMCV were validated using a commercially-available optical-based technology, which, however, failed in the B-CoV titration analysis, as expected. The OECTs proved to be reliable, fast, and versatile devices for viral infection monitoring, which could be scaled up at low cost, reducing the operator workload and speeding up in-vitro assays in the biomedical research field.
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Affiliation(s)
- Francesco Decataldo
- Department of Physics and Astronomy, Alma Mater Studiorum, University of Bologna, 40127 Bologna, Italy; (F.D.); (M.T.); (M.C.)
| | - Catia Giovannini
- Department of Experimental, Diagnostic and Specialty Medicine—DIMES, Universtity of Bologna, 40138 Bologna, Italy; (C.G.); (C.C.); (A.M.D.P.); (A.S.)
- Center for Applied Biomedical Research (CRBA), S. Orsola-Malpighi University Hospital, 40138 Bologna, Italy
| | - Laura Grumiro
- Unit of Microbiology, The Great Romagna Hub Laboratory, 47522 Pievesestina, Italy; (L.G.); (M.M.M.); (M.B.); (G.D.); (F.T.)
| | - Maria Michela Marino
- Unit of Microbiology, The Great Romagna Hub Laboratory, 47522 Pievesestina, Italy; (L.G.); (M.M.M.); (M.B.); (G.D.); (F.T.)
| | - Francesca Faccin
- Experimental Zooprofilactic Institute of Lombardy and Emilia Romagna“Bruno Ubertini” (IZSLER), 25124 Brescia, Italy; (F.F.); (D.L.); (A.L.)
| | - Martina Brandolini
- Unit of Microbiology, The Great Romagna Hub Laboratory, 47522 Pievesestina, Italy; (L.G.); (M.M.M.); (M.B.); (G.D.); (F.T.)
| | - Giorgio Dirani
- Unit of Microbiology, The Great Romagna Hub Laboratory, 47522 Pievesestina, Italy; (L.G.); (M.M.M.); (M.B.); (G.D.); (F.T.)
| | - Francesca Taddei
- Unit of Microbiology, The Great Romagna Hub Laboratory, 47522 Pievesestina, Italy; (L.G.); (M.M.M.); (M.B.); (G.D.); (F.T.)
| | - Davide Lelli
- Experimental Zooprofilactic Institute of Lombardy and Emilia Romagna“Bruno Ubertini” (IZSLER), 25124 Brescia, Italy; (F.F.); (D.L.); (A.L.)
| | - Marta Tessarolo
- Department of Physics and Astronomy, Alma Mater Studiorum, University of Bologna, 40127 Bologna, Italy; (F.D.); (M.T.); (M.C.)
| | - Maria Calienni
- Department of Physics and Astronomy, Alma Mater Studiorum, University of Bologna, 40127 Bologna, Italy; (F.D.); (M.T.); (M.C.)
| | - Carla Cacciotto
- Department of Experimental, Diagnostic and Specialty Medicine—DIMES, Universtity of Bologna, 40138 Bologna, Italy; (C.G.); (C.C.); (A.M.D.P.); (A.S.)
| | - Alessandra Mistral De Pascali
- Department of Experimental, Diagnostic and Specialty Medicine—DIMES, Universtity of Bologna, 40138 Bologna, Italy; (C.G.); (C.C.); (A.M.D.P.); (A.S.)
| | - Antonio Lavazza
- Experimental Zooprofilactic Institute of Lombardy and Emilia Romagna“Bruno Ubertini” (IZSLER), 25124 Brescia, Italy; (F.F.); (D.L.); (A.L.)
| | - Beatrice Fraboni
- Department of Physics and Astronomy, Alma Mater Studiorum, University of Bologna, 40127 Bologna, Italy; (F.D.); (M.T.); (M.C.)
| | - Vittorio Sambri
- Department of Experimental, Diagnostic and Specialty Medicine—DIMES, Universtity of Bologna, 40138 Bologna, Italy; (C.G.); (C.C.); (A.M.D.P.); (A.S.)
- Unit of Microbiology, The Great Romagna Hub Laboratory, 47522 Pievesestina, Italy; (L.G.); (M.M.M.); (M.B.); (G.D.); (F.T.)
| | - Alessandra Scagliarini
- Department of Experimental, Diagnostic and Specialty Medicine—DIMES, Universtity of Bologna, 40138 Bologna, Italy; (C.G.); (C.C.); (A.M.D.P.); (A.S.)
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8
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Schwenk HT, Pollock NR, Vaughan-Malloy AM. Pediatric Clostridioides difficile Infection: Diagnosis and Diagnostic Stewardship. J Pediatric Infect Dis Soc 2021; 10:S16-S21. [PMID: 34791395 DOI: 10.1093/jpids/piab054] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/14/2022]
Abstract
Although the pathogenesis of Clostridioides difficile infection (CDI) is complex and incompletely understood, it is believed that the elaboration of C. difficile toxins is necessary for disease. There are a variety of tests available for the detection of both the C. difficile organism and its toxins; however, each has limitations and the best application of these tests to the diagnosis of CDI in children remains uncertain. Nucleic acid amplification tests are unable to reliably discriminate between CDI and C. difficile colonization, while commercially available enzyme immunoassays for toxin detection lack sensitivity. An understanding of preanalytic factors, relevant patient features, and test performance characteristics is essential to the accurate diagnosis of CDI in children. Specific diagnostic stewardship strategies can also increase the likelihood that positive tests reflect disease rather than colonization. Ultimately, CDI remains a clinical diagnosis and clinical judgment is essential when interpreting test results, regardless of the methods used.
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Affiliation(s)
- Hayden T Schwenk
- Department of Pediatrics, Division of Pediatric Infectious Diseases, Stanford University School of Medicine, Stanford, California, USA
| | - Nira R Pollock
- Department of Laboratory Medicine, Boston Children's Hospital, Boston, Massachusetts, USA
| | - Ana M Vaughan-Malloy
- Department of Pediatrics, Boston Children's Hospital, Boston, Massachusetts, USA
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Hassanain WA, Spoors J, Johnson CL, Faulds K, Keegan N, Graham D. Rapid ultra-sensitive diagnosis of clostridium difficile infection using a SERS-based lateral flow assay. Analyst 2021; 146:4495-4505. [PMID: 34184680 DOI: 10.1039/d1an00726b] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
Clostridium difficile (C. diff) infection is one of the most contagious diseases associated with high morbidity and mortality rates in hospitalised patients. Accurate diagnosis can slow its spread by determining the most effective treatment. Herein, we report a novel testing platform as a proof-of-concept for the selective, sensitive, rapid and cost-effective diagnosis of C. diff infection (CDI) based on a duplex measurement. This was achieved by detecting two specific biomarkers, surface layer protein A (SlpA) and toxin B (ToxB), using a surface enhanced Raman scattering-based lateral flow assay (SERS-based LFA). The simultaneous duplex detection of SlpA with ToxB has not been described for the clinical diagnosis of CDI previously. The SlpA biomarker "AKDGSTKEDQLVDALA" was first reported by our group in 2018 as a species-specific identification tool. The second biomarker, ToxB, is the essential virulence biomarker of C. diff pathogenic strains and is required to confirm true infection pathogenicity. The proposed SERS-based LFA platform enabled rapid duplex detection of SlpA and ToxB on separate test lines using a duplex LF test strip within 20 minutes. The use of a handheld Raman spectrometer to scan test lines allowed for the highly sensitive quantitative detection of both biomarkers with a lowest observable concentration of 0.01 pg μL-1. The use of a handheld device in this SERS-based LFA instead of benchtop machine paves the way for rapid, selective, sensitive and cheap clinical evaluation of CDI at the point of care (POC) with minimal sample backlog.
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Affiliation(s)
- Waleed A Hassanain
- Department of Pure and Applied Chemistry, Technology and Innovation Centre, University of Strathclyde, Glasgow, G1 1RD, UK.
| | - Julia Spoors
- Diagnostic and Therapeutic Technologies, Translational and Clinical Research Institute, Newcastle University, Newcastle-Upon-Tyne, NE2 4HH, UK.
| | - Christopher L Johnson
- Diagnostic and Therapeutic Technologies, Translational and Clinical Research Institute, Newcastle University, Newcastle-Upon-Tyne, NE2 4HH, UK.
| | - Karen Faulds
- Department of Pure and Applied Chemistry, Technology and Innovation Centre, University of Strathclyde, Glasgow, G1 1RD, UK.
| | - Neil Keegan
- Diagnostic and Therapeutic Technologies, Translational and Clinical Research Institute, Newcastle University, Newcastle-Upon-Tyne, NE2 4HH, UK.
| | - Duncan Graham
- Department of Pure and Applied Chemistry, Technology and Innovation Centre, University of Strathclyde, Glasgow, G1 1RD, UK.
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Mizusawa M, Carroll KC. Advances and required improvements in methods to diagnosing Clostridioides difficile infections in the healthcare setting. Expert Rev Mol Diagn 2021; 21:311-321. [PMID: 33682564 DOI: 10.1080/14737159.2021.1900737] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
INTRODUCTION Clostrididioides difficile is associated with adverse clinical outcomes and increased morbidity, mortality, length of hospital stay, and health-care costs.Areas Covered: We searched relevant papers in PubMed for the last 10 years. In major papers, we scanned the bibliographies to ensure that important articles were included. This review addresses the evolving epidemiology of Clostridioides difficile infection (CDI) and discusses novel methods/approaches for improving the diagnosis of this important disease. EXPERT OPINION No single diagnostic test to date has demonstrated optimum sensitivity and specificity for detection of CDI. Many institutions have developed multi-step algorithms consistent with guidelines established by various professional societies. Some institutions have successfully tried to improve the pretest probability of molecular assays by implementing appropriate sample rejection criteria and establishing best practice alerts at the time of electronic order entry. Others have established PCR cycle threshold cutoffs to attempt to differentiate symptomatic patients from asymptomatic carriers or to make predictions about severity of disease with variable success. As research advances our understanding of C. difficile pathogenesis and pathophysiology, more information on CDI specific biomarkers is emerging. Finally, assessments of the microbiome and metabolome may expand the diagnostic armamentarium with advances in mass spectrometry and sequencing technologies.
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Affiliation(s)
- Masako Mizusawa
- Section of Infectious Diseases, Department of Internal Medicine, University of Missouri, Kansas City, Missouri, Kansas City, MO, USA
| | - Karen C Carroll
- Director Division of Medical Microbiology, The Johns Hopkins University School of Medicine, Baltimore, MD, USA
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Bernardo L, Corallo L, Caterini J, Su J, Gisonni-Lex L, Gajewska B. Application of xCELLigence real-time cell analysis to the microplate assay for pertussis toxin induced clustering in CHO cells. PLoS One 2021; 16:e0248491. [PMID: 33720984 PMCID: PMC7959359 DOI: 10.1371/journal.pone.0248491] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2020] [Accepted: 02/27/2021] [Indexed: 02/06/2023] Open
Abstract
The microplate assay with Chinese Hamster Ovary (CHO) cells is currently used as a safety test to monitor the residual pertussis toxin (PT) amount in acellular pertussis antigens prior to vaccine formulation. The assay is based on the findings that the exposure of CHO cells to PT results in a concentration-dependent clustering response which can be used to estimate the amount of PT in a sample preparation. A major challenge with the current CHO cell assay methodology is that scoring of PT-induced clustering is dependent on subjective operator visual assessment using light microscopy. In this work, we have explored the feasibility of replacing the microscopy readout for the CHO cell assay with the xCELLigence Real-Time Cell Analysis system (ACEA BioSciences, a part of Agilent). The xCELLigence equipment is designed to monitor cell adhesion and growth. The electrical impedance generated from cell attachment and proliferation is quantified via gold electrodes at the bottom of the cell culture plate wells, which is then translated into a unitless readout called cell index. Results showed significant decrease in the cell index readouts of CHO cells exposed to PT compared to the cell index of unexposed CHO cells. Similar endpoint concentrations were obtained when the PT reference standard was titrated with either xCELLigence or microscopy. Testing genetically detoxified pertussis samples unspiked or spiked with PT further supported the sensitivity and reproducibility of the xCELLigence assay in comparison with the conventional microscopy assay. In conclusion, the xCELLigence RTCA system offers an alternative automated and higher throughput method for evaluating PT-induced clustering in CHO cells.
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Affiliation(s)
- Lidice Bernardo
- Department of Analytical Sciences, Sanofi Pasteur, Toronto, ON, Canada
- * E-mail:
| | - Lucas Corallo
- Department of Analytical Sciences, Sanofi Pasteur, Toronto, ON, Canada
| | - Judy Caterini
- Department of Analytical Sciences, Sanofi Pasteur, Toronto, ON, Canada
| | - Jin Su
- Department of Analytical Sciences, Sanofi Pasteur, Toronto, ON, Canada
| | - Lucy Gisonni-Lex
- Department of Analytical Sciences, Sanofi Pasteur, Toronto, ON, Canada
| | - Beata Gajewska
- Department of Analytical Sciences, Sanofi Pasteur, Toronto, ON, Canada
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Han DK, Oh J, Lee J, Cho YG, Park JS, Choi JS, Kim DS, Kwon J. Paper-based multiplex analytical device for simultaneous detection of Clostridioides difficile toxins and glutamate dehydrogenase. Biosens Bioelectron 2021; 176:112894. [PMID: 33358286 DOI: 10.1016/j.bios.2020.112894] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2020] [Revised: 11/27/2020] [Accepted: 12/02/2020] [Indexed: 02/04/2023]
Abstract
We report a new paper-based multiplex analytical device (mPAD) for simultaneous screening of three analytes (glutamate dehydrogenase, toxin A, and toxin B) known as biomarkers for Clostridioides difficile infection (CDI). To overcome the limitation of common rapid assays (e.g. lateral flow immunochromatographic and enzyme immunoassays) in terms of multiplexing, sensitivity, simplicity, and ease-of-use, the mPAD is constructed with a three dimensional (3D) configuration of paper components with a multi-channel design. Multiple fluidic paths developed with wax-patterned paper allow the simultaneous detection of glutamate dehydrogenase, toxin A, and toxin B without any cross-reactivity. The 3D fluidic network on the mPAD facilitates a self-operating test procedure for the mixing and addition of amplification reagents with a one-step sliding operation. The results of the multiplex CDI assay can be easily interpreted by the naked eye within 10 min, and are visually intensified over time resulting in up to 3-fold signal amplification. Our device exhibited remarkable analytical performances for the simultaneous detection of three CDI biomarkers, providing a sensitivity of 97%, specificity of 88%, accuracy of 95%, and limits of detection for glutamate dehydrogenase, toxin A, and toxin B of 0.16 ng mL-1, 0.09 ng mL-1, and 0.03 ng mL-1, respectively. These results indicate the high applicability and feasibility of mPAD for multiplex testing for CDI with the advantages of being simple, sensitive, inexpensive, user-friendly, and equipment-free.
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Affiliation(s)
- Do Kyoung Han
- Research Center for Materials Analysis, Korea Basic Science Institute, 169-148, Gwahak-ro, Yuseong-Gu, Daejeon, 34133, Republic of Korea
| | - Jeonghyun Oh
- Research Center for Materials Analysis, Korea Basic Science Institute, 169-148, Gwahak-ro, Yuseong-Gu, Daejeon, 34133, Republic of Korea; Graduate School of Analytical Science and Technology, Chungnam National University, Daejeon, 34134, Republic of Korea
| | - Jaehyeon Lee
- Department of Laboratory Medicine, Jeonbuk National University Hospital, Jeonbuk National University Medical School, Jeonju, 54907, Republic of Korea
| | - Yong Gon Cho
- Department of Laboratory Medicine, Jeonbuk National University Hospital, Jeonbuk National University Medical School, Jeonju, 54907, Republic of Korea
| | - Ju Seong Park
- Research Center for Materials Analysis, Korea Basic Science Institute, 169-148, Gwahak-ro, Yuseong-Gu, Daejeon, 34133, Republic of Korea; Graduate School of Analytical Science and Technology, Chungnam National University, Daejeon, 34134, Republic of Korea
| | - Jong Soon Choi
- Research Center for Materials Analysis, Korea Basic Science Institute, 169-148, Gwahak-ro, Yuseong-Gu, Daejeon, 34133, Republic of Korea; Graduate School of Analytical Science and Technology, Chungnam National University, Daejeon, 34134, Republic of Korea.
| | - Dal Sik Kim
- Department of Laboratory Medicine, Jeonbuk National University Hospital, Jeonbuk National University Medical School, Jeonju, 54907, Republic of Korea.
| | - Joseph Kwon
- Research Center for Materials Analysis, Korea Basic Science Institute, 169-148, Gwahak-ro, Yuseong-Gu, Daejeon, 34133, Republic of Korea.
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Parnell JM, Fazili I, Bloch SC, Lacy DB, Garcia-Lopez VA, Bernard R, Skaar EP, Edwards KM, Nicholson MR. Two-step Testing for Clostridioides Difficile is Inadequate in Differentiating Infection From Colonization in Children. J Pediatr Gastroenterol Nutr 2021; 72:378-383. [PMID: 32925555 PMCID: PMC7870537 DOI: 10.1097/mpg.0000000000002944] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
OBJECTIVES Recent Infectious Disease Society of America guidelines recommend multistep testing algorithms to diagnose Clostridioides difficile infection (CDI), including a combination of nucleic acid amplification-based testing (NAAT) and toxin enzyme immunoassay (EIA). The use of these algorithms in children, including the ability to differentiate between C. difficile colonization and CDI, however, has not been evaluated. METHODS We prospectively enrolled asymptomatic pediatric patients with cancer, cystic fibrosis (CF), or inflammatory bowel disease (IBD) and obtained a stool sample for NAAT testing. If positive by NAAT (colonized), EIA was performed. In addition, children with symptomatic CDI who tested positive by NAAT via the clinical laboratory were enrolled, and EIA was performed on residual stool. A functional cell cytotoxicity neutralization assay (CCNA) was also applied to stool samples from both the colonized and symptomatic cohorts. RESULTS Of the 225 asymptomatic children enrolled in the study, 47 (21%) were colonized with C. difficile including 9/59 (15.5%) with cancer, 30/92 (32.6%) with CF, and 8/74 (10.8%) with IBD. An additional 41 children with symptomatic CDI were enrolled. When symptomatic and colonized children were compared, neither EIA positivity (44% vs 26%, P = 0.07) nor CCNA positivity (49% vs 45%, P = 0.70) differed significantly or were able to predict disease severity in the symptomatic cohort. CONCLUSIONS Use of a multistep testing algorithm with NAAT followed by EIA failed to differentiate symptomatic CDI from asymptomatic colonization in our pediatric cohort. As multistep algorithms are moved into clinical care, the pediatric provider will need to be aware of their limitations.
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Affiliation(s)
- Jacob M. Parnell
- Department of Medicine, Vanderbilt University Medical Center, Nashville, TN
| | - Irtiqa Fazili
- University of Tennessee Health Science Center, Memphis, TN
| | - Sarah C. Bloch
- Department of Pathology, Microbiology, and Immunology, Vanderbilt University Medical Center, Nashville, TN
| | - D. Borden Lacy
- Department of Pathology, Microbiology, and Immunology, Vanderbilt University Medical Center, Nashville, TN
| | - Valeria A. Garcia-Lopez
- Vanderbilt Institute of Infection, Immunology, and Inflammation, Vanderbilt University Medical Center, Nashville TN
| | - Rachel Bernard
- Division of Pediatric Gastroenterology, Hepatology, and Nutrition, Vanderbilt University Medical Center, Nashville, TN
| | - Eric P. Skaar
- Vanderbilt Institute of Infection, Immunology, and Inflammation, Vanderbilt University Medical Center, Nashville TN
| | - Kathryn M. Edwards
- Division of Pediatric Infectious Diseases, Vanderbilt University Medical Center, Nashville TN
| | - Maribeth R. Nicholson
- Division of Pediatric Gastroenterology, Hepatology, and Nutrition, Vanderbilt University Medical Center, Nashville, TN
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Prospective Evaluation of the mariPOC Test for Detection of Clostridioides difficile Glutamate Dehydrogenase and Toxins A/B. J Clin Microbiol 2020; 58:JCM.01872-19. [PMID: 31941691 DOI: 10.1128/jcm.01872-19] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2019] [Accepted: 12/18/2019] [Indexed: 11/20/2022] Open
Abstract
The objective of this study was to evaluate a novel automated random-access test, mariPOC CDI (ArcDia Ltd., Finland), for the detection of Clostridioides difficile glutamate dehydrogenase (GDH) and toxins A and B directly from fecal specimens. The mariPOC test was compared with both the GenomEra C. difficile PCR assay (Abacus Diagnostica Oy, Finland) and the TechLab C. diff Quik Chek Complete (Alere Inc.; now Abbot) membrane enzyme immunoassay (MEIA). Culture and the Xpert C. difficile assay (Cepheid Inc., USA) were used to resolve discrepant results. In total, 337 specimens were tested with the mariPOC CDI test and GenomEra PCR. Of these specimens, 157 were also tested with the TechLab MEIA. The sensitivity of the mariPOC test for GDH was slightly lower (95.2%) than that obtained with the TechLab assay (100.0%), but no toxin-positive cases were missed. The sensitivity of the mariPOC test for the detection of toxigenic C. difficile by analyzing toxin expression was better (81.6%) than that of the TechLab assay (71.1%). The analytical specificities for the mariPOC and the TechLab tests were 98.3% and 100.0% for GDH and 100.0% and 99.2% for toxin A/B, respectively. The analytical specificity of the GenomEra method was 100.0%. The mariPOC and TechLab GDH tests and GenomEra PCR had high negative predictive values of 99.3%, 98.3%, and 99.7%, respectively, in excluding infection with toxigenic C. difficile The mariPOC toxin A/B test and GenomEra PCR had an identical analytical positive predictive value of 100%, providing highly reliable information about toxin expression and the presence of toxin genes, respectively.
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High Agreement Between an Ultrasensitive Clostridioides difficile Toxin Assay and a C. difficile Laboratory Algorithm Utilizing GDH-and-Toxin Enzyme Immunoassays and Cytotoxin Testing. J Clin Microbiol 2020; 58:JCM.01629-19. [PMID: 31776192 DOI: 10.1128/jcm.01629-19] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2019] [Accepted: 11/14/2019] [Indexed: 12/18/2022] Open
Abstract
The Singulex Clarity C. diff toxins A/B (Clarity) assay is an automated, ultrasensitive immunoassay for the detection of Clostridioides difficile toxins in stool. In this study, the performance of the Clarity assay was compared to that of a multistep algorithm using an enzyme immunoassay (EIA) for detection of glutamate dehydrogenase (GDH) and toxins A and B arbitrated by a semiquantitative cell cytotoxicity neutralization assay (CCNA). The performance of the assay was evaluated using 211 residual deidentified stool samples tested with a GDH-and-toxin EIA (C. Diff Quik Chek Complete; Techlab), with GDH-and-toxin discordant samples tested with CCNA. The stool samples were stored at -80°C before being tested with the Clarity assay. For samples discordant between Clarity and the standard-of-care algorithm, the samples were tested with PCR (Xpert C. difficile; Cepheid), and chart review was performed. The testing algorithm resulted in 34 GDH+/toxin+, 53 GDH-/toxin-, and 124 GDH+/toxin- samples, of which 39 were CCNA+ and 85 were CCNA- Clarity had 96.2% negative agreement with GDH-/toxin- samples, 100% positive agreement with GDH+/toxin+ samples, and 95.3% agreement with GDH+/toxin-/CCNA- samples. The Clarity result was invalid for one sample. Clarity agreed with 61.5% of GDH+/toxin-/CCNA+ samples, 90.0% of GDH+/toxin-/CCNA+ (high-positive) samples, and 31.6% of GDH+/toxin-/CCNA+ (low-positive) samples. The Singulex Clarity C. diff toxins A/B assay demonstrated high agreement with a testing algorithm utilizing a GDH-and-toxin EIA and CCNA. This novel automated assay may offer an accurate, stand-alone solution for C. difficile infection (CDI) diagnostics, and further prospective clinical studies are merited.
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Yang L, Zhang Y, Wang Q, Zhang L. An Automated Microrobotic Platform for Rapid Detection of C. diff Toxins. IEEE Trans Biomed Eng 2019; 67:1517-1527. [PMID: 31494540 DOI: 10.1109/tbme.2019.2939419] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
OBJECTIVE Clostridium difficile (C. diff) infection leads to hundreds of nosocomial infections, and early diagnosis of this toxin-mediated disease is important. This paper aims to develop a microrobotic system and related methods that enable the automated and rapid detection of toxins secreted by C. diff that exist in patient's stool. METHODS We utilize the fluorescent magnetic spore-based microrobot (FMSM), a microscale mobile sensing tool, to efficiently detect C. diff toxins by utilizing its property of selective fluorescence responses to C. diff toxins. A plug-and-play (PnP) electromagnetic coil system integrated with fluorescence microscopy is developed for actuation, control and observation of FMSMs. In order to track in real time and accurately obtain the fluorescence parameters of a FMSM under varied background noise in fluorescence signal, an image gradient-based method is proposed. For accelerating the FMSM-toxin interaction in different samples, an automated navigation control scheme for the FMSM is proposed and implemented. Moreover, data post-processing methods that can optimally extract the fluorescence decay trend from the dense and fluctuated fluorescence data are developed. RESULTS This automated mobile detection process finishes within only 20 minutes, and the toxin detection result is immediately given by adopting the proposed system and methods. Experimental results on different biological samples confirm the qualitative detection capability. And, C. diff toxins are automatically detected from the clinical stool of infectious patients and the relationship between the fluorescence decay and the toxin concentration is calibrated for semi-quantitative detection purpose. SIGNIFICANCE The proposed automated microrobotic platform provides a rapid and low-cost detection technique for C. diff toxins, and it has good competency for future clinical use.
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Ultrasensitive Detection of Clostridium difficile Toxins Reveals Suboptimal Accuracy of Toxin Gene Cycle Thresholds for Toxin Predictions. J Clin Microbiol 2019; 57:JCM.01885-18. [PMID: 30944188 DOI: 10.1128/jcm.01885-18] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
The use of nucleic acid amplification tests (NAATs) for the diagnosis of Clostridium (Clostridioides) difficile infection (CDI) leads to overdiagnosis. To improve the clinical specificity of NAATs, there has been a recent interest in using toxin gene cycle thresholds (CT s) to predict the presence and absence of toxins. Although there is an association between CT values and fecal toxin concentrations, the predictive accuracy of the former is suboptimal for use in clinical practice. Ultrasensitive toxin immunoassays to quantify free toxins in stool offer a novel option for high-sensitivity fecal toxin detection rather than using surrogate markers for prediction.
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Brukner I, Eintracht S, Forgetta V, Papadakis AI, Spatz A, Oughton M. Laboratory-developed test for detection of acute Clostridium difficile infections with the capacity for quantitative sample normalization. Diagn Microbiol Infect Dis 2019; 95:113-118. [PMID: 31176521 DOI: 10.1016/j.diagmicrobio.2019.04.017] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2019] [Revised: 04/30/2019] [Accepted: 04/30/2019] [Indexed: 12/14/2022]
Abstract
We describe a laboratory-developed test intended for the detection of acute Clostridium difficile infections (CDI) with the capacity for quantitative sample normalization. The test is based on the detection of the tcdB gene. However, this biomarker is also present among people without symptoms, implying that individuals with diarrhea, not caused by C. difficile may nonetheless test positive. Therefore, clinical diagnosis based on this format of testing can be challenging. In order to improve diagnostic assays capability, tcdB-based quantification methods were suggested as a potential solution, however they did not increase clinical specificity. We report methodology for a dual biomarker monitoring (total bacterial load and tcdB assay), allowing for the calculation of the relative presence of tcdB in the total bacterial population in the tested samples. We believe that this approach is clinically relevant to current assays and can improve CDI testing algorithms.
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Affiliation(s)
- Ivan Brukner
- Department of Medical Microbiology, Jewish General Hospital, Quebec, Canada; Lady Davis Institute for Medical Research, Quebec, Canada; McGill University, Faculty of Medicine, Montreal, Quebec, Canada.
| | - Shaun Eintracht
- Department of Medicine, Jewish General Hospital, Quebec, Canada; McGill University, Faculty of Medicine, Montreal, Quebec, Canada
| | | | | | - Alan Spatz
- Lady Davis Institute for Medical Research, Quebec, Canada; McGill University, Department of Pathology, Quebec, Canada
| | - Matthew Oughton
- Department of Medical Microbiology, Jewish General Hospital, Quebec, Canada; McGill University, Faculty of Medicine, Montreal, Quebec, Canada.
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Advances in Diagnostic Testing that Impact Infection Prevention and Antimicrobial Stewardship Programs. Curr Infect Dis Rep 2019; 21:20. [PMID: 31044313 DOI: 10.1007/s11908-019-0676-7] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
PURPOSE OF REVIEW The primary purpose of this review is to provide a summary of new and emerging laboratory technologies and testing platforms that impact infection prevention and antimicrobial stewardship programs. This review also summarizes available data describing the clinical impact of implementing these new technologies. RECENT FINDINGS While there is ample evidence that rapid organism identification technologies for positive blood cultures can ameliorate antimicrobial utilization, an assay that also provides expedited antimicrobial susceptibility testing results is now available and its clinical impact is under investigation. For C. difficile infection diagnosis, data related to performance and impact of "ultrasensitive" toxin assays is emerging in the literature although their role in C. difficile infection diagnosis remains unclear. For hospital-acquired pneumonia, a variety of rapid, automated, multiplexed, "pneumonia" panels have become commercially available and may impact surveillance definitions for ventilator-associated events. Finally, recent FDA clearance of various biochemical and molecular carbapenemase detection tests will facilitate rapid characterization of carbapenem-resistant organisms. Innovations in infectious diseases diagnostics have been making swift strides, broadening diagnostic scope; increasing accuracy and sensitivity; and reducing turnaround time. Many of these innovations directly impact infection prevention and antimicrobial stewardship operations. Close collaboration between infection control, antimicrobial stewardship, and the microbiology laboratory is necessary to ensure that new tests improve patient outcomes.
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Sandlund J, Mills R, Griego-Fullbright C, Wagner A, Estis J, Bartolome A, Almazan A, Tam S, Biscocho S, Abusali S, Nolan N, Bishop JJ, Todd J, Young S. Laboratory comparison between cell cytotoxicity neutralization assay and ultrasensitive single molecule counting technology for detection of Clostridioides difficile toxins A and B, PCR, enzyme immunoassays, and multistep algorithms. Diagn Microbiol Infect Dis 2019; 95:20-24. [PMID: 31129008 DOI: 10.1016/j.diagmicrobio.2019.04.002] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2018] [Revised: 02/25/2019] [Accepted: 04/01/2019] [Indexed: 01/05/2023]
Abstract
Diagnostic tests for Clostridioides difficile infection (CDI) lack either specificity (nucleic acid amplification tests) or sensitivity (enzyme immunoassays; EIAs). The performance of the Singulex Clarity® C. diff toxins A/B assay was compared to cell cytotoxicity neutralization assay. Testing was also performed using an EIA for glutamate dehydrogenase (GDH) and C. difficile toxins A and B (C. Diff Quik Chek Complete®), polymerase chain reaction (PCR) (BD MAX™ Cdiff Assay), and 2 multistep algorithms: algorithm 1 (discordant GDH/toxin results arbitrated by PCR) and algorithm 2 (PCR-positive samples tested with toxin EIA). The Clarity assay and PCR both had 97% sensitivity, while specificity was 100% for Clarity and 79% for PCR. Algorithm 1 yielded 41% discordant results, and both toxin EIA and algorithm 2 had 58% sensitivity. Median toxin concentrations, as measured by the Clarity C. difficile toxin assay, were 3590, 11.5, 0.4, and 0 pg/mL for GDH+/toxin+, GDH+/toxin-/PCR+, GDH+/toxin-/PCR-, and GDH-/toxin- samples, respectively (P < 0.001). The Clarity assay may offer a single-test solution for CDI.
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Affiliation(s)
| | - Ray Mills
- TriCore Reference Laboratories, Albuquerque, NM, USA
| | | | - Aaron Wagner
- TriCore Reference Laboratories, Albuquerque, NM, USA
| | | | | | | | | | | | | | | | | | | | - Stephen Young
- TriCore Reference Laboratories, Albuquerque, NM, USA; Department of Pathology, The University of New Mexico Health Science Center, Albuquerque, NM, USA.
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Zhang Y, Zhang L, Yang L, Vong CI, Chan KF, Wu WKK, Kwong TNY, Lo NWS, Ip M, Wong SH, Sung JJY, Chiu PWY, Zhang L. Real-time tracking of fluorescent magnetic spore-based microrobots for remote detection of C. diff toxins. SCIENCE ADVANCES 2019; 5:eaau9650. [PMID: 30746470 PMCID: PMC6357761 DOI: 10.1126/sciadv.aau9650] [Citation(s) in RCA: 114] [Impact Index Per Article: 22.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/01/2018] [Accepted: 11/30/2018] [Indexed: 05/15/2023]
Abstract
A rapid, direct, and low-cost method for detecting bacterial toxins associated with common gastrointestinal diseases remains a great challenge despite numerous studies and clinical assays. Motion-based detection through tracking the emerging micro- and nanorobots has shown great potential in chemo- and biosensing due to accelerated "chemistry on the move". Here, we described the use of fluorescent magnetic spore-based microrobots (FMSMs) as a highly efficient mobile sensing platform for the detection of toxins secreted by Clostridium difficile (C. diff) that were present in patients' stool. These microrobots were synthesized rapidly and inexpensively by the direct deposition of magnetic nanoparticles and the subsequent encapsulation of sensing probes on the porous natural spores. Because of the cooperation effect of natural spore, magnetic Fe3O4 nanoparticles, and functionalized carbon nanodots, selective fluorescence detection of the prepared FMSMs is demonstrated in C. diff bacterial supernatant and even in actual clinical stool samples from infectious patients within tens of minutes, suggesting rapid response and good selectivity and sensitivity of FMSMs toward C. diff toxins.
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Affiliation(s)
- Yabin Zhang
- Department of Mechanical and Automation Engineering, Faculty of Engineering, The Chinese University of Hong Kong, Shatin NT, Hong Kong SAR, China
- Department of Biomedical Engineering, Faculty of Engineering, The Chinese University of Hong Kong, Shatin NT, Hong Kong SAR, China
| | - Lin Zhang
- Department of Anaesthesia and Intensive Care, The Chinese University of Hong Kong, Shatin NT, Hong Kong SAR, China
| | - Lidong Yang
- Department of Mechanical and Automation Engineering, Faculty of Engineering, The Chinese University of Hong Kong, Shatin NT, Hong Kong SAR, China
| | - Chi Ian Vong
- Department of Mechanical and Automation Engineering, Faculty of Engineering, The Chinese University of Hong Kong, Shatin NT, Hong Kong SAR, China
| | - Kai Fung Chan
- Department of Biomedical Engineering, Faculty of Engineering, The Chinese University of Hong Kong, Shatin NT, Hong Kong SAR, China
- Chow Yuk Ho Technology Centre for Innovative Medicine, The Chinese University of Hong Kong, Shatin NT, Hong Kong SAR, China
| | - William K. K. Wu
- Department of Anaesthesia and Intensive Care, The Chinese University of Hong Kong, Shatin NT, Hong Kong SAR, China
- Li Ka Shing Institute of Health Science, Faculty of Medicine, The Chinese University of Hong Kong, Shatin NT, Hong Kong SAR, China
| | - Thomas N. Y. Kwong
- Department of Medicine and Therapeutics, Faculty of Medicine, The Chinese University of Hong Kong, Shatin NT, Hong Kong SAR, China
- Institute of Digestive Disease, Faculty of Medicine, The Chinese University of Hong Kong, Shatin NT, Hong Kong SAR, China
| | - Norman W. S. Lo
- Department of Microbiology, Faculty of Medicine, The Chinese University of Hong Kong, Shatin NT, Hong Kong SAR, China
| | - Margaret Ip
- Department of Microbiology, Faculty of Medicine, The Chinese University of Hong Kong, Shatin NT, Hong Kong SAR, China
| | - Sunny H. Wong
- Li Ka Shing Institute of Health Science, Faculty of Medicine, The Chinese University of Hong Kong, Shatin NT, Hong Kong SAR, China
- Department of Medicine and Therapeutics, Faculty of Medicine, The Chinese University of Hong Kong, Shatin NT, Hong Kong SAR, China
- Institute of Digestive Disease, Faculty of Medicine, The Chinese University of Hong Kong, Shatin NT, Hong Kong SAR, China
- Department of Microbiology, Faculty of Medicine, The Chinese University of Hong Kong, Shatin NT, Hong Kong SAR, China
| | - Joseph J. Y. Sung
- Department of Medicine and Therapeutics, Faculty of Medicine, The Chinese University of Hong Kong, Shatin NT, Hong Kong SAR, China
- Institute of Digestive Disease, Faculty of Medicine, The Chinese University of Hong Kong, Shatin NT, Hong Kong SAR, China
| | - Philip W. Y. Chiu
- Chow Yuk Ho Technology Centre for Innovative Medicine, The Chinese University of Hong Kong, Shatin NT, Hong Kong SAR, China
- Institute of Digestive Disease, Faculty of Medicine, The Chinese University of Hong Kong, Shatin NT, Hong Kong SAR, China
- Department of Surgery, The Chinese University of Hong Kong, Shatin NT, Hong Kong SAR, China
- CUHK T Stone Robotics Institute, The Chinese University of Hong Kong, Shatin NT, Hong Kong SAR, China
| | - Li Zhang
- Department of Mechanical and Automation Engineering, Faculty of Engineering, The Chinese University of Hong Kong, Shatin NT, Hong Kong SAR, China
- Chow Yuk Ho Technology Centre for Innovative Medicine, The Chinese University of Hong Kong, Shatin NT, Hong Kong SAR, China
- CUHK T Stone Robotics Institute, The Chinese University of Hong Kong, Shatin NT, Hong Kong SAR, China
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Koya SK, Brusatori M, Martin JV, Yurgelevic S, Huang C, Liberati DM, Auner GW, Diebel LN. Rapid Detection of Clostridium difficile Toxins in Serum by Raman Spectroscopy. J Surg Res 2018; 232:195-201. [DOI: 10.1016/j.jss.2018.06.031] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2018] [Revised: 05/05/2018] [Accepted: 06/08/2018] [Indexed: 02/04/2023]
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Ultrasensitive Detection of Clostridioides difficile Toxins A and B by Use of Automated Single-Molecule Counting Technology. J Clin Microbiol 2018; 56:JCM.00908-18. [PMID: 30158195 DOI: 10.1128/jcm.00908-18] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2018] [Accepted: 08/27/2018] [Indexed: 12/12/2022] Open
Abstract
Current tests for the detection of Clostridioides (formerly Clostridium) difficile free toxins in feces lack sensitivity, while nucleic acid amplification tests lack clinical specificity. We have evaluated the Singulex Clarity C. diff toxins A/B assay (currently in development), an automated and rapid ultrasensitive immunoassay powered by single-molecule counting technology, for detection of C. difficile toxin A (TcdA) and toxin B (TcdB) in stool. The analytical sensitivity, analytical specificity, repeatability, and stability of the assay were determined. In a clinical evaluation, frozen stool samples from 311 patients with suspected C. difficile infection were tested with the Clarity C. diff toxins A/B assay, using an established cutoff value. Samples were tested with the Xpert C. difficile/Epi assay, and PCR-positive samples were tested with an enzyme immunoassay (EIA) (C. Diff Quik Chek Complete). EIA-negative samples were further tested with a cell cytotoxicity neutralization assay. The limits of detection for TcdA and TcdB were 0.8 and 0.3 pg/ml in buffer and 2.0 and 0.7 pg/ml in stool, respectively. The assay demonstrated reactivity to common C. difficile strains, did not show cross-reactivity to common gastrointestinal pathogens, was robust against common interferents, allowed detection in fresh and frozen stool samples and in samples after three freeze-thaw cycles, and provided results with high reproducibility. Compared to multistep PCR and toxin-testing procedures, the Singulex Clarity C. diff toxins A/B assay yielded 97.7% sensitivity and 100% specificity. The Singulex Clarity C. diff toxins A/B assay is ultrasensitive and highly specific and may offer a standalone solution for rapid detection and quantitation of free toxins in stool.
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Madden GR, Poulter MD, Sifri CD. Diagnostic stewardship and the 2017 update of the IDSA-SHEA Clinical Practice Guidelines for Clostridium difficile Infection. Diagnosis (Berl) 2018; 5:119-125. [PMID: 29990306 PMCID: PMC7066535 DOI: 10.1515/dx-2018-0012] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2018] [Accepted: 06/08/2018] [Indexed: 01/05/2023]
Abstract
Diagnostic stewardship is an increasingly recognized means to reduce unnecessary tests and diagnostic errors. As a leading cause of healthcare-associated infection for which accurate laboratory diagnosis remains a challenge, Clostridium difficile offers an ideal opportunity to apply the principles of diagnostic stewardship. The recently updated 2017 Infectious Diseases Society of America (IDSA)-Society for Healthcare Epidemiology of America (SHEA) Clinical Practice Guidelines for C. difficile infection now recommend separate diagnostic strategies depending on whether an institution has adopted diagnostic stewardship in test decision making. IDSA-SHEA endorsement of diagnostic stewardship for C. difficile highlights the increasing role of diagnostic stewardship in hospitals. In this opinion piece, we introduce the concept of diagnostic stewardship by discussing the new IDSA-SHEA diagnostic recommendations for laboratory diagnosis of C. difficile . We outline recent examples of diagnostic stewardship, challenges to implementation, potential downsides and propose future areas of study.
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Affiliation(s)
- Gregory R. Madden
- Division of Infectious Diseases and International Health, Department of Medicine, University of Virginia Health System, Charlottesville, VA, USA
| | - Melinda D. Poulter
- Clinical Microbiology Laboratory, Department of Pathology, University of Virginia Health System, Charlottesville, VA, USA
| | - Costi D. Sifri
- Division of Infectious Diseases and International Health, Department of Medicine, University of Virginia Health System, P.O. Box 800473, Charlottesville, VA 22908-0473, USA; Office of Hospital Epidemiology/ Infection Prevention and Control, University of Virginia Health System, Charlottesville, VA, USA
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25
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A low-cost paper-based synthetic biology platform for analyzing gut microbiota and host biomarkers. Nat Commun 2018; 9:3347. [PMID: 30131493 PMCID: PMC6104080 DOI: 10.1038/s41467-018-05864-4] [Citation(s) in RCA: 139] [Impact Index Per Article: 23.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2017] [Accepted: 07/20/2018] [Indexed: 12/13/2022] Open
Abstract
There is a need for large-scale, longitudinal studies to determine the mechanisms by which the gut microbiome and its interactions with the host affect human health and disease. Current methods for profiling the microbiome typically utilize next-generation sequencing applications that are expensive, slow, and complex. Here, we present a synthetic biology platform for affordable, on-demand, and simple analysis of microbiome samples using RNA toehold switch sensors in paper-based, cell-free reactions. We demonstrate species-specific detection of mRNAs from 10 different bacteria that affect human health and four clinically relevant host biomarkers. We develop a method to quantify mRNA using our toehold sensors and validate our platform on clinical stool samples by comparison to RT-qPCR. We further highlight the potential clinical utility of the platform by showing that it can be used to rapidly and inexpensively detect toxin mRNA in the diagnosis of Clostridium difficile infections. Currently, gut microbiome profiling largely relies on next-generation sequencing, which is slow and expensive. Here, the authors develop a low-cost, paper-based synthetic biology platform that allows species-specific quantification of bacterial mRNAs and clinically relevant host biomarkers.
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Hryckowian AJ, Van Treuren W, Smits SA, Davis NM, Gardner JO, Bouley DM, Sonnenburg JL. Microbiota-accessible carbohydrates suppress Clostridium difficile infection in a murine model. Nat Microbiol 2018; 3:662-669. [PMID: 29686297 PMCID: PMC6126909 DOI: 10.1038/s41564-018-0150-6] [Citation(s) in RCA: 149] [Impact Index Per Article: 24.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2017] [Accepted: 03/21/2018] [Indexed: 12/18/2022]
Abstract
Clostridium difficile is an opportunistic diarrhoeal pathogen, and C. difficile infection (CDI) represents a major health care concern, causing an estimated 15,000 deaths per year in the United States alone 1 . Several enteric pathogens, including C. difficile, leverage inflammation and the accompanying microbial dysbiosis to thrive in the distal gut 2 . Although diet is among the most powerful available tools for affecting the health of humans and their relationship with their microbiota, investigation into the effects of diet on CDI has been limited. Here, we show in mice that the consumption of microbiota-accessible carbohydrates (MACs) found in dietary plant polysaccharides has a significant effect on CDI. Specifically, using a model of antibiotic-induced CDI that typically resolves within 12 days of infection, we demonstrate that MAC-deficient diets perpetuate CDI. We show that C. difficile burdens are suppressed through the addition of either a diet containing a complex mixture of MACs or a simplified diet containing inulin as the sole MAC source. We show that switches between these dietary conditions are coincident with changes to microbiota membership, its metabolic output and C. difficile-mediated inflammation. Together, our data demonstrate the outgrowth of MAC-utilizing taxa and the associated end products of MAC metabolism, namely, the short-chain fatty acids acetate, propionate and butyrate, are associated with decreased C. difficile fitness despite increased C. difficile toxin expression in the gut. Our findings, when placed into the context of the known fibre deficiencies of a human Western diet, provide rationale for pursuing MAC-centric dietary strategies as an alternate line of investigation for mitigating CDI.
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Affiliation(s)
- Andrew J Hryckowian
- Department of Microbiology and Immunology, Stanford University School of Medicine, Stanford, CA, USA
| | - William Van Treuren
- Department of Microbiology and Immunology, Stanford University School of Medicine, Stanford, CA, USA
| | - Samuel A Smits
- Department of Microbiology and Immunology, Stanford University School of Medicine, Stanford, CA, USA
| | - Nicole M Davis
- Department of Microbiology and Immunology, Stanford University School of Medicine, Stanford, CA, USA
| | - Jackson O Gardner
- Department of Microbiology and Immunology, Stanford University School of Medicine, Stanford, CA, USA
| | - Donna M Bouley
- Department of Comparative Medicine, Stanford University School of Medicine, Stanford, CA, USA
| | - Justin L Sonnenburg
- Department of Microbiology and Immunology, Stanford University School of Medicine, Stanford, CA, USA.
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27
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A Rapid, Accurate, Single Molecule Counting Method Detects Clostridium difficile Toxin B in Stool Samples. Sci Rep 2018; 8:8364. [PMID: 29849171 PMCID: PMC5976643 DOI: 10.1038/s41598-018-26353-0] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2018] [Accepted: 05/10/2018] [Indexed: 12/19/2022] Open
Abstract
We describe a new rapid and accurate immunoassay-based technology capable of counting single target molecules using digital imaging without magnification. Using the technology, we developed a rapid test for Clostridium difficile toxin B, which is responsible for the pathology underlying potentially fatal C. difficile infections (CDI). There are currently no tests for CDI that are rapid, sensitive, and specific. The MultiPath C. difficile toxin B test images and counts complexes of target-specific magnetic and fluorescent particles that have been tethered together by toxin B molecules in minimally processed stool samples. The performance characteristics of the 30 minute test include a limit of detection of 45 pg/mL, dynamic range covering 4-5 orders of magnitude, and coefficient of variation of less than 10%. The MultiPath test detected all toxinotypes and ribotypes tested, including the one most commonly occurring in the US and EU; shows no cross reactivity with relevant bacterial species; and is robust to potential interferants commonly present in stool samples. On a training set of 320 clinical stool samples, the MultiPath C. difficile toxin B test showed 97.0% sensitivity (95% CI, 91.4-99.4%); 98.3% specificity (95% CI, 96.8-99.2%); and 98.2% accuracy (95% CI, 96.7-99.0%) compared to the cellular cytotoxicity neutralization assay (CCNA) reference method. Based on these compelling performance characteristics, we believe the MultiPath technology can address the lack of rapid, sensitive, specific, and easy-to-use diagnostic tests for C. difficile.
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28
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Yu L, Li H, Zhao X, Wang X, Wei X, Lin W, Li P, Cui L, Yuan J. Rapid visual detection of binary toxin producing Clostridium difficile by loop-mediated isothermal amplification. Exp Ther Med 2017; 14:4781-4788. [PMID: 29201180 PMCID: PMC5704324 DOI: 10.3892/etm.2017.5178] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2017] [Accepted: 07/27/2017] [Indexed: 01/05/2023] Open
Abstract
The binary toxin Clostridium difficile transferase (CDT) is frequently observed in C. difficile strains and is associated with an increased severity of C. difficile infection. CDT-producing C. difficile infections cause higher fatality rates than infections with CDT negative isolates. Thus, the rapid and accurate identification of a CDT positive C. difficile infection is critical for effective treatment. The present study demonstrates how loop-mediated isothermal amplification (LAMP) can be used to detect CDT-producing C. difficile based on visual observation. This is a low complexity, rapid molecular method that has the potential to be used within a point of care setting. The specificity and sensitivity of the primers in the LAMP reactions for CDT detection were determined using two different methods, a real-time turbidity monitor and visual detection after the addition of calcein to the reaction tube. The results revealed that target DNA was amplified and visualized by these two detection methods within 60 min at a temperature of 60°C. The sensitivity of the LAMP assay was identified to be 10-fold greater than that of polymerase chain reaction analysis. When 25 alternative bacterial strains lacking CDT were tested, the results of the amplification were negative, confirming the specificity of the primers. In conclusion, the visual LAMP method established in the present study may be a rapid, reliable and cost-effective tool for detecting CDT-producing C. difficile strains at the point of care.
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Affiliation(s)
- Lan Yu
- Department of Gastroenterology, Navy General Hospital, Beijing 100048, P.R. China
| | - Huan Li
- Institute of Disease Control and Prevention, Academy of Military Medical Sciences, Beijing 100071, P.R. China
| | - Xiangna Zhao
- Institute of Disease Control and Prevention, Academy of Military Medical Sciences, Beijing 100071, P.R. China
| | - Xuesong Wang
- Institute of Disease Control and Prevention, Academy of Military Medical Sciences, Beijing 100071, P.R. China
| | - Xiao Wei
- Institute of Disease Control and Prevention, Academy of Military Medical Sciences, Beijing 100071, P.R. China
| | - Weishi Lin
- Institute of Disease Control and Prevention, Academy of Military Medical Sciences, Beijing 100071, P.R. China
| | - Puyuan Li
- Institute of Disease Control and Prevention, Academy of Military Medical Sciences, Beijing 100071, P.R. China
| | - Lihong Cui
- Department of Gastroenterology, Navy General Hospital, Beijing 100048, P.R. China
| | - Jing Yuan
- Institute of Disease Control and Prevention, Academy of Military Medical Sciences, Beijing 100071, P.R. China
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29
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Xiong S, Zhou Y, Huang X, Yu R, Lai W, Xiong Y. Ultrasensitive direct competitive FLISA using highly luminescent quantum dot beads for tuning affinity of competing antigens to antibodies. Anal Chim Acta 2017; 972:94-101. [DOI: 10.1016/j.aca.2017.03.039] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2017] [Revised: 03/14/2017] [Accepted: 03/20/2017] [Indexed: 01/07/2023]
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