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Abstract
Clostridioides difficile (C. difficile) infection is still a threat to many healthcare settings worldwide. Clostridioides difficile epidemiology has changed over the last 20 years, largely due to the emergence of hypervirulent and antimicrobial-resistant C. difficile strains. The excessive use of antimicrobials, the absence of optimal antibiotic policies, and suboptimal infection control practices have fueled the development of this pressing health issue. The prudent use of antimicrobials, particularly broad-spectrum agents, and simple infection control measures, such as hand hygiene, can significantly reduce C. difficile infection rates. Moreover, the early detection of these infections and understanding their epidemiological behavior using accurate laboratory methods are the cornerstone to decreasing the incidence of C. difficile infection and preventing further spread. Although there is no consensus on the single best laboratory method for the diagnosis of C. difficile infection, the use of 2 or more techniques can improve diagnostic accuracy, and it is recommended.
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Affiliation(s)
- Ibrahim A. Al-Zahrani
- From the Department of Medical Laboratory Sciences, Faculty of Applied Medical Sciences, King Abdulaziz University, and from the Special Infectious Agents Unit-Biosafety Level-3, King Fahad Medical Research Centre, King Abdulaziz University, Jeddah, Kingdom of Saudi Arabia
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2
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Sarma S, Catella CM, San Pedro ET, Xiao X, Durmusoglu D, Menegatti S, Crook N, Magness ST, Hall CK. Design of 8-mer peptides that block Clostridioides difficile toxin A in intestinal cells. Commun Biol 2023; 6:878. [PMID: 37634026 PMCID: PMC10460389 DOI: 10.1038/s42003-023-05242-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2023] [Accepted: 08/14/2023] [Indexed: 08/28/2023] Open
Abstract
Infections by Clostridioides difficile, a bacterium that targets the large intestine (colon), impact a large number of people worldwide. Bacterial colonization is mediated by two exotoxins: toxins A and B. Short peptides that can be delivered to the gut and inhibit the biocatalytic activity of these toxins represent a promising therapeutic strategy to prevent and treat C. diff. infection. We describe an approach that combines a Peptide Binding Design (PepBD) algorithm, molecular-level simulations, a rapid screening assay to evaluate peptide:toxin binding, a primary human cell-based assay, and surface plasmon resonance (SPR) measurements to develop peptide inhibitors that block Toxin A in colon epithelial cells. One peptide, SA1, is found to block TcdA toxicity in primary-derived human colon (large intestinal) epithelial cells. SA1 binds TcdA with a KD of 56.1 ± 29.8 nM as measured by surface plasmon resonance (SPR).
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Affiliation(s)
- Sudeep Sarma
- Department of Chemical Engineering, North Carolina State University, Raleigh, NC, 27695-7905, USA
| | - Carly M Catella
- Department of Chemical Engineering, North Carolina State University, Raleigh, NC, 27695-7905, USA
| | - Ellyce T San Pedro
- Department of Medicine, University of North Carolina at Chapel Hill, Chapel Hill, NC, 27514, USA
| | - Xingqing Xiao
- Department of Chemical Engineering, North Carolina State University, Raleigh, NC, 27695-7905, USA
| | - Deniz Durmusoglu
- Department of Chemical Engineering, North Carolina State University, Raleigh, NC, 27695-7905, USA
| | - Stefano Menegatti
- Department of Chemical Engineering, North Carolina State University, Raleigh, NC, 27695-7905, USA
- Biomanufacturing Training and Education Center (BTEC), North Carolina State University, Raleigh, NC, 27695, USA
| | - Nathan Crook
- Department of Chemical Engineering, North Carolina State University, Raleigh, NC, 27695-7905, USA
| | - Scott T Magness
- Department of Medicine, University of North Carolina at Chapel Hill, Chapel Hill, NC, 27514, USA
| | - Carol K Hall
- Department of Chemical Engineering, North Carolina State University, Raleigh, NC, 27695-7905, USA.
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3
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Biswas R, Dudani H, Lakhera P, Pal AK, Kurbah P, Bhatia D, Dhok A, Kashyap RS. Challenges and future solutions for detection of Clostridioides difficile in adults. Ann Gastroenterol 2023; 36:369-377. [PMID: 37396008 PMCID: PMC10304531 DOI: 10.20524/aog.2023.0802] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/23/2022] [Accepted: 02/17/2023] [Indexed: 07/04/2023] Open
Abstract
There are no established standards for the diagnosis of Clostridioides difficile infection (CDI), even though the importance of this infection in humans is well known. The effectiveness of the commercially available techniques, which are all standardized for use with human feces, is also limited in terms of the accuracy of the tests. Furthermore, the current approach lacks a point-of-care diagnosis with an acceptable range of sensitivity and specificity. This article reviews the challenges and possible future solutions for the detection of CDI in adults. Existing diagnostic methods, such as enzyme-linked immunoassays and microbial culturing for the detection of toxins A and B, appear to work poorly in samples but exhibit great sensitivity for glutamate dehydrogenase. Real-time polymerase chain reaction and nucleic acid amplification tests have been investigated in a few studies on human samples, but so far have shown poor turnaround times. Thus, developing a multiplex point-of-care test assay with high sensitivity and specificity is required as a bedside approach for diagnosing this emerging infection.
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Affiliation(s)
- Rima Biswas
- Research Laboratory, Dr. G.M. Taori Central India Institute of Medical Sciences, Nagpur (Rima Biswas, Hemanshi Dudani, Rajpal Singh Kashyap)
| | - Hemanshi Dudani
- Research Laboratory, Dr. G.M. Taori Central India Institute of Medical Sciences, Nagpur (Rima Biswas, Hemanshi Dudani, Rajpal Singh Kashyap)
| | - Praveen Lakhera
- Academy of Scientific and Innovative Research (AcSIR), Ghaziabad, Uttar Pradesh and CSIR-Central Scientific Instruments Organization, Chandigarh (Praveen Lakhera)
| | - Arun Kumar Pal
- Department of Molecular and Cellular Engineering, Sam Higginbottom University of Agriculture, Technology, and Sciences, Prayagraj (Arun Kumar Pal)
| | - Phibalari Kurbah
- Department of Biomedical Engineering, North Eastern Hill University, Shillong, Meghalaya (Phibalari Kurbah, Dinesh Bhatia)
| | - Dinesh Bhatia
- Department of Biomedical Engineering, North Eastern Hill University, Shillong, Meghalaya (Phibalari Kurbah, Dinesh Bhatia)
| | - Archana Dhok
- Department of Biochemistry, Datta Meghe Institute of Medical Sciences, Sawangi (Archana Dhok), India
| | - Rajpal Singh Kashyap
- Research Laboratory, Dr. G.M. Taori Central India Institute of Medical Sciences, Nagpur (Rima Biswas, Hemanshi Dudani, Rajpal Singh Kashyap)
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4
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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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5
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Abstract
This paper reviews methods for detecting proteins based on molecular digitization, i.e., the isolation and detection of single protein molecules or singulated ensembles of protein molecules. The single molecule resolution of these methods has resulted in significant improvements in the sensitivity of immunoassays beyond what was possible using traditional "analog" methods: the sensitivity of some digital immunoassays approach those of methods for measuring nucleic acids, such as the polymerase chain reaction (PCR). The greater sensitivity of digital protein detection has resulted in immuno-diagnostics with high potential societal impact, e.g., the early diagnosis and therapeutic intervention of Alzheimer's Disease. In this review, we will first provide the motivation for developing digital protein detection methods given the limitations in the sensitivity of analog methods. We will describe the paradigm shift catalyzed by single molecule detection, and will describe in detail one digital approach - which we call digital bead assays (DBA) - based on the capture and labeling of proteins on beads, identifying "on" and "off" beads, and quantification using Poisson statistics. DBA based on the single molecule array (Simoa) technology have sensitivities down to attomolar concentrations, equating to ∼10 proteins in a 200 μL sample. We will describe the concept behind DBA, the different single molecule labels used, the ways of analyzing beads (imaging of arrays and flow), the binding reagents and substrates used, and integration of these technologies into fully automated and miniaturized systems. We provide an overview of emerging approaches to digital protein detection, including those based on digital detection of nucleic acids labels, single nanoparticle detection, measurements using nanopores, and methods that exploit the kinetics of single molecule binding. We outline the initial impact of digital protein detection on clinical measurements, highlighting the importance of customized assay development and translational clinical research. We highlight the use of DBA in the measurement of neurological protein biomarkers in blood, and how these higher sensitivity methods are changing the diagnosis and treatment of neurological diseases. We conclude by summarizing the status of digital protein detection and suggest how the lab-on-a-chip community might drive future innovations in this field.
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Affiliation(s)
- David C Duffy
- Quanterix Corporation, 900 Middlesex Turnpike, Billerica, MA 01821, USA.
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Sarma S, Catella CM, Pedro ETS, Xiao X, Durmusoglu D, Menegatti S, Crook N, Magness ST, Hall CK. Design of 8-mer Peptides that Block Clostridioides difficile Toxin A in Intestinal Cells. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.01.10.523493. [PMID: 36711911 PMCID: PMC9882058 DOI: 10.1101/2023.01.10.523493] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Abstract
Clostridioides difficile ( C. diff .) is a bacterium that causes severe diarrhea and inflammation of the colon. The pathogenicity of C. diff . infection is derived from two major toxins, toxins A (TcdA) and B (TcdB). Peptide inhibitors that can be delivered to the gut to inactivate these toxins are an attractive therapeutic strategy. In this work, we present a new approach that combines a pep tide b inding d esign algorithm (PepBD), molecular-level simulations, rapid screening of candidate peptides for toxin binding, a primary human cell-based assay, and surface plasmon resonance (SPR) measurements to develop peptide inhibitors that block the glucosyltransferase activity of TcdA by targeting its glucosyltransferase domain (GTD). Using PepBD and explicit-solvent molecular dynamics simulations, we identified seven candidate peptides, SA1-SA7. These peptides were selected for specific TcdA GTD binding through a custom solid-phase peptide screening system, which eliminated the weaker inhibitors SA5-SA7. The efficacies of SA1-SA4 were then tested using a trans-epithelial electrical resistance (TEER) assay on monolayers of the human gut epithelial culture model. One peptide, SA1, was found to block TcdA toxicity in primary-derived human jejunum (small intestinal) and colon (large intestinal) epithelial cells. SA1 bound TcdA with a K D of 56.1 ± 29.8 nM as measured by surface plasmon resonance (SPR). Significance Statement Infections by Clostridioides difficile , a bacterium that targets the large intestine (colon), impact a significant number of people worldwide. Bacterial colonization is mediated by two exotoxins: toxins A and B. Short peptides that can inhibit the biocatalytic activity of these toxins represent a promising strategy to prevent and treat C. diff . infection. We describe an approach that combines a Peptide B inding D esign (PepBD) algorithm, molecular-level simulations, a rapid screening assay to evaluate peptide:toxin binding, a primary human cell-based assay, and surface plasmon resonance (SPR) measurements to develop peptide inhibitors that block Toxin A in small intestinal and colon epithelial cells. Importantly, our designed peptide, SA1, bound toxin A with nanomolar affinity and blocked toxicity in colon cells.
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Affiliation(s)
- Sudeep Sarma
- Department of Chemical Engineering, North Carolina State University, Raleigh NC 27695-7905, USA
| | - Carly M. Catella
- Department of Chemical Engineering, North Carolina State University, Raleigh NC 27695-7905, USA
| | - Ellyce T. San Pedro
- Department of Medicine, University of North Carolina at Chapel Hill, NC 27514, United States
| | - Xingqing Xiao
- Department of Chemical Engineering, North Carolina State University, Raleigh NC 27695-7905, USA
| | - Deniz Durmusoglu
- Department of Chemical Engineering, North Carolina State University, Raleigh NC 27695-7905, USA
| | - Stefano Menegatti
- Department of Chemical Engineering, North Carolina State University, Raleigh NC 27695-7905, USA
- Biomanufacturing Training and Education Center (BTEC), North Carolina State University, Raleigh, NC 27695, United States
| | - Nathan Crook
- Department of Chemical Engineering, North Carolina State University, Raleigh NC 27695-7905, USA
| | - Scott T. Magness
- Department of Medicine, University of North Carolina at Chapel Hill, NC 27514, United States
| | - Carol K. Hall
- Department of Chemical Engineering, North Carolina State University, Raleigh NC 27695-7905, USA
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7
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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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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
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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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9
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Alawode DOT, Fox NC, Zetterberg H, Heslegrave AJ. Alzheimer’s Disease Biomarkers Revisited From the Amyloid Cascade Hypothesis Standpoint. Front Neurosci 2022; 16:837390. [PMID: 35573283 PMCID: PMC9091905 DOI: 10.3389/fnins.2022.837390] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2021] [Accepted: 04/04/2022] [Indexed: 11/25/2022] Open
Abstract
Alzheimer’s disease (AD) is the most common neurodegenerative disease worldwide. Amyloid beta (Aβ) is one of the proteins which aggregate in AD, and its key role in the disease pathogenesis is highlighted in the amyloid cascade hypothesis, which states that the deposition of Aβ in the brain parenchyma is a crucial initiating step in the future development of AD. The sensitivity of instruments used to measure proteins in blood and cerebrospinal fluid has significantly improved, such that Aβ can now successfully be measured in plasma. However, due to the peripheral production of Aβ, there is significant overlap between diagnostic groups. The presence of pathological Aβ within the AD brain has several effects on the cells and surrounding tissue. Therefore, there is a possibility that using markers of tissue responses to Aβ may reveal more information about Aβ pathology and pathogenesis than looking at plasma Aβ alone. In this manuscript, using the amyloid cascade hypothesis as a starting point, we will delve into how the effect of Aβ on the surrounding tissue can be monitored using biomarkers. In particular, we will consider whether glial fibrillary acidic protein, triggering receptor expressed on myeloid cells 2, phosphorylated tau, and neurofilament light chain could be used to phenotype and quantify the tissue response against Aβ pathology in AD.
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Affiliation(s)
- Deborah O. T. Alawode
- Department of Neurodegenerative Disease, UCL Queen Square Institute of Neurology, London, United Kingdom
- UK Dementia Research Institute at UCL, London, United Kingdom
- *Correspondence: Deborah O. T. Alawode,
| | - Nick C. Fox
- UK Dementia Research Institute at UCL, London, United Kingdom
- Department of Neurodegenerative Disease, Dementia Research Centre, UCL Queen Square Institute of Neurology, London, United Kingdom
| | - Henrik Zetterberg
- Department of Neurodegenerative Disease, UCL Queen Square Institute of Neurology, London, United Kingdom
- UK Dementia Research Institute at UCL, London, United Kingdom
- Department of Psychiatry and Neurochemistry, Institute of Neuroscience and Physiology, The Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
- Clinical Neurochemistry Laboratory, Sahlgrenska University Hospital, Mölndal, Sweden
| | - Amanda J. Heslegrave
- Department of Neurodegenerative Disease, UCL Queen Square Institute of Neurology, London, United Kingdom
- UK Dementia Research Institute at UCL, London, United Kingdom
- Amanda J. Heslegrave,
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Xiao X, Sarma S, Menegatti S, Crook N, Magness ST, Hall CK. In Silico Identification and Experimental Validation of Peptide-Based Inhibitors Targeting Clostridium difficile Toxin A. ACS Chem Biol 2022; 17:118-128. [PMID: 34965093 DOI: 10.1021/acschembio.1c00743] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
Clostridium difficile infection is mediated by two major exotoxins: toxins A (TcdA) and B (TcdB). Inhibiting the biocatalytic activities of these toxins with targeted peptide-based drugs can reduce the risk of C. difficile infection. In this work, we used a computational strategy that integrates a peptide binding design (PepBD) algorithm and explicit-solvent atomistic molecular dynamics simulation to determine promising toxin A-targeting peptides that can recognize and bind to the catalytic site of the TcdA glucosyltransferase domain (GTD). Our simulation results revealed that two out of three in silico discovered peptides, viz. the neutralizing peptides A (NPA) and B (NPB), exhibit lower binding free energies when bound to the TcdA GTD than the phage-display discovered peptide, viz. the reference peptide (RP). These peptides may serve as potential inhibitors against C. difficile infection. The efficacy of the peptides RP, NPA, and NPB to neutralize the cytopathic effects of TcdA was tested in vitro in human jejunum cells. Both phage-display peptide RP and in silico peptide NPA were found to exhibit strong toxin-neutralizing properties, thereby preventing the TcdA toxicity. However, the in silico peptide NPB demonstrates a relatively low efficacy against TcdA.
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Affiliation(s)
- Xingqing Xiao
- Department of Chemical and Biomolecular Engineering, North Carolina State University, Raleigh, North Carolina 27695, United States
| | - Sudeep Sarma
- Department of Chemical and Biomolecular Engineering, North Carolina State University, Raleigh, North Carolina 27695, United States
| | - Stefano Menegatti
- Department of Chemical and Biomolecular Engineering, North Carolina State University, Raleigh, North Carolina 27695, United States
- Biomanufacturing Training and Education Center (BTEC), North Carolina State University, Raleigh, North Carolina 27695, United States
| | - Nathan Crook
- Department of Chemical and Biomolecular Engineering, North Carolina State University, Raleigh, North Carolina 27695, United States
| | - Scott T Magness
- Department of Medicine, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27514, United States
| | - Carol K Hall
- Department of Chemical and Biomolecular Engineering, North Carolina State University, Raleigh, North Carolina 27695, United States
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11
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Absence of Toxemia in Clostridioides difficile Infection: Results from Ultrasensitive Toxin Assay of Serum. Dig Dis Sci 2021; 66:3303-3306. [PMID: 33164145 PMCID: PMC8105423 DOI: 10.1007/s10620-020-06683-8] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/13/2020] [Accepted: 10/15/2020] [Indexed: 12/18/2022]
Abstract
Clostridioides difficile infection (CDI) is caused by Toxins A and B, secreted from pathogenic strains of C. difficle. This infection can vary greatly in symptom severity and in clinical presentation. Current assays used to diagnose CDI may lack the required sensitivity to detect the exotoxins circulating in blood. The ultrasensitive single molecule array (Simoa) assay was modified to separately detect toxin A and toxin B in serum with a limit of detection at the low picogram level. When applied to a diverse cohort, Simoa was unable to detect toxins A or B in serum from patients with CDI, including many classified as having severe disease. The detection of toxin may be limited by the inference of antitoxin antibodies circulating in serum. This result does not support the hypothesis that toxemia occurs in C. difficile infection, conflicting with the findings of other published reports.
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12
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Mizusawa M, Carroll KC. The future of Clostridioides difficile diagnostics. Curr Opin Infect Dis 2021; 34:483-490. [PMID: 34524199 DOI: 10.1097/qco.0000000000000754] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
PURPOSE OF REVIEW Although the epidemiology of Clostridioides difficile has changed, this organism continues to cause significant morbidity and mortality. This review addresses current and future approaches to the diagnosis of C. difficile disease. RECENT FINDINGS Over the last several years, large prospective studies have confirmed that there is no single optimal test for the diagnosis of C. difficile disease. The pendulum has swung from a focus on rapid molecular diagnosis during the years of the ribotype 027 epidemic, to a call for use of algorithmic approaches that include a test for toxin detection. In addition, diagnostic stewardship has been shown to improve test utilization, especially with molecular methods. Advances in testing include development of ultrasensitive toxin tests and an expansion of biomarkers that may be more C. difficile specific. Microbiome research may be leveraged to inform novel diagnostic approaches based on measurements of volatile and nonvolatile organic compounds in stool. SUMMARY As rates of C. difficile infection decline, emphasis is now on improving test utilization and a quest for improved diagnostic approaches. These approaches may involve implementation of technologies that improve toxin testing, predict patients likely to have disease and/or a severe outcome, and harnessing research on changes in the microbiome to advance metabolomics.
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Affiliation(s)
- Masako Mizusawa
- Section of Infectious Diseases, Department of Internal Medicine, University of Missouri, Kansas City, Missouri
| | - Karen C Carroll
- Division of Medical Microbiology, The Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
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13
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Ingannato A, Bagnoli S, Mazzeo S, Bessi V, Matà S, Del Mastio M, Lombardi G, Ferrari C, Sorbi S, Nacmias B. Neurofilament Light Chain and Intermediate HTT Alleles as Combined Biomarkers in Italian ALS Patients. Front Neurosci 2021; 15:695049. [PMID: 34539331 PMCID: PMC8446383 DOI: 10.3389/fnins.2021.695049] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2021] [Accepted: 08/06/2021] [Indexed: 11/29/2022] Open
Abstract
Objective To study the possible implication of the two biomarkers, intermediate alleles (IAs) of the Huntingtin (HTT) gene and neurofilament light chain (NfL) levels in plasma, in amyotrophic lateral sclerosis (ALS) patients. Methods We analyzed IAs in a cohort of 106 Italian ALS patients and measured the plasma NfL levels in 20% of the patients of the cohort. We correlated the two biomarkers with clinical phenotypes. Results Intermediate alleles were present in 7.5% of the patients of our cohort, a frequency higher than that reported in general population. Plasma NfL levels increased with age at onset (p < 0.05). Patients with bulbar onset (BO) had higher plasma NfL concentration (CI −0.61 to −0.06, p = 0.02) and a later age at onset of the disease (CI −24.78 to −4.93, p = 0.006) with respect to the spinal onset (SO) form. Additionally, two of the patients, with IAs and plasma NfL concentration lower with respect to normal alleles’ carriers, presented an age at onset higher than the mean of the entire cohort. Conclusion According to our findings, plasma NfL and IAs of HTT gene may represent potential biomarkers in ALS, providing evidence of a possible implication in clinical phenotype.
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Affiliation(s)
| | - Silvia Bagnoli
- NEUROFARBA Department, University of Florence, Florence, Italy
| | | | - Valentina Bessi
- NEUROFARBA Department, University of Florence, Florence, Italy
| | - Sabrina Matà
- SOD Neurologia 1, Dipartimento Neuromuscolo-Scheletrico e Degli Organi di Senso, Azienda Ospedaliero Universitaria Careggi, Florence, Italy
| | - Monica Del Mastio
- SOD Neurologia 1, Dipartimento Neuromuscolo-Scheletrico e Degli Organi di Senso, Azienda Ospedaliero Universitaria Careggi, Florence, Italy
| | | | - Camilla Ferrari
- NEUROFARBA Department, University of Florence, Florence, Italy
| | - Sandro Sorbi
- NEUROFARBA Department, University of Florence, Florence, Italy.,IRCCS Fondazione Don Carlo Gnocchi, Florence, Italy
| | - Benedetta Nacmias
- NEUROFARBA Department, University of Florence, Florence, Italy.,IRCCS Fondazione Don Carlo Gnocchi, Florence, Italy
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14
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Alonso CD, Kelly CP, Garey KW, Gonzales-Luna AJ, Williams D, Daugherty K, Cuddemi C, Villafuerte-Gálvez J, White NC, Chen X, Xu H, Sprague R, Barrett C, Miller M, Foussadier A, Lantz A, Banz A, Pollock NR. Ultrasensitive and quantitative toxin measurement correlates with baseline severity, severe outcomes, and recurrence among hospitalized patients with Clostridioides difficile infection. Clin Infect Dis 2021; 74:2142-2149. [PMID: 34537841 DOI: 10.1093/cid/ciab826] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2021] [Indexed: 11/15/2022] Open
Abstract
BACKGROUND Stool toxin concentrations may impact Clostridioides difficile infection (CDI) severity and outcomes. We correlated fecal C. difficile toxin concentrations, measured by an ultrasensitive and quantitative assay, with CDI baseline severity, attributable outcomes, and recurrence. METHODS We enrolled 615 hospitalized adults (≥ 18y) with CDI (acute diarrhea, positive stool NAAT, and decision to treat). Baseline stool toxin A and B concentrations were measured by Single Molecule Array. Subjects were classified by baseline CDI severity (four scoring methods) and outcomes within 40 days (death, ICU stay, colectomy, and recurrence). RESULTS Among 615 patients (median 68.0 years), in all scoring systems, subjects with severe baseline disease had higher stool toxin A+B concentrations than those without (P<0.01). Nineteen subjects (3.1%) had a severe outcome primarily-attributed to CDI (group 1). This group had higher median toxin A+B [14,303 pg/mL (IQR 416.0, 141,967)] than subjects in whom CDI only contributed to the outcome [group 2, 163.2 pg/mL(0.0, 8423.3)], subjects with severe outcome unrelated to CDI [group 3, 158.6 pg/mL (0.0, 1795.2)], or no severe outcome [group 4, 209.5 pg/mL (0.0, 8566.3)](P=0.003). Group 1 was more likely to have detectable toxin (94.7%) than groups 2-4 (60.5-66.1%)(P=0.02). Individuals with recurrence had higher toxin A+B [2266.8 pg/mL(188.8, 29411)] than those without [154.0 pg/mL(0.0, 5864.3)](P<0.001) and higher rates of detectable toxin (85.7% versus 64.0%, P=0.004). CONCLUSIONS In CDI patients, ultrasensitive stool toxin detection and concentration correlated with severe baseline disease, severe CDI-attributable outcomes, and recurrence, confirming the contribution of toxin quantity to disease presentation and clinical course.
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Affiliation(s)
- Carolyn D Alonso
- Division of Infectious Disease, Department of Medicine, Beth Israel Deaconess Medical Center, Boston, MA, USA.,Harvard Medical School, Boston, MA, USA
| | - Ciarán P Kelly
- Harvard Medical School, Boston, MA, USA.,Division of Gastroenterology, Department of Medicine, Beth Israel Deaconess Medical Center, Boston, MA, USA
| | - Kevin W Garey
- Department of Pharmacy Practice and Translational Research, University of Houston College, of Pharmacy, Houston, TX, USA
| | - Anne J Gonzales-Luna
- Department of Pharmacy Practice and Translational Research, University of Houston College, of Pharmacy, Houston, TX, USA
| | - David Williams
- Institutional Centers for Clinical and Translational Research, Boston Children's Hospital, Boston, MA, USA
| | - Kaitlyn Daugherty
- Division of Gastroenterology, Department of Medicine, Beth Israel Deaconess Medical Center, Boston, MA, USA
| | - Christine Cuddemi
- Division of Gastroenterology, Department of Medicine, Beth Israel Deaconess Medical Center, Boston, MA, USA
| | - Javier Villafuerte-Gálvez
- Division of Gastroenterology, Department of Medicine, Beth Israel Deaconess Medical Center, Boston, MA, USA
| | - Nicole C White
- Division of Infectious Disease, Department of Medicine, Beth Israel Deaconess Medical Center, Boston, MA, USA
| | - Xinhua Chen
- Division of Gastroenterology, Department of Medicine, Beth Israel Deaconess Medical Center, Boston, MA, USA
| | - Hua Xu
- Division of Gastroenterology, Department of Medicine, Beth Israel Deaconess Medical Center, Boston, MA, USA
| | - Rebecca Sprague
- Division of Infectious Disease, Department of Medicine, Beth Israel Deaconess Medical Center, Boston, MA, USA.,Division of Gastroenterology, Department of Medicine, Beth Israel Deaconess Medical Center, Boston, MA, USA
| | - Caitlin Barrett
- Division of Infectious Disease, Department of Medicine, Beth Israel Deaconess Medical Center, Boston, MA, USA.,Division of Gastroenterology, Department of Medicine, Beth Israel Deaconess Medical Center, Boston, MA, USA
| | | | | | | | | | - Nira R Pollock
- Division of Infectious Disease, Department of Medicine, Beth Israel Deaconess Medical Center, Boston, MA, USA.,Harvard Medical School, Boston, MA, USA.,Department of Laboratory Medicine, Boston Children's Hospital, Boston, Massachusetts, USA
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15
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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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16
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Alonso CD, Papamichael K, Sprague R, Barrett C, Gonzales-Luna AJ, Daugherty K, Garey KW, Villafuerte-Gálvez J, Xu H, Lin Q, Wang L, Chen X, Pollock NR, Kelly CP. Humoral Immune Response to Clostridioides difficile Toxins A and B in Hospitalized Immunocompromised Patients With C difficile Infection. Open Forum Infect Dis 2021; 8:ofab286. [PMID: 34258317 PMCID: PMC8271131 DOI: 10.1093/ofid/ofab286] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2021] [Accepted: 05/26/2021] [Indexed: 11/14/2022] Open
Abstract
Background The humoral immune response to Clostridioides difficile toxins in C difficile infection (CDI) is incompletely characterized in immunocompromised hosts (ICHs). Methods We conducted a prospective study of hospitalized adults with CDI, with and without immunosuppression (hematologic malignancy, active solid tumor, solid organ or stem cell transplant, inflammatory bowel disease, autoimmune disease, congenital or acquired immunodeficiency, asplenia, chronic receipt of high-dose steroids, or receipt of immunosuppressing medications within 12 months). Serum and stool antibody concentrations of immunoglobulin (Ig)M, IgG, and IgA to C difficile toxins A and B at treatment days 0, 3, and 10–14 were compared. Results Ninety-eight subjects (47 ICH; 51 non-ICH) were enrolled. Baseline serum antitoxin A and B antibody levels were similar. At day 3, ICHs demonstrated lower serum levels of antitoxin A IgG, antitoxin A IgA, and antitoxin B IgA (all P < .05). At day 10–14, lower antitoxin A IgG concentrations were observed in ICHs (ICH, 21 enzyme-linked immunosorbent assay [ELISA] units; interquartile range [IQR], 16.4–44.6) compared with non-ICH subjects (49.0 ELISA units; IQR, 21.5–103; P = .045). In stool, we observed lower concentrations of antitoxin B IgA antibodies at baseline and at day 3 for ICH subjects, with a notable difference in concentrations of antitoxin B IgA at day 3 (ICH, 6.7 ELISA units [IQR, 1.9–13.9] compared with non-ICH, 18.1 ELISA units [IQR, 4.9–31.7]; P = .003). Conclusions The ICHs with CDI demonstrated lower levels of C difficile antitoxin antibodies in serum and stool during early CDI therapy compared with non-ICHs. These data provide insight into the humoral response to CDI in ICHs.
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Affiliation(s)
- Carolyn D Alonso
- Division of Infectious Diseases, Department of Medicine, Beth Israel Deaconess Medical Center, Boston, Massachusetts, USA.,Harvard Medical School, Boston, Massachusetts, USA
| | - Konstantinos Papamichael
- Harvard Medical School, Boston, Massachusetts, USA.,Division of Gastroenterology, Department of Medicine, Beth Israel Deaconess Medical Center, Boston, Massachusetts, USA
| | - Rebecca Sprague
- Division of Infectious Diseases, Department of Medicine, Beth Israel Deaconess Medical Center, Boston, Massachusetts, USA.,Harvard Medical School, Boston, Massachusetts, USA.,Division of Gastroenterology, Department of Medicine, Beth Israel Deaconess Medical Center, Boston, Massachusetts, USA
| | - Caitlin Barrett
- Division of Infectious Diseases, Department of Medicine, Beth Israel Deaconess Medical Center, Boston, Massachusetts, USA.,Harvard Medical School, Boston, Massachusetts, USA.,Division of Gastroenterology, Department of Medicine, Beth Israel Deaconess Medical Center, Boston, Massachusetts, USA
| | - Anne J Gonzales-Luna
- Department of Pharmacy Practice and Translational Research, University of Houston College of Pharmacy, Houston, Texas, USA
| | - Kaitlyn Daugherty
- Division of Gastroenterology, Department of Medicine, Beth Israel Deaconess Medical Center, Boston, Massachusetts, USA
| | - Kevin W Garey
- Department of Pharmacy Practice and Translational Research, University of Houston College of Pharmacy, Houston, Texas, USA
| | - Javier Villafuerte-Gálvez
- Division of Gastroenterology, Department of Medicine, Beth Israel Deaconess Medical Center, Boston, Massachusetts, USA
| | - Hua Xu
- Division of Gastroenterology, Department of Medicine, Beth Israel Deaconess Medical Center, Boston, Massachusetts, USA
| | - Qianyun Lin
- Department of Gastroenterology, Beijing Friendship Hospital, Capital Medical University, Beijing, China
| | - Lamei Wang
- Division of Gastroenterology, Department of Medicine, Beth Israel Deaconess Medical Center, Boston, Massachusetts, USA.,College of Animal Science and Technology, Northwest A&F University, Yangling, Shaanxi Province, China
| | - Xinhua Chen
- Division of Gastroenterology, Department of Medicine, Beth Israel Deaconess Medical Center, Boston, Massachusetts, USA
| | - Nira R Pollock
- Division of Infectious Diseases, Department of Medicine, Beth Israel Deaconess Medical Center, Boston, Massachusetts, USA.,Harvard Medical School, Boston, Massachusetts, USA.,Department of Laboratory Medicine, Boston Children's Hospital, Boston, Massachusetts, USA
| | - Ciarán P Kelly
- Harvard Medical School, Boston, Massachusetts, USA.,Division of Gastroenterology, Department of Medicine, Beth Israel Deaconess Medical Center, Boston, Massachusetts, USA
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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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18
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Kohyama A, Watanabe K, Sugita A, Futami K, Ikeuchi H, Takahashi KI, Suzuki Y, Fukushima K. Ulcerative colitis-related severe enteritis: an infrequent but serious complication after colectomy. J Gastroenterol 2021; 56:240-249. [PMID: 33155079 DOI: 10.1007/s00535-020-01742-3] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/06/2020] [Accepted: 10/19/2020] [Indexed: 02/07/2023]
Abstract
BACKGROUND AND AIM After colectomy for ulcerative colitis (UC), very severe and sometimes lethal enteritis can develop. However, the clinical features remain uncertain because of the low incidence, diversity of symptoms, and undefined diagnostic criteria. The aim of this study was to define postoperative ulcerative colitis-related severe enteritis (UCRSE) and to investigate its clinical features. METHODS A retrospective multicenter study was performed as a survey of major medical facilities utilizing surgical supplies for inflammatory bowel disease in Japan from 2001 to 2014. UCRSE was defined as a case with massive intestinal bleeding, intestinal perforation, high-output stoma, and/or a requirement for medications, such as steroids and biologics. Patients with gastroduodenal lesions or pouchitis alone were excluded. The incidence, symptoms, involvement of bacteria, cytomegalovirus reactivation, treatment, and prognosis were examined for patients with UCRSE after colectomy. RESULTS Forty-two (0.8%) out of 5284 cases met the criteria for UCRSE. Major symptoms were massive intestinal bleeding (76.2%), which required a median of 3850 (560-18900) mL blood transfusion; high-output stoma (38.1%) with excretion of fluid of 5000 (2000-7800) mL/day; and intestinal perforation (7.1%). Hypovolemic shock (35.7%) and/or disseminated intravascular coagulation (31.0%) developed as serious complications. Tests for cytomegalovirus reactivation were positive in 26.2% of cases. The presence of pathogenic bacteria was confirmed in only 5 cases. Corticosteroids or infliximabs were effective in half of the patients. Thirteen cases (31.0%) were treated surgically and 22 cases (56.4%) required maintenance therapy. The mortality rate was 11.9%. CONCLUSION UCRSE is a rare but serious complication after colectomy and is sometimes life-threatening.
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Affiliation(s)
- Atsushi Kohyama
- Department of Surgery, Tohoku University Graduate School of Medicine, 1-1 Seiryo-machi, Aoba-ku, Sendai, 980-8574, Japan.
| | - Kazuhiro Watanabe
- Department of Surgery, Tohoku University Graduate School of Medicine, 1-1 Seiryo-machi, Aoba-ku, Sendai, 980-8574, Japan
| | - Akira Sugita
- Department of Inflammatory Bowel Disease, Yokohama Municipal Citizen's Hospital, Yokohama, Japan
| | - Kitaro Futami
- Department of Surgery, Fukuoka University, Chikushi Hospital, Fukuoka, Japan
| | - Hiroki Ikeuchi
- Department of Inflammatory Bowel Disease, Hyogo College of Medicine, Nishinomiya, Japan
| | | | - Yasuo Suzuki
- Inflammatory Bowel Disease Center, Toho University Sakura Medical Center, Sakura, Japan
| | - Kouhei Fukushima
- Division of Surgical and Molecular Pathophysiology, Tohoku University Graduate School of Medicine, Sendai, Japan
- Laboratory of Gastrointestinal Tract Reconstruction, Tohoku University Graduate School of Biomedical Engineering, Sendai, Japan
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19
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Lin Q, Pollock NR, Banz A, Lantz A, Xu H, Gu L, Gerding DN, Garey KW, Gonzales-Luna AJ, Zhao M, Song L, Duffy DC, Kelly CP, Chen X. Toxin A-Predominant Pathogenic Clostridioides difficile: A Novel Clinical Phenotype. Clin Infect Dis 2021; 70:2628-2633. [PMID: 31400280 DOI: 10.1093/cid/ciz727] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2019] [Accepted: 07/30/2019] [Indexed: 02/06/2023] Open
Abstract
BACKGROUND Most Clostridioides difficile toxinogenic strains produce both toxins A and B (A+B+), but toxin A-negative, toxin B-positive (A-B+) variants also cause disease. We report the identification of a series of pathogenic clinical C. difficile isolates that produce high amounts of toxin A with low or nondetectable toxin B. METHODS An ultrasensitive, quantitative immunoassay was used to measure toxins A and B in stool samples from 187 C. difficile infection (CDI) patients and 44 carriers. Isolates were cultured and assessed for in vitro toxin production and in vivo phenotypes (mouse CDI model). RESULTS There were 7 CDI patients and 6 carriers who had stools with detectable toxin A (TcdA, range 23-17 422 pg/mL; 5.6% of samples overall) but toxin B (TcdB) below the clinical detection limit (<20 pg/mL; median TcdA:B ratio 17.93). Concentrations of toxin A far exceeded B in in vitro cultures of all 12 recovered isolates (median TcdA:B ratio 26). Of 8 toxin A>>B isolates tested in mice, 4 caused diarrhea, and 3 of those 4 caused lethal disease. Ribotyping demonstrated strain diversity. TcdA-predominant samples were also identified at 2 other centers, with similar frequencies (7.5% and 6.8%). CONCLUSIONS We report the discovery of clinical pathogenic C. difficile strains that produce high levels of toxin A but minimal or no toxin B. This pattern of toxin production is not rare (>5% of isolates) and is consistently observed in vitro and in vivo in humans and mice. Our study highlights the significance of toxin A in human CDI pathogenesis and has important implications for CDI diagnosis, treatment, and vaccine development.
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Affiliation(s)
- Qianyun Lin
- Guangdong Provincial Key Laboratory of Gastroenterology, Department of Gastroenterology, Nanfang Hospital, Southern Medical University, Guangzhou, China.,Divisions of Gastroenterology, Massachusetts
| | - Nira R Pollock
- Infectious Diseases, Beth Israel Deaconess Medical Center, Massachusetts.,Department of Laboratory Medicine, Boston Children's Hospital, Massachusetts
| | | | | | - Hua Xu
- Divisions of Gastroenterology, Massachusetts
| | - Limei Gu
- Divisions of Gastroenterology, Massachusetts
| | - Dale N Gerding
- Department of Veterans Affairs, Edward Hines Jr Veterans Affairs Hospital, Hines, Illinois
| | - Kevin W Garey
- Department of Pharmacy Practice and Translational Research, University of Houston College of Pharmacy, Texas
| | - Anne J Gonzales-Luna
- Department of Pharmacy Practice and Translational Research, University of Houston College of Pharmacy, Texas
| | | | | | | | | | - Xinhua Chen
- Divisions of Gastroenterology, Massachusetts
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20
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Kelly CP, Chen X, Williams D, Xu H, Cuddemi CA, Daugherty K, Barrett C, Miller M, Foussadier A, Lantz A, Banz A, Pollock NR. Host Immune Markers Distinguish Clostridioides difficile Infection From Asymptomatic Carriage and Non-C. difficile Diarrhea. Clin Infect Dis 2021; 70:1083-1093. [PMID: 31211839 DOI: 10.1093/cid/ciz330] [Citation(s) in RCA: 26] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2019] [Accepted: 04/22/2019] [Indexed: 12/18/2022] Open
Abstract
BACKGROUND Recent data indicate that Clostridioides difficile toxin concentrations in stool do not differentiate between C. difficile infection (CDI) and asymptomatic carriage. Thus, we lack a method to distinguish a symptomatic patient with CDI from a colonized patient with diarrhea from another cause. To address this, we evaluated markers of innate and adaptive immunity in adult inpatients with CDI (diagnosed per US guidelines), asymptomatic carriage, or non-CDI diarrhea. METHODS CDI-NAAT patients had clinically significant diarrhea and positive nucleic acid amplification testing (NAAT) and received CDI treatment. Carrier-NAAT patients had positive stool NAAT but no diarrhea. NAAT-negative patients (with and without diarrhea) were also enrolled. A panel of cytokines and anti-toxin A and B immunoglobulin (Ig) were measured in serum; calprotectin and anti-toxin B Ig A/G were measured in stool. NAAT-positive stool samples were tested by an ultrasensitive toxin assay (clinical cutoff, 20 pg/mL). RESULTS Median values for interleukin (IL)-4, IL-6, IL-8, IL-10, IL-15, granulocyte colony-stimulating factor (GCSF), MCP-1, tumor necrosis factor α (TNF-α), and IgG anti-toxin A in blood and IgA/G anti-toxin B in stool were significantly higher in CDI patients compared with all other groups (P < .05). Concentration distributions for IL-6, GCSF, TNF-α, and IgG anti-toxin A in blood, as well as IgA and IgG anti-toxin B in stool, separated CDI patients from all other groups. CONCLUSIONS Specific markers of innate and adaptive immunity distinguish CDI from all other groups, suggesting potential clinical utility for identifying which NAAT- and toxin-positive patients with diarrhea truly have CDI.
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Affiliation(s)
- Ciaran P Kelly
- Division of Gastroenterology, Department of Medicine, Beth Israel Deaconess Medical Center, Massachusetts
| | - Xinhua Chen
- Division of Gastroenterology, Department of Medicine, Beth Israel Deaconess Medical Center, Massachusetts
| | - David Williams
- Institutional Centers for Clinical and Translational Research, Boston Children's Hospital, Massachusetts
| | - Hua Xu
- Division of Gastroenterology, Department of Medicine, Beth Israel Deaconess Medical Center, Massachusetts
| | - Christine A Cuddemi
- Division of Gastroenterology, Department of Medicine, Beth Israel Deaconess Medical Center, Massachusetts
| | - Kaitlyn Daugherty
- Division of Gastroenterology, Department of Medicine, Beth Israel Deaconess Medical Center, Massachusetts
| | - Caitlin Barrett
- Division of Gastroenterology, Department of Medicine, Beth Israel Deaconess Medical Center, Massachusetts
| | | | | | | | | | - Nira R Pollock
- Division of Infectious Disease, Department of Medicine, Beth Israel Deaconess Medical Center.,Department of Laboratory Medicine, Boston Children's Hospital, Massachusetts
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21
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Kan CW, Tobos CI, Rissin DM, Wiener AD, Meyer RE, Svancara DM, Comperchio A, Warwick C, Millington R, Collier N, Duffy DC. Digital enzyme-linked immunosorbent assays with sub-attomolar detection limits based on low numbers of capture beads combined with high efficiency bead analysis. LAB ON A CHIP 2020; 20:2122-2135. [PMID: 32391827 DOI: 10.1039/d0lc00267d] [Citation(s) in RCA: 40] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
We report the development of digital enzyme-linked immunosorbent assays (ELISAs) based on single molecule arrays (Simoa) with improved sensitivities over conventional digital ELISA, enabling detection of proteins at sub-attomolar concentrations. The improvements in sensitivity were based on using fewer beads to capture the target proteins (≤5000 vs.∼500 000 beads) that increased the ratio of molecules to beads, and increasing the fraction of beads that were analyzed (bead read efficiency) from ∼5% to ∼50%. Bead read efficiency was increased by: a) improving the loading of beads into arrays of microwells by combining capillary and magnetic forces in a method called magnetic-meniscus sweeping (MMS); b) using a centrifugal washer to minimize bead loss during the assay; and, c) improved optics and image analysis to enable the analysis of more microwells. Using this approach, we developed an assay for IL-17A with a limit of detection (LOD) of 0.7 aM, 437-fold more sensitive than standard digital ELISA. A digital ELISA with improved sensitivity was used to measure IL-17A in 100 serum and plasma samples with 100% detectability, compared to 51% for standard digital ELISA. Low numbers of capture beads yielded improved LODs for IL-12p70 (0.092 aM), p24 (9.1 aM), and interferon alpha (45.9 aM). IL-4 and PSA showed no improvements in sensitivity using fewer beads, primarily due to low antibody loading on beads and increased non-specific binding, respectively. The results were consistent with a kinetic model of binding that showed that combining capture antibodies with high on-rates with high antibodies per bead yields the greatest improvement in sensitivity.
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Affiliation(s)
- Cheuk W Kan
- Quanterix Corporation, 900 Middlesex Turnpike, Billerica, MA 01821, USA.
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Ultrasensitive Clostridioides difficile Toxin Testing for Higher Diagnostic Accuracy. J Clin Microbiol 2020; 58:JCM.01913-19. [PMID: 32269098 DOI: 10.1128/jcm.01913-19] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Abstract
Currently available diagnostic tests for Clostridioides difficile infection (CDI) lack specificity or sensitivity, which has led to guideline recommendations for multistep testing algorithms. Ultrasensitive assays for detection of C. difficile toxins provide measurements of disease-specific markers at very low concentrations. These assays may show improved accuracy compared to that of current testing methods and offer a potential standalone solution for CDI diagnosis, although large studies of clinical performance and accuracy are lacking.
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Emberger J, Hitchcock MM, Markley JD. Diagnostic Stewardship Approaches to Clostridioides difficile Infection in the Era of Two-Step Testing: a Shifting Landscape. CURRENT TREATMENT OPTIONS IN INFECTIOUS DISEASES 2020. [DOI: 10.1007/s40506-020-00223-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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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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Boly FJ, Reske KA, Kwon JH. The Role of Diagnostic Stewardship in Clostridioides difficile Testing: Challenges and Opportunities. Curr Infect Dis Rep 2020; 22:7. [PMID: 33762897 PMCID: PMC7987129 DOI: 10.1007/s11908-020-0715-4] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
PURPOSE OF REVIEW Accurate and timely diagnosis of Clostridioides difficile infection (CDI) is imperative to prevent C. difficile transmission and reduce morbidity and mortality due to CDI, but CDI laboratory diagnostics are complex. The purpose of this article is to review the role of laboratory tests in the diagnosis of CDI, and the role of diagnostic stewardship in optimization of C. difficile testing. RECENT FINDINGS Results from C. difficile diagnostic tests should be interpreted with an understanding of the strengths and limitations inherent in each testing approach. Use of highly sensitive molecular diagnostic tests without accounting for clinical signs and symptoms may lead to over-diagnosis of CDI and increased facility CDI rates. Current guidelines recommend a two-step, algorithmic approach for testing. Diagnostic stewardship interventions, such as education, order sets, order search menus, reflex orders, hard and soft stop alerts, electronic references, feedback and benchmarking, decision algorithms, and predictive analytics may help improve use of C. difficile laboratory tests and CDI diagnosis. The diagnostic stewardship approaches with the highest reported success rates include computerized clinical decision support (CCDS) interventions, face-to-face feedback, and real-time evaluations. SUMMARY CDI is a clinical diagnosis supported by laboratory findings. Together, clinical evaluation combined with diagnostic stewardship can optimize the accurate diagnosis of CDI.
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Carroll KC, Mizusawa M. Laboratory Tests for the Diagnosis of Clostridium difficile. Clin Colon Rectal Surg 2020; 33:73-81. [PMID: 32104159 PMCID: PMC7042017 DOI: 10.1055/s-0039-3400476] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Clostridium (reclassified as " Clostridioides ") difficile is an anaerobic, gram-positive bacterium that causes significant disease through elaboration of two potent toxins in patients whose normal gut microbiota has been altered through antimicrobial or chemotherapeutic agents (dysbiosis). The optimum method of laboratory diagnosis is still somewhat controversial. Recent practice guidelines published by professional societies recommend a two-step approach beginning with a test for glutamate dehydrogenase (GDH), followed by a toxin test and/or a nucleic acid test. Alternatively, in institutions where established clinical algorithms guide testing, a nucleic acid test alone is acceptable. Nucleic acid tests are the methods of choice in approximately 50% of laboratories in the United States. These tests are considered as the most sensitive methods for detection of C. difficile in stool and are the least specific. Because of the lower specificity with nucleic acid tests, some clinicians believe that toxin enzyme immunoassays are better predictors of disease, despite their known poor performance in certain patient populations. This review will discuss the advantages and disadvantages of the currently available test methods for the diagnosis of C. difficile with a brief mention of some novel assays that are currently in clinical trials.
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Affiliation(s)
- Karen C. Carroll
- Division of Medical Microbiology, Department of Pathology, the Johns Hopkins University School of Medicine, Baltimore, Maryland
- Address for correspondence Karen C. Carroll, MD Division of Medical Microbiology, Department of Pathology, the Johns Hopkins University School of MedicineMeyer B1-193, 600 North Wolfe Street, Baltimore MD 21287
| | - Masako Mizusawa
- Section of Infectious Diseases, Department of Internal Medicine, University of Missouri, Kansas City, Missouri
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Duffy DC. Short Keynote Paper: Single Molecule Detection of Protein Biomarkers to Define the Continuum From Health to Disease. IEEE J Biomed Health Inform 2020; 24:1864-1868. [PMID: 32031955 DOI: 10.1109/jbhi.2020.2971553] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
This paper describes the need for technologies that improve analytical sensitivity to proteins to better define and monitor the progression from heath to disease over the course of an individual's life. These technologies have the potential to allow the early diagnosis of disease, and trigger treatments at the time when they have the greatest opportunity to be effective. We will describe a technology that we have developed for high sensitivity protein detection, namely, single molecule arrays (Simoa). Simoa is based on the capture of protein molecules on magnetic beads, labeling each protein with an enzyme, and counting of single enzyme labels on beads that are isolated in arrays of femtoliter wells. Simoa has enabled the detection of proteins at subfemtomolar concentrations in a variety of biological fluids. We describe the impact of higher sensitivity of proteins using Simoa on: less invasive testing; earlier detection of disease; providing biomarker baseline profiles for healthy individuals; testing of small sample volumes; monitoring of therapeutic efficacy; faster tests; and detection of proteins in complex samples. We also provide a perspective of how new technologies that allow the low-cost manufacture and miniaturization of Simoa could drive the next wave of analytical devices, including wearables.
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Pollock NR, Banz A, Chen X, Williams D, Xu H, Cuddemi CA, Cui AX, Perrotta M, Alhassan E, Riou B, Lantz A, Miller MA, Kelly CP. Comparison of Clostridioides difficile Stool Toxin Concentrations in Adults With Symptomatic Infection and Asymptomatic Carriage Using an Ultrasensitive Quantitative Immunoassay. Clin Infect Dis 2020; 68:78-86. [PMID: 29788296 DOI: 10.1093/cid/ciy415] [Citation(s) in RCA: 40] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2018] [Accepted: 05/09/2018] [Indexed: 12/18/2022] Open
Abstract
Background We used an ultrasensitive, quantitative single molecule array (Simoa) immunoassay to test whether concentrations of Clostridioides (formerly Clostridium) difficile toxins A and/or B in the stool of adult inpatients with C. difficile infection (CDI) were higher than in asymptomatic carriers of toxinogenic C. difficile. Methods Patients enrolled as CDI-NAAT had clinically significant diarrhea and a positive nucleic acid amplification test (NAAT), per US guidelines, and received CDI treatment. Potential carriers had recently received antibiotics and did not have diarrhea; positive NAAT confirmed carriage. Baseline stool samples were tested by Simoa for toxin A and B. Results Stool toxin concentrations in both CDI-NAAT (n = 122) and carrier-NAAT (n = 44) cohorts spanned 5 logs (0 pg/mL to >100000 pg/mL). Seventy-nine of 122 (65%) CDI-NAAT and 34 of 44 (77%) carrier-NAAT had toxin A + B concentration ≥20 pg/mL (clinical cutoff). Median toxin A, toxin B, toxin A + B, and NAAT cycle threshold (Ct) values in CDI-NAAT and carrier-NAAT cohorts were similar (toxin A, 50.6 vs 60.0 pg/mL, P = .958; toxin B, 89.5 vs 42.3 pg/mL, P = .788; toxin A + B, 197.2 vs 137.3 pg/mL, P = .766; Ct, 28.1 vs 28.6, P = .354). However, when CDI/carrier cohorts were limited to those with detectable toxin, respective medians were significantly different (A: 874.0 vs 129.7, P = .021; B: 1317.0 vs 81.7, P = .003, A + B, 4180.7 vs 349.6, P = .004; Ct, 25.8 vs 27.7, P = .015). Conclusions Toxin concentration did not differentiate an individual with CDI from one with asymptomatic carriage. Median stool toxin concentrations in groups with CDI vs carriage differed, but only when groups were defined by detectable stool toxin (vs positive NAAT).
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Affiliation(s)
- Nira R Pollock
- Divisions of Infectious Disease and Gastroenterology, Department of Medicine, Beth Israel Deaconess Medical Center, Boston.,Department of Laboratory Medicine, Boston Children's Hospital, Massachusetts
| | | | - Xinhua Chen
- Divisions of Infectious Disease and Gastroenterology, Department of Medicine, Beth Israel Deaconess Medical Center, Boston
| | - David Williams
- Institutional Centers for Clinical and Translational Research, Boston Children's Hospital, Massachusetts
| | - Hua Xu
- Divisions of Infectious Disease and Gastroenterology, Department of Medicine, Beth Israel Deaconess Medical Center, Boston
| | - Christine A Cuddemi
- Divisions of Infectious Disease and Gastroenterology, Department of Medicine, Beth Israel Deaconess Medical Center, Boston
| | - Alice X Cui
- Divisions of Infectious Disease and Gastroenterology, Department of Medicine, Beth Israel Deaconess Medical Center, Boston
| | - Matthew Perrotta
- Divisions of Infectious Disease and Gastroenterology, Department of Medicine, Beth Israel Deaconess Medical Center, Boston
| | - Eaman Alhassan
- Divisions of Infectious Disease and Gastroenterology, Department of Medicine, Beth Israel Deaconess Medical Center, Boston
| | | | | | | | - Ciaran P Kelly
- Divisions of Infectious Disease and Gastroenterology, Department of Medicine, Beth Israel Deaconess Medical Center, Boston
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Abstract
Clostridioides difficile (formerly Clostridium) is a major cause of healthcare associated diarrhea, and is increasingly present in the community. Historically, C difficile infection was considered easy to diagnose and treat. Over the past two decades, however, diagnostic techniques have changed in line with a greater understanding of the physiopathology of C difficile infection and the use of new therapeutic molecules. The evolution of diagnosis showed there was an important under- and misdiagnosis of C difficile infection, emphasizing the importance of algorithms recommended by European and North American infectious diseases societies to obtain a reliable diagnosis. Previously, metronidazole was considered the reference drug to treat C difficile infection, but more recently vancomycin and other newer drugs are shown to have higher cure rates. Recurrence of infection represents a key parameter in the evaluation of new drugs, and the challenge is to target the right population with the adapted therapeutic molecule. In multiple recurrences, fecal microbiota transplantation is recommended. New approaches, including antibodies, vaccines, and new molecules are already available or in the pipeline, but more data are needed to support the inclusion of these in practice guidelines. This review aims to provide a baseline for clinicians to understand and stratify their choice in the diagnosis and treatment of C difficile infection based on the most recent data available.
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Affiliation(s)
- Benoit Guery
- Infectious Diseases Service, Department of Medicine, University Hospital and University of Lausanne, Lausanne, Switzerland
- French Group of Faecal Microbiota Transplantation
- European Study Group on Host and Microbiota Interactions
- European Study Group on Clostridium difficile
| | - Tatiana Galperine
- Infectious Diseases Service, Department of Medicine, University Hospital and University of Lausanne, Lausanne, Switzerland
- French Group of Faecal Microbiota Transplantation
| | - Frédéric Barbut
- National Reference Laboratory for Clostridium difficile, Paris, France
- INSERM, Faculté de Pharmacie de Paris, Université Paris Descartes, Paris, France
- European Study Group on Clostridium difficile
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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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Poorbaugh J, Samanta T, Bright SW, Sissons SE, Chang CY, Oberoi P, MacDonald AJ, Martin AP, Cox KL, Benschop RJ. Measurement of IL-21 in human serum and plasma using ultrasensitive MSD S-PLEX® and Quanterix SiMoA methodologies. J Immunol Methods 2018; 466:9-16. [PMID: 30590020 DOI: 10.1016/j.jim.2018.12.005] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2018] [Revised: 12/21/2018] [Accepted: 12/21/2018] [Indexed: 11/18/2022]
Abstract
IL-21 is a pleiotropic cytokine that plays a key role in modulating inflammatory responses, including the promotion of autoimmune diseases. Several groups have quantitated circulating levels of IL-21 in plasma and serum samples using various commercial ELISAs. We determined, however, that the most commonly used commercial assays in published literature were not specific or sensitive enough to detect levels of IL-21 in heparin plasma or serum from healthy human individuals. This finding prompted an effort to develop more specific and sensitive methods to quantitate IL-21 in complex biological matrices using proprietary anti-IL-21 antibodies with the Quanterix SiMoA platform and the Meso Scale Discovery (MSD) S-PLEX® format. Assays developed on both technology platforms were characterized in heparin plasma and serum using spike recoveries across a range of concentrations. Each method was able to detect sub-pg/mL levels of IL-21 (predicted Limit of Detection [LOD] of approximately 1.0 fg/mL for both the Quanterix SiMoA and MSD S-PLEX® platforms) which is 200-500 times lower than current commercial assays. Additionally we demonstrated that rheumatoid factor did not interfere with measuring IL-21 in the Quanterix SiMoA assay. Results obtained with the two new ultrasensitive assays showed a strong correlation (r = 0.9428; p < .0001). Additionally, IL-21 levels were significantly increased in samples from patients with Systemic Lupus Erythematosus (mean+/- SD: n = 14, 202.64 +/- 111.47 fg/mL, p = .0001 for Quanterix SiMoA and 275.4 +/- 174.66 fg/mL p = .0001 for MSD S-PLEX®) as well as in samples from patients with Sjögren's Syndrome (mean+/- SD: n = 11, 122.18 +/- 84.50 fg/mL, p = .0029 for Quanterix SiMoA and 183.64 +/- 153.00 fg/mL, p = .0082 for MSD S-PLEX®) when compared to healthy donors (mean+/- SD: n = 11, 38.1 +/- 27.8 fg/mL for Quanterix SiMoA and 58.1 +/- 30.7 fg/mL for MSD S-PLEX®). These ultrasensitive assays, for the first time, allow for the accurate quantitation of human IL-21 in heparin plasma and serum. In addition, these experiments also provide a direct comparison of the MSD S-PLEX® format and Quanterix SiMoA platform technologies, which may have broader implications to future application of these methods to evaluate low abundance proteins in complex biological matrices.
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Affiliation(s)
- Josh Poorbaugh
- Immunology Discovery, Eli Lilly and Company, Indianapolis, IN 46285, USA.
| | - Tanushree Samanta
- Immunology Discovery, Eli Lilly and Company, Indianapolis, IN 46285, USA
| | - Stuart W Bright
- Immunology Discovery, Eli Lilly and Company, Indianapolis, IN 46285, USA
| | - Sean E Sissons
- Immunology Discovery, Eli Lilly and Company, Indianapolis, IN 46285, USA
| | - Ching-Yun Chang
- Immunology Discovery, Eli Lilly and Company, Indianapolis, IN 46285, USA
| | | | - Angus J MacDonald
- Immunology Discovery, Eli Lilly and Company, Indianapolis, IN 46285, USA
| | - Andrea P Martin
- Immunology Discovery, Eli Lilly and Company, Indianapolis, IN 46285, USA
| | - Karen L Cox
- Immunology Discovery, Eli Lilly and Company, Indianapolis, IN 46285, USA
| | - Robert J Benschop
- Immunology Discovery, Eli Lilly and Company, Indianapolis, IN 46285, USA
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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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Sensitivity of Single-Molecule Array Assays for Detection of Clostridium difficile Toxins in Comparison to Conventional Laboratory Testing Algorithms. J Clin Microbiol 2018; 56:JCM.00452-18. [PMID: 29898996 PMCID: PMC6062787 DOI: 10.1128/jcm.00452-18] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2018] [Accepted: 06/01/2018] [Indexed: 01/05/2023] Open
Abstract
Guidelines recommend the use of an algorithm for the laboratory diagnosis of Clostridium difficile infection (CDI). Enzyme immunoassays (EIAs) detecting C. difficile toxins cannot be used as standalone tests due to suboptimal sensitivity, and molecular tests suffer from nonspecificity by detecting colonization. Guidelines recommend the use of an algorithm for the laboratory diagnosis of Clostridium difficile infection (CDI). Enzyme immunoassays (EIAs) detecting C. difficile toxins cannot be used as standalone tests due to suboptimal sensitivity, and molecular tests suffer from nonspecificity by detecting colonization. Sensitive immunoassays have recently been developed to improve and simplify CDI diagnosis. Assays detecting CD toxins have been developed using single-molecule array (SIMOA) technology. SIMOA performance was assessed relative to a laboratory case definition of CDI defined by positive glutamate dehydrogenase (GDH) screen and cell cytotoxicity neutralizing assay (CCNA). Samples were tested with SIMOA assays and a commercial toxin EIA to compare performance, with discrepancy resolution using a commercial nucleic acid-based test and a second cell cytotoxicity assay. The SIMOA toxin A and toxin B assays showed limits of detection of 0.6 and 2.9 pg/ml, respectively, and intra-assay coefficients of variation of less than 10%. The optimal clinical thresholds for the toxin A and toxin B assays were determined to be 22.1 and 18.8 pg/ml, respectively, with resultant sensitivities of 84.8 and 95.5%. In contrast, a high-performing EIA toxin test had a sensitivity of 71.2%. Thus, the SIMOA assays detected toxins in 24% more samples with laboratory-defined CDI than the high performing toxin EIA (95% [63/66] versus 71% [47/66]). This study shows that SIMOA C. difficile toxin assays have a higher sensitivity than currently available toxin EIA and have the potential to improve CDI diagnosis.
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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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Clostridium difficile disease: Diagnosis, pathogenesis, and treatment update. Surgery 2017; 162:325-348. [DOI: 10.1016/j.surg.2017.01.018] [Citation(s) in RCA: 82] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2017] [Accepted: 01/25/2017] [Indexed: 12/16/2022]
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Clostridium difficile PCR Cycle Threshold Predicts Free Toxin. J Clin Microbiol 2017; 55:2651-2660. [PMID: 28615471 DOI: 10.1128/jcm.00563-17] [Citation(s) in RCA: 58] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2017] [Accepted: 06/09/2017] [Indexed: 12/18/2022] Open
Abstract
There is no stand-alone Clostridium difficile diagnostic that can sensitively and rapidly detect fecal free toxins. We investigated the performance of the C. difficile PCR cycle threshold (CT ) for predicting free toxin status. Consecutive stool samples (n = 312) positive for toxigenic C. difficile by the GeneXpert C. difficile/Epi tcdB PCR assay were tested with the rapid membrane C. Diff Quik Chek Complete immunoassay (RMEIA). RMEIA toxin-negative samples were tested with the cell cytotoxicity neutralization assay (CCNA) and tgcBIOMICS enzyme-linked immunosorbent assay (ELISA). Using RMEIA alone or in combination with CCNA and/or ELISA as the reference method, the accuracy of CT was measured at different CT cutoffs. Using RMEIA as the reference method, a CT cutoff of 26.35 detected toxin-positive samples with a sensitivity, specificity, positive predictive value, and negative predictive value of 96.0% (95% confidence interval [CI], 90.2% to 98.9%), 65.9% (95% CI, 59.0% to 72.2%), 57.4% (95% CI, 52.7% to 62%), and 97.1% (95% CI, 92.8% to 98.9), respectively. Inclusion of CCNA in the reference method improved CT specificity to 78.0% (95% CI, 70.7% to 84.2%). Intercartridge lot CT variability measured as the average coefficient of variation was 2.8% (95% CI, 1.2% to 3.2%). Standardizing the input stool volume did not improve CT toxin specificity. The median CT values were not significantly different between stool samples with Bristol scores of 5, 6, and 7, between pediatric and adult samples, or between presumptive 027 and non-027 strains. In addition to sensitively detecting toxigenic C. difficile in stool, on-demand PCR may also be used to accurately predict toxin-negative stool samples, thus providing additional results in PCR-positive stool samples to guide therapy.
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Strategies for Optimizing the Diagnostic Predictive Value of Clostridium difficile Molecular Diagnostics. J Clin Microbiol 2017; 55:1244-1248. [PMID: 28275072 DOI: 10.1128/jcm.00147-17] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
Because nucleic acid amplification tests (NAATs) do not distinguish Clostridium difficile infection (CDI) and asymptomatic C. difficile carriage, the diagnostic predictive value of NAATs is limited when used in patients with a low probability of CDI. In this issue of the Journal of Clinical Microbiology, Truong et al. (J. Clin. Microbiol., 55:1276-1284, 2017, https://doi.org/10.1128/JCM.02319-16) report significant reductions in hospital-onset CDI and oral vancomycin utilization at their institution following implementation of a novel intervention that leveraged their clinical bioinformatics resources to prevent C. difficile testing of stools from patients without clinically significant diarrhea and in patients with recent laxative use.
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Point-Counterpoint: What Is the Optimal Approach for Detection of Clostridium difficile Infection? J Clin Microbiol 2017; 55:670-680. [PMID: 28077697 DOI: 10.1128/jcm.02463-16] [Citation(s) in RCA: 93] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
INTRODUCTIONIn 2010, we published an initial Point-Counterpoint on the laboratory diagnosis of Clostridium difficile infection (CDI). At that time, nucleic acid amplification tests (NAATs) were just becoming commercially available, and the idea of algorithmic approaches to CDI was being explored. Now, there are numerous NAATs in the marketplace, and based on recent proficiency test surveys, they have become the predominant method used for CDI diagnosis in the United States. At the same time, there is a body of literature that suggests that NAATs lack clinical specificity and thus inflate CDI rates. Hospital administrators are taking note of institutional CDI rates because they are publicly reported. They have become an important metric impacting hospital safety ratings and value-based purchasing; hospitals may have millions of dollars of reimbursement at risk. In this Point-Counterpoint using a frequently asked question approach, Ferric Fang of the University of Washington, who has been a consistent advocate for a NAAT-only approach for CDI diagnosis, will discuss the value of a NAAT-only approach, while Christopher Polage of the University of California Davis and Mark Wilcox of Leeds University, Leeds, United Kingdom, each of whom has recently written important articles on the value of toxin detection in the diagnosis, will discuss the impact of toxin detection in CDI diagnosis.
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Neemann K, Freifeld A. Clostridium difficile–Associated Diarrhea in the Oncology Patient. J Oncol Pract 2017; 13:25-30. [DOI: 10.1200/jop.2016.018614] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Abstract
Clostridium difficile is the most common cause of nosocomial diarrhea, resulting in significant morbidity and mortality in hospitalized patients. Oncology patients are particularly at risk of this infection secondary to frequent exposure to known risk factors. In a population in which diarrhea is a common adverse effect of chemotherapeutic regimens, diagnosis can be challenging secondary to current limitations in testing to differentiate between colonization and active infection. Although several currently available antimicrobial therapies achieve resolution of symptoms in this population, further research is needed to determine which agent least affects the host intestinal microbiota, especially in times of neutropenia and mucosal barrier injury. The purpose of this article is to review the current literature on the epidemiology, pathogenesis, and management of C difficile–associated diarrhea in the oncology population.
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Affiliation(s)
- Kari Neemann
- University of Nebraska Medical Center, Omaha, NE
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Affiliation(s)
- Yi Zhang
- Department of Applied Chemistry, School of Engineering, The University of Tokyo , 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8656, Japan
| | - Hiroyuki Noji
- Department of Applied Chemistry, School of Engineering, The University of Tokyo , 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8656, Japan.,Japan Science and Technology Agency , Tokyo 102-0076, Japan
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Chen S, Gu H, Sun C, Wang H, Wang J. Rapid detection of Clostridium difficile toxins and laboratory diagnosis of Clostridium difficile infections. Infection 2016; 45:255-262. [PMID: 27601055 DOI: 10.1007/s15010-016-0940-9] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2016] [Accepted: 08/11/2016] [Indexed: 02/08/2023]
Abstract
BACKGROUND Clostridium difficile is an anaerobic, spore-forming and Gram-positive bacillus. It is the major cause of antibiotic-associated diarrhea prevailing in hospital settings. The morbidity and mortality of C. difficile infection (CDI) has increased significantly due to the emergence of hypervirulent strains. Because of the poor clinical different between CDI and other causes of hospital-acquired diarrhea, laboratory test for C. difficile is an important intervention for diagnosis of CDI. OBJECTIVE Laboratory tests for CDI can broadly detect either the organisms or its toxins. Currently, several laboratory tests are used for diagnosis of CDI, including toxigenic culture, glutamate dehydrogenase detection, nucleic acid amplification testing, cell cytotoxicity assay, and enzyme immunoassay towards toxin A and/or B. This review focuses on the rapid testing of C. difficile toxins and currently available methods for diagnosis of CDI, giving an overview of the role that the toxins rapid detecting plays in clinical diagnosis of CDI.
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Affiliation(s)
- Shuyi Chen
- School of Bioscience and Bioengineering, South China University of Technology, Guangzhou, China
| | - Huawei Gu
- School of Bioscience and Bioengineering, South China University of Technology, Guangzhou, China
| | - Chunli Sun
- School of Bioscience and Bioengineering, South China University of Technology, Guangzhou, China
| | - Haiying Wang
- School of Bioscience and Bioengineering, South China University of Technology, Guangzhou, China
| | - Jufang Wang
- School of Bioscience and Bioengineering, South China University of Technology, Guangzhou, China.
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Lectin binding studies on a glycopolymer brush flow-through biosensor by localized surface plasmon resonance. Anal Bioanal Chem 2016; 408:5633-40. [DOI: 10.1007/s00216-016-9667-9] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2016] [Revised: 05/20/2016] [Accepted: 05/25/2016] [Indexed: 01/01/2023]
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Frädrich C, Beer LA, Gerhard R. Reactive Oxygen Species as Additional Determinants for Cytotoxicity of Clostridium difficile Toxins A and B. Toxins (Basel) 2016; 8:toxins8010025. [PMID: 26797634 PMCID: PMC4728547 DOI: 10.3390/toxins8010025] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2015] [Revised: 01/07/2016] [Accepted: 01/13/2016] [Indexed: 12/18/2022] Open
Abstract
Clostridium difficile infections can induce mild to severe diarrhoea and the often associated characteristic pseudomembranous colitis. Two protein toxins, the large glucosyltransferases TcdA and TcdB, are the main pathogenicity factors that can induce all clinical symptoms in animal models. The classical molecular mode of action of these homologous toxins is the inhibition of Rho GTPases by mono-glucosylation. Rho-inhibition leads to breakdown of the actin cytoskeleton, induces stress-activated and pro-inflammatory signaling and eventually results in apoptosis of the affected cells. An increasing number of reports, however, have documented further qualities of TcdA and TcdB, including the production of reactive oxygen species (ROS) by target cells. This review summarizes observations dealing with the production of ROS induced by TcdA and TcdB, dissects pathways that contribute to this phenomenon and speculates about ROS in mediating pathogenesis. In conclusion, ROS have to be considered as a discrete, glucosyltransferase-independent quality of at least TcdB, triggered by different mechanisms.
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Affiliation(s)
- Claudia Frädrich
- Postgraduate Course for Toxicology and Environmental Toxicology, Institute for Legal Medicine, University of Leipzig, Johannisallee 28, Leipzig 04103, Germany.
| | - Lara-Antonia Beer
- Institute of Toxicology, Hannover Medical School, Carl-Neuberg-Str. 1, Hannover 30625, Germany.
| | - Ralf Gerhard
- Postgraduate Course for Toxicology and Environmental Toxicology, Institute for Legal Medicine, University of Leipzig, Johannisallee 28, Leipzig 04103, Germany.
- Institute of Toxicology, Hannover Medical School, Carl-Neuberg-Str. 1, Hannover 30625, Germany.
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Ultrasensitive Detection and Quantification of Toxins for Optimized Diagnosis of Clostridium difficile Infection. J Clin Microbiol 2015; 54:259-64. [PMID: 26659205 DOI: 10.1128/jcm.02419-15] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
Recently developed ultrasensitive and quantitative methods for detection of Clostridium difficile toxins provide new tools for diagnosis and, potentially, for management of C. difficile infection (CDI). Compared to methods that detect toxigenic organism, ultrasensitive toxin detection may allow diagnosis of CDI with increased clinical specificity, without sacrificing clinical sensitivity; measurement of toxin levels may also provide information relevant to disease prognosis. This minireview provides an overview of these new toxin detection technologies and considers what these new tools might add to the field.
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