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Ziaei Chamgordani S, Yadegar A, Ghourchian H. C. difficile biomarkers, pathogenicity and detection. Clin Chim Acta 2024; 558:119674. [PMID: 38621586 DOI: 10.1016/j.cca.2024.119674] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2024] [Revised: 04/12/2024] [Accepted: 04/12/2024] [Indexed: 04/17/2024]
Abstract
BACKGROUND Clostridioides difficile infection (CDI) is the main etiologic agent of antibiotic-associated diarrhea. CDI contributes to gut inflammation and can lead to disruption of the intestinal epithelial barrier. Recently, the rate of CDI cases has been increased. Thus, early diagnosis of C. difficile is critical for controlling the infection and guiding efficacious therapy. APPROACH A search strategy was set up using the terms C. difficile biomarkers and diagnosis. The found references were classified into two general categories; conventional and advanced methods. RESULTS The pathogenicity and biomarkers of C. difficile, and the collection manners for CDI-suspected specimens were briefly explained. Then, the conventional CDI diagnostic methods were subtly compared in terms of duration, level of difficulty, sensitivity, advantages, and disadvantages. Thereafter, an extensive review of the various newly proposed techniques available for CDI detection was conducted including nucleic acid isothermal amplification-based methods, biosensors, and gene/single-molecule microarrays. Also, the detection mechanisms, pros and cons of these methods were highlighted and compared with each other. In addition, approximately complete information on FDA-approved platforms for CDI diagnosis was collected. CONCLUSION To overcome the deficiencies of conventional methods, the potential of advanced methods for C. difficile diagnosis, their direction, perspective, and challenges ahead were discussed.
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Affiliation(s)
- Sepideh Ziaei Chamgordani
- Laboratory of Bioanalysis, Institute of Biochemistry & Biophysics, University of Tehran, 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.
| | - Hedayatollah Ghourchian
- Laboratory of Bioanalysis, Institute of Biochemistry & Biophysics, University of Tehran, Tehran, Iran.
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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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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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Hassanain WA, Spoors J, Johnson CL, Faulds K, Keegan N, Graham D. Rapid ultra-sensitive diagnosis of clostridium difficile infection using a SERS-based lateral flow assay. Analyst 2021; 146:4495-4505. [PMID: 34184680 DOI: 10.1039/d1an00726b] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
Clostridium difficile (C. diff) infection is one of the most contagious diseases associated with high morbidity and mortality rates in hospitalised patients. Accurate diagnosis can slow its spread by determining the most effective treatment. Herein, we report a novel testing platform as a proof-of-concept for the selective, sensitive, rapid and cost-effective diagnosis of C. diff infection (CDI) based on a duplex measurement. This was achieved by detecting two specific biomarkers, surface layer protein A (SlpA) and toxin B (ToxB), using a surface enhanced Raman scattering-based lateral flow assay (SERS-based LFA). The simultaneous duplex detection of SlpA with ToxB has not been described for the clinical diagnosis of CDI previously. The SlpA biomarker "AKDGSTKEDQLVDALA" was first reported by our group in 2018 as a species-specific identification tool. The second biomarker, ToxB, is the essential virulence biomarker of C. diff pathogenic strains and is required to confirm true infection pathogenicity. The proposed SERS-based LFA platform enabled rapid duplex detection of SlpA and ToxB on separate test lines using a duplex LF test strip within 20 minutes. The use of a handheld Raman spectrometer to scan test lines allowed for the highly sensitive quantitative detection of both biomarkers with a lowest observable concentration of 0.01 pg μL-1. The use of a handheld device in this SERS-based LFA instead of benchtop machine paves the way for rapid, selective, sensitive and cheap clinical evaluation of CDI at the point of care (POC) with minimal sample backlog.
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Affiliation(s)
- Waleed A Hassanain
- Department of Pure and Applied Chemistry, Technology and Innovation Centre, University of Strathclyde, Glasgow, G1 1RD, UK.
| | - Julia Spoors
- Diagnostic and Therapeutic Technologies, Translational and Clinical Research Institute, Newcastle University, Newcastle-Upon-Tyne, NE2 4HH, UK.
| | - Christopher L Johnson
- Diagnostic and Therapeutic Technologies, Translational and Clinical Research Institute, Newcastle University, Newcastle-Upon-Tyne, NE2 4HH, UK.
| | - Karen Faulds
- Department of Pure and Applied Chemistry, Technology and Innovation Centre, University of Strathclyde, Glasgow, G1 1RD, UK.
| | - Neil Keegan
- Diagnostic and Therapeutic Technologies, Translational and Clinical Research Institute, Newcastle University, Newcastle-Upon-Tyne, NE2 4HH, UK.
| | - Duncan Graham
- Department of Pure and Applied Chemistry, Technology and Innovation Centre, University of Strathclyde, Glasgow, G1 1RD, UK.
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Mizusawa M, Carroll KC. Advances and required improvements in methods to diagnosing Clostridioides difficile infections in the healthcare setting. Expert Rev Mol Diagn 2021; 21:311-321. [PMID: 33682564 DOI: 10.1080/14737159.2021.1900737] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
INTRODUCTION Clostrididioides difficile is associated with adverse clinical outcomes and increased morbidity, mortality, length of hospital stay, and health-care costs.Areas Covered: We searched relevant papers in PubMed for the last 10 years. In major papers, we scanned the bibliographies to ensure that important articles were included. This review addresses the evolving epidemiology of Clostridioides difficile infection (CDI) and discusses novel methods/approaches for improving the diagnosis of this important disease. EXPERT OPINION No single diagnostic test to date has demonstrated optimum sensitivity and specificity for detection of CDI. Many institutions have developed multi-step algorithms consistent with guidelines established by various professional societies. Some institutions have successfully tried to improve the pretest probability of molecular assays by implementing appropriate sample rejection criteria and establishing best practice alerts at the time of electronic order entry. Others have established PCR cycle threshold cutoffs to attempt to differentiate symptomatic patients from asymptomatic carriers or to make predictions about severity of disease with variable success. As research advances our understanding of C. difficile pathogenesis and pathophysiology, more information on CDI specific biomarkers is emerging. Finally, assessments of the microbiome and metabolome may expand the diagnostic armamentarium with advances in mass spectrometry and sequencing technologies.
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Affiliation(s)
- Masako Mizusawa
- Section of Infectious Diseases, Department of Internal Medicine, University of Missouri, Kansas City, Missouri, Kansas City, MO, USA
| | - Karen C Carroll
- Director Division of Medical Microbiology, The Johns Hopkins University School of Medicine, Baltimore, MD, USA
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Prabhakaran M, Narpala S, Andrews SF, O'Connell S, Lin CL, Coates EE, Flach B, Ledgerwood JE, McDermott AB. A sensitive method to quantify HIV-1 antibodies in mucosal samples. J Immunol Methods 2021; 491:112995. [PMID: 33582148 DOI: 10.1016/j.jim.2021.112995] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2020] [Revised: 01/21/2021] [Accepted: 02/02/2021] [Indexed: 10/22/2022]
Abstract
Human immunodeficiency virus (HIV) remains a significant public health issue. In recent years, passive immunization with broadly neutralizing antibodies (bNabs) is being considered as a potentially efficacious approach for fighting HIV. One candidate that holds great promise is represented by the CD4-binding site targeted bNab capable of neutralizing over 90% of circulating HIV strains, VRC01. VRC01 along with its variants and clonal relatives - VRC01-LS and VRC07-523LS are currently being evaluated as vaccines in a number of clinical trials for HIV treatment and prevention. While mucosal areas of the body serve as major ports of HIV entry, reliable quantification of bNabs for pharmacokinetic and bioavailability analyses has been challenging due to low antibody concentrations in these samples. We developed an immunoassay on the Singulex platform which enables ultra-sensitive quantification of VRC01, VRC07, VRC01-LS and VRC07-523LS with a greater than 4-log linear dynamic range (LDR) and less than 120 pg/mL lower limit of quantitation (LLOQ). We implemented this assay to quantify VRC01 levels in rectal, cervical and oral mucosal samples in two passive immunization studies conducted with VRC01 - VRC 601 and VRC 602. Our assay was able to successfully quantify VRC01 levels in mucosal samples from all dosage groups (5 - -40 mg/kg) in these trials. VRC01 levels in a significant proportion of these samples (37% in oral and 25% in rectal mucosa) were below the lower limits of quantitation of other traditional immunoassays used for VRC01 quantification. We also measured VRC01 levels in sera from these trials and found that VRC01 measurements made using our assay exhibited excellent correlation (r2 = 0.9509) with measurements made previously using Enzyme-linked immunosorbent assay (ELISA). Our assay provides a reliable, sensitive and accurate method for quantification of clinically relevant bNabs and will help delineate antibody infiltration and bioavailability characteristics in complex biological matrices (CBM) such as mucosal tissues. This will in turn help determine clinical antibody threshold concentrations required to mediate protection against HIV acquisition and serve to inform dosing regimens and clinical trial design for future efficacy trials with these bNabs.
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Affiliation(s)
- Madhu Prabhakaran
- Vaccine Research Center, National Institute of Allergy and Infectious Diseases, National Institutes of Health, 40 Convent Drive, Bethesda, MD 20814, USA
| | - Sandeep Narpala
- Vaccine Research Center, National Institute of Allergy and Infectious Diseases, National Institutes of Health, 40 Convent Drive, Bethesda, MD 20814, USA
| | - Sarah F Andrews
- Vaccine Research Center, National Institute of Allergy and Infectious Diseases, National Institutes of Health, 40 Convent Drive, Bethesda, MD 20814, USA
| | - Sarah O'Connell
- Vaccine Research Center, National Institute of Allergy and Infectious Diseases, National Institutes of Health, 40 Convent Drive, Bethesda, MD 20814, USA
| | - Chien L Lin
- Vaccine Research Center, National Institute of Allergy and Infectious Diseases, National Institutes of Health, 40 Convent Drive, Bethesda, MD 20814, USA
| | - Emily E Coates
- Vaccine Research Center, National Institute of Allergy and Infectious Diseases, National Institutes of Health, 40 Convent Drive, Bethesda, MD 20814, USA
| | - Britta Flach
- Vaccine Research Center, National Institute of Allergy and Infectious Diseases, National Institutes of Health, 40 Convent Drive, Bethesda, MD 20814, USA
| | - Julie E Ledgerwood
- Vaccine Research Center, National Institute of Allergy and Infectious Diseases, National Institutes of Health, 40 Convent Drive, Bethesda, MD 20814, USA
| | - Adrian B McDermott
- Vaccine Research Center, National Institute of Allergy and Infectious Diseases, National Institutes of Health, 40 Convent Drive, Bethesda, MD 20814, USA.
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Diagnostic and therapy of severe Clostridioides difficile infections in the ICU. Curr Opin Crit Care 2021; 26:450-458. [PMID: 32739967 DOI: 10.1097/mcc.0000000000000753] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
PURPOSE OF REVIEW The purpose of the review is to provide all the recent data focusing on the diagnostic and treatment of Clostridioides difficile infection in patients admitted in the ICU. RECENT FINDINGS In the ICU, diagnosis remains complicated with a large number of alternative diagnosis. The treatment classically relies on vancomycin but fidaxomicin and fecal microbiota transplantation are now potential solutions in selected indications. SUMMARY Data on ICU-related CDI remain limited and conflicting. To date, there is no unique and simple way to obtain a diagnosis for CDI, the combination of clinical signs and a two-step testing algorithm remains the recommended gold-standard. Two molecules can be proposed for first line treatment: vancomycin and fidaxomicin. Although metronidazole may still be discussed as a treatment option for mild CDI in low-risk patients, its use for ICU-patients does not seem reasonable. Several reports suggest that fecal microbiota transplantation could be discussed, as it is well tolerated and associated with a high rate of clinical cure. CDI is a dynamic and active area of research with new diagnostic techniques, molecules, and management concepts likely changing our approach to this old disease in the near future.
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Lenggenhager L, Zanella MC, Poncet A, Kaiser L, Schrenzel J. Discordant Clostridioides difficile diagnostic assay and treatment practice: a cross-sectional study in a tertiary care hospital, Geneva, Switzerland. BMJ Open 2020; 10:e036342. [PMID: 32928850 PMCID: PMC7488797 DOI: 10.1136/bmjopen-2019-036342] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
OBJECTIVES To determine the proportion of patients who received a treatment for Clostridioides difficile infection (CDI) among those presenting a discordant C. difficile diagnostic assay and to identify patient characteristics associated with the decision to treat CDI. DESIGN Cross-sectional study. SETTING Monocentric study in a tertiary care hospital, Geneva, Switzerland. PARTICIPANTS Among 4562 adult patients tested for C. difficile between March 2017 and March 2019, 208 patients with discordant tests' results (positive nucleic acid amplification test (NAAT+)/negative enzyme immunoassay (EIA-)) were included. MAIN OUTCOME MEASURES Treatment for CDI. RESULTS CDI treatment was administered in 147 (71%) cases. In multivariate analysis, an abdominal CT scan with signs of colitis (OR 14.7; 95% CI 1.96 to 110.8) was the only factor associated with CDI treatment. CONCLUSIONS The proportion of NAAT+/EIA- patients who received treatment questions the contribution of the EIA for the detection of toxin A/B after NAAT to limit overtreatment. Additional studies are needed to investigate if other factors are associated with the decision to treat.
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Affiliation(s)
- Lauriane Lenggenhager
- Division of Infectious Diseases, Geneva University Hospitals, Geneve, Switzerland
- University of Geneva Medical School, Geneve, Switzerland
| | - Marie-Céline Zanella
- Division of Infectious Diseases, Geneva University Hospitals, Geneve, Switzerland
- Laboratory of Bacteriology, Division of Laboratory Medicine, Geneva University Hospitals, Geneva, Switzerland
| | - Antoine Poncet
- Division of Clinical Epidemiology, Geneva University Hospitals, Geneve, Switzerland
| | - Laurent Kaiser
- Division of Infectious Diseases, Geneva University Hospitals, Geneve, Switzerland
- University of Geneva Medical School, Geneve, Switzerland
- Laboratory of Virology, Division of Laboratory Medicine and Division of Infectious Diseases, Geneva University Hospitals, Geneva, Switzerland
| | - Jacques Schrenzel
- Division of Infectious Diseases, Geneva University Hospitals, Geneve, Switzerland
- University of Geneva Medical School, Geneve, Switzerland
- Laboratory of Bacteriology, Division of Laboratory Medicine, Geneva University Hospitals, Geneva, Switzerland
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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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Pettengill MA. Hindsight Is 2019-the Year in Clinical Microbiology. ACTA ACUST UNITED AC 2020; 42:87-92. [PMID: 32461708 PMCID: PMC7241978 DOI: 10.1016/j.clinmicnews.2020.05.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Much changed in clinical microbiology in 2019, and, like the organisms, we, as clinical microbiologists, are responsible to detect, characterize, and teach others about our discipline. Also, it is important for us to adapt to changes in the field. In this review, I highlight some of the papers, practices, and regulatory issues that defined 2019 for our field, from my perspective.
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Affiliation(s)
- Matthew A Pettengill
- Thomas Jefferson University, Department of Pathology, Anatomy, and Cell Biology, Philadelphia, Pennsylvania
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Evaluation of Cycle Threshold, Toxin Concentration, and Clinical Characteristics of Clostridioides difficile Infection in Patients with Discordant Diagnostic Test Results. J Clin Microbiol 2020; 58:JCM.01681-19. [PMID: 32051264 DOI: 10.1128/jcm.01681-19] [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] [Received: 10/07/2019] [Accepted: 02/04/2020] [Indexed: 12/14/2022] Open
Abstract
Clostridioides difficile infection (CDI) is one of the most common health care-associated infections that can cause significant morbidity and mortality. CDI diagnosis involves laboratory testing in conjunction with clinical assessment. The objective of this study was to assess the performance of various C. difficile tests and to compare clinical characteristics, Xpert C. difficile/Epi (PCR) cycle threshold (CT ), and Singulex Clarity C. diff toxins A/B (Clarity) concentrations between groups with discordant test results. Unformed stool specimens from 200 hospitalized adults (100 PCR positive and 100 negative) were tested by cell cytotoxicity neutralization assay (CCNA), C. diff Quik Chek Complete (Quik Chek), Premier Toxins A and B, and Clarity. Clinical data, including CDI severity and CDI risk factors, were compared between discordant test results. Compared to CCNA, PCR had the highest sensitivity at 100% and Quik Chek had the highest specificity at 100%. Among clinical and laboratory data studied, prevalences of leukocytosis, prior antibiotic use, and hospitalizations were consistently higher across all subgroups in comparisons of toxin-positive to toxin-negative patients. Among PCR-positive samples, the median CT was lower in toxin-positive samples than in toxin-negative samples; however, CT ranges overlapped. Among Clarity-positive samples, the quantitative toxin concentration was significantly higher in toxin-positive samples than in toxin-negative samples as determined by CCNA and Quik Chek Toxin A and B. Laboratory tests for CDI vary in sensitivity and specificity. The quantitative toxin concentration may offer value in guiding CDI diagnosis and treatment. The presence of leukocytosis, prior antibiotic use, and previous hospitalizations may assist with CDI diagnosis, while other clinical parameters may not be consistently reliable.
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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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High Agreement Between an Ultrasensitive Clostridioides difficile Toxin Assay and a C. difficile Laboratory Algorithm Utilizing GDH-and-Toxin Enzyme Immunoassays and Cytotoxin Testing. J Clin Microbiol 2020; 58:JCM.01629-19. [PMID: 31776192 DOI: 10.1128/jcm.01629-19] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2019] [Accepted: 11/14/2019] [Indexed: 12/18/2022] Open
Abstract
The Singulex Clarity C. diff toxins A/B (Clarity) assay is an automated, ultrasensitive immunoassay for the detection of Clostridioides difficile toxins in stool. In this study, the performance of the Clarity assay was compared to that of a multistep algorithm using an enzyme immunoassay (EIA) for detection of glutamate dehydrogenase (GDH) and toxins A and B arbitrated by a semiquantitative cell cytotoxicity neutralization assay (CCNA). The performance of the assay was evaluated using 211 residual deidentified stool samples tested with a GDH-and-toxin EIA (C. Diff Quik Chek Complete; Techlab), with GDH-and-toxin discordant samples tested with CCNA. The stool samples were stored at -80°C before being tested with the Clarity assay. For samples discordant between Clarity and the standard-of-care algorithm, the samples were tested with PCR (Xpert C. difficile; Cepheid), and chart review was performed. The testing algorithm resulted in 34 GDH+/toxin+, 53 GDH-/toxin-, and 124 GDH+/toxin- samples, of which 39 were CCNA+ and 85 were CCNA- Clarity had 96.2% negative agreement with GDH-/toxin- samples, 100% positive agreement with GDH+/toxin+ samples, and 95.3% agreement with GDH+/toxin-/CCNA- samples. The Clarity result was invalid for one sample. Clarity agreed with 61.5% of GDH+/toxin-/CCNA+ samples, 90.0% of GDH+/toxin-/CCNA+ (high-positive) samples, and 31.6% of GDH+/toxin-/CCNA+ (low-positive) samples. The Singulex Clarity C. diff toxins A/B assay demonstrated high agreement with a testing algorithm utilizing a GDH-and-toxin EIA and CCNA. This novel automated assay may offer an accurate, stand-alone solution for C. difficile infection (CDI) diagnostics, and further prospective clinical studies are merited.
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15
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Nana T, Moore C, Boyles T, Brink AJ, Cleghorn J, Devenish LM, du Toit B, Fredericks ES, Lekalakala-Mokaba MR, Maluleka C, Rajabally MN, Reubenson G, Shuping L, Swart K, Swe Han KS, Wadula J, Wojno J, Lowman W. South African Society of Clinical Microbiology Clostridioides difficile infection diagnosis, management and infection prevention and control guideline. S Afr J Infect Dis 2020; 35:219. [PMID: 34485483 PMCID: PMC8378053 DOI: 10.4102/sajid.v35i1.219] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2020] [Accepted: 06/24/2020] [Indexed: 12/17/2022] Open
Abstract
Clostridioides difficile infection (CDI) is a problem in both developed and developing countries and is a common hospital-acquired infection. This guideline provides evidence-based practical recommendations for South Africa and other developing countries. The scope of the guideline includes CDI diagnostic approaches; adult, paediatric and special populations treatment options; and surveillance and infection prevention and control recommendations.
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Affiliation(s)
- Trusha Nana
- Department of Clinical Microbiology and Infectious Diseases, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa
- Charlotte Maxeke Johannesburg Academic Hospital Microbiology Laboratory, National Health Laboratory Services, Johannesburg, South Africa
| | | | - Tom Boyles
- Department of Medicine, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa
- Department of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, London, United Kingdom
| | - Adrian J. Brink
- Department of Medical Microbiology, Faculty of Health Sciences, University of Cape Town, Cape Town, South Africa
| | - Joy Cleghorn
- Life Healthcare Group, Johannesburg, South Africa
| | - Lesley M. Devenish
- Department of Clinical Microbiology and Infectious Diseases, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa
- Infection Control Services Laboratory, National Health Laboratory Services, Johannesburg, South Africa
| | | | - Ernst S. Fredericks
- Department of Physiology, Faculty of Science, Nelson Mandela University, Port Elizabeth, South Africa
| | - Molebogeng R. Lekalakala-Mokaba
- Department of Microbiology, Faculty of Health Sciences, Sefako Makgatho Health Sciences University, Pretoria, South Africa
- Dr George Mukhari Academic Hospital Microbiology Laboratory, National Health Laboratory Services, Pretoria, South Africa
| | - Caroline Maluleka
- Department of Microbiology, Faculty of Health Sciences, Sefako Makgatho Health Sciences University, Pretoria, South Africa
- Dr George Mukhari Academic Hospital Microbiology Laboratory, National Health Laboratory Services, Pretoria, South Africa
| | | | - Gary Reubenson
- Department of Paediatrics and Child Health, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa
| | - Liliwe Shuping
- Centre for Healthcare-Associated Infections, National Institute for Communicable Diseases, a division of National Health Laboratory Service, Johannesburg, South Africa
| | - Karin Swart
- Netcare Hospitals Limited, Johannesburg, South Africa
| | - Khine Swe Swe Han
- Medical Microbiology Department, Inkosi Albert Luthuli Central Hospital Academic Complex, National Health Laboratory Services, Durban, South Africa
- Department of Medical Microbiology, School of Laboratory Medicine and Medical Sciences, University of KwaZulu-Natal, Durban, South Africa
| | - Jeannette Wadula
- Department of Clinical Microbiology and Infectious Diseases, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa
- Chris Hani Baragwanath Hospital Microbiology Laboratory, National Health Laboratory Services, Johannesburg, South Africa
| | | | - Warren Lowman
- Department of Clinical Microbiology and Infectious Diseases, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa
- Department of Clinical Microbiology, PathCare/Vermaak Pathologists, Johannesburg, South Africa
- Department of Clinical Microbiology and Infection Prevention and Control, WITS Donald Gordon Medical Centre, Johannesburg, South Africa
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Hitchcock MM, Holubar M, Hogan CA, Tompkins LS, Banaei N. Dual Reporting of Clostridioides difficile PCR and Predicted Toxin Result Based on PCR Cycle Threshold Reduces Treatment of Toxin-Negative Patients without Increases in Adverse Outcomes. J Clin Microbiol 2019; 57:e01288-19. [PMID: 31511334 PMCID: PMC6812995 DOI: 10.1128/jcm.01288-19] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2019] [Accepted: 09/05/2019] [Indexed: 12/21/2022] Open
Abstract
Nucleic acid amplification tests are commonly used to diagnose Clostridioides difficile infection (CDI). Two-step testing with a toxin enzyme immunoassay is recommended to discriminate between infection and colonization but requires additional resources. Prior studies showed that PCR cycle threshold (CT ) can predict toxin positivity with high negative predictive value. Starting in October 2016, the predicted toxin result (CT-toxin) based on a validated cutoff was routinely reported at our facility. To evaluate the clinical efficacy of this reporting, all adult patients with positive GeneXpert PCR results from October 2016 through October 2017 underwent a chart review to measure the recurrence of or conversion to a CT-toxin+ result and 30-day all-cause mortality. There were 482 positive PCR tests in 430 unique patients, 282 CT-toxin+ and 200 CT-toxin- Patient characteristics were similar at testing, though CT-toxin+ patients had higher white blood cell (WBC) counts (12.5 × 103 versus 9.3 × 103 cells/μl; P = 0.001). All cases (n = 21) of fulminant CDI had a CT-toxin+ result. Index CT-toxin+ patients were significantly more likely to have a CT-toxin+ result within 90 days than CT-toxin- patients (17.4% [n = 49] versus 8.0% [n = 16], respectively; P = 0.003). Thirty-day all-cause mortality was higher in CT-toxin- patients (11.1% versus 6.8%; P = 0.1), though no deaths in CT-toxin- patients were directly attributable to CDI. Of the 200 CT-toxin- patients, 51.5% (n = 103) were treated for CDI. The rates of conversion to a CT-toxin+ result (8.8% versus 7.2%; P = 0.8) and all-cause mortality (8.8% versus 13.4%; P = 0.3) were similar between treated and untreated CT-toxin- patients, respectively. CT -based toxin prediction may identify patients at higher risk for CDI-related complications and reduce treatment among CT-toxin- patients.
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Affiliation(s)
- Matthew M Hitchcock
- Division of Infectious Diseases and Geographic Medicine, Department of Medicine, Stanford University School of Medicine, Stanford, California, USA
| | - Marisa Holubar
- Division of Infectious Diseases and Geographic Medicine, Department of Medicine, Stanford University School of Medicine, Stanford, California, USA
| | - Catherine A Hogan
- Department of Pathology, Stanford University School of Medicine, Stanford, California, USA
- Clinical Microbiology Laboratory, Stanford Health Care, Stanford, California, USA
| | - Lucy S Tompkins
- Division of Infectious Diseases and Geographic Medicine, Department of Medicine, Stanford University School of Medicine, Stanford, California, USA
- Department of Microbiology and Immunology, Stanford University School of Medicine, Stanford, California, USA
| | - Niaz Banaei
- Division of Infectious Diseases and Geographic Medicine, Department of Medicine, Stanford University School of Medicine, Stanford, California, USA
- Department of Pathology, Stanford University School of Medicine, Stanford, California, USA
- Clinical Microbiology Laboratory, Stanford Health Care, Stanford, California, USA
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17
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Ultrasensitive Detection of Clostridioides difficile Toxins in Stool by Use of Single-Molecule Counting Technology: Comparison with Detection of Free Toxin by Cell Culture Cytotoxicity Neutralization Assay. J Clin Microbiol 2019; 57:JCM.00719-19. [PMID: 31434724 DOI: 10.1128/jcm.00719-19] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2019] [Accepted: 08/13/2019] [Indexed: 12/18/2022] Open
Abstract
Laboratory tests for Clostridioides difficile infection (CDI) rely on the detection of free toxin or molecular detection of toxin genes. The Singulex Clarity C. diff toxins A/B assay is a rapid, automated, and ultrasensitive assay that detects C. difficile toxins A and B in stool. We compared CDI assays across two prospective multicenter studies to set a cutoff for the Clarity assay and to independently validate the performance compared with that of a cell culture cytotoxicity neutralization assay (CCCNA). The cutoff was set by two sites testing fresh samples from 897 subjects with suspected CDI and then validated at four sites testing fresh samples from 1,005 subjects with suspected CDI. CCCNA testing was performed at a centralized laboratory. Samples with discrepant results between the Clarity assay and CCCNA were retested with CCCNA when the Clarity result agreed with that of at least one comparator method; toxin enzyme immunoassays (EIA), glutamate dehydrogenase (GDH) detection, and PCR were performed on all samples. The cutoff for the Clarity assay was set at 12.0 pg/ml. Compared to results with CCCNA, the Clarity assay initially had 85.2% positive agreement and 92.4% negative agreement. However, when samples with discrepant results between the Clarity assay and CCCNA in the validation study were retested by CCCNA, 13/17 (76.5%) Clarity-negative but CCCNA-positive samples (Clarity+/CCCNA-) became CCCNA-, and 5/26 (19.2%) Clarity+/CCCNA- samples became CCCNA+, resulting in a 96.3% positive agreement and 93.0% negative agreement between Clarity and CCCNA results. The toxin EIA had 59.8% positive agreement with CCCNA. The Clarity assay was the most sensitive free-toxin immunoassay, capable of providing CDI diagnosis in a single-step solution. A different CCCNA result was reported for 42% of retested samples, increasing the positive agreement between Clarity and CCCNA from 85.2% to 96.3% and indicating the challenges of comparing free-toxin results to CCCNA results as a reference standard.
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Increased Clinical Specificity with Ultrasensitive Detection of Clostridioides difficile Toxins: Reduction of Overdiagnosis Compared to Nucleic Acid Amplification Tests. J Clin Microbiol 2019; 57:JCM.00945-19. [PMID: 31434726 DOI: 10.1128/jcm.00945-19] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2019] [Accepted: 08/13/2019] [Indexed: 12/18/2022] Open
Abstract
Clostridioides difficile infection (CDI) is one of the most common health care-associated infections, resulting in significant morbidity, mortality, and economic burden. Diagnosis of CDI relies on the assessment of clinical presentation and laboratory tests. We evaluated the clinical performance of ultrasensitive single-molecule counting technology for detection of C. difficile toxins A and B. Stool specimens from 298 patients with suspected CDI were tested with the nucleic acid amplification test (NAAT; BD MAX Cdiff assay or Xpert C. difficile assay) and Singulex Clarity C. diff toxins A/B assay. Specimens with discordant results were tested with the cell cytotoxicity neutralization assay (CCNA), and the results were correlated with disease severity and outcome. There were 64 NAAT-positive and 234 NAAT-negative samples. Of the 32 NAAT+/Clarity- and 4 NAAT-/Clarity+ samples, there were 26 CCNA- and 4 CCNA- samples, respectively. CDI relapse was more common in NAAT+/toxin+ patients than in NAAT+/toxin- and NAAT-/toxin- patients. The clinical specificity of Clarity and NAAT was 97.4% and 89.0%, respectively, and overdiagnosis was more than three times more common in NAAT+/toxin- than in NAAT+/toxin+ patients. The Clarity assay was superior to NAATs for the diagnosis of CDI, by reducing overdiagnosis and thereby increasing clinical specificity, and the presence of toxins was associated with negative patient outcomes.
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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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Ultrasensitive Detection of Clostridium difficile Toxins Reveals Suboptimal Accuracy of Toxin Gene Cycle Thresholds for Toxin Predictions. J Clin Microbiol 2019; 57:JCM.01885-18. [PMID: 30944188 DOI: 10.1128/jcm.01885-18] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
The use of nucleic acid amplification tests (NAATs) for the diagnosis of Clostridium (Clostridioides) difficile infection (CDI) leads to overdiagnosis. To improve the clinical specificity of NAATs, there has been a recent interest in using toxin gene cycle thresholds (CT s) to predict the presence and absence of toxins. Although there is an association between CT values and fecal toxin concentrations, the predictive accuracy of the former is suboptimal for use in clinical practice. Ultrasensitive toxin immunoassays to quantify free toxins in stool offer a novel option for high-sensitivity fecal toxin detection rather than using surrogate markers for prediction.
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21
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Brukner I, Eintracht S, Forgetta V, Papadakis AI, Spatz A, Oughton M. Laboratory-developed test for detection of acute Clostridium difficile infections with the capacity for quantitative sample normalization. Diagn Microbiol Infect Dis 2019; 95:113-118. [PMID: 31176521 DOI: 10.1016/j.diagmicrobio.2019.04.017] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2019] [Revised: 04/30/2019] [Accepted: 04/30/2019] [Indexed: 12/14/2022]
Abstract
We describe a laboratory-developed test intended for the detection of acute Clostridium difficile infections (CDI) with the capacity for quantitative sample normalization. The test is based on the detection of the tcdB gene. However, this biomarker is also present among people without symptoms, implying that individuals with diarrhea, not caused by C. difficile may nonetheless test positive. Therefore, clinical diagnosis based on this format of testing can be challenging. In order to improve diagnostic assays capability, tcdB-based quantification methods were suggested as a potential solution, however they did not increase clinical specificity. We report methodology for a dual biomarker monitoring (total bacterial load and tcdB assay), allowing for the calculation of the relative presence of tcdB in the total bacterial population in the tested samples. We believe that this approach is clinically relevant to current assays and can improve CDI testing algorithms.
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Affiliation(s)
- Ivan Brukner
- Department of Medical Microbiology, Jewish General Hospital, Quebec, Canada; Lady Davis Institute for Medical Research, Quebec, Canada; McGill University, Faculty of Medicine, Montreal, Quebec, Canada.
| | - Shaun Eintracht
- Department of Medicine, Jewish General Hospital, Quebec, Canada; McGill University, Faculty of Medicine, Montreal, Quebec, Canada
| | | | | | - Alan Spatz
- Lady Davis Institute for Medical Research, Quebec, Canada; McGill University, Department of Pathology, Quebec, Canada
| | - Matthew Oughton
- Department of Medical Microbiology, Jewish General Hospital, Quebec, Canada; McGill University, Faculty of Medicine, Montreal, Quebec, Canada.
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Advances in Diagnostic Testing that Impact Infection Prevention and Antimicrobial Stewardship Programs. Curr Infect Dis Rep 2019; 21:20. [PMID: 31044313 DOI: 10.1007/s11908-019-0676-7] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
PURPOSE OF REVIEW The primary purpose of this review is to provide a summary of new and emerging laboratory technologies and testing platforms that impact infection prevention and antimicrobial stewardship programs. This review also summarizes available data describing the clinical impact of implementing these new technologies. RECENT FINDINGS While there is ample evidence that rapid organism identification technologies for positive blood cultures can ameliorate antimicrobial utilization, an assay that also provides expedited antimicrobial susceptibility testing results is now available and its clinical impact is under investigation. For C. difficile infection diagnosis, data related to performance and impact of "ultrasensitive" toxin assays is emerging in the literature although their role in C. difficile infection diagnosis remains unclear. For hospital-acquired pneumonia, a variety of rapid, automated, multiplexed, "pneumonia" panels have become commercially available and may impact surveillance definitions for ventilator-associated events. Finally, recent FDA clearance of various biochemical and molecular carbapenemase detection tests will facilitate rapid characterization of carbapenem-resistant organisms. Innovations in infectious diseases diagnostics have been making swift strides, broadening diagnostic scope; increasing accuracy and sensitivity; and reducing turnaround time. Many of these innovations directly impact infection prevention and antimicrobial stewardship operations. Close collaboration between infection control, antimicrobial stewardship, and the microbiology laboratory is necessary to ensure that new tests improve patient outcomes.
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Sandlund J, Mills R, Griego-Fullbright C, Wagner A, Estis J, Bartolome A, Almazan A, Tam S, Biscocho S, Abusali S, Nolan N, Bishop JJ, Todd J, Young S. Laboratory comparison between cell cytotoxicity neutralization assay and ultrasensitive single molecule counting technology for detection of Clostridioides difficile toxins A and B, PCR, enzyme immunoassays, and multistep algorithms. Diagn Microbiol Infect Dis 2019; 95:20-24. [PMID: 31129008 DOI: 10.1016/j.diagmicrobio.2019.04.002] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2018] [Revised: 02/25/2019] [Accepted: 04/01/2019] [Indexed: 01/05/2023]
Abstract
Diagnostic tests for Clostridioides difficile infection (CDI) lack either specificity (nucleic acid amplification tests) or sensitivity (enzyme immunoassays; EIAs). The performance of the Singulex Clarity® C. diff toxins A/B assay was compared to cell cytotoxicity neutralization assay. Testing was also performed using an EIA for glutamate dehydrogenase (GDH) and C. difficile toxins A and B (C. Diff Quik Chek Complete®), polymerase chain reaction (PCR) (BD MAX™ Cdiff Assay), and 2 multistep algorithms: algorithm 1 (discordant GDH/toxin results arbitrated by PCR) and algorithm 2 (PCR-positive samples tested with toxin EIA). The Clarity assay and PCR both had 97% sensitivity, while specificity was 100% for Clarity and 79% for PCR. Algorithm 1 yielded 41% discordant results, and both toxin EIA and algorithm 2 had 58% sensitivity. Median toxin concentrations, as measured by the Clarity C. difficile toxin assay, were 3590, 11.5, 0.4, and 0 pg/mL for GDH+/toxin+, GDH+/toxin-/PCR+, GDH+/toxin-/PCR-, and GDH-/toxin- samples, respectively (P < 0.001). The Clarity assay may offer a single-test solution for CDI.
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Affiliation(s)
| | - Ray Mills
- TriCore Reference Laboratories, Albuquerque, NM, USA
| | | | - Aaron Wagner
- TriCore Reference Laboratories, Albuquerque, NM, USA
| | | | | | | | | | | | | | | | | | | | - Stephen Young
- TriCore Reference Laboratories, Albuquerque, NM, USA; Department of Pathology, The University of New Mexico Health Science Center, Albuquerque, NM, USA.
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Johnson S. The Rise and Fall and Rise Again of Toxin Testing for the Diagnosis of Clostridioides difficile Infection. Clin Infect Dis 2019; 69:1675-1677. [DOI: 10.1093/cid/ciz012] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2018] [Accepted: 01/04/2019] [Indexed: 01/05/2023] Open
Affiliation(s)
- Stuart Johnson
- Loyola University Chicago Stritch School of Medicine, Maywood
- Hines Veterans Affairs Hospital, Illinois
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Orenstein R, Patron RL. Clostridioides difficile therapeutics: guidelines and beyond. Ther Adv Infect Dis 2019; 6:2049936119868548. [PMID: 31448117 PMCID: PMC6693025 DOI: 10.1177/2049936119868548] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2019] [Revised: 07/17/2019] [Indexed: 12/21/2022] Open
Abstract
Clostridioides difficile infection (CDI) has become an increasingly common infection both within and outside of the hospital setting. The management of this infection has been evolving as we learn more about the role of the human microbiota in protecting us from this gastrointestinal opportunist. For many years the focus of treatment had been on eradication of the vegetative, toxin-producing form of the organism, with little regard for its collateral impact on the host's microbiota or risk of recurrence. With the marked increase in C. difficile disease, and, particularly, recurrent disease in the last decade, new guidelines are more focused on targeting and reducing collateral damage to the colonic microbiota. Immune-based strategies that manipulate the microbiota and provide a humoral response to toxins have now become mainstream. Newer strategies are needed to look beyond simply resolving the primary episode but are focused on delayed outcomes such as cure at 90 days, reduced morbidity and mortality, and patient quality of life. The purpose of this review is to familiarize readers with the most recent evidence-based guidelines for C. difficile management, and to describe the role of newer antimicrobials, immunological-, and microbiota-based therapeutics to prevent recurrence and improve the outcomes of people with CDI.
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Affiliation(s)
- Robert Orenstein
- Division of Infectious Diseases, Mayo Clinic
Arizona, 5777 East Mayo Boulevard, Phoenix, AZ 85054, USA
| | - Roberto L. Patron
- Division of Infectious Diseases, Mayo Clinic
Arizona, Phoenix, AZ, USA
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