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van Prehn J, Crobach MJT, Baktash A, Duszenko N, Kuijper EJ. Diagnostic Guidance for C. difficile Infections. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2024; 1435:33-56. [PMID: 38175470 DOI: 10.1007/978-3-031-42108-2_3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/05/2024]
Abstract
Diagnosis of Clostridioides difficile infection (CDI) can be challenging. First of all, there has been debate on which of the two reference assays, cell cytotoxicity neutralization assay (CCNA) or toxigenic culture (TC), should be considered the gold standard for CDI detection. Although the CCNA suffers most from suboptimal storage conditions and subsequent toxin degradation, TC is reported to falsely increase CDI detection rates as it cannot differentiate CDI patients from patients asymptomatically colonised by toxigenic C. difficile. Several rapid assays are available for CDI detection and fall into three broad categories: (1) enzyme immunoassays for glutamate dehydrogenase, (2) enzyme immunoassays or single-molecule array assays for toxins A/B and (3) nucleic acid amplification tests detecting toxin genes. All three categories have their own limitations, being suboptimal specificity and/or sensitivity or the inability to discern colonised patients from CDI patients. In light of these limitations, multi-step algorithmic testing has been advocated by international guidelines (IDSA/SHEA and ESCMID) in order to optimize diagnostic accuracy. As a result, a survey performed in 2018-2019 in Europe revealed that most of all hospital sites reported using more than one test to diagnose CDI. CDI incidence rates are also influenced by sample selection criteria, as several studies have shown that if not all unformed stool samples are tested for CDI, many cases may be missed due to an absence of clinical suspicion. Since methods for diagnosing CDI remain imperfect, there has been a growing interest in alternative testing strategies like faecal microbiota biomarkers, immune modulating interleukins, cytokines and imaging methods. At the moment, these alternative methods might play an adjunctive role, but they are not suitable to replace conventional CDI testing strategies.
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Affiliation(s)
- Joffrey van Prehn
- Department of Medical Microbiology, Leiden University Centre for Infectious Diseases (LU-CID), Leiden University Medical Centre, Leiden, The Netherlands.
- ESCMID Study Group for C. difficile (ESGCD) and Study Group for Host and Microbiota Interaction (ESGHAMI), Basel, Switzerland.
| | - Monique J T Crobach
- Department of Medical Microbiology, Leiden University Centre for Infectious Diseases (LU-CID), Leiden University Medical Centre, Leiden, The Netherlands
| | - Amoe Baktash
- Department of Medical Microbiology, Leiden University Centre for Infectious Diseases (LU-CID), Leiden University Medical Centre, Leiden, The Netherlands
| | - Nikolas Duszenko
- Department of Medical Microbiology, Leiden University Centre for Infectious Diseases (LU-CID), Leiden University Medical Centre, Leiden, The Netherlands
| | - Ed J Kuijper
- Department of Medical Microbiology, Leiden University Centre for Infectious Diseases (LU-CID), Leiden University Medical Centre, Leiden, The Netherlands
- ESCMID Study Group for C. difficile (ESGCD) and Study Group for Host and Microbiota Interaction (ESGHAMI), Basel, Switzerland
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Bocchetti M, Ferraro MG, Melisi F, Grisolia P, Scrima M, Cossu AM, Yau TO. Overview of current detection methods and microRNA potential in Clostridioides difficile infection screening. World J Gastroenterol 2023; 29:3385-3399. [PMID: 37389232 PMCID: PMC10303512 DOI: 10.3748/wjg.v29.i22.3385] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/25/2023] [Revised: 03/23/2023] [Accepted: 05/04/2023] [Indexed: 06/06/2023] Open
Abstract
Clostridioides difficile (formerly called Clostridium difficile, C. difficile) infection (CDI) is listed as an urgent threat on the 2019 antibiotic resistance threats report in the United States by the Centers for Disease Control and Prevention. Early detection and appropriate disease management appear to be essential. Meanwhile, although the majority of cases are hospital-acquired CDI, community-acquired CDI cases are also on the rise, and this vulnerability is not limited to immunocompromised patients. Gastrointestinal treatments and/or gastrointestinal tract surgeries may be required for patients diagnosed with digestive diseases. Such treatments could suppress or interfere with the patient’s immune system and disrupt gut flora homeostasis, creating a suitable microecosystem for C. difficile overgrowth. Currently, stool-based non-invasive screening is the first-line approach to CDI diagnosis, but the accuracy is varied due to different clinical microbiology detection methods; therefore, improving reliability is clearly required. In this review, we briefly summarised the life cycle and toxicity of C. difficile, and we examined existing diagnostic approaches with an emphasis on novel biomarkers such as microRNAs. These biomarkers can be easily detected through non-invasive liquid biopsy and can yield crucial information about ongoing pathological phenomena, particularly in CDI.
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Affiliation(s)
- Marco Bocchetti
- Department of Precision Medicine, University of Campania “Luigi Vanvitelli,” Naples 80138, Italy
- Department of Molecular Oncology, Precision Medicine Laboratory and COVID19 Laboratory, Biogem Scarl, Ariano Irpino 83031, Italy
| | - Maria Grazia Ferraro
- School of Infection and Immunity, College of Medical Veterinary and Life Sciences, University of Glasgow, Glasgow G12 8QQ, United Kingdom
- Department of Pharmacy, School of Medicine and Surgery, University of Naples “Federico II,” Naples 80131, Italy
| | - Federica Melisi
- Department of Precision Medicine, University of Campania “Luigi Vanvitelli,” Naples 80138, Italy
- Department of Molecular Oncology, Precision Medicine Laboratory and COVID19 Laboratory, Biogem Scarl, Ariano Irpino 83031, Italy
| | - Piera Grisolia
- Department of Precision Medicine, University of Campania “Luigi Vanvitelli,” Naples 80138, Italy
- Department of Molecular Oncology, Precision Medicine Laboratory and COVID19 Laboratory, Biogem Scarl, Ariano Irpino 83031, Italy
| | - Marianna Scrima
- Department of Molecular Oncology, Precision Medicine Laboratory and COVID19 Laboratory, Biogem Scarl, Ariano Irpino 83031, Italy
| | - Alessia Maria Cossu
- Department of Precision Medicine, University of Campania “Luigi Vanvitelli,” Naples 80138, Italy
- Department of Molecular Oncology, Precision Medicine Laboratory and COVID19 Laboratory, Biogem Scarl, Ariano Irpino 83031, Italy
| | - Tung On Yau
- School of Science and Technology, Nottingham Trent University, Nottingham NG11 8NS, United Kingdom
- Department of Rural Land Use, Scotland’s Rural College, Aberdeen AB21 9YA, Scotland, United Kingdom
- Department of Health Science, University of the People, Pasadena, CA 9110112, United States
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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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Performances of the BD MAX™ CDIFF assay for the detection of toxigenic Clostridioides difficile using Cary-Blair preserved samples. Diagn Microbiol Infect Dis 2022; 103:115701. [DOI: 10.1016/j.diagmicrobio.2022.115701] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2021] [Revised: 03/24/2022] [Accepted: 04/02/2022] [Indexed: 11/19/2022]
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Giles J, Roberts A. Clostridioides difficile: Current overview and future perspectives. ADVANCES IN PROTEIN CHEMISTRY AND STRUCTURAL BIOLOGY 2022; 129:215-245. [PMID: 35305720 DOI: 10.1016/bs.apcsb.2021.11.003] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
The most common world-wide cause of antibiotic-associated infectious diarrhea and colitis is the toxin producing bacterium, Clostridioides difficile (C. difficile). Here we review the background and characteristics of the bacterium and the toxins produced together with the epidemiology and the complex pathogenesis that leads to a broad clinical spectrum of disease. The review describes the difficulties faced in obtaining a quick and accurate diagnosis despite the range of sensitive and specific diagnostic tools available. We also discuss the problem of disease recurrence and the importance of disease prevention. The high rates of infection recurrence mean that treatment strategies are constantly under review and we outline the diverse treatment options that are currently in use and explore the emerging treatment options of pulsed antibiotic use, microbial replacement therapies and the use of monoclonal antibodies. We summarize the future direction of treatment strategies which include the development of novel antibiotics, the administration of oral polyclonal antibody formulations, the use of vaccines, the administration of competitive non-toxigenic spores and the neutralization of antibiotics at the microbiota level. Future successful treatments will likely involve a combination of therapies to provide the most effective and robust approach to C. difficile management.
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Affiliation(s)
- Joanna Giles
- MicroPharm Ltd, Newcastle Emlyn, United Kingdom.
| | - April Roberts
- Toxins Group, National Infection Service, Public Health England, Porton Down, United Kingdom
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van Prehn J, Reigadas E, Vogelzang EH, Bouza E, Hristea A, Guery B, Krutova M, Norén T, Allerberger F, Coia JE, Goorhuis A, van Rossen TM, Ooijevaar RE, Burns K, Scharvik Olesen BR, Tschudin-Sutter S, Wilcox MH, Vehreschild MJGT, Fitzpatrick F, Kuijper EJ. European Society of Clinical Microbiology and Infectious Diseases: 2021 update on the treatment guidance document for Clostridioides difficile infection in adults. Clin Microbiol Infect 2021; 27 Suppl 2:S1-S21. [PMID: 34678515 DOI: 10.1016/j.cmi.2021.09.038] [Citation(s) in RCA: 248] [Impact Index Per Article: 82.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2021] [Revised: 09/23/2021] [Accepted: 09/30/2021] [Indexed: 12/13/2022]
Abstract
SCOPE In 2009, the European Society of Clinical Microbiology and Infectious Diseases (ESCMID) published the first treatment guidance document for Clostridioides difficile infection (CDI). This document was updated in 2014. The growing literature on CDI antimicrobial treatment and novel treatment approaches, such as faecal microbiota transplantation (FMT) and toxin-binding monoclonal antibodies, prompted the ESCMID study group on C. difficile (ESGCD) to update the 2014 treatment guidance document for CDI in adults. METHODS AND QUESTIONS Key questions on CDI treatment were formulated by the guideline committee and included: What is the best treatment for initial, severe, severe-complicated, refractory, recurrent and multiple recurrent CDI? What is the best treatment when no oral therapy is possible? Can prognostic factors identify patients at risk for severe and recurrent CDI and is there a place for CDI prophylaxis? Outcome measures for treatment strategy were: clinical cure, recurrence and sustained cure. For studies on surgical interventions and severe-complicated CDI the outcome was mortality. Appraisal of available literature and drafting of recommendations was performed by the guideline drafting group. The total body of evidence for the recommendations on CDI treatment consists of the literature described in the previous guidelines, supplemented with a systematic literature search on randomized clinical trials and observational studies from 2012 and onwards. The Grades of Recommendation Assessment, Development and Evaluation (GRADE) system was used to grade the strength of our recommendations and the quality of the evidence. The guideline committee was invited to comment on the recommendations. The guideline draft was sent to external experts and a patients' representative for review. Full ESCMID endorsement was obtained after a public consultation procedure. RECOMMENDATIONS Important changes compared with previous guideline include but are not limited to: metronidazole is no longer recommended for treatment of CDI when fidaxomicin or vancomycin are available, fidaxomicin is the preferred agent for treatment of initial CDI and the first recurrence of CDI when available and feasible, FMT or bezlotoxumab in addition to standard of care antibiotics (SoC) are preferred for treatment of a second or further recurrence of CDI, bezlotoxumab in addition to SoC is recommended for the first recurrence of CDI when fidaxomicin was used to manage the initial CDI episode, and bezlotoxumab is considered as an ancillary treatment to vancomycin for a CDI episode with high risk of recurrence when fidaxomicin is not available. Contrary to the previous guideline, in the current guideline emphasis is placed on risk for recurrence as a factor that determines treatment strategy for the individual patient, rather than the disease severity.
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Affiliation(s)
- Joffrey van Prehn
- Department of Medical Microbiology, Centre for Infectious Diseases, Leiden University Medical Center, Leiden, the Netherlands
| | - Elena Reigadas
- Department of Clinical Microbiology and Infectious Diseases, Hospital General Universitario Gregorio Marañón, Madrid, Spain
| | - Erik H Vogelzang
- Department of Medical Microbiology and Infection Control, Amsterdam University Medical Center, Location VUmc, Amsterdam, the Netherlands
| | - Emilio Bouza
- Department of Clinical Microbiology and Infectious Diseases, Hospital General Universitario Gregorio Marañón, Madrid, Spain
| | - Adriana Hristea
- University of Medicine and Pharmacy Carol Davila, National Institute for Infectious Diseases Prof Dr Matei Bals, Romania
| | - Benoit Guery
- Infectious Diseases Specialist, Centre Hospitalier Universitaire Vaudois, Lausanne, Switzerland
| | - Marcela Krutova
- Department of Medical Microbiology, Charles University in Prague and Motol University Hospital, Czech Republic
| | - Torbjorn Norén
- Faculty of Medicine and Health, Department of Laboratory Medicine, National Reference Laboratory for Clostridioides difficile, Clinical Microbiology, Örebro University Hospital, Örebro, Sweden
| | | | - John E Coia
- Department of Clinical Microbiology, Hospital South West Jutland and Department of Regional Health Research IRS, University of Southern Denmark, Esbjerg, Denmark
| | - Abraham Goorhuis
- Department of Infectious Diseases, Amsterdam University Medical Centers, Academic Medical Center, Amsterdam, the Netherlands
| | - Tessel M van Rossen
- Department of Medical Microbiology and Infection Control, Amsterdam University Medical Center, Location VUmc, Amsterdam, the Netherlands
| | - Rogier E Ooijevaar
- Department of Gastroenterology, Amsterdam University Medical Center, Location VUmc, Amsterdam, the Netherlands
| | - Karen Burns
- Departments of Clinical Microbiology, Beaumont Hospital & Royal College of Surgeons in Ireland, Dublin, Ireland
| | | | - Sarah Tschudin-Sutter
- Department of Infectious Diseases and Infection Control, University Hospital Basel, University Basel, Universitatsspital, Basel, Switzerland
| | - Mark H Wilcox
- Department of Microbiology, Old Medical, School Leeds General Infirmary, Leeds Teaching Hospitals & University of Leeds, Leeds, United Kingdom
| | - Maria J G T Vehreschild
- German Centre for Infection Research (DZIF), Partner Site Bonn-Cologne, Cologne, Germany; Department of Internal Medicine, Infectious Diseases, University Hospital Frankfurt, Goethe University Frankfurt, Frankfurt am Main, Germany
| | - Fidelma Fitzpatrick
- Department of Clinical Microbiology, Beaumont Hospital, Dublin, Ireland; Department of Clinical Microbiology, Royal College of Surgeons in Ireland, Dublin, Ireland
| | - Ed J Kuijper
- Department of Medical Microbiology, Centre for Infectious Diseases, Leiden University Medical Center, Leiden, the Netherlands; National Institute for Public Health and the Environment (RIVM), Bilthoven, the Netherlands.
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Bonacorsi S, Visseaux B, Bouzid D, Pareja J, Rao SN, Manissero D, Hansen G, Vila J. Systematic Review on the Correlation of Quantitative PCR Cycle Threshold Values of Gastrointestinal Pathogens With Patient Clinical Presentation and Outcomes. Front Med (Lausanne) 2021; 8:711809. [PMID: 34631732 PMCID: PMC8496934 DOI: 10.3389/fmed.2021.711809] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2021] [Accepted: 08/19/2021] [Indexed: 02/04/2023] Open
Abstract
Background: Quantitative (q) polymerase chain reaction (PCR) cycle threshold (Ct) values represent the number of amplification cycles required for a positive PCR result and are a proxy of pathogen quantity in the tested sample. The clinical utility of Ct values remains unclear for gastrointestinal infections. Objectives: This systematic review assesses the global medical literature for associations between Ct values of gastrointestinal pathogens and patient presentation and clinical outcomes. Data Sources: MEDLINE, EMBASE, Cochrane library databases: searched January 14-17, 2020. Study Eligibility Criteria: Studies reporting on the presence or absence of an association between Ct values and clinical outcomes in adult and pediatric populations were included. Animal studies, reviews, meta-analyses, and non-English language studies were excluded. Participants: Humans infected with gastrointestinal pathogens, detected with qPCR. Interventions: Diagnostics assessing Ct values. Extracted data were reported narratively. Results: Thirty-three eligible studies were identified; the most commonly studied pathogens were Clostridioides difficile (n = 15), norovirus (n = 10), and rotavirus (n = 9). Statistically significant associations between low C. difficile Ct values and increased symptom severity or poor outcome were reported in 4/8 (50%) studies, and increased risk of death in 1/2 (50%) studies; no significant associations were found between Ct value and duration of symptoms or length of hospital stay. Among studies of norovirus, 5/7 (71%), mainly genogroup II, reported symptomatic cases with significantly lower median Ct values than controls. Significantly lower rotavirus Ct values were also observed in symptomatic cases vs. controls in 3/7 (43%) studies, and associated with more severe symptoms in 2/2 studies. Contradictory associations were identified for non-C. difficile bacterial and parasitic pathogens. Conclusions: In conclusion, some studies reported clinically useful associations between Ct values and patient or healthcare outcomes; additional, well-designed, large-scale trials are warranted based on these findings. Systematic Review Registration: [PROSPERO], identifier [CRD42020167239].
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Affiliation(s)
- Stéphane Bonacorsi
- Department of Microbiology, Robert Debré University Hospital, AP-HP, Paris, France
| | - Benoit Visseaux
- Université de Paris, IAME, INSERM, Paris, France
- Université de Paris, Laboratoire de Virologie, Hôpital Bichat Claude Bernard, Assistance Publique-Hôpitaux de Paris, Paris, France
| | - Donia Bouzid
- Université de Paris, IAME, INSERM, Paris, France
- Université de Paris, Service d'Accueil des Urgences, Hôpital Bichat Claude Bernard, Assistance Publique-Hôpitaux de Paris, Paris, France
| | - Josep Pareja
- STAT-Dx Life, S.L. (a QIAGEN Company), Medical Affairs, Barcelona, Spain
| | - Sonia N. Rao
- QIAGEN Inc., Medical Affairs, Germantown, MD, United States
| | - Davide Manissero
- QIAGEN Manchester Ltd, Medical Affairs, Manchester, United Kingdom
| | - Glen Hansen
- Microbiology and Molecular Diagnostics, Hennepin County Medical Center, Department of Infectious Diseases, School of Medicine, University of Minnesota, Minneapolis, MN, United States
- Department of Pathology and Laboratory Medicine, School of Medicine, University of Minnesota, Minneapolis, MN, United States
| | - Jordi Vila
- Biomedical Diagnostic Centre, Department of Clinical Microbiology, Institute of Global Health, School of Medicine, Hospital Clinic, University of Barcelona, Barcelona, Spain
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Bai Y, Hao Y, Song Z, Chu W, Jin Y, Wang Y. Evaluation of the Cepheid Xpert C. difficile diagnostic assay: an update meta-analysis. Braz J Microbiol 2021; 52:1937-1949. [PMID: 34455573 PMCID: PMC8578272 DOI: 10.1007/s42770-021-00563-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/25/2020] [Accepted: 06/27/2021] [Indexed: 11/28/2022] Open
Abstract
Background Accurate and rapid diagnosis of Clostridium difficile infection (CDI) is critical for effective patient management and implementation of infection control measures to prevent transmission. Objectives We updated our previous meta-analysis to provide a more reliable evidence base for the clinical diagnosis of Xpert C. difficile (Xpert C. difficile) assay. Methods We searched PubMed, EMBASE, Cochrane Library, Chinese National Knowledge Infrastructure (CNKI), and the Chinese Biomedical Literature Database (CBM) databases to identify studies according to predetermined criteria. STATA 13.0 software was used to analyze the tests for sensitivity, specificity, positive likelihood ratio, negative likelihood ratio, diagnostic odds ratio, and area under the summary receiver operating characteristic curves (AUC). QUADAS-2 was used to assess the quality of included studies with RevMan 5.2. Heterogeneity in accuracy measures was tested with Spearman correlation coefficient and chi-square. Meta-regressions and subgroup analyses were performed to figure out the potential sources of heterogeneity. Model diagnostics were used to evaluate the veracity of the data. Results A total of 26 studies were included in the meta-analysis. The pooled sensitivity (95% confidence intervals [CI]) for diagnosis was 0.97(0.95–0.98), and specificity was 0.96(0.95–0.97). The AUC was 0.99 (0.98–1.00). Model diagnostics confirmed the robustness of our meta-analysis’s results. Significant heterogeneity was still observed when we pooled most of the accuracy measures of selected studies. Meta-regression and subgroup analyses showed that the sample size and type, ethnicity, and disease prevalence might be the conspicuous sources of heterogeneity. Conclusions The up-to-date meta-analysis showed the Xpert CD assay had good accuracy for detecting CDI. However, the diagnosis of CDI must combine clinical presentation with diagnostic testing to better answer the question of whether the patient actually has CDI in the future, and inclusion of preanalytical parameters and clinical outcomes in study design would provide a more objective evidence base.
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Affiliation(s)
- Yuanyuan Bai
- Department of Clinical Laboratory, Shandong Provincial Hospital Affiliated to Shandong First Medical University, 324 Jingwu Road, Jinan, People's Republic of China
| | - Yingying Hao
- Department of Clinical Laboratory, Shandong Provincial Hospital Affiliated to Shandong First Medical University, 324 Jingwu Road, Jinan, People's Republic of China
| | - Zhen Song
- Department of Clinical Laboratory, Shandong Provincial Hospital Affiliated to Shandong First Medical University, 324 Jingwu Road, Jinan, People's Republic of China
| | - Wenjun Chu
- Department of Clinical Laboratory, Shandong Provincial Hospital Affiliated to Shandong First Medical University, 324 Jingwu Road, Jinan, People's Republic of China
| | - Yan Jin
- Department of Clinical Laboratory, Shandong Provincial Hospital Affiliated to Shandong First Medical University, 324 Jingwu Road, Jinan, People's Republic of China.
| | - Yueling Wang
- Department of Clinical Laboratory, Shandong Provincial Hospital Affiliated to Shandong First Medical University, 324 Jingwu Road, Jinan, People's Republic of China.
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Noori M, Ghalavand Z, Azimirad M, Yadegar A, Eslami G, Krutova M, Brajerova M, Goudarzi M, Zali MR. Genetic diversity and phylogenetic analysis of the surface layer protein A gene (slpA) among Clostridioides difficile clinical isolates from Tehran, Iran. Anaerobe 2021; 70:102403. [PMID: 34111549 DOI: 10.1016/j.anaerobe.2021.102403] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2020] [Revised: 05/24/2021] [Accepted: 06/04/2021] [Indexed: 12/15/2022]
Abstract
Clostridioides difficile is the most common causative agent of healthcare-associated diarrhea. C. difficile strains produce a crystalline surface layer protein (SlpA), encoded by the slpA gene. Previous studies have shown that SlpA varies among C. difficile strains. In this study, we used the SlpA sequence-based typing system (SlpAST) for the molecular genotyping of C. difficile clinical isolates identified in Iran; the PCR ribotypes (RTs) and toxin profiles of the isolates were also characterized. Forty-eight C. difficile isolates were obtained from diarrheal patients, and characterized by capillary electrophoresis (CE) PCR ribotyping and the detection of toxin genes. In addition, the genetic diversity of the slpA gene was investigated by Sanger sequencing. The most common RTs were RT126 (20.8%), followed by RT001 (12.5%) and RT084 (10.4%). The intact PaLoc arrangement representing cdu2+/tcdR+/tcdB+/tcdE+/tcdA+/tcdC+/cdd3+ profile was the predominant pattern and cdtA and cdtB genes were found in one-third of the isolates. Using the SlpA genotyping, 12 main genotypes and 16 subtypes were identified. The SlpA type 078-1 was the most prevalent genotype (20.8%), and identified within the isolates of RT126. The yok-1, gr-1, cr-1 and kr-3 genotypes were detected in 14.5%, 12.5%, 12.5% and 8.3% of isolates, respectively. Almost all the isolates with the same RT were clustered in similar SlpA sequence types. In comparison to PCR ribotyping, SlpAST, as a simple and highly reproducible sequenced-based technique, can discriminate well between C. difficile isolates. This typing method appears to be a valuable tool for the epidemiological study of C. difficile isolates worldwide.
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Affiliation(s)
- Maryam Noori
- Department of Microbiology, School of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran; Foodborne and Waterborne Diseases Research Center, Research Institute for Gastroenterology and Liver Diseases, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Zohreh Ghalavand
- Department of Microbiology, School of Medicine, 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
| | - Abbas Yadegar
- Foodborne and Waterborne Diseases Research Center, Research Institute for Gastroenterology and Liver Diseases, Shahid Beheshti University of Medical Sciences, Tehran, Iran.
| | - Gita Eslami
- Department of Microbiology, School of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran.
| | - Marcela Krutova
- Department of Medical Microbiology, Charles University, 2nd Faculty of Medicine and Motol University Hospital, Prague, Czech Republic
| | - Marie Brajerova
- Department of Medical Microbiology, Charles University, 2nd Faculty of Medicine and Motol University Hospital, Prague, Czech Republic
| | - Mehdi Goudarzi
- Department of Microbiology, School of Medicine, 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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Jaqueti Aroca J, Molina Esteban LM, García-Arata I, García-Martínez J, Cano De Torres I, Prieto Menchero S. Significance of a polymerase chain reaction method in the detection of Clostridioides difficile. REVISTA ESPANOLA DE QUIMIOTERAPIA 2021; 34:141-144. [PMID: 33601876 PMCID: PMC8019460 DOI: 10.37201/req/010.2020] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
OBJECTIVE Clostridioides difficile (CD) is the most common cause of nosocomial diarrhea. Detection of CD toxin in patients' faecal samples is the traditional rapid method for the diagnosis of CD infection. Various testing algorithms have been proposed: an initial screening test using a rapid test, and a confirmatory test (cytotoxicity neutralization assay, toxigenic culture, nucleic acid amplification test) for discordant results. The aim of this study was to evaluate the effectiveness of a two-step algorithm using an immunochromatographic test followed of a polymerase chain reaction (PCR). METHODS The specimens have been tested according to the following schedule: 1) Step one: All samples were tested for detection of glutamate dehydrogenase antigen (GDH) and toxin A/B using the C. diff QUIK CHEK Complete test. All GDH and toxins positive results were considered CD positives; 2) Step two: When the results were discrepant (only GDH+ or toxins+), the samples were confirmed using the PCR test BD MAX Cdiff. All PCR positive results were considered CD positives. RESULTS A total of 2,138 specimens were initially tested. 139 were positive for GDH and toxins. 160 discrepant results (148 GDH+ and 12 toxins+) were tested by PCR, 117 were positive (107/148 GDH+ and 10/12 toxins+). CONCLUSIONS The implementation of a PCR method showed an increase de 117 positive results (73.1% of discrepant). Considering the sensitivity of C.diff QUIK CHEK (instructions of manufacturer), the GDH discrepant results may be false negatives, y the samples PCR and toxins positives may be real positives results.
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Affiliation(s)
- J Jaqueti Aroca
- Jerónimo Jaqueti Aroca, Laboratorio Clínico, Hospital Universitario de Fuenlabrada, Camino del Molino, 2. 28942 Madrid, Spain.
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11
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Lyerly DM, Boone JH, Carman RJ, Tillotson GS. Clostridioides difficile Infection: The Challenge, Tests, and Guidelines. ACS Infect Dis 2020; 6:2818-2829. [PMID: 32960044 DOI: 10.1021/acsinfecdis.0c00290] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Clostridioides difficile is a dangerous human pathogen because it can grow to high numbers in the intestine, cause colitis with its potent toxins, and persist as spores. C. difficile infection (CDI) is the primary hospital-acquired infection in North America and Europe, and it now is a global disease. Even with newer laboratory tests, there still is confusion on accurately diagnosing this disease. Three guidelines from three different healthcare-affiliated societies have recently been published. Consensus consolidated recommendations from these guidelines should be recognized by healthcare professionals, who need to understand why this disease continues to be difficult to diagnose and need a clear understanding of the advantages and limitations of current tests. Hopefully, these combined efforts will lead to an improvement in the recognition of this pathogen and a reduction in the suffering and economic loss caused by CDI.
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Affiliation(s)
- David M Lyerly
- TechLab, Inc., 2001 Kraft Drive, Blacksburg, Virginia 24060, United States
| | - James H Boone
- TechLab, Inc., 2001 Kraft Drive, Blacksburg, Virginia 24060, United States
| | - Robert J Carman
- TechLab, Inc., 2001 Kraft Drive, Blacksburg, Virginia 24060, United States
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12
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Lloyd CD, Shah-Gandhi B, Parsons BD, Morin SBN, Du T, Golding GR, Chui L. Direct Clostridioides difficile ribotyping from stool using capillary electrophoresis. Diagn Microbiol Infect Dis 2020; 99:115259. [PMID: 33217718 DOI: 10.1016/j.diagmicrobio.2020.115259] [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] [Received: 08/24/2020] [Revised: 10/26/2020] [Accepted: 10/29/2020] [Indexed: 01/05/2023]
Abstract
Clostridioides difficile(C. difficile) genotyping is essential for surveillance of emerging strains, transmissions, and outbreak investigations, but culture is lengthy and may not be routinely performed, which necessitates culture-independent genotyping methods. We aimed to develop a direct from stool C. difficile PCR ribotyping algorithm using capillary electrophoresis. Ribotypes were generated directly from 66.8% of stools with 33.2% requiring broth enrichment. 16S and tcdB cycle thresholds (Ct) were significantly lower (P< 0.001) in directly ribotyped stools compared to enriched stools, and Ct correlated with direct ribotyping (area under the curve: 0.97 and 0.96, respectively). Direct and isolate ribotypes were 94.7% concordant. Mixed C. difficile ribotypes were presumptively identified in 14 (7.5%) samples with 12 (6.4%) mixtures confirmed. We have developed a rapid PCR ribotyping algorithm allowing for direct C. difficile genotyping from stool using capillary electrophoresis with occasional detection of mixed C. difficile populations in stool, which is a limitation of conventional isolate genotyping.
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Affiliation(s)
- Colin D Lloyd
- Department of Laboratory Medicine and Pathology, University of Alberta, Edmonton, Alberta, Canada
| | - Binal Shah-Gandhi
- Department of Laboratory Medicine and Pathology, University of Alberta, Edmonton, Alberta, Canada
| | - Brendon D Parsons
- Department of Laboratory Medicine and Pathology, University of Alberta, Edmonton, Alberta, Canada
| | - Sarah B N Morin
- Department of Laboratory Medicine and Pathology, University of Alberta, Edmonton, Alberta, Canada
| | - Tim Du
- National Microbiology Laboratory, Public Health Agency of Canada, Winnipeg, Manitoba, Canada
| | - George R Golding
- National Microbiology Laboratory, Public Health Agency of Canada, Winnipeg, Manitoba, Canada
| | - Linda Chui
- Department of Laboratory Medicine and Pathology, University of Alberta, Edmonton, Alberta, Canada; Provincial Laboratory for Public Health, Alberta Precision Laboratories, Edmonton, Alberta, Canada.
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13
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Doolan CP, Louie T, Lata C, Larios OE, Stokes W, Kim J, Brown K, Beck P, Deardon R, Pillai DR. Latent class analysis for the diagnosis of Clostridioides difficile infection. Clin Infect Dis 2020; 73:e2673-e2679. [PMID: 33053174 DOI: 10.1093/cid/ciaa1553] [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: 07/24/2020] [Indexed: 01/05/2023] Open
Abstract
BACKGROUND Clostridioides difficile infection (CDI) is an opportunistic disease that lacks a gold standard test. Nucleic acid amplification tests (NAATs) such as real-time PCR demonstrate excellent an limit of detection (LOD) whereas antigenic methods are able to detect free toxin. Latent class analysis (LCA) provides an unbiased statistical approach to resolving true disease. METHODS A cross-sectional study was conducted with suspected CDI patients (n=96). Four commercial real-time PCR tests, toxin antigen detection by enzyme immunoassay (EIA), toxigenic culture, and fecal calprotectin were performed. CDI clinical diagnosis was determined by consensus majority of three experts. LCA was performed using laboratory and clinical variables independent of any gold standard. RESULTS Six LCA models were generated to determine CDI probability using four variables including toxin EIA, toxigenic culture, clinical diagnosis, and fecal calprotectin levels. Three defined zones as a function of real-time PCR cycle threshold (Ct) were identified using LCA: CDI likely (>90% probability), equivocal (<90% and >10%), CDI unlikely (<10%). A single model comprising toxigenic culture, clinical diagnosis, and toxin EIA showed the best fitness. The following Ct cut-offs for four commercial test platforms were obtained using this model to delineate three CDI probability zones: [GeneXpert ® : 24.00, 33.61], [Simplexa ® 28.97, 36.85], [Elite MGB ® 30.18, 37.43], and [BD Max ™ 27.60, 34.26]. CONCLUSION The clinical implication of applying LCA to CDI is to report Ct values assigned to probability zones based on the commercial real-time PCR platform. A broad range of equivocation suggests clinical judgement is essential to the confirmation of CDI.
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Affiliation(s)
- Cody P Doolan
- Clinical Section of Microbiology, Alberta Precision Laboratories, Calgary, AB, Canada.,Department of Microbiology, Immunology, and Infectious Diseases, University of Calgary, AB, Canada.,Department Pathology and Laboratory Medicine, University of Calgary, Calgary, AB, Canada
| | - Thomas Louie
- Clinical Section of Infectious Diseases, Department of Medicine, University of Calgary, Calgary, AB, Canada
| | | | - Oscar E Larios
- Clinical Section of Microbiology, Alberta Precision Laboratories, Calgary, AB, Canada.,Department Pathology and Laboratory Medicine, University of Calgary, Calgary, AB, Canada.,Clinical Section of Infectious Diseases, Department of Medicine, University of Calgary, Calgary, AB, Canada
| | - William Stokes
- Clinical Section of Microbiology, Alberta Precision Laboratories, Calgary, AB, Canada.,Department Pathology and Laboratory Medicine, University of Calgary, Calgary, AB, Canada.,Clinical Section of Infectious Diseases, Department of Medicine, University of Calgary, Calgary, AB, Canada
| | - Joseph Kim
- Clinical Section of Infectious Diseases, Department of Medicine, University of Calgary, Calgary, AB, Canada
| | - Kristen Brown
- Clinical Section of Microbiology, Alberta Precision Laboratories, Calgary, AB, Canada.,Department Pathology and Laboratory Medicine, University of Calgary, Calgary, AB, Canada.,Clinical Section of Infectious Diseases, Department of Medicine, University of Calgary, Calgary, AB, Canada
| | - Paul Beck
- Clinical Section of Gastroenterology, Department of Medicine, University of Calgary, Calgary, AB, Canada
| | - Rob Deardon
- Department of Mathematics and Statistics, Faculty of Science, University of Calgary, Calgary, AB, Canada.,Department of Production Animal Health, Faculty of Veterinary Medicine, University of Calgary, Calgary, AB, Canada
| | - Dylan R Pillai
- Clinical Section of Microbiology, Alberta Precision Laboratories, Calgary, AB, Canada.,Department of Microbiology, Immunology, and Infectious Diseases, University of Calgary, AB, Canada.,Department Pathology and Laboratory Medicine, University of Calgary, Calgary, AB, Canada.,Clinical Section of Infectious Diseases, Department of Medicine, University of Calgary, Calgary, AB, Canada
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14
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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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15
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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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16
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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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17
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Schwenk HT, Bio LL, Kruger JF, Banaei N. Clinical Impact of Clostridium difficile PCR Cycle Threshold-Predicted Toxin Reporting in Pediatric Patients. J Pediatric Infect Dis Soc 2020; 9:44-50. [PMID: 30476169 DOI: 10.1093/jpids/piy117] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/12/2018] [Accepted: 10/25/2018] [Indexed: 02/07/2023]
Abstract
BACKGROUND Reliance on tests that detect only the presence of toxigenic Clostridium difficile can result in overdiagnosis and overtreatment of C difficile infection (CDI). The C difficile polymerase chain reaction (PCR) cycle threshold (CT) can sensitively predict the presence of free C difficile toxins; however, the clinical application for this testing strategy remains unexplored. We evaluated the impact of dual PCR and toxin result reporting, as predicted by the CT, on CDI management and outcomes in children. METHODS Before the intervention, results for C difficile testing at Lucile Packard Children's Hospital Stanford were reported as PCR positive (PCR+) or negative (PCR-) according to the GeneXpert C diff Epi tcdB PCR assay (Cepheid, Sunnyvale, California). Beginning October 5, 2016, the presence of free toxins, as predicted by the CT, was reported also. The CDI treatment rates 1 year before and 18 months after implementation of toxin reporting were compared. Demographic and treatment-related data were collected, and patient outcomes were followed up 8 weeks later. RESULTS CDI treatment decreased 22% after the intervention (96% [preintervention] vs 74% [postintervention]; P < .001). During the postintervention period, there were 152 PCR+C difficile results, and 94 (62%) of them were toxin positive (toxin+) according to the CT. Of the 58 PCR+/toxin-negative (toxin-) results, 38 (66%) did not result in CDI treatment. Seven (18%) of the untreated PCR+/toxin- patients underwent repeat testing within 8 weeks, and 5 (13%) of them were subsequently PCR+/toxin+ and treated. No CDI-related complications were identified. CONCLUSIONS Addition of the CT-predicted C difficile toxin result to PCR reporting reduces the proportion of PCR+ children treated for CDI.
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Affiliation(s)
- Hayden T Schwenk
- Division of Infectious Diseases, Department of Pediatrics, Stanford University School of Medicine, Stanford, California
| | - Laura L Bio
- Department of Pharmacy, Lucile Packard Children's Hospital Stanford, Palo Alto, California
| | - Jenna F Kruger
- Center for Quality and Clinical Effectiveness, Lucile Packard Children's Hospital Stanford, Palo Alto, California
| | - Niaz Banaei
- Department of Pathology, Stanford University School of Medicine, Stanford, California.,Division of Infectious Diseases and Geographic Medicine, Department of Medicine, Stanford University School of Medicine, Stanford, California.,Clinical Microbiology Laboratory, Stanford University Medical Center, Palo Alto, California
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18
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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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19
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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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20
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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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21
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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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22
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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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23
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Hetem DJ, Bos-Sanders I, Nijhuis RHT, Tamminga S, Berlinger L, Kuijper EJ, Sickler JJ, Claas ECJ. Evaluation of the Liat Cdiff Assay for Direct Detection of Clostridioides difficile Toxin Genes within 20 Minutes. J Clin Microbiol 2019; 57:JCM.00416-19. [PMID: 30944191 PMCID: PMC6535596 DOI: 10.1128/jcm.00416-19] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2019] [Accepted: 03/22/2019] [Indexed: 12/24/2022] Open
Abstract
Clostridioides difficile is the main causative agent of antibiotic-associated diarrhea. Prompt diagnosis is required for initiation of timely infection control measures and appropriate adjustment of antibiotic treatment. The cobas Cdiff assay for use on the cobas Liat system enables a diagnostic result in 20 minutes. A total of 252 prospective (n = 150) and retrospective (n = 102) stool specimens from The Netherlands, France, and Switzerland were tested on the cobas Cdiff assay using the Xpert C. difficile assay as a reference method. The overall positive and negative percent agreement (PPA and NPA, respectively) of the cobas Cdiff assay compared with the Xpert C. difficile assay was 98.0% (100/102; 95% confidence interval [CI], 93.1% to 99.5%) and 94.0% (141/150; 95% CI, 89.0% to 96.8%), respectively. When comparing the PPAs of cobas Cdiff and Xpert C. difficile with culture, the results were 91.7% (55/60; 95% CI, 81.9% to 96.4%) and 85.0% (51/60; 95% CI, 73.9% to 91.9%), respectively. The difference was not statistically significant. The cobas Cdiff assay offers a very rapid alternative for diagnosing C. difficile infection. The 20-minute turnaround time provides the potential for point-of-care testing so that adequate infection control measures can be initiated promptly.
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Affiliation(s)
- David J Hetem
- Haaglanden Medical Center, Department of Microbiology, The Hague, The Netherlands
| | - Ingrid Bos-Sanders
- Leiden University Medical Center, Department of Medical Microbiology, Leiden, The Netherlands
| | - Roel H T Nijhuis
- Haaglanden Medical Center, Department of Microbiology, The Hague, The Netherlands
- Leiden University Medical Center, Department of Medical Microbiology, Leiden, The Netherlands
| | - Sven Tamminga
- Haaglanden Medical Center, Department of Microbiology, The Hague, The Netherlands
| | - Livia Berlinger
- BioAnalytica AG, Department of Microbiology, Luzern, Switzerland
| | - Ed J Kuijper
- Leiden University Medical Center, Department of Medical Microbiology, Leiden, The Netherlands
| | | | - Eric C J Claas
- Leiden University Medical Center, Department of Medical Microbiology, Leiden, The Netherlands
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24
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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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25
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Han SH, Yi J, Kim JH, Lee S, Moon HW. Composition of gut microbiota in patients with toxigenic Clostridioides (Clostridium) difficile: Comparison between subgroups according to clinical criteria and toxin gene load. PLoS One 2019; 14:e0212626. [PMID: 30785932 PMCID: PMC6382146 DOI: 10.1371/journal.pone.0212626] [Citation(s) in RCA: 30] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2018] [Accepted: 02/06/2019] [Indexed: 12/19/2022] Open
Abstract
Data concerning the human microbiota composition during Clostridioides (Clostridium) difficile infection (CDI) using next-generation sequencing are still limited. We aimed to confirm key features indicating tcdB positive patients and compare the microbiota composition between subgroups based on toxin gene load (tcdB gene) and presence of significant diarrhea. Ninety-nine fecal samples from 79 tcdB positive patients and 20 controls were analyzed using 16S rRNA gene sequencing. Chao1 index for alpha diversity were calculated and principal coordinate analysis was performed for beta diversity using Quantitative Insights into Microbial Ecology (QIIME) pipeline. The mean relative abundance in each group was compared at phylum, family, and genus levels. There were significant alterations in alpha and beta diversity in tcdB positive patients (both colonizer and CDI) compared with those in the control. The mean Chao1 index of tcdB positive patients was significantly lower than the control group (P<0.001), whereas there was no significant difference between tcdB groups and between colonizer and CDI. There were significant differences in microbiota compositions between tcdB positive patients and the control at phylum, family, and genus levels. Several genera such as Phascolarctobacterium, Lachnospira, Butyricimonas, Catenibacterium, Paraprevotella, Odoribacter, and Anaerostipes were not detected in most CDI cases. We identified several changes in the microbiota of CDI that could be further evaluated as predictive markers. Microbiota differences between clinical subgroups of CDI need to be further studied in larger controlled studies.
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Affiliation(s)
- Sung-Hee Han
- BioCore Co. Ltd., Biotechnology, Yongin, Republic of Korea
| | - Joowon Yi
- Department of Laboratory Medicine, Konkuk University School of Medicine, Seoul, Republic of Korea
| | - Ji-Hoon Kim
- BioCore Co. Ltd., R&D Center, Seoul, Republic of Korea
| | - SangWon Lee
- College of Veterinary Medicine, Konkuk University, Seoul, Republic of Korea
| | - Hee-Won Moon
- Department of Laboratory Medicine, Konkuk University School of Medicine, Seoul, Republic of Korea
- * E-mail:
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26
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The predictive value of quantitative nucleic acid amplification detection of Clostridium difficile toxin gene for faecal sample toxin status and patient outcome. PLoS One 2018; 13:e0205941. [PMID: 30517094 PMCID: PMC6281240 DOI: 10.1371/journal.pone.0205941] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2018] [Accepted: 11/06/2018] [Indexed: 12/16/2022] Open
Abstract
BACKGROUND Laboratory diagnosis of Clostridium difficile infection (CDI) remains unsettled, despite updated guidelines. We investigated the potential utility of quantitative data from a nucleic acid amplification test (NAAT) for C. difficile toxin gene (tg) for patient management. METHODS Using data from the largest ever C. difficile diagnostic study (8853 diarrhoeal samples from 7335 patients), we determined the predicative value of C. difficile tgNAAT (Cepheid Xpert C.diff) low cycle threshold (CT) value for patient toxin positive status, CDI severity, mortality and CDI recurrence. Reference methods for CDI diagnosis were cytotoxicity assay (CTA) and cytotoxigenic culture (CTC). RESULTS Of 1281 tgNAAT positive faecal samples, 713 and 917 were CTA and CTC positive, respectively. The median tgNAAT CT for patients who died was 25.5 vs 27.5 for survivors (p = 0.021); for toxin-positivity was 24.9 vs 31.6 for toxin-negative samples (p<0.001) and for patients with a recurrence episode was 25.6 vs 27.3 for those who did not have a recurrent episode (p = 0.111). Following optimal cut-off determination, low CT was defined as ≤25 and was significantly associated with a toxin-positive result (P<0.001, positive predictive value 83.9%), presence of PCR-ribotype 027 (P = 0.025), and mortality (P = 0.032). Recurrence was not associated with low CT (p 0.111). CONCLUSIONS Low tgNAAT CT could indicate CTA positive patients, have more severe infection, increased risk of mortality and possibly recurrence. Although, the limited specificity of tgNAAT means it cannot be used as a standalone test, it could augment a more timely diagnosis, and optimise management of these at-risk patients.
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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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