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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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Zangiabadian M, Ghorbani A, Nojookambari NY, Ahmadbeigi Y, Hosseini SS, Karimi-Yazdi M, Goudarzi M, Chirani AS, Nasiri MJ. Accuracy of diagnostic assays for the detection of Clostridioides difficile: A systematic review and meta-analysis. J Microbiol Methods 2023; 204:106657. [PMID: 36528183 DOI: 10.1016/j.mimet.2022.106657] [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: 10/06/2022] [Revised: 12/13/2022] [Accepted: 12/13/2022] [Indexed: 12/24/2022]
Abstract
INTRODUCTION Clostridioides difficile Infection (CDI) has been identified as one of the main causes of nosocomial infection all across the world. Rapid diagnosis of CDI is difficult and poses a significant challenge to physicians worldwide. We undertook a systematic review and meta-analysis to evaluate rapid tests' diagnostic accuracy against toxigenic culture as the reference standard for CDI. METHOD We searched the PubMed/MEDLINE and EMBASE databases for the relevant records. The QUADAS-2 tool was used to assess the quality of the studies. Diagnostic accuracy measures [i.e., sensitivity, specificity, diagnostic odds ratio (DOR), positive likelihood ratios (PLR), negative likelihood ratios (NLR), and the area under the curve (AUC)] were pooled with a random-effects model. All statistical analyses were performed with Meta-DiSc (Version 1.4, Cochrane Colloquium, Barcelona, Spain) and RevMan (version 5.3; The Nordic Cochrane Centre, the Cochrane Collaboration, Copenhagen, Denmark). RESULTS We reviewed retrieved records and identified 63 studies that met the inclusion criteria. 26 were about enzyme immunoassay (EIA) (our main index test). The sensitivity of GDH and Tox A/B EIAs were 82% (95% CI: 79-84) and 75% (95% CI: 70-79), respectively. On the other hand, the specificity of GDH EIA was 91% (95% CI: 90-92) and the specificity of Tox A/B EIA was 95% (95% CI: 94-96). Among other index tests, BD Max with 92% has the most sensitivity and cell cytotoxicity neutralization assay (CCNA) has the most specificity (100%). CONCLUSION This meta-analysis demonstrated that EIAs could be reliable methods for detecting CDI based on their sensitivity, specificity, time and cost-effectiveness, and simplicity in the procedure. Further work to improve rapid tests would benefit from improvements to the methodology.
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Affiliation(s)
- Moein Zangiabadian
- Endocrinology and Metabolism Research Center, Institute of Basic and Clinical Physiology Sciences, Kerman University of Medical Sciences, Kerman, Iran
| | - Alireza Ghorbani
- Department of Microbiology, school of medicine, Shahid Beheshti University of medical sciences, Tehran, Iran
| | - Neda Yousefi Nojookambari
- Department of Microbiology, school of medicine, Shahid Beheshti University of medical sciences, Tehran, Iran
| | - Yasaman Ahmadbeigi
- Department of Microbiology and Microbial Biotechnology, Faculty of Life Sciences and Biotechnology, Shahid Beheshti University, Tehran, Iran
| | - Sareh Sadat Hosseini
- Department of Microbiology, school of medicine, Shahid Beheshti University of medical sciences, Tehran, Iran
| | | | - Mehdi Goudarzi
- Department of Microbiology, school of medicine, Shahid Beheshti University of medical sciences, Tehran, Iran.
| | | | - Mohammad Javad Nasiri
- Department of Microbiology, school of medicine, Shahid Beheshti University of medical sciences, Tehran, Iran.
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Leitner E, Bozic M, Kienesberger S, Cosic A, Landt O, Högenauer C, Kessler HH. Improved diagnosis of antibiotic-associated haemorrhagic colitis (AAHC) in faecal specimens by a new qualitative real-time PCR assay detecting relevant toxin genes of Klebsiella oxytoca sensu lato. Clin Microbiol Infect 2022; 28:690-694. [PMID: 34582979 DOI: 10.1016/j.cmi.2021.09.017] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2021] [Revised: 08/27/2021] [Accepted: 09/15/2021] [Indexed: 02/04/2023]
Abstract
OBJECTIVE Toxin-producing Klebsiella oxytoca causes antibiotic-associated haemorrhagic colitis (AAHC). The disease-relevant cytotoxins tilivalline and tilimycine produced by certain K. oxytoca isolates are encoded by the non-ribosomal peptide synthetase genes A (npsA) and B (npsB). In this study, the new LightMix® Modular kit for the detection of relevant K. oxytoca sensu lato (s.l.) toxin genes was evaluated. METHODS DNA was extracted on the automated EMAG® platform. Amplification was done on the Light Cycler® 480 II instrument. In total, 130 residual faecal specimens collected from patients with antibiotic-associated diarrhoea were studied to determine the clinical sensitivity and specificity. Toxigenic culture served as reference method. RESULTS With the new kit, the limit of detection was 15 CFU/mL for all targets. For the pehX target specific to K. oxytoca s.l., 65 of 130 clinical specimens were positive, while toxin-specific targets (npsA/npsB) were positive in 47 of 130. The npsA/npsB PCR targets showed a clinical sensitivity of 100% (95%CI 80.5-100%) and a specificity of 73.5% (95%CI 64.3-81.3%) with a positive predictive value of 16.5% (95%CI 12.7-21.2%) and a negative predictive value of 100%. CONCLUSION Compared with culture, additional clinical specimens positive for K. oxytoca s.l. were detected with real-time PCR. The specificity of the toxin targets appears moderate due to the inferior sensitivity of the culture-based reference method. Since the developed assay is highly sensitive, it may be used as first-line method to improve the diagnosis of AAHC.
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Affiliation(s)
- Eva Leitner
- Diagnostic and Research Institute of Hygiene, Microbiology and Environmental Medicine, Medical University of Graz, Austria.
| | - Michael Bozic
- Diagnostic and Research Institute of Hygiene, Microbiology and Environmental Medicine, Medical University of Graz, Austria
| | - Sabine Kienesberger
- Institute of Molecular Biosciences, University of Graz, Austria; BioTechMed-Graz, Austria; Field of Excellence BioHealth, University of Graz, Austria
| | - Amar Cosic
- Institute of Molecular Biosciences, University of Graz, Austria
| | | | - Christoph Högenauer
- BioTechMed-Graz, Austria; Division of Gastroenterology and Hepatology, Department of Internal Medicine, Medical University of Graz, Austria
| | - Harald H Kessler
- Diagnostic and Research Institute of Hygiene, Microbiology and Environmental Medicine, Medical University of Graz, Austria
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Martins JP, Felgueiras M, Santos R. The reference method influence on the sensitivity of the Clostridium difficile enzyme immunoassays: A meta analysis. J Microbiol Methods 2020; 173:105912. [PMID: 32278778 DOI: 10.1016/j.mimet.2020.105912] [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: 06/06/2019] [Revised: 03/22/2020] [Accepted: 03/31/2020] [Indexed: 11/16/2022]
Abstract
The use of enzyme immunoassays to screen for toxins A and B produced by Clostridium difficile is a common procedure in algorithms designed for its detection. Moreover, the absence of a unique test capable of providing reliable results at low cost motivates a great discussion about which algorithm is the best. Thus, several studies have evaluated the performance of these enzyme immunoassays. However, all fail to provide sufficient explanations for the different behaviours observed in different studies that evaluate the same index test against a common reference method. Our main goal was to find out which factors affect the sensitivity of these assays, since the specificity is very close to 1. In this research, we verified that sensitivity increases with the prevalence rate and with the proportion of reported cases of onset diarrhea. Therefore, its use is advisable for high prevalence rates (e.g. in an epidemic setting). As far as reference methods are concerned, nucleic acid amplification tests can be used as a reference method, with a performance similar to the well-accepted toxigenic culture. The method chosen for toxigenicity screening in a toxigenic culture also seems to affect the evaluation performance of tests and should be better studied in the future.
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Affiliation(s)
- João Paulo Martins
- ESTG, Polytechnic Institute of Leiria, Campus 2, Morro do Lena Alto do Vieiro, Apartado 4163, 2411-901 Leiria, Portugal; CEAUL - Centre of Statistics and its Applications, Faculdade de Ciências da Universidade de Lisboa, Campo Grande, 1749-016 Lisboa, Portugal.
| | - Miguel Felgueiras
- ESTG, Polytechnic Institute of Leiria, Campus 2, Morro do Lena Alto do Vieiro, Apartado 4163, 2411-901 Leiria, Portugal; CARME, Polytechnic Institute of Leiria, Campus 2, Morro do Lena Alto do Vieiro, Apartado 4163, 2411-901 Leiria, Portugal; CEAUL - Centre of Statistics and its Applications, Faculdade de Ciências da Universidade de Lisboa, Campo Grande, 1749-016 Lisboa, Portugal
| | - Rui Santos
- ESTG, Polytechnic Institute of Leiria, Campus 2, Morro do Lena Alto do Vieiro, Apartado 4163, 2411-901 Leiria, Portugal; CEAUL - Centre of Statistics and its Applications, Faculdade de Ciências da Universidade de Lisboa, Campo Grande, 1749-016 Lisboa, Portugal
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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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Kraft CS, Parrott JS, Cornish NE, Rubinstein ML, Weissfeld AS, McNult P, Nachamkin I, Humphries RM, Kirn TJ, Dien Bard J, Lutgring JD, Gullett JC, Bittencourt CE, Benson S, Bobenchik AM, Sautter RL, Baselski V, Atlas MC, Marlowe EM, Miller NS, Fischer M, Richter SS, Gilligan P, Snyder JW. A Laboratory Medicine Best Practices Systematic Review and Meta-analysis of Nucleic Acid Amplification Tests (NAATs) and Algorithms Including NAATs for the Diagnosis of Clostridioides ( Clostridium) difficile in Adults. Clin Microbiol Rev 2019; 32:32/3/e00032-18. [PMID: 31142497 PMCID: PMC6589859 DOI: 10.1128/cmr.00032-18] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
The evidence base for the optimal laboratory diagnosis of Clostridioides (Clostridium) difficile in adults is currently unresolved due to the uncertain performance characteristics and various combinations of tests. This systematic review evaluates the diagnostic accuracy of laboratory testing algorithms that include nucleic acid amplification tests (NAATs) to detect the presence of C. difficile The systematic review and meta-analysis included eligible studies (those that had PICO [population, intervention, comparison, outcome] elements) that assessed the diagnostic accuracy of NAAT alone or following glutamate dehydrogenase (GDH) enzyme immunoassays (EIAs) or GDH EIAs plus C. difficile toxin EIAs (toxin). The diagnostic yield of NAAT for repeat testing after an initial negative result was also assessed. Two hundred thirty-eight studies met inclusion criteria. Seventy-two of these studies had sufficient data for meta-analysis. The strength of evidence ranged from high to insufficient. The uses of NAAT only, GDH-positive EIA followed by NAAT, and GDH-positive/toxin-negative EIA followed by NAAT are all recommended as American Society for Microbiology (ASM) best practices for the detection of the C. difficile toxin gene or organism. Meta-analysis of published evidence supports the use of testing algorithms that use NAAT alone or in combination with GDH or GDH plus toxin EIA to detect the presence of C. difficile in adults. There is insufficient evidence to recommend against repeat testing of the sample using NAAT after an initial negative result due to a lack of evidence of harm (i.e., financial, length of stay, or delay of treatment) as specified by the Laboratory Medicine Best Practices (LMBP) systematic review method in making such an assessment. Findings from this systematic review provide clarity to diagnostic testing strategies and highlight gaps, such as low numbers of GDH/toxin/PCR studies, in existing evidence on diagnostic performance, which can be used to guide future clinical research studies.
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Affiliation(s)
| | - J Scott Parrott
- Department of Interdisciplinary Studies, School of Health Professions, Rutgers University, Newark, New Jersey, USA
- Department of Epidemiology, School of Public Health, Rutgers University, Piscataway, New Jersey, USA
| | - Nancy E Cornish
- Centers for Disease Control and Prevention, Atlanta, Georgia, USA
| | | | | | - Peggy McNult
- American Society for Microbiology, Washington, DC, USA
| | - Irving Nachamkin
- Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | | | - Thomas J Kirn
- Department of Interdisciplinary Studies, School of Health Professions, Rutgers University, Newark, New Jersey, USA
- Department of Epidemiology, School of Public Health, Rutgers University, Piscataway, New Jersey, USA
| | - Jennifer Dien Bard
- Children's Hospital Los Angeles, Los Angeles, California, USA
- Keck School of Medicine, University of Southern California, Los Angeles, California, USA
| | | | - Jonathan C Gullett
- Kaiser Permanente (Southern California Permanente Medical Group) Regional Reference Laboratories, Greater Los Angeles, Los Angeles, California, USA
| | | | - Susan Benson
- PathWest Laboratory Medicine, Perth, Western Australia, Australia
- University of Western Australia, Perth, Western Australia, Australia
| | - April M Bobenchik
- Rhode Island Hospital/Lifespan Academic Medical Center, Warren Alpert Medical School of Brown University, Providence, Rhode Island, USA
| | | | - Vickie Baselski
- University of Tennessee Health Science Center, Memphis, Tennessee, USA
| | - Michel C Atlas
- Kornhauser Health Sciences Library, University of Louisville, Louisville, Kentucky, USA
| | | | - Nancy S Miller
- Boston Medical Center, Boston, Massachusetts, USA
- Boston University School of Medicine, Boston, Massachusetts, USA
| | | | | | - Peter Gilligan
- University of North Carolina School of Medicine, Chapel Hill, North Carolina, USA
| | - James W Snyder
- Kornhauser Health Sciences Library, University of Louisville, Louisville, Kentucky, USA
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Crobach MJT, Planche T, Eckert C, Barbut F, Terveer EM, Dekkers OM, Wilcox MH, Kuijper EJ. European Society of Clinical Microbiology and Infectious Diseases: update of the diagnostic guidance document for Clostridium difficile infection. Clin Microbiol Infect 2016; 22 Suppl 4:S63-81. [PMID: 27460910 DOI: 10.1016/j.cmi.2016.03.010] [Citation(s) in RCA: 350] [Impact Index Per Article: 43.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2015] [Revised: 03/02/2016] [Accepted: 03/10/2016] [Indexed: 12/14/2022]
Abstract
In 2009 the first European Society of Clinical Microbiology and Infectious Diseases (ESCMID) guideline for diagnosing Clostridium difficile infection (CDI) was launched. Since then newer tests for diagnosing CDI have become available, especially nucleic acid amplification tests. The main objectives of this update of the guidance document are to summarize the currently available evidence concerning laboratory diagnosis of CDI and to formulate and revise recommendations to optimize CDI testing. This update is essential to improve the diagnosis of CDI and to improve uniformity in CDI diagnosis for surveillance purposes among Europe. An electronic search for literature concerning the laboratory diagnosis of CDI was performed. Studies evaluating a commercial laboratory test compared to a reference test were also included in a meta-analysis. The commercial tests that were evaluated included enzyme immunoassays (EIAs) detecting glutamate dehydrogenase, EIAs detecting toxins A and B and nucleic acid amplification tests. Recommendations were formulated by an executive committee, and the strength of recommendations and quality of evidence were graded using the Grades of Recommendation Assessment, Development and Evaluation (GRADE) system. No single commercial test can be used as a stand-alone test for diagnosing CDI as a result of inadequate positive predictive values at low CDI prevalence. Therefore, the use of a two-step algorithm is recommended. Samples without free toxin detected by toxins A and B EIA but with positive glutamate dehydrogenase EIA, nucleic acid amplification test or toxigenic culture results need clinical evaluation to discern CDI from asymptomatic carriage.
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Affiliation(s)
- M J T Crobach
- Department of Medical Microbiology, Centre for Infectious Diseases, Leiden University Medical Center, Leiden, The Netherlands
| | - T Planche
- Department of Medical Microbiology, St. George's Hospital, London, UK
| | - C Eckert
- National Reference Laboratory for Clostridium difficile, Paris, France
| | - F Barbut
- National Reference Laboratory for Clostridium difficile, Paris, France
| | - E M Terveer
- Department of Medical Microbiology, Centre for Infectious Diseases, Leiden University Medical Center, Leiden, The Netherlands
| | - O M Dekkers
- Departments of Clinical Epidemiology and Internal Medicine, Leiden University Medical Center, Leiden, The Netherlands; Department of Clinical Epidemiology, Aarhus University, Aarhus, Denmark
| | - M H Wilcox
- Department of Microbiology, Leeds Teaching Hospitals & University of Leeds, Leeds, UK
| | - E J Kuijper
- Department of Medical Microbiology, Centre for Infectious Diseases, Leiden University Medical Center, Leiden, The Netherlands.
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Evaluation of the BD Max Cdiff assay for the detection of toxigenic Clostridium difficile in human stool specimens. Pathology 2015; 47:165-8. [PMID: 25551308 DOI: 10.1097/pat.0000000000000214] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
The Becton Dickinson (BD) PCR-based GeneOhm Cdiff assay has demonstrated a high sensitivity and specificity for detecting Clostridium difficile. Recently, the BD Max platform, using the same principles as BD GeneOhm, has become available in Australia. This study aimed to investigate the sensitivity and specificity of BD Max Cdiff assay for the detection of toxigenic C. difficile in an Australian setting. Between December 2013 and January 2014, 406 stool specimens from 349 patients were analysed with the BD Max Cdiff assay. Direct and enrichment toxigenic culture were performed on bioMérieux ChromID C. difficile agar as a reference method. isolates from specimens with discrepant results were further analysed with an in-house PCR to detect the presence of toxin genes. The overall prevalence of toxigenic C. difficile was 7.2%. Concordance between the BD Max assay and enrichment culture was 98.5%. The sensitivity, specificity, positive predictive value and negative predictive value for the BD Max Cdiff assay were 95.5%, 99.0%, 87.5% and 99.7%, respectively, when compared to direct culture, and 91.7%, 99.0%, 88.0% and 99.4%, respectively, when compared to enrichment culture. The new BD Max Cdiff assay appeared to be an excellent platform for rapid and accurate detection of toxigenic C. difficile.
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