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Lee HW, Yu HJ, Kim H, Yun SA, Suh E, Kang M, Kim TY, Huh HJ, Lee NY. Comparative evaluation of the STANDARD M10 and Xpert C. difficile assays for detection of toxigenic Clostridioides difficile in stool specimens. J Clin Microbiol 2024; 62:e0052424. [PMID: 38934589 PMCID: PMC11250526 DOI: 10.1128/jcm.00524-24] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2024] [Accepted: 06/11/2024] [Indexed: 06/28/2024] Open
Abstract
This study compared the performance of two commercial molecular assays, the STANDARD M10 Clostridioides difficile assay (M10) and the Xpert C. difficile assay (Xpert), for detecting toxigenic C. difficile in stool specimens. A total of 487 consecutive stool specimens submitted for routine C. difficile testing between June and November 2023 were included. Following routine testing using C. DIFF QUIK CHEK COMPLETE (QCC), M10 and Xpert were tested in parallel, alongside toxigenic culture (reference standard). Additionally, two-step algorithms, using QCC on the first step and either M10 or Xpert on the second step, were assessed. Both M10 and Xpert demonstrated a sensitivity and negative predictive value (NPV) of 100%. M10 exhibited significantly higher specificity and positive predictive value (PPV; 91.9% and 64.2%, respectively) than Xpert (90.3% and 59.8%, respectively). Both two-step algorithms showed a sensitivity and NPV of 98.4% and 99.8%, respectively. The specificity and PPV of the two-step algorithm using M10 (95.2% and 75.0%, respectively) were slightly higher than those of the one using Xpert (94.8% and 73.2%, respectively), without statistical significance. Receiver operating characteristic curve analysis, assessing the predictive ability of cycle threshold (Ct) values for the detection of free toxin, exhibited an area under the curve of 0.825 for M10 and 0.843 for Xpert. This indicates the utility of Ct values as predictors for the detection of free toxin in both assays. In conclusion, M10 proves to be an effective diagnostic tool with performance comparable to Xpert, whether utilized independently or as part of a two-step algorithm.
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Affiliation(s)
- Hyun-Woo Lee
- Department of Laboratory Medicine and Genetics, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, South Korea
| | - Hui-Jin Yu
- Department of Laboratory Medicine, Seoul Medical Center, Seoul, South Korea
| | - Heejung Kim
- Department of Laboratory Medicine, Seoul Medical Center, Seoul, South Korea
| | - Sun Ae Yun
- Center for Clinical Medicine, Samsung Biomedical Research Institute, Samsung Medical Center, Seoul, South Korea
| | - Eunsang Suh
- Department of Laboratory Medicine and Genetics, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, South Korea
| | - Minhee Kang
- Biomedical Engineering Research Center, Smart Healthcare Research Institute, Samsung Medical Center, Seoul, South Korea
- Department of Medical Device Management and Research, Samsung Advanced Institute for Health Sciences and Technology, Sungkyunkwan University, Seoul, South Korea
| | - Tae Yeul Kim
- Department of Laboratory Medicine and Genetics, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, South Korea
| | - Hee Jae Huh
- Department of Laboratory Medicine and Genetics, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, South Korea
| | - Nam Yong Lee
- Department of Laboratory Medicine and Genetics, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, South Korea
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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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Geleta GS. A colorimetric aptasensor based on gold nanoparticles for detection of microbial toxins: an alternative approach to conventional methods. Anal Bioanal Chem 2022; 414:7103-7122. [PMID: 35902394 DOI: 10.1007/s00216-022-04227-9] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2022] [Revised: 07/06/2022] [Accepted: 07/08/2022] [Indexed: 11/01/2022]
Abstract
Frequent contamination of foods with microbial toxins produced by microorganisms such as bacteria, fungi, and algae represents an increasing public health problem that requires the development of quick and easy tools to detect them at trace levels. Recently, it has been found that colorimetric detection methods may replace traditional methods in the field because of their ease of use, quick response, ease of manufacture, low cost, and naked-eye visibility. Therefore, it is suitable for fieldwork, especially for work in remote areas of the world. However, the development of colorimetric detection methods with low detection limits is a challenge that limits their wide applicability in the detection of food contaminants. To address these challenges, nanomaterial-based transduction systems are used to construct colorimetric biosensors. For example, gold nanoparticles (AuNPs) provide an excellent platform for the development of colorimetric biosensors because they offer the advantages of easy synthesis, biocompatibility, advanced surface functionality, and adjustable physicochemical properties. The selectivity of the colorimetric biosensor can be achieved by the combination of aptamers and gold nanoparticles, which provides an unprecedented opportunity to detect microbial toxins. Compared to antibodies, aptamers have significant advantages in the analysis of microbial toxins due to their smaller size, higher binding affinity, reproducible chemical synthesis and modification, stability, and specificity. Two colorimetric mechanisms for the detection of microbial toxins based on AuNPs have been described. First, sensors that use the localized surface plasmon resonance (LSPR) phenomenon of gold nanoparticles can exhibit very strong colors in the visible range because of changes caused by aggregation or disaggregation. Second, the detection mechanism of AuNPs is based on their enzyme mimetic properties and it is possible to construct a colorimetric biosensor based on the 3,3',5,5'-tetramethylbenzidine/Hydrogen peroxide, TMB/H2O2 reaction to detect microbial toxins. Therefore, this review summarizes the recent applications of AuNP-based colorimetric aptasensors for detecting microbial toxins, including bacterial toxins, fungal toxins, and algal toxins focusing on selectivity, sensitivity, and practicality. Finally, the most important current challenges in this field and future research opportunities are discussed.
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Affiliation(s)
- Girma Salale Geleta
- Department of Chemistry, College of Natural Sciences, Salale University, P.O. Box 245, Oromia, Fiche, Ethiopia.
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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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Nho SW, Kim M, Kim SJ, Foley SL, Nayak R, Kweon O, Cerniglia CE. Pragmatic Strategy for Fecal Specimen Storage and the Corresponding Test Methods for Clostridioides difficile Diagnosis. Pathogens 2021; 10:pathogens10081049. [PMID: 34451512 PMCID: PMC8400358 DOI: 10.3390/pathogens10081049] [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: 07/27/2021] [Revised: 08/12/2021] [Accepted: 08/13/2021] [Indexed: 12/02/2022] Open
Abstract
The quality of fecal specimens is one of the factors responsible for successful Clostridioides difficile infection (CDI) diagnosis. The quality depends largely on the storage conditions, including the temperature and time period. In this study, we organized the outputs of previous studies, filled experimental gaps in the knowledge of storage conditions, and introduced a pragmatic strategy for fecal storage for CDI diagnosis. A 5-step pathway was adopted to develop the fecal specimen storage strategy as follows: step 1, bibliomic analysis; step 2, experimental gap-filling; step 3, comparative evaluation; step 4, strategy development; step 5, internal review. Step 1 identified eight articles providing experimental information on the effects of fecal specimen storage conditions on the effectiveness of C. difficile detection methods. Step 2 provided additional quantitative data on C. difficile vegetative and spore cell viability and DNA stability. All previous and current results were compared (step 3). In step 4, fir general and nine special strategies were developed, followed by an internal review of the overall approaches (step 5). It is recommended to separate fecal samples into aliquots before testing and storing them. It is particularly recommended that fecal specimen samples be stored for CDI diagnosis at 4 °C for up to 60 days for all test methods.
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Affiliation(s)
- Seong Won Nho
- Division of Microbiology, National Center for Toxicological Research, U.S. Food and Drug Administration, Jefferson, AR 72079, USA; (S.W.N.); (M.K.); (S.-J.K.); (S.L.F.)
| | - Minjae Kim
- Division of Microbiology, National Center for Toxicological Research, U.S. Food and Drug Administration, Jefferson, AR 72079, USA; (S.W.N.); (M.K.); (S.-J.K.); (S.L.F.)
| | - Seong-Jae Kim
- Division of Microbiology, National Center for Toxicological Research, U.S. Food and Drug Administration, Jefferson, AR 72079, USA; (S.W.N.); (M.K.); (S.-J.K.); (S.L.F.)
| | - Steven L. Foley
- Division of Microbiology, National Center for Toxicological Research, U.S. Food and Drug Administration, Jefferson, AR 72079, USA; (S.W.N.); (M.K.); (S.-J.K.); (S.L.F.)
| | - Rajesh Nayak
- Office of Regulatory Compliance and Risk Management, National Center for Toxicological Research, U.S. Food and Drug Administration, Jefferson, AR 72079, USA;
| | - Ohgew Kweon
- Division of Microbiology, National Center for Toxicological Research, U.S. Food and Drug Administration, Jefferson, AR 72079, USA; (S.W.N.); (M.K.); (S.-J.K.); (S.L.F.)
- Correspondence: (O.K.); (C.E.C.)
| | - Carl E. Cerniglia
- Division of Microbiology, National Center for Toxicological Research, U.S. Food and Drug Administration, Jefferson, AR 72079, USA; (S.W.N.); (M.K.); (S.-J.K.); (S.L.F.)
- Correspondence: (O.K.); (C.E.C.)
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Loderstädt U, Hagen RM, Hahn A, Frickmann H. New Developments in PCR-Based Diagnostics for Bacterial Pathogens Causing Gastrointestinal Infections-A Narrative Mini-Review on Challenges in the Tropics. Trop Med Infect Dis 2021; 6:tropicalmed6020096. [PMID: 34199650 PMCID: PMC8293448 DOI: 10.3390/tropicalmed6020096] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2021] [Revised: 05/31/2021] [Accepted: 05/31/2021] [Indexed: 12/15/2022] Open
Abstract
The application of modern PCR approaches for the diagnosis of bacterial gastrointestinal pathogens is on the rise due to their rapidly available results combined with high sensitivity. While multiple studies describe the ongoing implementation of this technique for routine diagnostic purposes in laboratories in Western industrialized countries, reports on successful and also sustainable respective approaches in resource-poor tropical settings are still scarce. In order to shed light on potential reasons for this marked discrepancy, this narrative review summarizes identified challenges for the application of diagnostic PCR targeting bacterial gastrointestinal pathogens from stool samples in the tropics. The identified and discussed issues comprise the lack of generally accepted definitions for (1) minimum standards regarding sample acquisition, storage and transport time for diagnostic PCR analyses in the tropics, (2) nucleic acid extraction standards allowing an optimum detection of all types of pathogens which may be responsible for gastroenteritis in the tropics, (3) validation standards to ensure comparable quality of applied diagnostic assays, and (4) cut-offs for a reliable discrimination of infection and mere colonization in areas where semi-immunity due to repeated exposition associated with poor hygiene conditions has to be expected. Further implementation research is needed to solve those issues.
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Affiliation(s)
- Ulrike Loderstädt
- Institute for Infection Control and Infectious Diseases, University Medical Center Göttingen, 37075 Göttingen, Germany;
| | - Ralf Matthias Hagen
- Department of Microbiology and Hospital Hygiene, Bundeswehr Central Hospital Koblenz, Andernacher Str. 100, 56070 Koblenz, Germany;
| | - Andreas Hahn
- Institute for Medical Microbiology, Virology and Hygiene, University Medicine Rostock, 18057 Rostock, Germany;
| | - Hagen Frickmann
- Institute for Medical Microbiology, Virology and Hygiene, University Medicine Rostock, 18057 Rostock, Germany;
- Department of Microbiology and Hospital Hygiene, Bundeswehr Hospital Hamburg, 20359 Hamburg, Germany
- Correspondence: or or ; Tel.: +49-40-6947-28743
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Dichtl K, Zimmermann J, Koeppel MB, Böhm S, Osterman A. Evaluation of a Novel CLIA Monotest Assay for the Detection of Anti-Hepatitis E Virus-IgG and IgM: A Retrospective Comparison with a Line Blot and an ELISA. Pathogens 2021; 10:pathogens10060689. [PMID: 34206114 PMCID: PMC8228023 DOI: 10.3390/pathogens10060689] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2021] [Revised: 05/25/2021] [Accepted: 05/28/2021] [Indexed: 12/27/2022] Open
Abstract
Despite the increasing relevance of Hepatitis E, an emerging disease endemic in developing and with increasing numbers of sporadic cases in industrialized countries, commercial tests are mainly based on batch oriented serological assays. In this retrospective study, we compared a line immunoassay (LIA; recomLine HEV, Mikrogen) and an ELISA (EIA; Anti-Hepatitis E Virus ELISA, Euroimmun) with a novel chemoluminescence immunoassay in a monotest format (CLIA; Hepatitis E VirClia, Vircell). Twenty sera of PCR proven cases of hepatitis E and 68 blood samples serologically pre-characterized were included. Applying the WHO reference standard, the CLIA demonstrated the highest analytical sensitivity for IgG and IgM. The combinations of CLIA/EIA (IgG and IgM) and CLIA/LIA (IgG) measurements showed substantial correlation. Compared to overall antibody detection (seropositivity in ≥2 assays), CLIA correlation was excellent, outperforming LIA (IgM) and EIA (IgG and IgM). Minor IgM cross reactivity in samples of patients with acute EBV infection was observed in all three assays. The CLIA showed good performance in diagnostic samples compared to established LIA and EIA assays. Due to its ready-to-use monotest format, the CLIA allows simple, time- and cost-effective handling of single samples. These qualities make the assay suitable for diagnostics, especially in the emergency setting and for low-throughput laboratories.
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Affiliation(s)
- Karl Dichtl
- Chair of Medical Microbiology and Hospital Epidemiology, Faculty of Medicine, Max von Pettenkofer-Institute, LMU Munich, D-80336 München, Germany; (K.D.); (J.Z.)
| | - Julia Zimmermann
- Chair of Medical Microbiology and Hospital Epidemiology, Faculty of Medicine, Max von Pettenkofer-Institute, LMU Munich, D-80336 München, Germany; (K.D.); (J.Z.)
- Chair of Virology, National Reference Center for Retroviruses, Faculty of Medicine, Max von Pettenkofer Institut, LMU München, D-80336 München, Germany;
- German Center for Infection Research (DZIF), Partner Site Munich, D-80539 Munich, Germany
| | | | - Stephan Böhm
- Chair of Virology, National Reference Center for Retroviruses, Faculty of Medicine, Max von Pettenkofer Institut, LMU München, D-80336 München, Germany;
- German Center for Infection Research (DZIF), Partner Site Munich, D-80539 Munich, Germany
| | - Andreas Osterman
- Chair of Virology, National Reference Center for Retroviruses, Faculty of Medicine, Max von Pettenkofer Institut, LMU München, D-80336 München, Germany;
- German Center for Infection Research (DZIF), Partner Site Munich, D-80539 Munich, Germany
- Correspondence:
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Brotons P, Saucedo J, Simó S, Gené A, Muñoz-Almagro C. Performance Comparison of a Novel Rapid Stand-alone Molecular Test and a 2-Step Diagnostic Algorithm for Clostridioides difficile Detection in Children. Pediatr Infect Dis J 2021; 40:169-172. [PMID: 33055503 DOI: 10.1097/inf.0000000000002907] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
BACKGROUND We aimed to evaluate diagnostic performance of the cobas® Liat® Cdiff test, a novel single-step automated polymerase chain reaction (PCR) assay for rapid diagnosis of toxigenic Clostridioides difficile infection (CDI) in stool samples from children with clinical symptoms of CDI. METHODS Assessment of cobas Liat Cdiff diagnostic yield, time of analytical process and agreement of results with those of a 2-step diagnostic algorithm. The sequential algorithm combined an enzyme immunoassay (EIA) targeting antigen glutamate dehydrogenase (GDH), enterotoxin-A and cytotoxin-B, and a confirmatory PCR in EIA GDH-positive and toxin-negative samples. Fresh stool samples were collected prospectively from patients 2-18 years of age that were attended in Hospital Sant Joan de Deu (Barcelona, Spain) during December 2018-August 2019. RESULTS A total of 122 specimens were collected from 91 children (mean age, 8 years; 69.7% male). cobas Liat Cdiff identified 24 (19.7%) positive samples. EIA yielded 97 (79.5%) GDH- and toxin-negative results, 11 (9.0%) GDH- and toxin-positive results, and 14 (11.5%) GDH-positive and toxin-negative results, of which 11 (9.0%) were positive for the toxin by the confirmatory PCR. Overall, GDH- and toxin-positive samples detected by the sequential algorithm were 22 (18.0%). Comparatively, the new test reduced time of the analytical process significantly (20 vs. 35.4 minutes, P < 0.001). CONCLUSION Use of cobas Liat Cdiff showed similar detection yield compared with a 2-step diagnostic algorithm that combined an EIA and a confirmatory PCR while decreasing the time of the analytical process markedly in stool samples from children suspected of CDI.
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Affiliation(s)
- Pedro Brotons
- From the Institut de Recerca Sant Joan de Deu, Barcelona, Spain
- CIBER de Epidemiología y Salud Pública CIBERESP, Madrid, Spain
- Universitat Internacional de Catalunya, Barcelona, Spain
| | - Jesica Saucedo
- Department of Molecular Microbiology, Clinical Laboratory, Hospital Sant Joan de Déu, Barcelona, Spain
| | - Silvia Simó
- From the Institut de Recerca Sant Joan de Deu, Barcelona, Spain
- CIBER de Epidemiología y Salud Pública CIBERESP, Madrid, Spain
| | - Amadeu Gené
- Department of Molecular Microbiology, Clinical Laboratory, Hospital Sant Joan de Déu, Barcelona, Spain
| | - Carmen Muñoz-Almagro
- From the Institut de Recerca Sant Joan de Deu, Barcelona, Spain
- CIBER de Epidemiología y Salud Pública CIBERESP, Madrid, Spain
- Universitat Internacional de Catalunya, Barcelona, Spain
- Department of Molecular Microbiology, Clinical Laboratory, Hospital Sant Joan de Déu, Barcelona, Spain
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Tanida K, Hahn A, Frickmann H. Comparison of two commercial and one in-house real-time PCR assays for the diagnosis of bacterial gastroenteritis. Eur J Microbiol Immunol (Bp) 2020; 10:210-216. [PMID: 33279885 PMCID: PMC7753976 DOI: 10.1556/1886.2020.00030] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2020] [Accepted: 11/18/2020] [Indexed: 12/14/2022] Open
Abstract
Introduction The aim of the study was a comparative evaluation of in-house real-time PCR and commercial real-time PCR (Fast Track Diagnostics (FTD), ampliCube/Mikrogen) targeting enteropathogenic bacteria from stool in preparation of Regulation (EU) 2017/746 on in vitro diagnostic medical devices. Methods Both 241 stool samples from patients and 100 samples from German laboratory control schemes (“Ringversuche”) were used to comparatively assess in-house real-time PCR, the FTD bacterial gastroenteritis kit, and the ampliCube gastrointestinal bacterial panels 1&2 either with the in-house PCRs as gold standard and as a test comparison without gold standard applying latent class analysis. Sensitivity, specificity, intra- and inter-assay variation and Cohen’s kappa were assessed. Results In comparison with the gold standard, sensitivity was 75–100% for strongly positive samples, 20–100% for weakly positive samples, and specificity ranged from 96 to 100%. Latent class analysis suggested that sensitivity ranges from 81.2 to 100% and specificity from 58.5 to 100%. Cohen’s kappa varied between moderate and nearly perfect agreement, intra- and inter-assay variation was 1–3 to 1–4 Ct values. Conclusion Acceptable agreement and performance characteristics suggested replaceability of the in-house PCR assays by the commercial approaches.
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Affiliation(s)
- Konstantin Tanida
- 1Department of Microbiology and Hospital Hygiene, Bundeswehr Hospital Hamburg, Hamburg, Germany
| | - Andreas Hahn
- 2Institute for Medical Microbiology, Virology and Hygiene, University Medicine Rostock, Rostock, Germany
| | - Hagen Frickmann
- 1Department of Microbiology and Hospital Hygiene, Bundeswehr Hospital Hamburg, Hamburg, Germany.,2Institute for Medical Microbiology, Virology and Hygiene, University Medicine Rostock, Rostock, Germany
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10
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Using diagnostic stewardship to reduce rates, healthcare expenditures and accurately identify cases of hospital-onset Clostridioides difficile infection. Infect Control Hosp Epidemiol 2020; 42:51-56. [PMID: 32943129 DOI: 10.1017/ice.2020.375] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
OBJECTIVE Lack of judicious testing can result in the incorrect diagnosis of Clostridioides difficile infection (CDI), unnecessary CDI treatment, increased costs and falsely augmented hospital-acquired infection (HAI) rates. We evaluated facility-wide interventions used at the VA San Diego Healthcare System (VASDHS) to reduce healthcare-onset, healthcare-facility-associated CDI (HO-HCFA CDI), including the use of diagnostic stewardship with test ordering criteria. DESIGN We conducted a retrospective study to assess the effectiveness of measures implemented to reduce the rate of HO-HCFA CDI at the VASDHS from fiscal year (FY)2015 to FY2018. INTERVENTIONS Measures executed in a stepwise fashion included a hand hygiene initiative, prompt isolation of CDI patients, enhanced terminal room cleaning, reduction of fluoroquinolone and proton-pump inhibitor use, laboratory rejection of solid stool samples, and lastly diagnostic stewardship with C. difficile toxin B gene nucleic acid amplification testing (NAAT) criteria instituted in FY2018. RESULTS From FY2015 to FY2018, 127 cases of HO-HCFA CDI were identified. All rate-reducing initiatives resulted in decreased HO-HCFA cases (from 44 to 13; P ≤ .05). However, the number of HO-HCFA cases (34 to 13; P ≤ .05), potential false-positive testing associated with colonization and laxative use (from 11 to 4), hospital days (from 596 to 332), CDI-related hospitalization costs (from $2,780,681 to $1,534,190) and treatment cost (from $7,158 vs $1,476) decreased substantially following the introduction of diagnostic stewardship with test criteria from FY2017 to FY2018. CONCLUSIONS Initiatives to decrease risk for CDI and diagnostic stewardship of C. difficile stool NAAT significantly reduced HO-HCFA CDI rates, detection of potential false-positives associated with laxative use, and lowered healthcare costs. Diagnostic stewardship itself had the most dramatic impact on outcomes observed and served as an effective tool in reducing HO-HCFA CDI rates.
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Jaffal H, Achram R, Araj G, Mahfouz R. Diagnosis of Clostridiodes difficile infection: Assessing the performance of Quik Chek complete kit assay versus the GeneXpert PCR assay at a major tertiary care center in Lebanon. Meta Gene 2020. [DOI: 10.1016/j.mgene.2020.100715] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022] Open
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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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Bouza E, Aguado JM, Alcalá L, Almirante B, Alonso-Fernández P, Borges M, Cobo J, Guardiola J, Horcajada JP, Maseda E, Mensa J, Merchante N, Muñoz P, Pérez Sáenz JL, Pujol M, Reigadas E, Salavert M, Barberán J. Recommendations for the diagnosis and treatment of Clostridioides difficile infection: An official clinical practice guideline of the Spanish Society of Chemotherapy (SEQ), Spanish Society of Internal Medicine (SEMI) and the working group of Postoperative Infection of the Spanish Society of Anesthesia and Reanimation (SEDAR). REVISTA ESPANOLA DE QUIMIOTERAPIA : PUBLICACION OFICIAL DE LA SOCIEDAD ESPANOLA DE QUIMIOTERAPIA 2020; 33:151-175. [PMID: 32080996 PMCID: PMC7111242 DOI: 10.37201/req/2065.2020] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/02/2020] [Accepted: 01/26/2020] [Indexed: 12/12/2022]
Abstract
This document gathers the opinion of a multidisciplinary forum of experts on different aspects of the diagnosis and treatment of Clostridioides difficile infection (CDI) in Spain. It has been structured around a series of questions that the attendees considered relevant and in which a consensus opinion was reached. The main messages were as follows: CDI should be suspected in patients older than 2 years of age in the presence of diarrhea, paralytic ileus and unexplained leukocytosis, even in the absence of classical risk factors. With a few exceptions, a single stool sample is sufficient for diagnosis, which can be sent to the laboratory with or without transportation media for enteropathogenic bacteria. In the absence of diarrhoea, rectal swabs may be valid. The microbiology laboratory should include C. difficile among the pathogens routinely searched in patients with diarrhoea. Laboratory tests in different order and sequence schemes include GDH detection, presence of toxins, molecular tests and toxigenic culture. Immediate determination of sensitivity to drugs such as vancomycin, metronidazole or fidaxomycin is not required. The evolution of toxin persistence is not a suitable test for follow up. Laboratory diagnosis of CDI should be rapid and results reported and interpreted to clinicians immediately. In addition to the basic support of all diarrheic episodes, CDI treatment requires the suppression of antiperistaltic agents, proton pump inhibitors and antibiotics, where possible. Oral vancomycin and fidaxomycin are the antibacterials of choice in treatment, intravenous metronidazole being restricted for patients in whom the presence of the above drugs in the intestinal lumen cannot be assured. Fecal material transplantation is the treatment of choice for patients with multiple recurrences but uncertainties persist regarding its standardization and safety. Bezlotoxumab is a monoclonal antibody to C. difficile toxin B that should be administered to patients at high risk of recurrence. Surgery is becoming less and less necessary and prevention with vaccines is under research. Probiotics have so far not been shown to be therapeutically or preventively effective. The therapeutic strategy should be based, rather than on the number of episodes, on the severity of the episodes and on their potential to recur. Some data point to the efficacy of oral vancomycin prophylaxis in patients who reccur CDI when systemic antibiotics are required again.
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Affiliation(s)
- E Bouza
- Emilio Bouza MD, PhD, Instituto de Investigación Sanitaria Gregorio Marañón, Servicio de Microbiología Clínica y E. Infecciosas C/ Dr. Esquerdo, 46 - 28007 Madrid, Spain.
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Comparative Study of Clostridium difficile Clinical Detection Methods in Patients with Diarrhoea. CANADIAN JOURNAL OF INFECTIOUS DISEASES & MEDICAL MICROBIOLOGY 2020; 2020:8753284. [PMID: 32064010 PMCID: PMC6996696 DOI: 10.1155/2020/8753284] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/07/2019] [Accepted: 11/30/2019] [Indexed: 12/16/2022]
Abstract
Objectives The aim of this study was to evaluate the clinical application of three methods for detecting Clostridium difficile in fecal samples. Methods One hundred and fifty fecal specimens were collected and tested for C. difficile using three methods: (1) the toxigenic culture (TC); (2) the VIDAS enzyme immunoassay (EIA): the VIDAS glutamate dehydrogenase (GDH) assay and toxin A/B assay were used to detect GDH antigen and A/B toxin; and (3) the GeneXpert PCR assay. The toxigenic culture was used as a reference to evaluate the performance of the VIDAS EIA and the GeneXpert PCR assay. Results Of 150 specimens, 26 carried both A and B toxin genes, and none of the samples were positive for the binary toxin gene. Toxin-producing C. difficile using three methods: (1) the toxigenic culture (TC); (2) the VIDAS enzyme immunoassay (EIA): the VIDAS glutamate dehydrogenase (GDH) assay and toxin A/B assay were used to detect GDH antigen and A/B toxin; and (3) the GeneXpert PCR assay. The toxigenic culture was used as a reference to evaluate the performance of the VIDAS EIA and the GeneXpert PCR assay. C. difficile using three methods: (1) the toxigenic culture (TC); (2) the VIDAS enzyme immunoassay (EIA): the VIDAS glutamate dehydrogenase (GDH) assay and toxin A/B assay were used to detect GDH antigen and A/B toxin; and (3) the GeneXpert PCR assay. The toxigenic culture was used as a reference to evaluate the performance of the VIDAS EIA and the GeneXpert PCR assay. Conclusion The VIDAS GDH assay is useful for initial screening of C. difficile using three methods: (1) the toxigenic culture (TC); (2) the VIDAS enzyme immunoassay (EIA): the VIDAS glutamate dehydrogenase (GDH) assay and toxin A/B assay were used to detect GDH antigen and A/B toxin; and (3) the GeneXpert PCR assay. The toxigenic culture was used as a reference to evaluate the performance of the VIDAS EIA and the GeneXpert PCR assay.
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Impact of molecular testing on reported Clostridoides difficile infection rates. Infect Control Hosp Epidemiol 2019; 41:306-312. [PMID: 31852562 DOI: 10.1017/ice.2019.327] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
BACKGROUND The reported incidence of Clostridoides difficile infection (CDI) has increased in recent years, partly due to broadening adoption of nucleic acid amplification tests (NAATs) replacing enzyme immunoassay (EIA) methods. Our aim was to quantify the impact of this switch on reported CDI rates using a large, multihospital, empirical dataset. METHODS We analyzed 9 years of retrospective CDI data (2009-2017) from 47 hospitals in the southeastern United States; 37 hospitals switched to NAAT during this period, including 24 with sufficient pre- and post-switch data for statistical analyses. Poisson regression was used to quantify the NAAT-over-EIA incidence rate ratio (IRR) at hospital and network levels while controlling for longitudinal trends, the proportion of intensive care unit patient days, changes in surveillance methodology, and previously detected infection cluster periods. We additionally used change-point detection methods to identify shifts in the mean and/or slope of hospital-level CDI rates, and we compared results to recorded switch dates. RESULTS For hospitals that transitioned to NAAT, average unadjusted CDI rates increased substantially after the test switch from 10.9 to 23.9 per 10,000 patient days. Individual hospital IRRs ranged from 0.75 to 5.47, with a network-wide IRR of 1.75 (95% confidence interval, 1.62-1.89). Reported CDI rates significantly changed 1.6 months on average after switching to NAAT testing (standard deviation, 1.9 months). CONCLUSION Hospitals that switched from EIA to NAAT testing experienced an average postswitch increase of 75% in reported CDI rates after adjusting for other factors, and this increase was often gradual or delayed.
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Azrad M, Tkhawkho L, Hamo Z, Peretz A. The diagnostic performance and accuracy of 3 molecular assays for the detection of Clostridium difficile in stool samples, compared with the Xpert® C. difficile assay. J Microbiol Methods 2019; 168:105784. [PMID: 31758952 DOI: 10.1016/j.mimet.2019.105784] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2019] [Revised: 11/19/2019] [Accepted: 11/19/2019] [Indexed: 11/19/2022]
Abstract
This research compares the performance and diagnostic accuracy of three molecular tests for the detection of Clostridium difficile in stool samples, with the Xpert® C. difficile assay. Fifty-nine positive and twenty-five stool negative samples were analyzed by the BDmax™ Cdiff, the Simplexa C. difficile Direct, and the GenomEra™ C. difficile, and compared with the Xpert® C. difficile routinely used in our laboratory. The highest sensitivity was 94.9% for the BDmax™ Cdiff, followed by GenomEra™ C. difficile with 93.2%, and Simplexa™ C. difficile Direct with 89.8%. The specificities of all assays were 100%. GenomEra™ C. difficile had the highest retesting rate (12%). Simplexa™ C. difficile Direct benefits from both short hands-on time and total-turnaround time and 0% retesting. The differences in performance and accuracy between these three molecular assays are insignificant and all may be used as part of the routine algorithm for detection of C. difficile.
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Affiliation(s)
- Maya Azrad
- Clinical Microbiology Laboratory, The Baruch Padeh Medical Center, Poriya, Tiberias, Israel
| | - Linda Tkhawkho
- Clinical Microbiology Laboratory, The Baruch Padeh Medical Center, Poriya, Tiberias, Israel
| | - Zohar Hamo
- Clinical Microbiology Laboratory, The Baruch Padeh Medical Center, Poriya, Tiberias, Israel
| | - Avi Peretz
- Clinical Microbiology Laboratory, The Baruch Padeh Medical Center, Poriya, Tiberias, Israel; The Azrieli Faculty of Medicine, Bar-Ilan University, Safed, Israel.
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Han S, Soylu MC, Kirimli CE, Wu W, Sen B, Joshi SG, Emery CL, Au G, Niu X, Hamilton R, Krevolin K, Shih WH, Shih WY. Rapid, label-free genetic detection of enteropathogens in stool without genetic isolation or amplification. Biosens Bioelectron 2019; 130:73-80. [PMID: 30731348 PMCID: PMC6469511 DOI: 10.1016/j.bios.2019.01.025] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2018] [Revised: 12/22/2018] [Accepted: 01/12/2019] [Indexed: 12/13/2022]
Abstract
Current genetic detection methods require gene isolation, gene amplification and detection with a fluorescent-tagged probe. They typically require sophisticated equipment and expensive fluorescent probes, rendering them not widely available for rapid acute infection diagnoses at the point of care to ensure timely treatment of the diseases. Here we report a rapid genetic detection method that can detect the bacterial gene directly from patient stools using a piezoelectric plate sensor (PEPS) in conjunction with a continuous flow system with two temperature zones. With stools spiked with sodium dodecyl sulfate (SDS) in situ bacteria lysing and DNA denaturation occurred in the high-temperature zone whereas in situ specific detection of the denatured DNA by the PEPS occurred in the lower-temperature zone. The outcome was a rapid genetic detection method that directly detected bacterial genes from stool in < 40 min without the need of gene isolation, gene amplification, or expensive fluorescent tag but with polymerase chain reaction (PCR) sensitivity. In 40 blinded patient stools, it detected the toxin B gene of Clostridium difficile with 95% sensitivity and 95% specificity. The all-electrical, label-free nature of the detection further supports its potential as a low-cost genetic test that can be used at the point of care.
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Affiliation(s)
- Song Han
- School of Biomedical Engineering, Science, and Health Systems, Drexel University, Philadelphia, PA 19104, USA
| | - Mehmet C Soylu
- School of Biomedical Engineering, Science, and Health Systems, Drexel University, Philadelphia, PA 19104, USA
| | - Ceyhun E Kirimli
- School of Biomedical Engineering, Science, and Health Systems, Drexel University, Philadelphia, PA 19104, USA
| | - Wei Wu
- Department of Materials Science and Engineering, Drexel University, PA 19104, USA
| | - Bhaswati Sen
- Department of Microbiology and Immunology, Drexel University, Philadelphia, PA 10102, USA
| | - Suresh G Joshi
- Department of Microbiology and Immunology, Drexel University, Philadelphia, PA 10102, USA
| | | | - Giang Au
- School of Biomedical Engineering, Science, and Health Systems, Drexel University, Philadelphia, PA 19104, USA
| | - Xiaomin Niu
- School of Biomedical Engineering, Science, and Health Systems, Drexel University, Philadelphia, PA 19104, USA
| | - Richard Hamilton
- Department of Emergency Medicine, Drexel University, Philadelphia, PA 10102, USA
| | - Kyle Krevolin
- Microbiology & SIVM Laboratories, Hahnemann University Hospital, Philadelphia, PA 10102, USA
| | - Wei-Heng Shih
- Department of Materials Science and Engineering, Drexel University, PA 19104, USA
| | - Wan Y Shih
- School of Biomedical Engineering, Science, and Health Systems, Drexel University, Philadelphia, PA 19104, USA.
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Tokimatsu I, Shigemura K, Osawa K, Kinugawa S, Kitagawa K, Nakanishi N, Yoshida H, Arakawa S, Fujisawa M. Molecular epidemiologic study of Clostridium difficile infections in university hospitals: Results of a nationwide study in Japan. J Infect Chemother 2018; 24:641-647. [PMID: 29685855 DOI: 10.1016/j.jiac.2018.03.015] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2018] [Revised: 03/21/2018] [Accepted: 03/27/2018] [Indexed: 12/19/2022]
Abstract
We conducted a nationwide molecular epidemiological study of Clostridium difficile infection (CDI) in Japan investigated the correlation between the presence of binary toxin genes and CDI severity. This is the first report on molecular epidemiological analyses for CDI in multiple university hospitals in Japan, to our knowledge. We examined 124,484 hospitalized patients in 25 national and public university hospitals in Japan between December 2013 and March 2014, investigating antimicrobial susceptibilities and toxin-related genes for C. difficile isolates from stools. Epidemiological genetic typing was performed by PCR-ribotyping and repetitive sequence-based (rep)-PCR to examine the genetic similarities. The results detected toxin A-positive, toxin B-positive, binary toxin-negative (A+B+CDT-) detected from 135 isolates (80.8%) and toxin A-negative, toxin B-positive, binary toxin-negative (A- B+CDT-) in 23 (13.8%). Toxin A-positive, toxin B-positive, and binary toxin-positive (A+B+CDT+) were seen in 9 isolates (5.4%). Vancomycin (n = 81, 37.7%) or metronidazole (n = 88, 40.9%) therapies were undertaken in analyzed cases. Ribotypes detected from isolates were 017/subgroup 1, 070, 078, 126, 176, 449, 475/subgroup 1, 499, 451, 566 and newtypes. Rep-PCR classified 167 isolates into 28 cluster groups including 2-15 isolates. In addition, 2 pairs of strains isolated from different institutions belonged to the same clusters. Seven out of 9 (77.8%) of the patients with binary toxin producing strains had "mild to moderate" outcome in evaluated symptoms. In conclusion, we found that binary toxin did not show regional specificity and had no relevance to severity of CDI.
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Affiliation(s)
- Issei Tokimatsu
- Department of Infection Prevention and Control, Kobe University Hospital, Kobe, Japan
| | - Katsumi Shigemura
- Department of Infection Prevention and Control, Kobe University Hospital, Kobe, Japan; Division of Infectious Diseases, Department of International Health, Kobe University Graduate School of Health Sciences, Kobe, Japan; Division of Urology, Department of Organ Therapeutics, Faculty of Medicine, Kobe University Graduate School of Medicine, Kobe, Japan.
| | - Kayo Osawa
- Division of Biophysics, Kobe University Graduate School of Health Science, Kobe, Japan
| | - Shinya Kinugawa
- Division of Biophysics, Kobe University Graduate School of Health Science, Kobe, Japan
| | - Koichi Kitagawa
- Division of Translational Research for Biologics, Department of Internal Medicine Related, Kobe University Graduate School of Medicine, Kobe, Japan
| | - Noriko Nakanishi
- Department of Infectious Diseases, Kobe Institute of Health, Kobe, Japan
| | - Hiroyuki Yoshida
- Division of Biophysics, Kobe University Graduate School of Health Science, Kobe, Japan; Hyogo Clinical Laboratory Corporation, Himeji, Hyogo, Japan
| | - Soichi Arakawa
- Department of Urology, Sanda City Hospital, Sanda, Hyogo, Japan
| | - Masato Fujisawa
- Division of Urology, Department of Organ Therapeutics, Faculty of Medicine, Kobe University Graduate School of Medicine, Kobe, Japan
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Granato PA, Hansen G, Herding E, Chaudhuri S, Tang S, Garg SK, Rowell CR, Sickler JJ. Performance comparison of the cobas Liat and Cepheid GeneXpert systems for Clostridium difficile detection. PLoS One 2018; 13:e0200498. [PMID: 30040852 PMCID: PMC6057633 DOI: 10.1371/journal.pone.0200498] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2017] [Accepted: 06/27/2018] [Indexed: 12/19/2022] Open
Abstract
Clostridium difficile infection (CDI) is a high burden and significant cause of healthcare-acquired infectious diarrhea in the United States (US). Timely and accurate diagnosis of CDI enables the rapid initiation of antibiotic therapy and infection control policies to minimize disease transmission. Polymerase chain reaction (PCR) assays have become a preferred modality for diagnosing CDI in the US. The cobas Liat Cdiff PCR test is a novel assay that can be performed on-demand for hospital-based testing with a rapid 20-minute turnaround time from specimen collection to result reporting. We compared the clinical performance of the cobas Liat Cdiff test to the previously introduced Xpert C. difficile/Epi test; both tests are FDA-cleared PCR assays that detect the toxin B (tcdB) gene of C. difficile. Prospectively collected and remnant stool specimens from 310 patients with suspected CDI were obtained for analysis. The cobas Liat Cdiff and Xpert PCR tests showed an overall percent agreement of 97.4% (302/310; 95% CI: 95.0–98.9). Low bacterial burdens of toxigenic C. difficile, indicated by significantly delayed PCR cycle threshold (Ct) values, explained most of the discordance. Positive and negative percent agreement of the cobas Liat Cdiff test compared to the Xpert PCR test were 94.5% (52/55) and 98.0% (250/255), respectively. The clinical performance of the cobas Liat Cdiff test, combined with its simplicity of use and rapid result reporting, provides a reliable option for clinical laboratory use.
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Affiliation(s)
- Paul A. Granato
- Department of Clinical Microbiology, Laboratory Alliance of Central New York, Syracuse, NY, United States of America
- * E-mail:
| | - Glen Hansen
- Department of Microbiology and Molecular Diagnostics, Hennepin County Medical Center, Minneapolis, MN, United States of America
| | - Emily Herding
- Department of Microbiology and Molecular Biology, Hennepin County Medical Center, Minneapolis, MN, United States of America
| | - Sheena Chaudhuri
- Medical and Scientific Affairs, Roche Molecular Diagnostics, Pleasanton, CA, United States of America
| | - Shaowu Tang
- Medical and Scientific Affairs, Roche Molecular Diagnostics, Pleasanton, CA, United States of America
| | - Sachin K. Garg
- Medical and Scientific Affairs, Roche Molecular Diagnostics, Pleasanton, CA, United States of America
| | - Catherine R. Rowell
- Department of Laboratory Device Trials, Laboratory Alliance of Central New York, Syracuse, NY, United States of America
| | - Joanna Jackson Sickler
- Medical and Scientific Affairs, Roche Molecular Diagnostics, Pleasanton, CA, United States of America
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Affiliation(s)
- Lisa M Kodadek
- Department of Surgery, Johns Hopkins University School of Medicine, 600 North Wolfe Street, Tower 110, Baltimore, MD 21287, USA.
| | - Pamela A Lipsett
- Department of Surgery, Johns Hopkins University School of Medicine, 600 North Wolfe Street, Tower 110, Baltimore, MD 21287, USA; Anesthesiology and Critical Care Medicine, Johns Hopkins University School of Medicine, 600 North Wolfe Street, Osler 603, Baltimore, MD 21287, USA
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Aljefri DM, Christensen AB, Gibson AK, Postelnick M. Role of Antimicrobial Stewardship Programs in Decreasing Hospital-Associated Clostridium difficile Infections. CURRENT TREATMENT OPTIONS IN INFECTIOUS DISEASES 2018. [DOI: 10.1007/s40506-018-0151-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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Huang SH, Lin YF, Tsai MH, Yang S, Liao ML, Chao SW, Hwang CC. Detection of common diarrhea-causing pathogens in Northern Taiwan by multiplex polymerase chain reaction. Medicine (Baltimore) 2018; 97:e11006. [PMID: 29879060 PMCID: PMC5999487 DOI: 10.1097/md.0000000000011006] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
Conventional methods for identifying gastroenteritis pathogens are time consuming, more likely to result in a false-negative, rely on personnel with diagnostic expertise, and are dependent on the specimen status. Alternatively, molecular diagnostic methods permit the rapid, simultaneous detection of multiple pathogens with high sensitivity and specificity. The present study compared conventional methods with the Luminex xTAG Gastrointestinal Pathogen Panel (xTAG GPP) for the diagnosis of infectious gastroenteritis in northern Taiwan. From July 2015 to April 2016, 217 clinical fecal samples were collected from patients with suspected infectious gastroenteritis. All specimens were tested using conventional diagnostic techniques following physicians' orders as well as with the xTAG GPP. The multiplex polymerase chain reaction (PCR) approach detected significantly more positive samples with bacterial, viral, and/or parasitic infections as compared to conventional analysis (55.8% vs 40.1%, respectively; P < .001). Moreover, multiplex PCR could detect Escherichia coli O157, enterotoxigenic E coli, Shiga-like toxin-producing E coli, Cryptosporidium, and Giardia, which were undetectable by conventional methods. Furthermore, 48 pathogens in 23 patients (10.6%) with coinfections were identified only using the multiplex PCR approach. Of which, 82.6% were from pediatric patients. Because the detection rates using multiplex PCR are higher than conventional methods, and some pediatric pathogens could only be detected by multiplex PCR, this approach may be useful in rapidly diagnosing diarrheal disease in children and facilitating treatment initiation. Further studies are necessary to determine if multiplex PCR improves patient outcomes and reduces costs.
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Affiliation(s)
| | | | - Ming-Han Tsai
- Department of Pediatrics, Chang Gung Memorial Hospital, Keelung
| | - Shuan Yang
- Department of Laboratory Medicine, Chang Gung Memorial Hospital, Linkou, Taiwan
| | - Mei-Ling Liao
- Department of Laboratory Medicine, Chang Gung Memorial Hospital, Linkou, Taiwan
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Duarte-Chavez R, Wojda TR, Zanders TB, Geme B, Fioravanti G, Stawicki SP. Early Results of Fecal Microbial Transplantation Protocol Implementation at a Community-based University Hospital. J Glob Infect Dis 2018; 10:47-57. [PMID: 29910564 PMCID: PMC5987372 DOI: 10.4103/jgid.jgid_145_17] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Introduction: Clostridium difficile (CD) is a serious and increasingly prevalent healthcare-associated infection. The pathogenesis of CD infection (CDI) involves the acquisition of CD with a concurrent disruption of the native gut flora. Antibiotics are a major risk although other contributing factors have also been identified. Clinical management combines discontinuation of the offending antibiotic, initiation of CD-specific antibiotic therapy, probiotic agent use, fecal microbiota transplantation (FMT), and surgery as the “last resort” option. The aim of this study is to review short-term clinical results following the implementation of FMT protocol (FMTP) at our community-based university hospital. Methods: After obtaining Institutional Review Board and Infection Control Committee approvals, we implemented an institution-wide FMTP for patients diagnosed with CDI. Prospective tracking of all patients receiving FMT between July 1, 2015, and February 1, 2017, was conducted using REDCap™ electronic data capture system. According to the FMTP, indications for FMT included (a) three or more CDI recurrences, (b) two or more hospital admissions with severe CDI, or (c) first episode of complicated CDI (CCDI). Risk factors for initial infection and for treatment failure were assessed. Patients were followed for at least 3 months to monitor for cure/failure, relapse, and side effects. Frozen 250 mL FMT samples were acquired from OpenBiome (Somerville, MA, USA). After 4 h of thawing, the liquid suspension was applied using colonoscopy, beginning with terminal ileum and proceeding distally toward mid-transverse colon. Monitored clinical parameters included disease severity (Hines VA CDI Severity Score or HVCSS), concomitant medications, number of FMT treatments, non-FMT therapies, cure rates, and mortality. Descriptive statistics were utilized to outline the study results. Results: A total of 35 patients (mean age 58.5 years, 69% female) were analyzed, with FMT-attributable primary cure achieved in 30/35 (86%) cases. Within this subgroup, 2/30 (6.7%) patients recurred and were subsequently cured with long-term oral vancomycin. Among five primary FMT failures (14% total sample), 3 (60%) achieved medical cure with long-term oral vancomycin therapy and 2 (40%) required colectomy. For the seven patients who either failed FMT or recurred, long-term vancomycin therapy was curative in all but two cases. For patients with severe CDI (HVCSS ≥3), primary and overall cure rates were 6/10 (60%) and 8/10 (80%), respectively. Patients with CCDI (n = 4) had higher HVCSS (4 vs. 3) and a mortality of 25%. Characteristics of patients who failed initial FMT included older age (70 vs. 57 years), female sex (80% vs. 67%), severe CDI (80% vs. 13%), and active opioid use during the initial infection (60% vs. 37%) and at the time of FMT (60% vs. 27%). The most commonly reported side effect of FMT was loose stools. Conclusions: This pilot study supports the efficacy and safety of FMT administration for CDI in the setting of a community-based university hospital. Following FMTP implementation, primary (86%) and overall (94%) nonsurgical cure rates were similar to those reported in other studies. The potential role of opioids as a modulator of CDI warrants further clinical investigation.
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Affiliation(s)
- Rodrigo Duarte-Chavez
- Department of Internal Medicine, St. Luke's University Health Network, Bethlehem, PA, USA
| | - Thomas R Wojda
- Department of Family Medicine, Warren Hospital, St. Luke's University Health Network, Phillipsburg, NJ, USA
| | - Thomas B Zanders
- Division of Pulmonary/Critical Care Medicine, St. Luke's University Health Network, Bethlehem, PA, USA
| | - Berhanu Geme
- Division of Gastroenterology, St. Luke's University Health Network, Bethlehem, PA, USA
| | - Gloria Fioravanti
- Department of Internal Medicine, St. Luke's University Health Network, Bethlehem, PA, USA
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Lai H, Huang C, Cai J, Ye J, She J, Zheng Y, Wang L, Wei Y, Fang W, Wang X, Tang YW, Luo Y, Jin D. Simultaneous detection and characterization of toxigenic Clostridium difficile directly from clinical stool specimens. Front Med 2017; 12:196-205. [PMID: 29058256 DOI: 10.1007/s11684-017-0560-5] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2017] [Accepted: 05/17/2017] [Indexed: 02/08/2023]
Abstract
We employed a multiplex polymerase chain reaction (PCR) coupled with capillary electrophoresis (mPCR-CE) targeting six Clostridium difficile genes, including tpi, tcdA, tcdB, cdtA, cdtB, and a deletion in tcdC for simultaneous detection and characterization of toxigenic C. difficile directly from fecal specimens. The mPCR-CE had a limit of detection of 10 colony-forming units per reaction with no cross-reactions with other related bacterial genes. Clinical validation was performed on 354 consecutively collected stool specimens from patients with suspected C. difficile infection and 45 isolates. The results were compared with a reference standard combined with BD MAX Cdiff, real-time cell analysis assay (RTCA), and mPCR-CE. The toxigenic C. difficile species were detected in 36 isolates and 45 stool specimens by the mPCR-CE, which provided a positive rate of 20.3% (81/399). The mPCR-CE had a specificity of 97.2% and a sensitivity of 96.0%, which was higher than RTCA (x2 = 5.67, P = 0.017) but lower than BD MAX Cdiff (P = 0.245). Among the 45 strains, 44 (97.8%) were determined as nonribotype 027 by the mPCR-CE, which was fully agreed with PCR ribotyping. Even though ribotypes 017 (n = 8, 17.8%), 001 (n = 6, 13.3%), and 012 (n = 7, 15.6%) were predominant in this region, ribotype 027 was an important genotype monitored routinely. The mPCR-CE provided an alternative diagnosis tool for the simultaneous detection of toxigenic C. difficile in stool and potentially differentiated between RT027 and non-RT027.
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Affiliation(s)
- Hanjiang Lai
- The First People's Hospital of Xiaoshan District, Hangzhou, 311021, China
| | - Chen Huang
- Department of Microbiology, Zhejiang Provincial Center for Disease Control and Prevention, Hangzhou, 310051, China
| | - Jian Cai
- Department of Disease Control and Prevention, Zhejiang Provincial Center for Disease Control and Prevention, Hangzhou, 310051, China
| | - Julian Ye
- Department of Microbiology, Zhejiang Provincial Center for Disease Control and Prevention, Hangzhou, 310051, China
| | - Jun She
- The First People's Hospital of Xiaoshan District, Hangzhou, 311021, China
| | - Yi Zheng
- Biotherapy Center for Medical Oncology, the First Affiliated Hospital, Zhejiang University, Hangzhou, 310003, China
| | - Liqian Wang
- Department of Laboratory Medicine, Hangzhou First People's Hospital, Hangzhou, 310006, China
| | - Yelin Wei
- The First People's Hospital of Xiaoshan District, Hangzhou, 311021, China
| | - Weijia Fang
- Biotherapy Center for Medical Oncology, the First Affiliated Hospital, Zhejiang University, Hangzhou, 310003, China
| | - Xianjun Wang
- Department of Laboratory Medicine, Hangzhou First People's Hospital, Hangzhou, 310006, China
| | - Yi-Wei Tang
- Department of Laboratory Medicine, Memorial Sloan Kettering Cancer Center, New York, NY, 10065, USA.,Department of Pathology and Laboratory Medicine, Weill Medical College of Cornell University, New York, NY, 10065, USA
| | - Yun Luo
- Department of Microbiology, Zhejiang Provincial Center for Disease Control and Prevention, Hangzhou, 310051, China.
| | - Dazhi Jin
- Department of Microbiology, Zhejiang Provincial Center for Disease Control and Prevention, Hangzhou, 310051, China.
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Comparative performance study of six commercial molecular assays for rapid detection of toxigenic Clostridium difficile. Clin Microbiol Infect 2017; 23:567-572. [DOI: 10.1016/j.cmi.2017.02.016] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/26/2016] [Revised: 02/13/2017] [Accepted: 02/14/2017] [Indexed: 12/19/2022]
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26
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Alcalá Hernández L, Reigadas Ramírez E, Bouza Santiago E. Infección por Clostridium difficile. Med Clin (Barc) 2017; 148:456-463. [DOI: 10.1016/j.medcli.2017.01.033] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2016] [Revised: 01/22/2017] [Accepted: 01/29/2017] [Indexed: 12/17/2022]
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27
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Sommerkorn FM, Schauer B, Schreiner T, Fickenscher H, Krumbholz A. Performance of Hepatitis E Virus (HEV)-antibody tests: a comparative analysis based on samples from individuals with direct contact to domestic pigs or wild boar in Germany. Med Microbiol Immunol 2017; 206:277-286. [DOI: 10.1007/s00430-017-0503-4] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2016] [Accepted: 03/16/2017] [Indexed: 12/11/2022]
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28
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Brook I. Anaerobic Bacteria. Infect Dis (Lond) 2017. [DOI: 10.1016/b978-0-7020-6285-8.00184-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/21/2022] Open
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Chung HS, Lee M. Evaluation of the performance of C. DIFF QUIK CHEK COMPLETE and its usefulness in a hospital setting with a high prevalence of Clostridium difficile infection. J Investig Med 2016; 65:88-92. [PMID: 27625418 DOI: 10.1136/jim-2016-000231] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/20/2016] [Indexed: 02/06/2023]
Abstract
Rapid and accurate diagnosis of Clostridium difficile infection (CDI) is crucial for patient care, infection control, and efficient surveillance. We evaluated C. DIFF QUIK CHEK COMPLETE (QCC; TechLab), which detects glutamate dehydrogenase (GDH) antigen (QCC-Ag) and toxin A/B (QCC-Tox) simultaneously, and compared it to the laboratory diagnostics for CDI currently in use in a tertiary hospital setting with a high prevalence of CDI. QCC, RIDASCREEN C. difficile toxin A/B assay (Toxin EIA; R-Biopharm AG), chromID C. difficile agar (bioMérieux) culture (ChromID culture), and Xpert C. difficile PCR assay (Xpert PCR; Cepheid) were performed according to the manufacturers' instructions. Performances of the assays were compared against that of Xpert PCR as a reference. Of the 231 loose stool specimens, 83 (35.9%) were positive by Xpert PCR. The sensitivity, specificity, and positive and negative predictive values were 97.6%, 93.9%, 90.0%, and 98.6%, respectively, for QCC-Ag and 55.4%, 100%, 100%, and 80.0%, respectively, for QCC-Tox. The median threshold cycle values of the QCC-Tox(+) specimens were lower than those of the QCC-Tox(-) specimens. Results of QCC as an initial screening test were confirmed in 81.0% (187/231) of samples; these specimens did not require further testing. QCC is a rapid, easy, and cost-effective method that would be a useful first-line screening assay for laboratory diagnosis of CDI in a tertiary hospital with a high prevalence of CDI. A two-step algorithm using QCC as an initial screening tool, followed by Xpert PCR as a confirmatory test, is a practical and cost-effective approach.
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Affiliation(s)
- Hae-Sun Chung
- Department of Laboratory Medicine, Ewha Womans University School of Medicine, Seoul, Korea
| | - Miae Lee
- Department of Laboratory Medicine, Ewha Womans University School of Medicine, Seoul, Korea
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Performance of the artus C. difficile QS-RGQ Kit for the detection of toxigenic Clostridium difficile. Clin Biochem 2016; 50:84-87. [PMID: 27556286 DOI: 10.1016/j.clinbiochem.2016.08.013] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2016] [Revised: 08/11/2016] [Accepted: 08/18/2016] [Indexed: 12/21/2022]
Abstract
OBJECTIVES Nucleic acid amplification tests are commonly used for the direct detection of toxigenic Clostridium difficile. We evaluated the diagnostic performance of newly launched, artus C. difficile QS-RGQ Kit (artus C. difficile, QIAGEN, Hilden, Germany), in comparison with toxigenic culture (TC) and Xpert C. difficile (Cepheid, Sunnyvale, CA, USA). DESIGN AND METHODS In prospectively collected 261 diarrheal specimens, the artus C. difficile and the Xpert C. difficile assays were performed. TC using chromogenic agar (chromID CD agar, bioMérieux, Marcy-l'Etoile, France) was used a reference method. RESULTS Based on TC, the sensitivity and specificity of the artus C. difficile were 98.2% and 93.6%, respectively, and those of the Xpert C. difficile were 94.6% and 94.6%, respectively; there was no statistical difference. The agreement between the artus C. difficile and the Xpert C. difficile was almost perfect (kappa=0.918). In the artus C. difficile, the cycle threshold (Ct) values of tcdA were constantly lower than those of tcdB in all positive specimens (mean Ct, 24.5 vs. 26.4; mean difference of 1.9). Three specimens were considered tcdA+/tcdB- by the difference of Ct cutoffs between tcdA and tcdB (38.3 and 36.5, respectively). CONCLUSIONS The performance of the artus C. difficile is excellent compared with TC and is comparable to that of the Xpert C. difficile. Both PCR assays could be useful diagnostic options for the direct detection of toxigenic C. difficile in clinical laboratories. The optimal Ct cutoff of tcdA and tcdB for artus C. difficile may be further validated in following studies.
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Bouza E, Alcalá L, Reigadas E. Optimizing the diagnostic testing of Clostridium difficile infection. Expert Rev Anti Infect Ther 2016; 14:801-8. [PMID: 27462827 DOI: 10.1080/14787210.2016.1216313] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
INTRODUCTION Clostridium difficile infection (CDI) is the leading cause of hospital-acquired diarrhea and is associated with a considerable health and cost burden. However, there is still not a clear consensus on the best laboratory diagnosis approach and a wide variation of testing methods and strategies can be encountered. AREAS COVERED We aim to review the most practical aspects of CDI diagnosis providing our own view on how to optimize CDI diagnosis. Expert commentary: Laboratory diagnosis in search of C. difficile toxins should be applied to all fecal diarrheic samples reaching the microbiology laboratory in patients > 2 years old, with or without classic risk factors for CDI. Detection of toxins either directly in the fecal sample or in the bacteria isolated in culture confirm CDI in the proper clinical setting. Nuclear Acid Assay techniques (NAAT) allow to speed up the process with epidemiological and therapeutic consequences.
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Affiliation(s)
- Emilio Bouza
- a Department of Clinical Microbiology and Infectious Diseases , Hospital General Universitario Gregorio Marañón , Madrid , Spain.,b Facultad de Medicina , Universidad Complutense de Madrid (UCM) , Madrid , Spain.,c Instituto de Investigación Sanitaria Gregorio Marañón , Madrid , Spain.,d CIBER de Enfermedades Respiratorias (CIBERES CD06/06/0058) , Madrid , Spain
| | - Luis Alcalá
- a Department of Clinical Microbiology and Infectious Diseases , Hospital General Universitario Gregorio Marañón , Madrid , Spain.,d CIBER de Enfermedades Respiratorias (CIBERES CD06/06/0058) , Madrid , Spain
| | - Elena Reigadas
- a Department of Clinical Microbiology and Infectious Diseases , Hospital General Universitario Gregorio Marañón , Madrid , Spain.,c Instituto de Investigación Sanitaria Gregorio Marañón , Madrid , Spain
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Evaluation of the VIDAS glutamate dehydrogenase assay for the detection of Clostridium difficile. Anaerobe 2016; 40:68-72. [PMID: 27282799 DOI: 10.1016/j.anaerobe.2016.06.001] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2015] [Revised: 06/03/2016] [Accepted: 06/04/2016] [Indexed: 12/19/2022]
Abstract
We evaluated the performance of the VIDAS GDH assay for the detection of Clostridium difficile. In total, 350 fecal specimens collected from patients clinically suspected of having CDI were analyzed by C. difficile culture and enzyme-linked fluorescent immunoassay (VIDAS GDH); the results were compared with those of toxigenic C. difficile culture (TC), PCR (Xpert C. difficile assay), and toxin AB EIA (VIDAS CDAB). The numbers of culture-positive and culture-negative samples were 108 and 242, respectively. The concordance between the GDH assay and C. difficile culture was 90.3%. With PCR, 12 more samples were found to be positive in GDH-positive/C. difficile culture-negative specimens. Thus, the concordance between GDH assay and C. difficile culture/PCR was 93.7%. The sensitivity, specificity, positive predictive value, and negative predictive value of the VIDAS GDH assay were 97.2%, 87.2%, 77.2%, and 98.6%, respectively, based on the C. difficile culture, and 97.5%, 91.7%, 86.0%, and 98.6%, respectively, based on C. difficile culture/PCR. Positivity rates of the GDH assay were partially associated with those of semi-quantitative C. difficile cultures, which were maximized in grade 3 (>100 colony-forming unit [CFU]) compared with grade 1 (<10 CFU). We evaluated the two-step or three-step algorithm using GDH assay as a first step. No toxin EIA-positive case was found among GDH-negative samples, and 60.8% (48/79) were TC- and/or PCR-positive among the GDH-positive/toxin EIA-negative samples. Thus, approximately 25% of the 350 samples required a confirmatory test (TC or PCR) in the GDH-toxin EIA algorithm, whereas only 2.3% of the total samples in GDH-PCR algorithm was discrepant and required another confirmatory test like TC.
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Beal SG, Assarzadegan N, Rand KH. Sample-to-result molecular infectious disease assays: clinical implications, limitations and potential. Expert Rev Mol Diagn 2016; 16:323-41. [PMID: 26689497 PMCID: PMC7103687 DOI: 10.1586/14737159.2016.1134325] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2015] [Accepted: 12/17/2015] [Indexed: 01/01/2023]
Abstract
Molecular infectious disease diagnostic tests have undergone major advances in the past decade and will continue to rapidly evolve. Assays have become extraordinarily simple to perform, eliminating the need for pre-analytic sample preparation and post-amplification analysis. This allows these tests to be performed in settings without sophisticated expertise in molecular biology, including locations with limited resources. Additionally, the sensitivity and specificity of these assays is superb and many offer extremely fast turn-around times. These tests have major impacts on patient care, but also have some limitations.
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Affiliation(s)
- Stacy G. Beal
- Department of Pathology, Immunology and Laboratory Medicine,
University of Florida College of Medicine, Gainesville, FL,
USA
| | - Naziheh Assarzadegan
- Department of Pathology, Immunology and Laboratory Medicine,
University of Florida College of Medicine, Gainesville, FL,
USA
| | - Kenneth H. Rand
- Department of Pathology, Immunology and Laboratory Medicine,
University of Florida College of Medicine, Gainesville, FL,
USA
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Wrosch JK, Volbers B, Gölitz P, Gilbert DF, Schwab S, Dörfler A, Kornhuber J, Groemer TW. Feasibility and Diagnostic Accuracy of Ischemic Stroke Territory Recognition Based on Two-Dimensional Projections of Three-Dimensional Diffusion MRI Data. Front Neurol 2015; 6:239. [PMID: 26635717 PMCID: PMC4652171 DOI: 10.3389/fneur.2015.00239] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2015] [Accepted: 10/27/2015] [Indexed: 11/13/2022] Open
Abstract
This study was conducted to assess the feasibility and diagnostic accuracy of brain artery territory recognition based on geoprojected two-dimensional maps of diffusion MRI data in stroke patients. In this retrospective study, multiplanar diffusion MRI data of ischemic stroke patients was used to create a two-dimensional map of the entire brain. To guarantee correct representation of the stroke, a computer-aided brain artery territory diagnosis was developed and tested for its diagnostic accuracy. The test recognized the stroke-affected brain artery territory based on the position of the stroke in the map. The performance of the test was evaluated by comparing it to the reference standard of each patient's diagnosed stroke territory on record. This study was designed and conducted according to Standards for Reporting of Diagnostic Accuracy (STARD). The statistical analysis included diagnostic accuracy parameters, cross-validation, and Youden Index optimization. After cross-validation on a cohort of 91 patients, the sensitivity of this territory diagnosis was 81% with a specificity of 87%. With this, the projection of strokes onto a two-dimensional map is accurate for representing the affected stroke territory and can be used to provide a static and printable overview of the diffusion MRI data. The projected map is compatible with other two-dimensional data such as EEG and will serve as a useful visualization tool.
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Affiliation(s)
- Jana Katharina Wrosch
- Department of Psychiatry and Psychotherapy, Friedrich-Alexander University of Erlangen-Nuremberg , Erlangen , Germany
| | - Bastian Volbers
- Department of Psychiatry and Psychotherapy, Friedrich-Alexander University of Erlangen-Nuremberg , Erlangen , Germany ; Department of Neurology, Friedrich-Alexander University of Erlangen-Nuremberg , Erlangen , Germany
| | - Philipp Gölitz
- Department of Neuroradiology, Friedrich-Alexander University of Erlangen-Nuremberg , Erlangen , Germany
| | - Daniel Frederic Gilbert
- Institute of Medical Biotechnology, Friedrich-Alexander University of Erlangen-Nuremberg , Erlangen , Germany
| | - Stefan Schwab
- Department of Neurology, Friedrich-Alexander University of Erlangen-Nuremberg , Erlangen , Germany
| | - Arnd Dörfler
- Department of Neuroradiology, Friedrich-Alexander University of Erlangen-Nuremberg , Erlangen , Germany
| | - Johannes Kornhuber
- Department of Psychiatry and Psychotherapy, Friedrich-Alexander University of Erlangen-Nuremberg , Erlangen , Germany
| | - Teja Wolfgang Groemer
- Department of Psychiatry and Psychotherapy, Friedrich-Alexander University of Erlangen-Nuremberg , Erlangen , Germany ; Psychiatric and Neurological Ambulatory Care Office , Bamberg , Germany
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Senoh M, Kato H, Murase T, Hagiya H, Tagashira Y, Fukuda T, Iwaki M, Yamamoto A, Shibayama K. Reverse transcription polymerase chain reaction-based method for selectively detecting vegetative cells of toxigenic Clostridium difficile. Microbiol Immunol 2015; 58:615-20. [PMID: 25145894 DOI: 10.1111/1348-0421.12189] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2014] [Revised: 08/01/2014] [Accepted: 08/15/2014] [Indexed: 01/05/2023]
Abstract
The laboratory diagnostic methods for Clostridium difficile infection (CDI) include toxigenic culture, enzyme immunoassays (EIAs) to detect the toxins of C. difficile, and nucleic acid amplification tests (NAATs) to detect C. difficile toxin genes, but each of these methods has disadvantages; toxigenic cultures require a long time to produce results, EIAs have low sensitivity, and NAATs that target DNA cannot distinguish vegetative cells from spores and dead cells. Here we report a new detection method that uses reverse transcription polymerase chain reaction to target the toxin-gene transcripts. This method was able to specifically detect the vegetative cells of toxigenic C. difficile in fecal samples in spike tests, with a minimum detection limit of 5 × 10(2) colony-forming units per 100 mg of stool specimen. The performance of this method was also demonstrated in a pilot scale evaluation using clinical fecal specimens, which showed that this method may be more sensitive than EIA and requires a shorter time than toxigenic culture. This method could potentially be applied in the clinical laboratory to detect C. difficile in fecal specimens. The ability of this method to discriminate the presence of vegetative cells from spores and dead cells could help to further the understanding of CDI.
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Affiliation(s)
- Mitsutoshi Senoh
- National Institute of Infectious Diseases, Musashimurayama, Tokyo, Japan
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A large scale clinical evaluation of the AmpliVue and Illumigene molecular tests for the identification of Clostridium difficile-associated diarrhea in adult and pediatric patients. Diagn Microbiol Infect Dis 2015; 82:265-8. [PMID: 26008122 DOI: 10.1016/j.diagmicrobio.2015.03.007] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2014] [Revised: 02/11/2015] [Accepted: 03/07/2015] [Indexed: 02/04/2023]
Abstract
The AmpliVue (Quidel, San Diego, CA, USA) and Illumigene (Meridian Biosciences, Cincinnati, OH, USA) molecular tests were compared for the detection of C. difficile toxin in fresh fecal samples from adult and pediatric patients. A total of 758 samples were collected, in 3 clinical sites: Nationwide Children's (Columbus, OH, USA), Penn State Hershey (Hershey, PA, USA), Primary Children's (Salt Lake City, UT, USA). Each site tested the fecal specimens using both assays. Any discordant results were resolved by performing toxigenic culture. There were 16 discordant samples among the 3 sites. Following discordant resolution, the combined performance for all 3 sites for sensitivity, specificity, PPV, and NPV for AmpliVue was 96.1%, 99.2%, 96.1%, and 99.2%, respectively, while for Illumigene was 96.1%, 99.8%, 99.2%, and 99.2%, respectively. The AmpliVue and Illumigene methods are both relatively rapid and simple to use, sensitive, and specific for detection of C. difficile toxin and demonstrate similar performance.
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38
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Vocale C, Rimoldi SG, Pagani C, Grande R, Pedna F, Arghittu M, Lunghi G, Maraschini A, Gismondo MR, Landini MP, Torresani E, Topin F, Sambri V. Comparative evaluation of the new xTAG GPP multiplex assay in the laboratory diagnosis of acute gastroenteritis. Clinical assessment and potential application from a multicentre Italian study. Int J Infect Dis 2015; 34:33-7. [PMID: 25749649 DOI: 10.1016/j.ijid.2015.02.011] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2014] [Revised: 02/16/2015] [Accepted: 02/17/2015] [Indexed: 01/08/2023] Open
Abstract
OBJECTIVE Gastroenteritis caused by a single pathogen or multiple pathogens remains a major diagnostic challenge for the laboratory. The treatment of diarrhoea is based on microbiological results. Diagnosis is achieved using different laboratory techniques that have variable sensitivity and specificity. xTAG GPP is a new multiplex PCR assay that simultaneously detects 15 different pathogens responsible for diarrhoea. The results of the first multicentre study in Italy to evaluate the potential clinical application of the GPP assay in the laboratory diagnosis of diarrhoea are reported here. METHODS Faeces specimens (N=664) from hospitalized patients were tested with the GPP assay using a Luminex 200 instrument. All specimens were run using comparator methods following a routine algorithm: culture for bacteria, enzyme immunoassay and PCR for viruses, and microscopy for parasites. RESULTS Of the samples tested with the GPP, 53.61% (356/664) gave positive results, as compared to 45.33% by routine testing. Of the positive specimens, 34.55% showed the presence of genomic DNA from multiple pathogens. The Luminex method showed an increase in the percentage of positivity of 8.28%. CONCLUSIONS The GPP assay can be considered a helpful tool for the detection of gastrointestinal pathogens, with a hands-on time of 5h; it provides accurate data for the clinical management of hospitalized patients and for epidemiological surveillance.
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Affiliation(s)
- C Vocale
- Unit of Clinical Microbiology, Regional Reference Centre for Microbiological Emergencies, St. Orsola Malpighi University Hospital, Via Massarenti 9, 40138 Bologna, Italy.
| | - S G Rimoldi
- Laboratory of Clinical Microbiology, Virology and Bioemergency, "L. Sacco" University Hospital, Milan, Italy
| | - C Pagani
- Laboratory of Clinical Microbiology, Virology and Bioemergency, "L. Sacco" University Hospital, Milan, Italy
| | - R Grande
- Laboratory of Clinical Microbiology, Virology and Bioemergency, "L. Sacco" University Hospital, Milan, Italy
| | - F Pedna
- Unit of Clinical Microbiology, The Hub Laboratory of the Greater Romagna Area, Pievesestina, Cesena, Italy
| | - M Arghittu
- Department of Clinical Chemistry and Microbiology, Bacteriology and Virology Units, Fondazione IRCCS Ca' Granda, Ospedale Maggiore Policlinico, Milan, Italy
| | - G Lunghi
- Department of Clinical Chemistry and Microbiology, Bacteriology and Virology Units, Fondazione IRCCS Ca' Granda, Ospedale Maggiore Policlinico, Milan, Italy
| | - A Maraschini
- Department of Clinical Chemistry and Microbiology, Bacteriology and Virology Units, Fondazione IRCCS Ca' Granda, Ospedale Maggiore Policlinico, Milan, Italy
| | - M R Gismondo
- Laboratory of Clinical Microbiology, Virology and Bioemergency, "L. Sacco" University Hospital, Milan, Italy
| | - M P Landini
- Unit of Clinical Microbiology, Regional Reference Centre for Microbiological Emergencies, St. Orsola Malpighi University Hospital, Via Massarenti 9, 40138 Bologna, Italy; DIMES, University of Bologna, Bologna, Italy
| | - E Torresani
- Department of Clinical Chemistry and Microbiology, Bacteriology and Virology Units, Fondazione IRCCS Ca' Granda, Ospedale Maggiore Policlinico, Milan, Italy
| | - F Topin
- Luminex Corporation, Oosterhout NB, Netherlands
| | - V Sambri
- Unit of Clinical Microbiology, The Hub Laboratory of the Greater Romagna Area, Pievesestina, Cesena, Italy; DIMES, University of Bologna, Bologna, Italy
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Comparison of BD Max Cdiff and GenomEra C. difficile molecular assays for detection of toxigenic Clostridium difficile from stools in conventional sample containers and in FecalSwabs. Eur J Clin Microbiol Infect Dis 2015; 34:1005-9. [DOI: 10.1007/s10096-015-2320-2] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2014] [Accepted: 01/07/2015] [Indexed: 01/05/2023]
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The Clinician and the Microbiology Laboratory. MANDELL, DOUGLAS, AND BENNETT'S PRINCIPLES AND PRACTICE OF INFECTIOUS DISEASES 2015. [PMCID: PMC7151863 DOI: 10.1016/b978-1-4557-4801-3.00016-3] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Key Words] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
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Comparison of GenomEra C. difficile and Xpert C. difficile as confirmatory tests in a multistep algorithm for diagnosis of Clostridium difficile infection. J Clin Microbiol 2014; 53:332-5. [PMID: 25392360 DOI: 10.1128/jcm.03093-14] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
We compared two multistep diagnostic algorithms based on C. Diff Quik Chek Complete and, as confirmatory tests, GenomEra C. difficile and Xpert C. difficile. The sensitivity, specificity, positive predictive value, and negative predictive value were 87.2%, 99.7%, 97.1%, and 98.3%, respectively, for the GenomEra-based algorithm and 89.7%, 99.4%, 95.5%, and 98.6%, respectively, for the Xpert-based algorithm. GenomEra represents an alternative to Xpert as a confirmatory test of a multistep algorithm for Clostridium difficile infection (CDI) diagnosis.
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Sewell B, Rees E, Thomas I, Ch'ng CL, Isaac M, Berry N. Cost and Impact on Patient Length of Stay of Rapid Molecular Testing for Clostridium difficile. Infect Dis Ther 2014; 3:281-93. [PMID: 25183400 PMCID: PMC4269620 DOI: 10.1007/s40121-014-0034-x] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2014] [Indexed: 12/18/2022] Open
Abstract
Introduction A study was performed to assess the cost of a rapid molecular assay (PCR) for diagnosis of Clostridium difficile infection (CDI) and the impact of its routine use on patient length of stay (LOS) in comparison with cell culture cytotoxin neutralization assay (CCNA). Methods From March 2011 to September 2011, Xpert®C. difficile (Cepheid, Sunnyvale, CA, USA) PCR was used on patients with suspicion of CDI in two acute care hospitals in Abertawe Bro Morgannwg University Health Board, Swansea, Wales, UK. Test results were used for patient management. LOS and time to reportable result were compared for negative and positive prospective patients tested by PCR and historic control patients tested by CCNA during March 2010 to September 2010. Tests were priced using micro-costing and a cost comparison analysis was undertaken. Results In total, 506 patients were included. Time to reportable result for PCR samples was 1.53 h compared to 46.54 h for CCNA negatives and 22.45 h for CCNA positives. Patients tested by CCNA stayed 4.88 days longer in hospital compared to PCR patients if they tested positive and 7.03 days if tests were negative. The mean reduction in LOS observed in our study has the potential to generate cost savings of up to £2,292.62 for every patient with suspected CDI, if samples were to be tested routinely with PCR instead of CCNA. Conclusion A rapid molecular test for C. difficile in an acute hospital setting produced quick results that led to a decrease in LOS compared to historic CCNA control patients. This could result in considerable savings through reduced excess inpatient days. Electronic supplementary material The online version of this article (doi:10.1007/s40121-014-0034-x) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Bernadette Sewell
- Swansea Centre for Health Economics, College of Human and Health Sciences, Swansea University, Singleton Park, Swansea, UK.
| | - Eugene Rees
- Public Health Wales, Microbiology ABMUHB, Singleton Hospital, Swansea, UK
| | - Ian Thomas
- Public Health Wales, Microbiology ABMUHB, Singleton Hospital, Swansea, UK
| | - Chin Lye Ch'ng
- Gastroenterology Department, Singleton Hospital, Swansea, UK
| | - Mike Isaac
- Public Health Wales, Microbiology ABMUHB, Singleton Hospital, Swansea, UK
| | - Nidhika Berry
- Public Health Wales, Microbiology ABMUHB, Singleton Hospital, Swansea, UK
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Clinical characteristics of patients who test positive for Clostridium difficile by repeat PCR. J Clin Microbiol 2014; 52:3853-5. [PMID: 25122866 DOI: 10.1128/jcm.01659-14] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
The high sensitivity of PCR assays for diagnosing Clostridium difficile infection (CDI) has greatly reduced the need for repeat testing after a negative result. Nevertheless, a small subset of patients do test positive within 7 days of a negative test. The aim of this study was to evaluate the clinical characteristics of these patients to determine when repeat testing may be appropriate. The results of all Xpert C. difficile PCR (Cepheid, Sunnyvale CA) tests performed in the clinical microbiology laboratory at New York-Presbyterian Hospital, Columbia University Medical Center (NYPH/CUMC) from 1 May 2011 through 6 September 2013, were reviewed. A retrospective case-control study was performed, comparing patients who tested positive within 7 days of a negative test result to a random selection of 50 controls who tested negative within 7 days of a negative test result. During the study period, a total of 14,875 tests were performed, of which 1,066 were repeat tests (7.2%). Eleven of these repeat tests results were positive (1.0%). The only risk factor independently associated with repeat testing positive was history of a prior CDI (odds ratio [OR], 19.6 [95% confidence interval {CI}, 4.0 to 19.5], P < 0.001). We found that patients who test positive for C. difficile by PCR within 7 days of a negative test are more likely to have a history of CDI than are patients who test negative with repeat PCR. This finding may be due to the high rate of disease relapse or the increased likelihood of empirical therapy leading to false-negative results in these patients.
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Perry MD, Corden SA, Howe RA. Evaluation of the Luminex xTAG Gastrointestinal Pathogen Panel and the Savyon Diagnostics Gastrointestinal Infection Panel for the detection of enteric pathogens in clinical samples. J Med Microbiol 2014; 63:1419-1426. [PMID: 25102908 DOI: 10.1099/jmm.0.074773-0] [Citation(s) in RCA: 50] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023] Open
Abstract
Infectious gastrointestinal disease is caused by a diverse array of pathogens, and is a challenging syndrome to correctly diagnose and manage. Conventional laboratory diagnostic methods are often time-consuming and frequently suffer from low detection rates. Two commercial multiplex nucleic acid amplification tests [Luminex xTAG Gastrointestinal Pathogen Panel (GPP) and Savyon Diagnostics Gastrointestinal Infection Panel (GIP)] were applied to 1000 stored diarrhoeal clinical stool samples. The Luminex xTAG GPP and Savyon GIP detected Campylobacter in 42/44 and 44/44 culture-positive samples, Salmonella in 4/4 and 3/4 culture-positive samples, Shigella in 1/1 culture-positive sample, Clostridium difficile toxin in 32/35 ELISA-positive samples, and Giardia in 6/6 wet-preparation-microscopy-positive samples, respectively. When the Luminex GPP assay was used concurrently with conventional methods for 472 clinical samples, it detected Campylobacter in 22/22 culture-positive samples, Salmonella in 1/1 culture-positive sample, Clostridium difficile toxin in 14/14 ELISA-positive samples and Giardia in 4/4 wet-preparation-microscopy-positive samples. The pathogen/toxin detection rate for conventional methods in both sample sets was <10%. The Luminex xTAG GPP detection rate was 24.8% in the stored samples and 32.6% in the concurrently tested samples. The Savyon GIP detection rate was 22.5%. From stored samples, 2.4% of Luminex xTAG GPP detections and 3.1% of Savyon GIP detections could not be confirmed using alternative nucleic acid amplification tests. Enhanced detection rates resulted from increased detection of pathogens routinely sought using conventional methods and were also due to ascertainment of micro-organisms that current testing strategies do not diagnose. Use of multiplex nucleic acid amplification tests will allow clinical laboratories to diagnose infectious gastroenteritis in more patients with diarrhoeal disease by increasing the sensitivity of pathogen detection and by reducing the selective bias of current strategies. The clinical and economic impact of these results warrants further investigation.
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Affiliation(s)
- Michael D Perry
- Public Health Wales Microbiology Cardiff, University Hospital of Wales, Heath Park, Cardiff, UK
| | - Sally A Corden
- Public Health Wales Microbiology Cardiff, University Hospital of Wales, Heath Park, Cardiff, UK
| | - Robin A Howe
- Public Health Wales Microbiology Cardiff, University Hospital of Wales, Heath Park, Cardiff, UK
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Abstract
Gastroenteritis persists as a worldwide problem, responsible for approximately 2 million deaths annually. Traditional diagnostic methods used in the clinical microbiology laboratory include a myriad of tests, such as culture, microscopy, and immunodiagnostics, which can be labor intensive and suffer from long turnaround times and, in some cases, poor sensitivity. [corrected]. This article reviews recent advances in genomic and proteomic technologies that have been applied to the detection and identification of gastrointestinal pathogens. These methods simplify and speed up the detection of pathogenic microorganisms, and their implementation in the clinical microbiology laboratory has potential to revolutionize the diagnosis of gastroenteritis.
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Combination of culture, antigen and toxin detection, and cytotoxin neutralization assay for optimal Clostridium difficile diagnostic testing. CANADIAN JOURNAL OF INFECTIOUS DISEASES & MEDICAL MICROBIOLOGY 2014; 24:89-92. [PMID: 24421808 DOI: 10.1155/2013/934945] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
BACKGROUND There has been a growing interest in developing an appropriate laboratory diagnostic algorithm for Clostridium difficile, mainly as a result of increases in both the number and severity of cases of C difficile infection in the past decade. A C difficile diagnostic algorithm is necessary because diagnostic kits, mostly for the detection of toxins A and B or glutamate dehydrogenase (GDH) antigen, are not sufficient as stand-alone assays for optimal diagnosis of C difficile infection. In addition, conventional reference methods for C difficile detection (eg, toxigenic culture and cytotoxin neutralization [CTN] assays) are not routinely practiced in diagnostic laboratory settings. OBJECTIVE To review the four-step algorithm used at Diagnostic Services of Manitoba sites for the laboratory diagnosis of toxigenic C difficile. RESULT One year of retrospective C difficile data using the proposed algorithm was reported. Of 5695 stool samples tested, 9.1% (n=517) had toxigenic C difficile. Sixty per cent (310 of 517) of toxigenic C difficile stools were detected following the first two steps of the algorithm. CTN confirmation of GDH-positive, toxin A- and B-negative assays resulted in detection of an additional 37.7% (198 of 517) of toxigenic C difficile. Culture of the third specimen, from patients who had two previous negative specimens, detected an additional 2.32% (12 of 517) of toxigenic C difficile samples. DISCUSSION Using GDH antigen as the screening and toxin A and B as confirmatory test for C difficile, 85% of specimens were reported negative or positive within 4 h. Without CTN confirmation for GDH antigen and toxin A and B discordant results, 37% (195 of 517) of toxigenic C difficile stools would have been missed. Following the algorithm, culture was needed for only 2.72% of all specimens submitted for C difficile testing. CONCLUSION The overview of the data illustrated the significance of each stage of this four-step C difficile algorithm and emphasized the value of using CTN assay and culture as parts of an algorithm that ensures accurate diagnosis of toxigenic C difficile.
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Angione SL, Sarma AA, Novikov A, Seward L, Fieber JH, Mermel LA, Tripathi A. A novel subtyping assay for detection of Clostridium difficile virulence genes. J Mol Diagn 2014; 16:244-52. [PMID: 24434086 DOI: 10.1016/j.jmoldx.2013.11.006] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2013] [Revised: 11/15/2013] [Accepted: 11/20/2013] [Indexed: 12/17/2022] Open
Abstract
This proof-of-concept study demonstrates the application of a novel nucleic acid detection platform to detect Clostridium difficile in subjects presenting with acute diarrheal symptoms. This method amplifies three genes associated with C. difficile infection, including genes and deletions (cdtB and tcdC) associated with hypervirulence attributed to the NAP1/027/BI strain. Amplification of DNA from the tcdB, tcdC, and cdtB genes was performed using a droplet-based sandwich platform with quantitative real-time PCR in microliter droplets to detect and identify the amplified fragments of DNA. The device and identification system are simple in design and can be integrated as a point-of-care test to help rapidly detect and identify C. difficile strains that pose significant health threats in hospitals and other health-care communities.
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Affiliation(s)
- Stephanie L Angione
- Center for Biomedical Engineering, School of Engineering, Brown University, Providence, Rhode Island
| | - Aartik A Sarma
- Center for Biomedical Engineering, School of Engineering, Brown University, Providence, Rhode Island
| | - Aleksey Novikov
- Warren Alpert Medical School, Brown University, Providence, Rhode Island
| | - Leah Seward
- Division of Biology and Medicine, Brown University, Providence, Rhode Island
| | - Jennifer H Fieber
- Division of Biology and Medicine, Brown University, Providence, Rhode Island
| | - Leonard A Mermel
- Center for Biomedical Engineering, School of Engineering, Brown University, Providence, Rhode Island; Division of Infectious Diseases, Rhode Island Hospital, Providence, Rhode Island
| | - Anubhav Tripathi
- Center for Biomedical Engineering, School of Engineering, Brown University, Providence, Rhode Island.
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Diagnosis of Clostridium difficile infection: an ongoing conundrum for clinicians and for clinical laboratories. Clin Microbiol Rev 2014; 26:604-30. [PMID: 23824374 DOI: 10.1128/cmr.00016-13] [Citation(s) in RCA: 277] [Impact Index Per Article: 27.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Clostridium difficile is a formidable nosocomial and community-acquired pathogen, causing clinical presentations ranging from asymptomatic colonization to self-limiting diarrhea to toxic megacolon and fulminant colitis. Since the early 2000s, the incidence of C. difficile disease has increased dramatically, and this is thought to be due to the emergence of new strain types. For many years, the mainstay of C. difficile disease diagnosis was enzyme immunoassays for detection of the C. difficile toxin(s), although it is now generally accepted that these assays lack sensitivity. A number of molecular assays are commercially available for the detection of C. difficile. This review covers the history and biology of C. difficile and provides an in-depth discussion of the laboratory methods used for the diagnosis of C. difficile infection (CDI). In addition, strain typing methods for C. difficile and the evolving epidemiology of colonization and infection with this organism are discussed. Finally, considerations for diagnosing C. difficile disease in special patient populations, such as children, oncology patients, transplant patients, and patients with inflammatory bowel disease, are described. As detection of C. difficile in clinical specimens does not always equate with disease, the diagnosis of C. difficile infection continues to be a challenge for both laboratories and clinicians.
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Chapin K. Discrepancies in testing recommendations forClostridium difficileinfection: updated review favors amplification test systems. Expert Rev Mol Diagn 2014; 12:223-6. [DOI: 10.1586/erm.12.13] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
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