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Joshi LT, Brousseau E, Morris T, Lees J, Porch A, Baillie L. Rapid, Point-of-Care Microwave Lysis and Electrochemical Detection of Clostridioides difficile Directly from Stool Samples. Bioengineering (Basel) 2024; 11:632. [PMID: 38927868 PMCID: PMC11200505 DOI: 10.3390/bioengineering11060632] [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: 04/11/2024] [Revised: 05/30/2024] [Accepted: 06/03/2024] [Indexed: 06/28/2024] Open
Abstract
The rapid detection of the spore form of Clostridioides difficile has remained a challenge for clinicians. To address this, we have developed a novel, precise, microwave-enhanced approach for near-spontaneous release of DNA from C. difficile spores via a bespoke microwave lysis platform. C. difficile spores were microwave-irradiated for 5 s in a pulsed microwave electric field at 2.45 GHz to lyse the spore and bacteria in each sample, which was then added to a screen-printed electrode and electrochemical DNA biosensor assay system to identify presence of the pathogen's two toxin genes. The microwave lysis method released both single-stranded and double-stranded genome DNA from the bacterium at quantifiable concentrations between 0.02 μg/mL to 250 μg/mL allowing for subsequent downstream detection in the biosensor. The electrochemical bench-top system comprises of oligonucleotide probes specific to conserved regions within tcdA and tcdB toxin genes of C. difficile and was able to detect 800 spores of C. difficile within 300 µL of unprocessed human stool samples in under 10 min. These results demonstrate the feasibility of using a solid-state power generated, pulsed microwave electric field to lyse and release DNA from human stool infected with C. difficile spores. This rapid microwave lysis method enhanced the rapidity of subsequent electrochemical detection in the development of a rapid point-of-care biosensor platform for C. difficile.
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Affiliation(s)
| | - Emmanuel Brousseau
- School of Engineering, Cardiff University, Cardiff CF24 3AA, UK; (E.B.); (J.L.); (A.P.)
| | - Trefor Morris
- Anaerobe Reference Laboratory, Public Health Wales, University Hospital of Wales, Cardiff CF14 4XW, UK;
| | - Jonathan Lees
- School of Engineering, Cardiff University, Cardiff CF24 3AA, UK; (E.B.); (J.L.); (A.P.)
| | - Adrian Porch
- School of Engineering, Cardiff University, Cardiff CF24 3AA, UK; (E.B.); (J.L.); (A.P.)
| | - Les Baillie
- School of Pharmacy & Pharmaceutical Sciences, Cardiff University, Cardiff CF10 3NB, UK;
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Impact of Nucleic Acid Amplification Test on Clinical Outcomes in Patients with Clostridioides difficile Infection. Antibiotics (Basel) 2023; 12:antibiotics12030428. [PMID: 36978295 PMCID: PMC10044602 DOI: 10.3390/antibiotics12030428] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/01/2023] [Revised: 02/06/2023] [Accepted: 02/17/2023] [Indexed: 02/24/2023] Open
Abstract
A nucleic acid amplification test (NAAT) is recommended to determine whether or not patients have a Clostridioides difficile infection (CDI) when the glutamate dehydrogenase activity assay is positive and the rapid membrane enzyme immunoassays for toxins is negative. In our hospital, a NAAT was introduced to diagnose CDI precisely in April 2020. This study aimed to investigate the impact of a NAAT on the clinical outcomes in patients with CDI at our hospital. Seventy-one patients diagnosed with CDI between April 2017 and March 2022 were included in our study. Patients with CDI were divided into two groups: before (pre-NAAT) and after (post-NAAT) the introduction of NAAT. The clinical outcome was compared between the two groups. Of the 71 patients with CDI, 41 were sorted into the pre-NAAT group and 30 into the post-NAAT group. The clinical cure rate was significantly higher in the post-NAAT group compared to the pre-NAAT group (76.7% vs. 48.8%, p = 0.018). In the multivariable analysis, the clinical cure was significantly associated with the introduction of NAAT (p = 0.022). Our findings suggest that the introduction of NAAT can improve the clinical outcomes in CDI patients.
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Johnston M, Irwin J, Roberts S, Leung A, Andersson HS, Orme G, Deroles-Main J, Bakker S. Clostridioides difficile Infection in a Rural New Zealand Secondary Care Centre: An Incidence Case-Control Study. Intern Med J 2021; 52:1009-1015. [PMID: 33528096 DOI: 10.1111/imj.15220] [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: 10/10/2020] [Revised: 01/05/2021] [Accepted: 01/06/2021] [Indexed: 12/01/2022]
Abstract
BACKGROUND Clostridioides difficile Infection (CDI) is a form of antibiotic associated infectious diarrhoea resulting in significant morbidity and mortality. Community acquired disease in low risk individuals is increasingly recognised. There are limited New Zealand data published. AIM To determine the incidence and location of onset of CDI cases in the Manawatu region, and further describe the demographics, risk factors and prevalent C. difficile ribotypes of the population. METHODS We performed an incidence case-control study of CDI in the Manawatu region between September 2018 and September 2019. Cases were matched to controls with a negative test for C. difficile. Demographic and comorbidity data, location of onset, drug exposure, disease recurrence and 30-day mortality were collected. Ribotype analysis was performed on C. difficile isolates. RESULTS 32 specimens tested toxin positive over twelve months, yielding an incidence of 18.3 cases per 100,000 person-years. 25% of cases had community onset disease. Cases were more likely to have had amoxicillin/clavulanate or ceftriaxone prescribed. Elevated blood white cell count and lower HbA1c were significantly associated with CDI. The dominant ribotype was 014/020, 2 cases were RT 023. CONCLUSION Our data are similar to previous national data. RT 023 has not been previously reported in New Zealand and has been associated with severe colitis. We demonstrated a significant proportion of community acquired cases and the true incidence may be higher. Vigilance for community onset disease is required. This data may allow observation of temporal changes in incidence and infection patterns of CDI in New Zealand. This article is protected by copyright. All rights reserved.
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Affiliation(s)
- Matthew Johnston
- Medical Registrar, ORA Department, Capital and Coast District Health Board, New Zealand
| | - James Irwin
- Department of Gastroenterology, Palmerston North Hospital, New Zealand
| | - Sally Roberts
- Clinical Microbiologist, LabPlus, Auckland City Hospital, New Zealand
| | - Almond Leung
- Medical Registrar, Department of General Medicine, Palmerston North Hospital, New Zealand
| | | | - Gareth Orme
- Director of Information Systems, Medlab Central, Palmerston North Hospital, New Zealand
| | - Jan Deroles-Main
- Charge Scientist and Manager, Microbiology Department, Medlab Central, Palmerston North Hospital, New Zealand
| | - Sarah Bakker
- Principal Technician, Nosocomial Infections Laboratory, Institute of Environmental Science and Research (ESR)
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Schlaberg R, Barrett A, Edes K, Graves M, Paul L, Rychert J, Lopansri BK, Leung DT. Fecal Host Transcriptomics for Non-Invasive Human Mucosal Immune Profiling: Proof of Concept in Clostridium Difficile Infection. Pathog Immun 2018; 3:164-180. [PMID: 30283823 PMCID: PMC6166656 DOI: 10.20411/pai.v3i2.250] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
Background: Host factors play an important role in pathogenesis and disease outcome in Clostridium difficile infection (CDI), and characterization of these responses could uncover potential host biomarkers to complement existing microbe-based diagnostics. Methods: We extracted RNA from fecal samples of patients with CDI and profiled human mRNA using amplicon-based next-generation sequencing (NGS). We compared the fecal host mRNA transcript expression profiles of patients with CDI to controls with non-CDI diarrhea. Results: We found that the ratio of human actin gamma 1 (ACTG1) to 16S ribosomal RNA (rRNA) was highly correlated with NGS quality as measured by percentage of reads on target. Patients with CDI could be differentiated from those with non-CDI diarrhea based on their fecal mRNA expression profiles using principal component analysis. Among the most differentially expressed genes were ones related to immune response (IL23A, IL34) and actin-cytoskeleton function (TNNT1, MYL4, SMTN, MYBPC3, all adjusted P-values < 1 x 10-3). Conclusions: In this proof-of-concept study, we used host fecal transcriptomics for non-invasive profiling of the mucosal immune response in CDI. We identified differentially expressed genes with biological plausibility based on animal and cell culture models. This demonstrates the potential of fecal transcriptomics to uncover host-based biomarkers for enteric infections.
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Affiliation(s)
- Robert Schlaberg
- Department of Pathology, University of Utah School of Medicine, Salt Lake City, Utah.,ARUP Laboratories, Salt Lake City, Utah
| | - Amanda Barrett
- Division of Infectious Diseases, University of Utah School of Medicine, Salt Lake City, Utah
| | - Kornelia Edes
- Department of Pathology, University of Utah School of Medicine, Salt Lake City, Utah
| | - Michael Graves
- Division of Infectious Diseases, University of Utah School of Medicine, Salt Lake City, Utah
| | - Litty Paul
- Department of Pathology, University of Utah School of Medicine, Salt Lake City, Utah
| | | | - Bert K Lopansri
- Division of Infectious Diseases, University of Utah School of Medicine, Salt Lake City, Utah.,Division of Infectious Diseases and Clinical Epidemiology, Intermountain Medical Center, Murray, Utah
| | - Daniel T Leung
- Department of Pathology, University of Utah School of Medicine, Salt Lake City, Utah.,Division of Infectious Diseases, University of Utah School of Medicine, Salt Lake City, Utah
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Bogaty C, Lévesque S, Garenc C, Frenette C, Bolduc D, Galarneau LA, Lalancette C, Loo V, Tremblay C, Trudeau M, Vachon J, Dionne M, Villeneuve J, Longtin J, Longtin Y. Trends in the use of laboratory tests for the diagnosis of Clostridium difficile infection and association with incidence rates in Quebec, Canada, 2010-2014. Am J Infect Control 2017; 45:964-968. [PMID: 28549882 DOI: 10.1016/j.ajic.2017.04.002] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2017] [Revised: 04/01/2017] [Accepted: 04/03/2017] [Indexed: 12/18/2022]
Abstract
BACKGROUND Several Clostridium difficile infection (CDI) surveillance programs do not specify laboratory strategies to use. We investigated the evolution in testing strategies used across Quebec, Canada, and its association with incidence rates. METHODS Cross-sectional study of 95 hospitals by surveys conducted in 2010 and in 2013-2014. The association between testing strategies and institutional CDI incidence rates was analyzed via multivariate Poisson regressions. RESULTS The most common assays in 2014 were toxin A/B enzyme immunoassays (EIAs) (61 institutions, 64%), glutamate dehydrogenase (GDH) EIAs (51 institutions, 53.7%), and nucleic acid amplification tests (NAATs) (34 institutions, 35.8%). The most frequent algorithm was a single-step NAAT (20 institutions, 21%). Between 2010 and 2014, 35 institutions (37%) modified their algorithm. Institutions detecting toxigenic C difficile instead of C difficile toxin increased from 14 to 37 (P < .001). Institutions detecting toxigenic C difficile had higher CDI rates (7.9 vs 6.6 per 10,000 patient days; P = .01). Institutions using single-step NAATs, GDH plus toxigenic cultures, and GDH plus cytotoxicity assays had higher CDI rates than those using an EIA-based algorithm (P < .05). CONCLUSIONS Laboratory detection of CDI has changed since 2010. There is an association between diagnostic algorithms and CDI incidence. Mitigation strategies are warranted.
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Affiliation(s)
- C Bogaty
- McGill University Faculty of Medicine, Montréal, QC, Canada
| | - S Lévesque
- Laboratoire de Santé Publique du Québec, Institute National de Santé Publique du Québec, Sainte-Anne-de-Bellevue, Quebec (QC), Canada
| | - C Garenc
- Institut National de Santé Publique du Québec, Quebec City, QC, Canada; Centre Hospitalier Universitaire de Québec, Québec City, QC, Canada
| | - C Frenette
- McGill University Faculty of Medicine, Montréal, QC, Canada; McGill University Health Centre, Montréal, QC, Canada
| | - D Bolduc
- Centre intégré de santé et de services sociaux du Bas-Saint-Laurent, Rimouski, Quebec (QC), Canada
| | - L-A Galarneau
- Centre intégré universitaire de santé et de services sociaux de la Mauricie-et-du-Centre-du-Québec, Trois-Rivières, Quebec (QC), Canada
| | - C Lalancette
- Laboratoire de Santé Publique du Québec, Institute National de Santé Publique du Québec, Sainte-Anne-de-Bellevue, Quebec (QC), Canada
| | - V Loo
- McGill University Faculty of Medicine, Montréal, QC, Canada; McGill University Health Centre, Montréal, QC, Canada
| | - C Tremblay
- Centre Hospitalier Universitaire de Québec, Québec City, QC, Canada; Laval University Faculty of Medicine, Quebec City, QC, Canada
| | - M Trudeau
- Laboratoire de Santé Publique du Québec, Institute National de Santé Publique du Québec, Sainte-Anne-de-Bellevue, Quebec (QC), Canada
| | - J Vachon
- Centre intégré de santé et de services sociaux de Chaudière-Appalaches, Thetford Mines, Quebec (QC), Canada
| | - M Dionne
- Institut National de Santé Publique du Québec, Quebec City, QC, Canada
| | - J Villeneuve
- Institut National de Santé Publique du Québec, Quebec City, QC, Canada
| | - J Longtin
- Laboratoire de Santé Publique du Québec, Institute National de Santé Publique du Québec, Sainte-Anne-de-Bellevue, Quebec (QC), Canada; Laval University Faculty of Medicine, Quebec City, QC, Canada.
| | - Y Longtin
- McGill University Faculty of Medicine, Montréal, QC, Canada
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Martínez-Meléndez A, Camacho-Ortiz A, Morfin-Otero R, Maldonado-Garza HJ, Villarreal-Treviño L, Garza-González E. Current knowledge on the laboratory diagnosis of Clostridium difficile infection. World J Gastroenterol 2017; 23:1552-1567. [PMID: 28321156 PMCID: PMC5340807 DOI: 10.3748/wjg.v23.i9.1552] [Citation(s) in RCA: 43] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/15/2016] [Revised: 01/21/2017] [Accepted: 02/17/2017] [Indexed: 02/06/2023] Open
Abstract
Clostridium difficile (C. difficile) is a spore-forming, toxin-producing, gram-positive anaerobic bacterium that is the principal etiologic agent of antibiotic-associated diarrhea. Infection with C. difficile (CDI) is characterized by diarrhea in clinical syndromes that vary from self-limited to mild or severe. Since its initial recognition as the causative agent of pseudomembranous colitis, C. difficile has spread around the world. CDI is one of the most common healthcare-associated infections and a significant cause of morbidity and mortality among older adult hospitalized patients. Due to extensive antibiotic usage, the number of CDIs has increased. Diagnosis of CDI is often difficult and has a substantial impact on the management of patients with the disease, mainly with regards to antibiotic management. The diagnosis of CDI is primarily based on the clinical signs and symptoms and is only confirmed by laboratory testing. Despite the high burden of CDI and the increasing interest in the disease, episodes of CDI are often misdiagnosed. The reasons for misdiagnosis are the lack of clinical suspicion or the use of inappropriate tests. The proper diagnosis of CDI reduces transmission, prevents inadequate or unnecessary treatments, and assures best antibiotic treatment. We review the options for the laboratory diagnosis of CDI within the settings of the most accepted guidelines for CDI diagnosis, treatment, and prevention of CDI.
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7
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Clarridge JE, Harrington A. Disparate prevalence of toxigenic and nontoxigenic Clostridium difficile among distinct adult patient populations in a single institution. J Med Microbiol 2016; 65:1237-1242. [PMID: 27624898 DOI: 10.1099/jmm.0.000350] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Clostridium difficile (CD) disease remains a costly and important hospital-associated infection. Although nontoxigenic CD is detected by some CD testing methods, can interfere with some detection algorithms and has been suggested as a treatment for CD disease, little is known about the relative occurrence of toxigenic and nontoxigenic CD in a single institution.We used both chromogenic and selective agar media to recover CD isolates and a molecular method to detect the toxin B gene from over 2400 fresh unformed stool specimens with isolates further tested for the toxin B gene. We recovered 74 nontoxigenic and 306 toxigenic CD isolates for which a collection site could be assigned.The frequency of recovery of toxigenic and nontoxigenic CD for each hospital location and the ratio of toxigenic to nontoxigenic CD were calculated. Although the overall prevalence of toxigenic and nontoxigenic CD was 12.7 % and 3.1 %, respectively, on some wards, 48 % of all CD were nontoxigenic, while on other wards, ≤5 % were nontoxigenic.The disparate ratios of nontoxigenic CD to toxigenic CD presented here for the various 'groups' within the adult veteran population are important to the ongoing discussion and reexamination of other published work on the occurrence of toxigenic and nontoxigenic CD, for evaluating the performance of CD detection tests, for designing infection control strategies and in ultimately understanding both CD carriage and disease.
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Affiliation(s)
- Jill E Clarridge
- Puget Sound Veterans Affairs Medical Center, Seattle, WA, USA.,Department of Laboratory Medicine, University of Washington, Seattle, WA, USA
| | - Amanda Harrington
- Department of Laboratory Medicine, University of Washington, Seattle, WA, USA.,Puget Sound Veterans Affairs Medical Center, Seattle, WA, USA
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8
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Abstract
Alteration in the host microbiome at skin and mucosal surfaces plays a role in the function of the immune system, and may predispose immunocompromised patients to infection. Because obligate anaerobes are the predominant type of bacteria present in humans at skin and mucosal surfaces, immunocompromised patients are at increased risk for serious invasive infection due to anaerobes. Laboratory approaches to the diagnosis of anaerobe infections that occur due to pyogenic, polymicrobial, or toxin-producing organisms are described. The clinical interpretation and limitations of anaerobe recovery from specimens, anaerobe-identification procedures, and antibiotic-susceptibility testing are outlined. Bacteriotherapy following analysis of disruption of the host microbiome has been effective for treatment of refractory or recurrent Clostridium difficile infection, and may become feasible for other conditions in the future.
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Affiliation(s)
- Deirdre L Church
- Departments of Pathology & Laboratory Medicine and Medicine, University of Calgary, and Division of Microbiology, Calgary Laboratory Services, Calgary, Alberta, Canada T2N 1N4
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9
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Yoldaş Ö, Altındiş M, Cufalı D, Aşık G, Keşli R. A Diagnostic Algorithm for the Detection of Clostridium difficile-Associated Diarrhea. Balkan Med J 2016; 33:80-6. [PMID: 26966622 DOI: 10.5152/balkanmedj.2015.15159] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2015] [Accepted: 08/28/2015] [Indexed: 12/12/2022] Open
Abstract
BACKGROUND Clostridium difficile is a common cause of hospital-acquired diarrhea, which is usually associated with previous antibiotic use. The clinical manifestations of C. difficile infection (CDI) may range from mild diarrhea to fulminant colitis. Clostridium difficile should be considered in diarrhea cases with a history of antibiotic use within the last 8 weeks (community-associated CDI) or with a hospital stay of at least 3 days, regardless of the duration of antibiotic use (hospital-acquired CDI). AIMS This study investigated the frequency of CDI in diarrheic patients and evaluated the efficacy of the triple diagnostic algorithm that is proposed here for C. difficile detection. STUDY DESIGN Cross-sectional study. METHODS In this study, we compared three methods currently employed for C. difficile detection using 95 patient stool samples: an enzyme immunoassay (EIA) for toxin A/B (C. diff Toxin A+B; Diagnostic Automation Inc.; Calabasas, CA, USA), an EIA for glutamate dehydrogenase (GDH) (C. DIFF CHEK-60TM, TechLab Inc.; Blacksburg, VA, USA), and a polymerase chain reaction (PCR)-based assay (GeneXpert(®) C. difficile; Cepheid, Sunnyvale, CA, USA) that detects C. difficile toxin genes and conventional methods as well. In this study, 50.5% of the patients were male, 50 patients were outpatients, 32 were from inpatient clinics and 13 patients were from the intensive care unit. RESULTS Of the 95 stool samples tested for GDH, 28 were positive. Six samples were positive by PCR, while nine samples were positive for toxin A/B. The hypervirulent strain NAP-1 and binary toxin was not detected. The rate of occurrence of toxigenic C. difficile was 5.1% in the samples. Cefaclor, ampicillin-sulbactam, ertapenem, and piperacillin-tazobactam were the most commonly used antibiotics by patients preceding the onset of diarrhea. Among the patients who were hospitalized in an intensive care unit for more than 7 days, 83.3% were positive for CDI by PCR screening. If the PCR test is accepted as the reference: C. difficile Toxin A/B ELISA sensitivity and specificity were 67% and 94%, respectively, and GDH sensitivity and specificity were 100% and 75%, respectively. CONCLUSION Tests targeting C. difficile toxins are frequently applied for the purpose of diagnosing CDI in a clinical setting. However, changes in the temperature and reductant composition of the feces may affect toxin stability, potentially yielding false-negative test results. Therefore, employment of a GDH EIA, which has high sensitivity, as a screening test for the detection of toxigenic strains, may prevent false-negative results, and its adoption as part of a multistep diagnostic algorithm may increase accuracy in the diagnosis of CDIs.
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Affiliation(s)
- Özlem Yoldaş
- Clinical Microbiology Laboratory, Türkan Özilhan Bornova State Hospital, İzmir, Turkey
| | - Mustafa Altındiş
- Department of Medical Microbiology, Sakarya University Faculty of Medicine, Sakarya, Turkey
| | - Davut Cufalı
- Department of Medical Microbiology, Afyon Kocatepe University Faculty of Medicine, Afyon, Turkey
| | - Gülşah Aşık
- Department of Medical Microbiology, Afyon Kocatepe University Faculty of Medicine, Afyon, Turkey
| | - Recep Keşli
- Department of Medical Microbiology, Afyon Kocatepe University Faculty of Medicine, Afyon, Turkey
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10
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Abstract
The best laboratory diagnostic approach to detect Clostridium difficile infection (CDI) is the subject of ongoing debate. In the United States, nucleic acid amplification tests (NAAT) have become the most widely used tests for making this diagnosis. Detection of toxin in stool may be a better predictor of CDI disease and severity. Laboratories that have switched from toxin-based to NAAT-based methods have significantly higher CDI detection rates. The important issue is whether all NAAT-positive patients have CDI or at least some of those patients are excretors of the organism and do not have clinical disease.
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Affiliation(s)
- Peter H Gilligan
- Clinical Microbiology-Immunology Laboratories, Microbiology-Immunology, UNC Health Care, UNC School of Medicine, CB 7600, Chapel Hill, NC 27516, USA; Pathology-Laboratory Medicine, UNC School of Medicine, CB 7600, Chapel Hill, NC 27516, USA.
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11
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Bauer KA, Perez KK, Forrest GN, Goff DA. Review of Rapid Diagnostic Tests Used by Antimicrobial Stewardship Programs. Clin Infect Dis 2014; 59 Suppl 3:S134-45. [DOI: 10.1093/cid/ciu547] [Citation(s) in RCA: 170] [Impact Index Per Article: 15.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
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12
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Gilligan PH. Contemporary approaches for the laboratory diagnosis of Clostridium difficile infections. SEMINARS IN COLON AND RECTAL SURGERY 2014. [DOI: 10.1053/j.scrs.2014.05.008] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
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13
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Variations in virulence and molecular biology among emerging strains of Clostridium difficile. Microbiol Mol Biol Rev 2014; 77:567-81. [PMID: 24296572 DOI: 10.1128/mmbr.00017-13] [Citation(s) in RCA: 71] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Clostridium difficile is a Gram-positive, spore-forming organism which infects and colonizes the large intestine, produces potent toxins, triggers inflammation, and causes significant systemic complications. Treating C. difficile infection (CDI) has always been difficult, because the disease is both caused and resolved by antibiotic treatment. For three and a half decades, C. difficile has presented a treatment challenge to clinicians, and the situation took a turn for the worse about 10 years ago. An increase in epidemic outbreaks related to CDI was first noticed around 2003, and these outbreaks correlated with a sudden increase in the mortality rate of this illness. Further studies discovered that these changes in CDI epidemiology were associated with the rapid emergence of hypervirulent strains of C. difficile, now collectively referred to as NAP1/BI/027 strains. The discovery of new epidemic strains of C. difficile has provided a unique opportunity for retrospective and prospective studies that have sought to understand how these strains have essentially replaced more historical strains as a major cause of CDI. Moreover, detailed studies on the pathogenesis of NAP1/BI/027 strains are leading to new hypotheses on how this emerging strain causes severe disease and is more commonly associated with epidemics. In this review, we provide an overview of CDI, discuss critical mechanisms of C. difficile virulence, and explain how differences in virulence-associated factors between historical and newly emerging strains might explain the hypervirulence exhibited by this pathogen during the past decade.
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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: 291] [Impact Index Per Article: 26.5] [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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15
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Impact of changes in Clostridium difficile testing practices on stool rejection policies and C. difficile positivity rates across multiple laboratories in the United States. J Clin Microbiol 2013; 52:632-4. [PMID: 24478500 DOI: 10.1128/jcm.02177-13] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Abstract
We describe the adoption of nucleic acid amplification tests (NAAT) for Clostridium difficile diagnosis and their impact on stool rejection policies and C. difficile positivity rates. Of the laboratories with complete surveys, 51 (43%) reported using NAAT in 2011. Laboratories using NAAT had stricter rejection policies and increased positivity rates.
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16
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Gould CV, Edwards JR, Cohen J, Bamberg WM, Clark LA, Farley MM, Johnston H, Nadle J, Winston L, Gerding DN, McDonald LC, Lessa FC. Effect of nucleic acid amplification testing on population-based incidence rates of Clostridium difficile infection. Clin Infect Dis 2013; 57:1304-7. [PMID: 23899677 DOI: 10.1093/cid/cit492] [Citation(s) in RCA: 85] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Nucleic acid amplification testing (NAAT) is increasingly being adopted for diagnosis of Clostridium difficile infection (CDI). Data from 3 states conducting population-based CDI surveillance showed increases ranging from 43% to 67% in CDI incidence attributable to changing from toxin enzyme immunoassays to NAAT. CDI surveillance requires adjustment for testing methods.
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Affiliation(s)
- Carolyn V Gould
- Division of Healthcare Quality Promotion, Centers for Disease Control and Prevention
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Ochsner UA, Katilius E, Janjic N. Detection of Clostridium difficile toxins A, B and binary toxin with slow off-rate modified aptamers. Diagn Microbiol Infect Dis 2013; 76:278-85. [PMID: 23680240 DOI: 10.1016/j.diagmicrobio.2013.03.029] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2012] [Revised: 03/27/2013] [Accepted: 03/29/2013] [Indexed: 12/18/2022]
Abstract
Rapid and accurate diagnostic tests for Clostridium difficile infections (CDI) are crucial for management of patients with suspected CDI and for infection control. Enzyme immunoassays for detection of the toxins are routinely used but lack adequate sensitivity. We generated slow off-rate modified aptamers (SOMAmer™ reagents) via in vitro selection (SELEX) that bind toxins A, B and binary toxin with high affinity and specificity. Using SOMAmers alone or in conjunction with antibodies, we have developed toxin assays with a 1 pmol/L (300 pg/mL) limit of detection and a 3 log dynamic range. SOMAmers proved useful as capture or detection agents in equilibrium solution binding radioassays, pull-down capture assays, dot blots, and plate- or membrane-based sandwich assays, thus represent a promising alternative to antibodies in diagnostic applications. SOMAmers detected toxins A, B and binary toxin in culture supernatants from toxigenic C. difficile, including a BI/NAP1 strain and historic strains.
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Affiliation(s)
- Urs A Ochsner
- SomaLogic, Inc., 2945 Wilderness Place, Boulder, CO 80301, USA.
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