scholarly journals Detection of Free Toxin B in the Stool of Asymptomatic Clostridioides difficile Carriers by the Cell Cytotoxicity Neutralization Assay

2021 ◽  
Author(s):  
Lorne Schweitzer ◽  
Phillippe Gervais ◽  
Bianka Paquet-Bolduc ◽  
Vivian G Loo ◽  
Yves Longtin
Keyword(s):  
Gold Standard ◽  
Neutralization Assay ◽  
Cell Cytotoxicity ◽  
Toxin B ◽  
Asymptomatic Carriers ◽  
Clostridioides Difficile ◽  
Admission Screening ◽  
Consecutive Admission ◽  
Rectal Swabs

Abstract Cell cytotoxicity neutralization assay (CCNA) is considered to be a gold standard to diagnose Clostridioides difficile infections. We performed CCNA on 77 consecutive admission screening rectal swabs from asymptomatic toxigenic C. difficile carriers. 39% of specimens from asymptomatic carriers were positive. Thus, CCNA specificity may be lower than previously thought.

scholarly journals Environmental shedding of toxigenic Clostridioides difficile by asymptomatic carriers: A prospective observational study

2020 ◽  
Author(s):  
Mayan Gilboa ◽  
Esther Houri Levi ◽  
Carmit Cohen ◽  
Ilana Tal ◽  
Carmit Rubin ◽  
...  
Keyword(s):  
Multivariate Analysis ◽  
Observational Study ◽  
Environmental Contamination ◽  
Prospective Observational Study ◽  
Toxin B ◽  
Asymptomatic Carriers ◽  
Clostridioides Difficile ◽  
Control Rooms ◽  
Toxigenic Strains ◽  
Pcr Test

AbstractObjectivesTo compare the burden of environmental shedding of toxigenic C. difficile among asymptomatic carriers, C. difficile infected (CDI) patients and non-carriers, in an inpatient non-epidemic setting.MethodsC. difficile carriage was determined by positive toxin-B PCR from rectal swabs of asymptomatc patients. Active CDI was defined as a positive 2-step EIA/PCR test in patients with >3 unformed stools/24 hours. C. difficile environmental contamination was assessed by obtaining specimens from 10 sites in the patients’ rooms. Toxigenic strains were identified by PCR. We created a contamination scale to define the overall level of room contamination that ranged from clean to heavy contamination.Results117 rooms were screened; 70 rooms inhabited by C. difficile carriers, 30 rooms by active CDI patients and 17 rooms by non C. difficile -carriers (Control). In the carrier rooms 29 (41%) had more than residual contamination, from which 17 (24%) were heavily contaminated. In the CDI rooms 12 (40%) had more than residual contamination from which 3 (10%) were heavily contaminated, while in the control rooms, one room (6%) had more than residual contamination and none were heavily contaminated. In a multivariate analysis, the contamination score of rooms inhabited by carriers did not differ from rooms of CDI patients, yet both were significantly more contaminated than those of none carriers OR 12.23 and 11.16 (95%CI:1.5-99.96 P=0.0195, and 1.19-104.49 p=0.035), respectively.ConclusionHere we show that C. difficile carriers’ rooms are as contaminated as those of patients with active CDI and significantly more than those of non-carriers.

scholarly journals 247. Validation of the Use of Oral Vancomycin Following Positive Admission Screening Testing for C. difficile

2020 ◽  
Vol 7 (Supplement_1) ◽  
pp. S123-S123
Author(s):  
Preethi Yeturu ◽  
Jorge P Parada ◽  
Maressa Santarossa ◽  
Laurie Labuszewski ◽  
Jenna Lopez ◽  
...  
Keyword(s):  
Clinical History ◽  
Inclusion Criteria ◽  
Infectious Colitis ◽  
First Line Therapy ◽  
Clostridioides Difficile ◽  
Admission Screening ◽  
Positive Stool ◽  
Number Of Patients ◽  
Polymerase Chain ◽  
Definition Of

Abstract Background Clostridioides difficile can cause a severe infectious colitis and is often associated with significant morbidity and mortality. C. difficile infection (CDI) is defined as the presence of diarrhea plus a positive stool test, whereas C. difficile colonization is defined as a positive stool test in the absence of diarrhea or the presence of diarrhea attributable to causes other than CDI. Widespread use of stool polymerase chain reaction (PCR) testing, especially within the first 3 days of admission, has become common at our institution and has been associated with increased number of positive C. difficile tests results. However, C. difficile colonization rates may be 15% or higher. Oral (PO) vancomycin (vanc) is first line therapy for the treatment of CDI. We sought to evaluate the appropriateness of use of PO vanc in patients who tested positive for C. difficile via stool PCR within 3 days of admission. Methods We reviewed the clinical history, presence of diarrhea, risk factors for diarrhea, treatment and use of an infectious disease (ID) consultation for all patients 18 years of age or older found to test positive for C. difficile by PCR on stool assays during the first 3 days of admission from 07/01/18 to 12/31/18. Results A total of 228 patients met inclusion criteria. 183 (80%) received PO vanc while 45 (20%) did not. 131 (71.6%) of patients who received PO vanc had diarrhea, 39 (21.3%) did not have diarrhea, 13 (7.1%) the presence of diarrhea was unknown. 41 of 143 (28.7%) of patients without ID consults received PO vanc despite not having diarrhea, while 11 of 40 (27.5%) patients seen by ID received PO vanc despite not having diarrhea (p=0.888). Conclusion Most patients who tested positive for C. difficile received PO vanc had documented diarrhea, meeting the definition of CDI. However, over 1 in 5 (21.3%) of patients who received PO vanc did not have diarrhea and may have been colonized rather than have true CDI. ID consultation did not decrease the number of patients without diarrhea who received PO vanc or prevent treatment of colonized patients. This work reveals there may be an opportunity for improvement regarding management of CDI vs. C. difficile colonization which may enhance antibiotic stewardship and the appropriate use of PO vanc. Disclosures All Authors: No reported disclosures

scholarly journals Proinflammatory Cytokines: Possible Accomplices for the Systemic Effects of Clostridioides difficile Toxin B

2021 ◽  
Vol Volume 14 ◽  
pp. 57-62
Author(s):  
Katia Fettucciari ◽  
Alessandro Fruganti ◽  
Andrea Marchegiani ◽  
Stefano Brancorsini ◽  
Pierfrancesco Marconi ◽  
...  
Keyword(s):  
Proinflammatory Cytokines ◽  
Systemic Effects ◽  
Toxin B ◽  
Clostridioides Difficile

scholarly journals Sensitivity of Single-Molecule Array Assays for Detection of Clostridium difficile Toxins in Comparison to Conventional Laboratory Testing Algorithms

2018 ◽  
Vol 56 (8) ◽  
Author(s):  
Alice Banz ◽  
Aude Lantz ◽  
Brigitte Riou ◽  
Agnès Foussadier ◽  
Mark Miller ◽  
...  
Keyword(s):  
Clostridium Difficile ◽  
Single Molecule ◽  
Laboratory Diagnosis ◽  
Case Definition ◽  
Cell Cytotoxicity ◽  
Toxin A ◽  
Toxin B ◽  
Content Type ◽  
High Performing ◽  
Molecular Tests

ABSTRACT Guidelines recommend the use of an algorithm for the laboratory diagnosis of Clostridium difficile infection (CDI). Enzyme immunoassays (EIAs) detecting C. difficile toxins cannot be used as standalone tests due to suboptimal sensitivity, and molecular tests suffer from nonspecificity by detecting colonization. Sensitive immunoassays have recently been developed to improve and simplify CDI diagnosis. Assays detecting CD toxins have been developed using single-molecule array (SIMOA) technology. SIMOA performance was assessed relative to a laboratory case definition of CDI defined by positive glutamate dehydrogenase (GDH) screen and cell cytotoxicity neutralizing assay (CCNA). Samples were tested with SIMOA assays and a commercial toxin EIA to compare performance, with discrepancy resolution using a commercial nucleic acid-based test and a second cell cytotoxicity assay. The SIMOA toxin A and toxin B assays showed limits of detection of 0.6 and 2.9 pg/ml, respectively, and intra-assay coefficients of variation of less than 10%. The optimal clinical thresholds for the toxin A and toxin B assays were determined to be 22.1 and 18.8 pg/ml, respectively, with resultant sensitivities of 84.8 and 95.5%. In contrast, a high-performing EIA toxin test had a sensitivity of 71.2%. Thus, the SIMOA assays detected toxins in 24% more samples with laboratory-defined CDI than the high performing toxin EIA (95% [63/66] versus 71% [47/66]). This study shows that SIMOA C. difficile toxin assays have a higher sensitivity than currently available toxin EIA and have the potential to improve CDI diagnosis.

scholarly journals High Agreement Between an Ultrasensitive Clostridioides difficile Toxin Assay and a C. difficile Laboratory Algorithm Utilizing GDH-and-Toxin Enzyme Immunoassays and Cytotoxin Testing

2019 ◽  
Vol 58 (2) ◽  
Author(s):  
Marie L. Landry ◽  
Jeffrey E. Topal ◽  
Joel Estis ◽  
Phoebe Katzenbach ◽  
Niamh Nolan ◽  
...  
Keyword(s):  
Standard Of Care ◽  
Neutralization Assay ◽  
High Agreement ◽  
Content Type ◽  
Clostridioides Difficile ◽  
Automated Assay ◽  
Toxin Assay ◽  
Stool Samples ◽  
Testing Algorithm ◽  
Positive Agreement

ABSTRACT The Singulex Clarity C. diff toxins A/B (Clarity) assay is an automated, ultrasensitive immunoassay for the detection of Clostridioides difficile toxins in stool. In this study, the performance of the Clarity assay was compared to that of a multistep algorithm using an enzyme immunoassay (EIA) for detection of glutamate dehydrogenase (GDH) and toxins A and B arbitrated by a semiquantitative cell cytotoxicity neutralization assay (CCNA). The performance of the assay was evaluated using 211 residual deidentified stool samples tested with a GDH-and-toxin EIA (C. Diff Quik Chek Complete; Techlab), with GDH-and-toxin discordant samples tested with CCNA. The stool samples were stored at –80°C before being tested with the Clarity assay. For samples discordant between Clarity and the standard-of-care algorithm, the samples were tested with PCR (Xpert C. difficile; Cepheid), and chart review was performed. The testing algorithm resulted in 34 GDH+/toxin+, 53 GDH−/toxin−, and 124 GDH+/toxin− samples, of which 39 were CCNA+ and 85 were CCNA−. Clarity had 96.2% negative agreement with GDH−/toxin− samples, 100% positive agreement with GDH+/toxin+ samples, and 95.3% agreement with GDH+/toxin−/CCNA− samples. The Clarity result was invalid for one sample. Clarity agreed with 61.5% of GDH+/toxin−/CCNA+ samples, 90.0% of GDH+/toxin−/CCNA+ (high-positive) samples, and 31.6% of GDH+/toxin−/CCNA+ (low-positive) samples. The Singulex Clarity C. diff toxins A/B assay demonstrated high agreement with a testing algorithm utilizing a GDH-and-toxin EIA and CCNA. This novel automated assay may offer an accurate, stand-alone solution for C. difficile infection (CDI) diagnostics, and further prospective clinical studies are merited.

scholarly journals Increased Clinical Specificity with Ultrasensitive Detection of Clostridioides difficile Toxins: Reduction of Overdiagnosis Compared to Nucleic Acid Amplification Tests

2019 ◽  
Vol 57 (11) ◽  
Author(s):  
Johanna Sandlund ◽  
Joel Estis ◽  
Phoebe Katzenbach ◽  
Niamh Nolan ◽  
Kirstie Hinson ◽  
...  
Keyword(s):  
Nucleic Acid ◽  
Patient Outcomes ◽  
Single Molecule ◽  
Clinical Performance ◽  
Neutralization Assay ◽  
Nucleic Acid Amplification ◽  
Content Type ◽  
Clostridioides Difficile ◽  
Health Care Associated Infections ◽  
Stool Specimens

ABSTRACT Clostridioides difficile infection (CDI) is one of the most common health care-associated infections, resulting in significant morbidity, mortality, and economic burden. Diagnosis of CDI relies on the assessment of clinical presentation and laboratory tests. We evaluated the clinical performance of ultrasensitive single-molecule counting technology for detection of C. difficile toxins A and B. Stool specimens from 298 patients with suspected CDI were tested with the nucleic acid amplification test (NAAT; BD MAX Cdiff assay or Xpert C. difficile assay) and Singulex Clarity C. diff toxins A/B assay. Specimens with discordant results were tested with the cell cytotoxicity neutralization assay (CCNA), and the results were correlated with disease severity and outcome. There were 64 NAAT-positive and 234 NAAT-negative samples. Of the 32 NAAT+/Clarity− and 4 NAAT−/Clarity+ samples, there were 26 CCNA− and 4 CCNA− samples, respectively. CDI relapse was more common in NAAT+/toxin+ patients than in NAAT+/toxin− and NAAT−/toxin− patients. The clinical specificity of Clarity and NAAT was 97.4% and 89.0%, respectively, and overdiagnosis was more than three times more common in NAAT+/toxin− than in NAAT+/toxin+ patients. The Clarity assay was superior to NAATs for the diagnosis of CDI, by reducing overdiagnosis and thereby increasing clinical specificity, and the presence of toxins was associated with negative patient outcomes.

scholarly journals Ultrasensitive Detection of Clostridioides difficile Toxins in Stool by Use of Single-Molecule Counting Technology: Comparison with Detection of Free Toxin by Cell Culture Cytotoxicity Neutralization Assay

2019 ◽  
Vol 57 (11) ◽  
Author(s):  
Glen Hansen ◽  
Stephen Young ◽  
Alan H. B. Wu ◽  
Emily Herding ◽  
Vickie Nordberg ◽  
...  
Keyword(s):  
Cell Culture ◽  
Single Molecule ◽  
Neutralization Assay ◽  
Single Step ◽  
Multicenter Studies ◽  
Content Type ◽  
Clostridioides Difficile ◽  
Ultrasensitive Assay ◽  
A Cell ◽  
Positive Agreement

ABSTRACT Laboratory tests for Clostridioides difficile infection (CDI) rely on the detection of free toxin or molecular detection of toxin genes. The Singulex Clarity C. diff toxins A/B assay is a rapid, automated, and ultrasensitive assay that detects C. difficile toxins A and B in stool. We compared CDI assays across two prospective multicenter studies to set a cutoff for the Clarity assay and to independently validate the performance compared with that of a cell culture cytotoxicity neutralization assay (CCCNA). The cutoff was set by two sites testing fresh samples from 897 subjects with suspected CDI and then validated at four sites testing fresh samples from 1,005 subjects with suspected CDI. CCCNA testing was performed at a centralized laboratory. Samples with discrepant results between the Clarity assay and CCCNA were retested with CCCNA when the Clarity result agreed with that of at least one comparator method; toxin enzyme immunoassays (EIA), glutamate dehydrogenase (GDH) detection, and PCR were performed on all samples. The cutoff for the Clarity assay was set at 12.0 pg/ml. Compared to results with CCCNA, the Clarity assay initially had 85.2% positive agreement and 92.4% negative agreement. However, when samples with discrepant results between the Clarity assay and CCCNA in the validation study were retested by CCCNA, 13/17 (76.5%) Clarity-negative but CCCNA-positive samples (Clarity+/CCCNA−) became CCCNA−, and 5/26 (19.2%) Clarity+/CCCNA− samples became CCCNA+, resulting in a 96.3% positive agreement and 93.0% negative agreement between Clarity and CCCNA results. The toxin EIA had 59.8% positive agreement with CCCNA. The Clarity assay was the most sensitive free-toxin immunoassay, capable of providing CDI diagnosis in a single-step solution. A different CCCNA result was reported for 42% of retested samples, increasing the positive agreement between Clarity and CCCNA from 85.2% to 96.3% and indicating the challenges of comparing free-toxin results to CCCNA results as a reference standard.

scholarly journals 972. Asymptomatic Carriage of Clostridiodes difficile and Risk of Subsequent Infection

2018 ◽  
Vol 5 (suppl_1) ◽  
pp. S38-S38
Author(s):  
Katrina Espiritu ◽  
Michael Vernon ◽  
Donna Schora ◽  
Lance Peterson ◽  
Kamaljit Singh
Keyword(s):  
Care Facility ◽  
The United States ◽  
Term Care ◽  
Asymptomatic Carriers ◽  
Long Term Care Facility ◽  
Patient Demographics ◽  
Asymptomatic Carriage ◽  
Admission Screening ◽  
History Of ◽  
Healthcare Associated

Abstract Background C. difficile is one of the most common healthcare-associated infections in the United States. Studies of patients with asymptomatic carriage of toxigenic C. difficile have reported conflicting results on the risk of subsequent C. difficile infection (CDI). Older studies suggest that the risk was low and colonization may be protective. Subsequent studies indicate that asymptomatic carriers have a 6-fold greater risk of developing CDI. The aims of our study were to assess the burden of asymptomatic C. difficile carriage and risk of subsequent CDI. Methods Adult inpatients at NorthShore University HealthSystem, Illinois hospitals between August 1, 2017 and February 28, 2018 were eligible for the study. Focused admission screening of patients at high risk of C. difficile carriage was performed: (1) history of CDI or colonization, (2) prior hospitalization past 2 months, or (3) admission from a long-term care facility. A rectal swab was collected and tested using the cobas® Cdif Test (Roche) real-time PCR. The development of hospital onset CDI (HO-CDI) in colonized patients was monitored prospectively for at least 2 months. HO-CDI testing of colonized patients was performed using the Cepheid GeneXpert RT-PCR. HO-CDI was defined as patients hospitalized for at least 72 hours with 3 or more episodes of diarrhea/24 hours, in the absence of other potential causes of diarrhea. Patient demographics were collected using a standardized form and data analyzed using VassarStats. Results There were 6,104 patients enrolled in the study and 528 (8.7%) were positive on admission for toxigenic C. difficile carriage. The mean age of colonized patients was 75.5 years (range 24–103) and 56.4% (298 patients) were females. Of 528 colonized patients, 21 (4%) had a positive CDI test. A total of 7 patients (1.3%) developed HO-CDI. Mean time to positive HO-CDI was 46.1 days (range 5–120 days). Of 5,576 patients that were negative for C difficile carriage on admission, 14 (0.3%) patients developed HO-CDI. The relative risk of HO-CDI was 5.28 (95% CI: 2.14–13.03, P = 0.05). Conclusion We found that 8.7% of at-risk admissions were asymptomatic toxigenic C. difficile carriers. While only 1.3% developed HO-CDI, asymptomatic carriers had a 5 times higher risk of subsequent CDI compared with non-carriers. Disclosures All authors: No reported disclosures.

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