Higher In Vivo Fecal Concentrations of Clostridioides difficile Toxins A and B in Patients With North American Pulsed-Field Gel Electrophoresis Type 1/Ribotype 027 Strain Infection.

Ultrasensitive, quantitative Clostridioides difficile stool toxin measurement demonstrated significantly higher concentrations of toxins A and B in patients infected with the North American pulsed-field gel electrophoresis type 1/ribotype 027 (NAP-1/027) strain compared with other strains, providing in vivo confirmation of the in vitro association between NAP-1/027 and elevated toxin production.

Ultrasensitive and Quantitative Toxin Measurement Correlates With Baseline Severity, Severe Outcomes, and Recurrence Among Hospitalized Patients With Clostridioides difficile Infection.

Background: Stool toxin concentrations may impact Clostridioides difficile infection (CDI) severity and outcomes. We correlated fecal C difficile toxin concentrations, measured by an ultrasensitive and quantitative assay, with CDI baseline severity, attributable outcomes, and recurrence.

Methods: We enrolled 615 hospitalized adults (≥18 years) with CDI (acute diarrhea, positive stool nucleic acid amplification testing, and decision to treat).

Host Immune Markers Distinguish Clostridioides difficile Infection From Asymptomatic Carriage and Non-C. difficile Diarrhea.

Background: Recent data indicate that Clostridioides difficile toxin concentrations in stool do not differentiate between C. difficile infection (CDI) and asymptomatic carriage. Thus, we lack a method to distinguish a symptomatic patient with CDI from a colonized patient with diarrhea from another cause.

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

Guidelines recommend the use of an algorithm for the laboratory diagnosis of infection (CDI). Enzyme immunoassays (EIAs) detecting 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.

New Vidas assay for Toxoplasma-specific IgG avidity: evaluation on 603 sera.

After the development of the new version of the test Vidas Toxo IgG with antigens obtained from tachyzoites cultured on cells, a Vidas avidity test has been recently developed. The aim of this study was to assess the value of the determination of avidity on the new Vidas test. This avidity test was performed on 553 sera obtained from pregnant women whose dates of infection had been determined and on 50 sera obtained from immunosuppressed patients.

Comparative analysis of the VIDAS Toxo IgG IV assay in the detection of antibodies to Toxoplasma gondii.

A new serological test, Vidas Toxo IgG IV, has been developed with antigens obtained from tachyzoites cultured on cells. Vidas Toxo IgG IV replaces Vidas Toxo IgG II by offering a more standardized antigenic production and a lower number of indeterminate results while retaining equivalent sensitivity and specificity.

Molecular cloning, overexpression in Escherichia coli, and purification of 6x his-tagged C-terminal domain of Clostridium difficile toxins A and B.

Genomic DNA from ribotype-01 and -17 Clostridium difficile strains was used for amplification of the sequences encoding the carboxy-terminal domain of toxins A (TcdA) and B (TcdB). The deduced C-terminal TcdB ribotype-01 and -17 domains share 99.5% amino acid sequence identity while TcdA ribotype-17 comprises a 607 amino acid deletion compared to TcdA-01.