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).

Absence of Toxemia in Clostridioides difficile Infection: Results from Ultrasensitive Toxin Assay of Serum.

Clostridioides difficile infection (CDI) is caused by Toxins A and B, secreted from pathogenic strains of C. difficle. This infection can vary greatly in symptom severity and in clinical presentation.

Laxative Use Does Not Preclude Diagnosis or Reduce Disease Severity in Clostridiodes difficile Infection.

Background: To optimize utility of laboratory testing for Clostridiodes difficile infection (CDI), the 2017 Infectious Diseases Society of America-Society for Healthcare Epidemiology of America (IDSA-SHEA) clinical practice guidelines recommend excluding patients from stool testing for C. difficile if they have received laxatives within the preceding 48 hours. Sparse data support this recommendation.

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.

Comparison of Clostridioides difficile Stool Toxin Concentrations in Adults With Symptomatic Infection and Asymptomatic Carriage Using an Ultrasensitive Quantitative Immunoassay.

Background: We used an ultrasensitive, quantitative single molecule array (Simoa) immunoassay to test whether concentrations of Clostridioides (formerly Clostridium) difficile toxins A and/or B in the stool of adult inpatients with C. difficile infection (CDI) were higher than in asymptomatic carriers of toxinogenic C. difficile.

Filter-based assay for Escherichia coli in aqueous samples using bacteriophage-based amplification.

This paper describes a method to detect the presence of bacteria in aqueous samples, based on the capture of bacteria on a syringe filter, and the infection of targeted bacterial species with a bacteriophage (phage). The use of phage as a reagent provides two opportunities for signal amplification: (i) the replication of phage inside a live bacterial host and (ii) the delivery and expression of the complementing gene that turns on enzymatic activity and produces a colored or fluorescent product. Here we demonstrate a phage-based amplification scheme with an M13KE phage that delivers a small peptide motif to an F(+), α-complementing strain of Escherichia coli K12, which expresses the ω-domain of β-galactosidase (β-gal).