A quantitative assay for Clostridium difficile cytotoxin has been developed, based on the observation that suspended fibroblasts exposed to cytotoxin fail to adhere to plastic. A dye-binding technique was used to quantitate adherent cells, in order to obviate microscopy. Adherent BHK cells were fixed with glutaraldehyde and cell protein was stained with Coomassie blue R-250. Cell-bound dye was eluted and estimated spectrophotometrically. The amount of eluted dye was proportional to the number of adherent cells and cell staining was time dependent. Cytotoxin was purified by gel-permeation and ion-exchange chromatography and migrated as a single band on SDS-PAGE. After exposure of suspended BHK cells to purified cytotoxin, their adhesion to plastic was inhibited in a manner which depended on concentration of cytotoxin and on time and temperature of exposure. This study provides the basis for a C. difficile cytotoxin assay that is quantitative, rapid and reproducible and may have wider applicability in the study of other toxins or agents that inhibit cell adhesion.
Download full-text PDF |
Source |
---|---|
http://dx.doi.org/10.1099/00222615-24-3-197 | DOI Listing |
Eur J Clin Microbiol Infect Dis
January 2025
Department of Clinical and Experimental Sciences, Unit of Infectious and Tropical Diseases, University of Brescia and ASST Spedali Civili Di Brescia, 25123, Brescia, Italy.
Background And Purpose: Clostridioides difficile infection (CDI) is a leading cause of healthcare-associated infections worldwide, with hypervirulent strains linked to severe disease and higher mortality. This study aims to analyze the epidemiology of CDI at a tertiary-care hospital in Italy and compare clinical outcomes between patients infected with hypervirulent and non-hypervirulent strains.
Methods: A retrospective comparative study was conducted on patients diagnosed with CDI at ASST Spedali Civili di Brescia, Italy, from January 2015 to June 2023.
Mol Biotechnol
October 2024
Centro de Desenvolvimento Tecnológico, Biotecnologia, Universidade Federal de Pelotas - Campus Universitário, Capão do Leão, Rio Grande Do Sul, CEP 96160-000, Brazil.
Commun Biol
July 2024
Instituto de Tecnologia Química e Biológica, NOVA University Lisbon, Oeiras, Portugal.
Clostridioides difficile causes a wide range of intestinal diseases through the action of two main cytotoxins, TcdA and TcdB. Ingested spores germinate in the intestine establishing a population of cells that produce toxins and spores. The pathogenicity locus, PaLoc, comprises several genes, including those coding for TcdA/B, for the holin-like TcdE protein, and for TcdR, an auto-regulatory RNA polymerase sigma factor essential for tcdA/B and tcdE expression.
View Article and Find Full Text PDFProtein Sci
July 2024
Bactolife A/S, Copenhagen East, Denmark.
Single-domain antibodies (sdAbs), such as VHs, are increasingly being developed for gastrointestinal (GI) applications against pathogens to strengthen gut health. However, what constitutes a suitable developability profile for applying these proteins in a gastrointestinal setting remains poorly explored. Here, we describe an in vitro methodology for the identification of sdAb derivatives, more specifically divalent VH constructs, that display extraordinary developability properties for oral delivery and functionality in the GI environment.
View Article and Find Full Text PDFToxins (Basel)
May 2024
Department of Medicine, Division of Molecular Medicine and Division of Infectious Disease, Boston University Medical Center, Boston, MA 02118, USA.
The pathophysiology of Lyme disease, especially in its persistent form, remains to be determined. As many of the neurologic symptoms are similar to those seen in other toxin-associated disorders, a hypothesis was generated that , the causative agent of Lyme disease, may produce a neurotoxin to account for some of the symptoms. Using primers against known conserved bacterial toxin groups, and PCR technology, a candidate neurotoxin was discovered.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!