Production of actin-specific ADP-ribosyltransferase (binary toxin) by strains of Clostridium difficile

• DOI: 10.1111/j.1574-6968.2000.tb09122.x
• Publication Date: 2006-01-10T07:50:36Z
• Authors: Simon Stubbs; Maja Rupnik; Maryse Gibert; Jon Brazier; Brian Duerden; Michel Popoff
• Keywords: ADP Ribose Transferases; 0303 health sciences; Clostridioides difficile; Bacterial Toxins; Polymerase Chain Reaction; Actins; Substrate Specificity; 3. Good health; 03 medical and health sciences; Bacterial Proteins; Poly(ADP-ribose) Polymerases; Phylogeny; Polymorphism, Restriction Fragment Length

In addition to the two large clostridial cytotoxins (TcdA and TcdB) certain strains of Clostridium difficile produce an actin-specific ADP-ribosyltransferase, or binary toxin. PCR reactions were developed to detect genes encoding the enzymatic (cdtA) and binding (cdtB) components of the binary toxin and 170 representative strains were tested to assess the prevalence of the toxin. Positive PCR results (n=59) were confirmed by immunoblotting and ADP-ribosyltransferase assay. PCR ribotype and toxinotype (restriction fragment length polymorphism analysis of genes for TcdA and TcdB) correlated with possession of binary toxin genes. All strains with cdtA and cdtB belonged to toxin-variable toxinotypes and five toxin-producing groups of strains have been described according to the presence or absence of TcdA, TcdB and binary toxin. Result indicate that ca. 6.4% of toxigenic isolates of C. difficile referred to the Anaerobe Reference Unit from UK hospitals have cdtA and cdtB genes.