Clostridium difficile toxins A and B are members of an important class of virulence factors known as large clostridial toxins (LCTs). Toxin action involves four major steps: receptor-mediated endocytosis, translocation of a catalytic glucosyltransferase domain across the membrane, release of the enzymatic moiety by autoproteolytic processing, and a glucosyltransferase-dependent inactivation of ...

Transfer RNA modifications play pivotal roles in protein synthesis. N6-threonylcarbamoyladenosine (t6A) and its derivatives are modifications found at position 37, 3΄-adjacent to the anticodon, in tRNAs responsible for ANN codons. These modifications are universally conserved in all domains of life. t6A and its derivatives have pleiotropic functions in protein synthesis including aminoacylation...

Abstract The nosocomial pathogen Clostridioides difficile colonizes the gastrointestinal tract of patients following microbiome disruption and secretes two major virulence factors toxin A (TcdA) B (TcdB). Approximately 25% infected with C. experience recurrent infection, rate recurrence increases each subsequent infection. quality protective capacity adaptive immune response generated infection...

background: reduced susceptibility of clostridium difficile to antibiotics is problematic in clinical settings. there is new evidence indicating the cotransfer of toxin-encoding genes and conjugative transposons encoding resistance to antibiotics among different c. difficile strains. to analyze this association, in the current study, we evaluated the frequency of toxigenic c. difficile among th...

The aim of this study was to isolate Clostridium difficile from dogs’ faeces, and to study the frequency of its virulence genes. A total of 151 samples of dogs’ faeces were collected. The isolation of C. difficile was performed by using the bacterial culture methods followed by DNA extraction using boiling method. Multiplex PCR method was performed for identification of tcdA, tcdB, cdtA and cdt...

The pathogenesis of colitis due to Clostridium difficile is closely linked to the elaboration of 2 large, single-unit glucosyltransferases referred to as toxin A (TcdA) and toxin B (TcdB). Clinical isolates from patients with symptomatic C. difficile infection (CDI) invariably produce both TcdA and TcdB or TcdB alone. Vaccination of experimental hamsters against both toxins prevents fatal C. di...

BACKGROUND AND OBJECTIVE Clostridium difficile NAP1/ribotype 027 is associated with severe disease and high mortality rates. Our aim was to determine the prevalence of NAP1/ribotype 027 among C. difficile isolates in a tertiary care hospital, and review the main clinical data. METHODS We included 106 stool samples from 106 patients. Samples were tested for A&B toxins and were cultured on CCFA...

Toxins A and B are the main virulence factors of Clostridium difficile and are the targets for molecular diagnostic tests. Here, we describe a new toxin A-negative, toxin B-positive, binary toxin CDT (Clostridium difficile transferase)-negative (A(-) B(+) CDT(-)) toxinotype (XXXII) characterized by a variant type of pathogenicity locus (PaLoc) without tcdA and with atypical organization of the ...

Clostridium difficile toxins A and B (TcdA and TcdB) are the causative agents of antibiotic-associated pseudomembranous colitis. Mucosal mast cells play a crucial role in the inflammatory processes underlying this disease. We studied the direct effects of TcdA and TcdB on the human mast cell line HMC-1 with respect to degranulation, cytokine release, and the activation of proinflammatory signal...