Biological activities of toxins A and B of Clostridium difficile

Lyerly, David M.; Lockwood, D. E.; Richardson, S H; Wilkins, Tracy D.

doi:10.1128/iai.35.3.1147-1150.1982

Cited by 256 publications

(111 citation statements)

References 21 publications

Supporting

Mentioning

106

Contrasting

Unclassified

Order By: Relevance

“…Lethal activity was determined by the intravenous inoculation of pairs of mice (18-22 g) with 0.5 ml volumes of sample followed by observation for up to 72 h. Cytotoxic activity was determined by the addition of 100 ttl sample to either MRC5 or HeLa tissue culture monolayers in wells containing 1-ml volumes of medium and examination for cellular disruption after 24, 48 or 72 h incubation at 37°C. Enterotoxic activity was tested using the rabbit ileal loop (RIL) assay [4] and using the infant mouse (IM) assay [5].…”

Section: Examination For Toxic Activitymentioning

confidence: 99%

Rabbit enterotoxaemia: Purification and preliminary characterisation of a toxin produced by Clostridium spiroforme

Fernie¹

1984

FEMS Microbiology Letters

View full text Add to dashboard Cite

Section: Examination For Toxic Activitymentioning

confidence: 99%

Rabbit enterotoxaemia: Purification and preliminary characterisation of a toxin produced by Clostridium spiroforme

Fernie¹

1984

FEMS Microbiology Letters

View full text Add to dashboard Cite

“…This disease or its mild form, antibiotic associated diarrhea, is observed after antibiotic treatment (Tedesco et al, 1974). The main virulence factors of C. difJicile are two high-molecularmass toxins, whose enterotoxic (TcdA) and cytotoxic (TcdB) character have been extensively described (Bartlett et al, 1978;Lyerly et al, 1982Lyerly et al, , 1985Triadafilopoulos et al, 1987). TcdB exceeds TcdA in its cytotoxicity by a factor of 100-1000 (Bette et al, 1991).…”

mentioning

confidence: 99%

Transcription Analysis of the Genes tcdA‐E of the Pathogenicity Locus of Clostridium Difficile

Hundsberger

Braun

Weidmann

et al. 1997

European Journal of Biochemistry

185

181

View full text Add to dashboard Cite

To analyse the transcription pattern of the five tcdA-E genes of the pathogenicity locus (PaLoc) of Clostridium difficile a protocol was established to purify RNA from strain VPI10463. Transcription analysis of the five tcdA-E genes showed that they were all transcribed. In the early exponential phase, a high level of tcdC and low levels of tcdA,B,D,E transcripts were detectable; this was inverted in the stationary phase, suggesting that TcdC might have a negative influence on transcription of the other genes. Three transcription initiation sites, one for tcdA and two for tcdB were determined by primer extension analysis. Readthrough transcripts from outside the locus were not obtainable, so that parts of the transcription of tcdD, tcdB, tcdA and tcdC must occur by monocistronic transcription. Within the locus all possible intergenic readthrough transcripts were detectable except that between tcdC and tcdA, a stretch of DNA interrupted by a functional transcription terminator. Thus we found mono-and polycistronic transcription of tcdA and tcdB to occur which should lead to production of a surplus of tcdA over tcdB transcripts. This would explain the surplus of TcdA over TcdB expression observed in vitro. Due to its basic nature and similarity to BcnA of Clostridium perjringens and to Orf-22 of Clostridium botulinum, TcdD is most probably a regulatory protein with DNA-binding properties. On the basis of the presented study we discuss a model for the growth-phase-related, coordinate regulation of toxin expression wherein tcdC has a negative and tcdD a positive regulatory function on transcription of the tcdD,B,E and tcdA genes.

show abstract

“…The two bacterial strains used in this study were C. di¤cile strains VPI 10463 [15], a highly toxigenic strain, and ATCC 8864 [11], a strain that was known to only produce TcdB but not TcdA. The bacteria were grown overnight before harvesting in brain heart infusion (Difco; Becton Dickinson, Cockeysville, MD, USA) broth at 37³C in an anaerobic chamber with 10% CO 2 , 10% H 2 and 80% N 2 .…”

Section: Bacterial Strains and Growth Conditionsmentioning

confidence: 99%

Sequence analysis of a new open reading frame located in the pathogenicity locus of Clostridium difficile strain 8864

Song¹

1999

FEMS Microbiology Letters

View full text Add to dashboard Cite

Strain 8864 is a natural isolate of Clostridium difficile that is toxin B-positive and toxin A-negative. Recent work showed that there is a genetic rearrangement occurring at the pathogenicity locus (PaLoc) of the bacteria. Our investigation in the PaLoc region revealed an open reading frame (tcdF) of 543 bp DNA not reported before. This tcdF could encode a putative polypeptide of 22 kDa. Although no peptide homology was found with other known proteins, we postulate that it could be a novel protein because not only highly consensus ribosome-binding and promoter sequences were found upstream of tcdF, transcript was also identified at the region occupied by tcdF. ß

show abstract

Biological activities of toxins A and B of Clostridium difficile

Cited by 256 publications

References 21 publications

Rabbit enterotoxaemia: Purification and preliminary characterisation of a toxin produced by Clostridium spiroforme

Rabbit enterotoxaemia: Purification and preliminary characterisation of a toxin produced by Clostridium spiroforme

Transcription Analysis of the Genes tcdA‐E of the Pathogenicity Locus of Clostridium Difficile

Sequence analysis of a new open reading frame located in the pathogenicity locus of Clostridium difficile strain 8864

Contact Info

Product

Resources

About