title: Nucleotide sequence of Clostridium difficile toxin A gene fragment and detection of toxigenic strains by polymerase chain reaction.
abstract: A 1947 base pair (bp) fragment of the toxin A gene of Clostridium difficile was sequenced. A continuous open reading frame was found, which contained 4 distinct groups of repeat nucleotide sequence with 88 to 100% identity within each group. The arrangement of the groups (A, 81 bp, B, C and D, 63 bp) was ABCCCDABCDDABCCCDABCCDABCDABC. Based on nucleotide sequence data from the C repeat group, a pair of oligonucleotide primers were synthesised and used in the polymerase chain reaction (PCR) to amplify fragments from the toxin A gene. Several products of multiples of 63 bp length were amplified for all 33 toxigenic C. difficile strains tested in contrast to the 12 non-toxigenic strains tested which failed to amplify any product. This rapid technique is of potential use in the specific identification of toxigenic C. difficile strains in mixed culture and from clinical specimens.
authors.affiliation: Department of Medical Microbiology, St. Bartholomew's Hospital Medical College, West Smithfield, London, U.K.
authors.forename: B W
authors.initials: BW
authors.lastname: Wren
authors.forename: C L
authors.initials: CL
authors.lastname: Clayton
authors.forename: S
authors.initials: S
authors.lastname: Tabaqchali
mesh_terms: D000595:Amino Acid Sequence; D001427:Bacterial Toxins / Q000235:genetics*; D001483:Base Sequence; D003013:Clostridium / Q000235:genetics* / Q000302:isolation & purification; D004269:DNA, Bacterial / Q000235:genetics; D004768:Enterotoxins; D005798:Genes, Bacterial; D008969:Molecular Sequence Data; D016133:Polymerase Chain Reaction; D012091:Repetitive Sequences, Nucleic Acid; D015183:Restriction Mapping; D012689:Sequence Homology, Nucleic Acid
chemical_list: D001427:Bacterial Toxins; D004269:DNA, Bacterial; D004768:Enterotoxins; C041348:tcdA protein, Clostridium difficile