title: A new subtype of the metalloprotease toxin gene and the incidence of the three bft subtypes among Bacteroides fragilis isolates in Japan.
abstract: The bft gene encoding Bacteroides fragilis toxin (BFT) has been devided into two subtypes, bft-1 and bft-2. We found a novel subtype by sequencing a segment of the bft gene from 64 enterotoxigenic B. fragilis (ETBF) strains isolated in Japan. The 1548-bp nucleotide sequences of the new bft, the bft-1, and bft-2 genes were determined for five, four, and four ETBF strains, respectively; the nucleotide sequence was identical among each bft subtype and the degree of identity between each subtype was between 89 and 94%. Most of the variations between the three subtypes were detected in the region encoding mature toxin. A multiplex PCR was developed with a four-primer mix to subtype the bft sequences. The subtyping of 143 ETBF isolates from extraintestinal and stool specimens of humans and cows showed that the bft-1 was the most prevalent subtype, followed by bft-2 and a new bft subtype. No other subtype was found among the strains tested.
authors.affiliation: Institute of Anaerobic Bacteriology, Gifu University School of Medicine, 40 Tsukasa-machi, Gifu, Japan. nk19@cc.gifu-u.ac.jp
authors.forename: N
authors.initials: N
authors.lastname: Kato
authors.forename: C X
authors.initials: CX
authors.lastname: Liu
authors.forename: H
authors.initials: H
authors.lastname: Kato
authors.forename: K
authors.initials: K
authors.lastname: Watanabe
authors.forename: Y
authors.initials: Y
authors.lastname: Tanaka
authors.forename: T
authors.initials: T
authors.lastname: Yamamoto
authors.forename: K
authors.initials: K
authors.lastname: Suzuki
authors.forename: K
authors.initials: K
authors.lastname: Ueno
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000595:Amino Acid Sequence; D000818:Animals; D001427:Bacterial Toxins / Q000737:chemistry / Q000235:genetics*; D001442:Bacteroides Infections / Q000453:epidemiology / Q000382:microbiology*; D001441:Bacteroides fragilis / Q000201:enzymology / Q000235:genetics / Q000302:isolation & purification*; D001483:Base Sequence; D002417:Cattle; D002648:Child; D002675:Child, Preschool; D003967:Diarrhea / Q000382:microbiology; D005243:Feces / Q000382:microbiology; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D007564:Japan / Q000453:epidemiology; D008666:Metalloendopeptidases / Q000737:chemistry / Q000235:genetics*; D008875:Middle Aged; D008969:Molecular Sequence Data; D016133:Polymerase Chain Reaction / Q000379:methods; D017422:Sequence Analysis, DNA
chemical_list: D001427:Bacterial Toxins; C405031:Bacteroides fragilis toxin; D008666:Metalloendopeptidases