title: Campylobacter upsaliensis isolated from dogs produces high titer of cytolethal distending toxin.
abstract: Cytolethal distending toxin (CDT) consisting of CdtA, CdtB and CdtC has been reported to be a possible virulence factor of campylobacters including Campylobacter upsaliensis. In our previous study, the cdtB gene-based PCR-restriction fragment length polymorphism (RFLP) assay for detection and differentiation of 7 Campylobacter species yielded 3 different RFLP patterns (Cu-I to Cu-III). In this study, entire cdt (Cucdt) genes of each pattern were sequenced to see whether there are any differences in cdt genes, its amino acid sequences and biological activity of CuCDT. We found that all 3 representative strains harbor the entire Cucdt genes and homology between prototype and newly determined Cucdt genes was 94 to 98% with cdtA, 93 to 94% with cdtB and 92 to 93% with cdtC, while that between amino acids of CuCDT was 95 to 99% with CdtA, 97 to 98% with CdtB and 92 to 93% with CdtC. Furthermore, CDT activity produced by C. upsaliensis strains was examined by cytotoxicity assay with HeLa cells. Interestingly, C. upsaliensis produced 64 to 2,340 times higher CDT titer in comparison to other campylobacters did. In addition, Cu-III showed 64 times higher CDT titer than Cu-II, although CDT production level was almost the same by western blotting. These data suggest that CDT produced by C. upsaliensis might contribute more to human diseases in comparison to that produced by other campylobacters and Cu-III CDT seems to be more toxic to HeLa cells in comparison to Cu-I and Cu-II CDTs.
authors.affiliation: Graduate School of Life and Environmental Sciences, Osaka Prefecture University, Osaka 598-8531, Japan.
authors.forename: Srinuan
authors.initials: S
authors.lastname: Somroop
authors.forename: Noritoshi
authors.initials: N
authors.lastname: Hatanaka
authors.forename: Sharda Prasad
authors.initials: SP
authors.lastname: Awasthi
authors.forename: Kentaro
authors.initials: K
authors.lastname: Okuno
authors.forename: Masahiro
authors.initials: M
authors.lastname: Asakura
authors.forename: Atsushi
authors.initials: A
authors.lastname: Hinenoya
authors.forename: Shinji
authors.initials: S
authors.lastname: Yamasaki
mesh_terms: D000818:Animals; D001427:Bacterial Toxins / Q000096:biosynthesis* / Q000235:genetics / Q000633:toxicity; D044885:Campylobacter upsaliensis / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism*; D003603:Cytotoxins / Q000235:genetics / Q000302:isolation & purification / Q000633:toxicity; D004269:DNA, Bacterial; D004285:Dogs / Q000382:microbiology*; D005798:Genes, Bacterial; D006367:HeLa Cells; D006801:Humans; D011994:Recombinant Proteins; D017422:Sequence Analysis, DNA; D013045:Species Specificity
chemical_list: D001427:Bacterial Toxins; D003603:Cytotoxins; D004269:DNA, Bacterial; D011994:Recombinant Proteins; C067044:cytolethal distending toxin