Flagellin A is essential for the virulence of Vibrio anguillarum.
1996 (English)In: Journal of Bacteriology, ISSN 0021-9193, E-ISSN 1098-5530, Vol. 178, no 5, 1310-1319 p.Article in journal (Refereed) Published
A flagellin gene from the fish pathogen Vibrio anguillarum was cloned, sequenced, and mutagenized. The DNA sequence suggests that the flaA gene encodes a 40.1-kDa protein and is a single transcriptional unit. A polar mutation and four in-frame deletion mutations (180 bp deleted from the 5' end of the gene, 153 bp deleted from the 3' end of the gene, a double deletion of both the 180- and 153-bp deletions, and 942 bp deleted from the entire gene) were made. Compared with the wild type, all mutants were partially motile, and a shortening of the flagellum was seen by electron microscopy. Wild-type phenotypes were regained when the mutations were transcomplemented with the flaA gene. Protein analysis indicated that the flaA gene corresponds to a 40-kDa protein and that the flagellum consists of three additional flagellin proteins with molecular masses of 41, 42, and 45 kDa. N-terminal sequence analysis confirmed that the additional proteins were flagellins with N termini that are 82 to 88% identical to the N terminus of FlaA. Virulence studies showed that the N terminal deletion, the double deletion, and the 942-bp deletion increased the 50% lethal dose between 70- and 700-fold via immersion infection, whereas infection via intraperitoneal injection showed no loss in virulence. In contrast, the polar mutant and the carboxy-terminal deletion mutant showed approximately a 10(4)-fold increase in the 50% lethal dose by both immersion and intraperitoneal infection. In summary, FlaA is needed for crossing the fish integument and may play a role in virulence after invasion of the host.
Place, publisher, year, edition, pages
1996. Vol. 178, no 5, 1310-1319 p.
IdentifiersURN: urn:nbn:se:umu:diva-121653PubMedID: 8631707OAI: oai:DiVA.org:umu-121653DiVA: diva2:933330