Vaccination Route Determines the Kinetics and Magnitude of Nasal Innate Immune Responses in Rainbow Trout ().

Many pathogens infect animal hosts via the nasal route. Thus, understanding how vaccination stimulates early nasal immune responses is critical for animal and human health. Vaccination is the most effective method to prevent disease outbreaks in farmed fish.

Unconventional gene arrangement and content revealed by full genome analysis of the white sturgeon adenovirus, the single member of the genus Ichtadenovirus.

Adenoviruses are commonly found in members of almost every vertebrate lineage except fish and amphibians, from each of which only a single isolate is available as yet. In this work, the complete genomic sequence of a fish adenovirus, originating from the white sturgeon (Acipenser transmontanus), was determined and analyzed. Several exceptional features were observed including the longest hitherto known genome size (of 48,395 bp) and a strange location of the putative fiber genes resulting in an unconventional organization pattern.

Flagellar regulation mediated by the Rcs pathway is required for virulence in the fish pathogen Yersinia ruckeri.

The flagellum is a complex surface structure necessary for a number of activities including motility, chemotaxis, biofilm formation and host attachment. Flagellin, the primary structural protein making up the flagellum, is an abundant and potent activator of innate and adaptive immunity and therefore expression of flagellin during infection could be deleterious to the infection process due to flagellin-mediated host recognition. Here, we use quantitative RT-PCR to demonstrate that expression of the flagellin locus fliC is repressed during the course of infection and subsequently up-regulated upon host mortality in a motile strain of Yersinia ruckeri.

Draft Genome Sequence of the Fish Pathogen Flavobacterium columnare Strain MS-FC-4.

MS-FC-4 is a highly virulent genetic group 1 (formerly genomovar I) strain isolated from rainbow trout (). The draft genome consists of three contigs totaling 3,449,277 bp with 2,811 predicted open reading frames. MS-FC-4 is a model strain for functional genomic analyses.

Metamorphosis of Ichthyophonus Schizonts Transiting the Gastrointestinal Tract of Experimentally Exposed Rainbow Trout.

Other than the initial infectious cell, schizonts are the only stage of the parasite Ichthyophonus sp. that has been identified in the tissues of a living host, and they are known to initiate new infections when ingested by a suitable host. However, after feeding Ichthyophonus-infected tissue to Rainbow Trout Oncorhynchus mykiss, we observed that once infection was initiated, some schizonts proceeded to develop into several other morphologic forms indistinguishable from those previously described from recently deceased hosts, decomposing infected corpses, and in vitro culture.