2008/749 Using the mucosal antibody response to recombinant Neoparamoeba perurans attachment proteins to design an experimental vaccine for amoebic gill disease

By Victoria Valdenegro Vega

Amoebic gill disease (AGD) is the main disease affecting the Tasmanian salmonid industry and the condition has also been described in other major salmon and trout producing countries. AGD is caused by Neoparamoeba perurans, and outbreaks of the disease appear during the marine grow-out phase, in particular when water temperature rises. A variety of treatments have been tested, but currently the only treatment option widely used in Tasmania is freshwater bathing, which represents a high economic burden for the industry. Therefore, the development of a vaccine remains a high priority for salmon producers and different types of vaccines have been previously tested against AGD without success.

This research focused mainly on developing a vaccine against Neoparamoeba perurans. Since the information available on mucosal responses against this particular pathogen was limited, the host immune responses and their effects on a potential vaccine candidate against AGD were investigated.

For the first time it was shown that antibody (IgM) developed in the mucus after immunisation is capable of binding the surface of the amoeba. The mucosal and systemic anti-N. perurans antibody responses to a recombinant putative attachment protein of the amoeba, first identified by the generation of a cDNA library from the parasite has been documented.