Health

Gill disease therapies

OF the pathogens implicated in causing gill disease, it is amoebic gill disease (AGD) that presents the greatest problems. The aetiological agent of AGD, Neopara

moeba perurans, contains a symbiotic partner, Perkinsela sp., which lives inside the amoeba and belongs to a group of organisms called kinetoplastids.

- ifornia in the late 1980s, but now this disease affects every major salmon producing country.

The disease exerts a heavy economic burden through direct mortalities, a reduction in growth performance and the need for expensive treatments, which presently are based mainly on hydrogen peroxide and freshwater bathing.

Drug based therapies in aquaculture are convenient, particularly when administered in feed, but few, if any, effective drugs are available to treat AGD. Indeed, the total number of drugs available in aquaculture is relatively limited, especially when compared to terrestrial farming.

Moreover, the drug approval process is time consuming and expensive, meaning any approaches that minimise these issues are attractive.

One possible approach is to repurpose existing drugs that are already approved for use in aquaculture or have been used to treat similar of Aquaculture.

‘First, we aimed to identify all diseases caused by amoeba and kinetoplastids in humans and

‘In total, 183 studies were collected and contained information relating to diseases similar to AGD, notably 107 studies relating to disease caused by amoebae and 76 studies of kinetoplastids.

or are used as treatments for these related diseases because they may prove to be effective against Neoparamoeba perurans and/or Perkinsela sp.

treat infections caused by both amoeba and kinetoplastid pathogens.

‘Next, we searched compound databases to identify known drugs with similar characteristics, and designed a scoring system to rank all the candidates according to the availability of information important to gaining

The MPhil candidate, who joined the IoA in March 2018, continued :‘ Finally, we looked at Neoparamoeba and Perkins el a genome sand metabol ranked candidate drugs are present in one or both of these organisms.

‘The next step of the project will be to evaluate these candidate drugs for activity against the AGD-causing pathogens in vitro, before ultimately

‘We hope that this project will lead to the introduction of a new thera

Other approaches being pursued in Stirling to prevent AGD include the development of a protective vaccine; however, until key gaps in the knowledge of the biology and ecology of Neoparamoeba perurans are addressed, this solution remains a longer term goal.

In the meantime, efforts continue to repurpose existing drugs as more effective and practical alternatives for treating AGD than hydrogen peroxide and freshwater bathing.

For updates and more information on this project, contact: c.p.henard@stir.ac.uk and andrew.desbois@stir.ac.uk FF