top


Principal Investigator
Sergio Fernández Boo

Leader Institution
A4F, Alga Fuel, S.A.

Research Teams


Program

CRAGIAMP: Search for Antimicrobial Peptides in Crassostrea gigas oysters and Paracentrotus lividus sea urchin. Diminution of mortality rate in oyster culture.

Molluscs constitute an important part of the worldwide aquaculture (around 23%), whose volume of production is rising progressively from 6,3 million tonnes in 1991 to 15,4 million tonnes in 2014. In Portugal, mollusc aquaculture is an incipient industry with high expectations. In order to consolidate the industry and make the aquaculture of oysters stronger, some disease problems should be minimized and production techniques should be improved. Unfortunately, the oyster production has suffered several outbreaks through the history, the presence of the viruses Iridovirus, herpesvirus (OsHV-1) and more recently, a variant of this one called OsHV-1 µVar, the protozoan parasites Marteilia refringens and Bonamia ostreae and the bacteria Vibrio aestuarinus are a major concerning. However, it does not seem possible to eradicate a pathogen once it has been introduced in a previously free zone. A good understanding of agent-host environment interactions may help to mitigate disease problems but also new strategies to prevent and minimize mortalities needs to be undertaken. In 2015, massive mortalities of pacific oyster (Crassostrea gigas) have been documented in Aveiro and Algarve. The presence of OsHV-1 µVar was detected in all outbreaks. The identification, isolation and immobilization of Antimicrobial Peptides (AMPs) in invertebrates is a promising strategy to avoid the entrance and dispersion of pathogens in aquaculture facilities. Therefore, the main objective of this project is the screening of AMPs production in the oyster C. gigas after immunostimulation with different host pathogens (V. aesturianus and OsHV-1) in order to identify compounds of interest. Also, a novel search of AMPs in the immune cells of the sea urchin P. lividus as well as the mucosa associated to their ambulacral feet will be evaluated. AMPs from the sea urchin species Tripneustes depressus have shown antiviral activity against some herpesvirus which are one of the major concerns of oyster culture. For that, we will like to characterize the AMPs presented in P. lividus and check if these compounds present antiviral activity too. These AMPs compounds are going to be classified according to their bactericidal, antiviral and antifungal activities. Some pathological bacteria and viruses which cause pathological problems in oysters but also other pathogens for humans are going to be used in order to identify the properties of these molecules. Those with high antimicrobial properties will be selected for immobilization, and posterior use in aquaculture industry equipment to avoid infection and dispersion of the pathogens in a hatchery, depuration system and in an extensive oyster farm.

Funding