Infectious microbial diseases and host defense responses in Sydney rock oysters.

David A. Raftos,Saleem Aladaileh,Daniel Butt,Rhiannon Kuchel

doi:10.3389/fmicb.2014.00135

Abstract

Aquaculture has long been seen as a sustainable solution to some of the world's growing food shortages. However, experience over the past 50 years indicates that infectious diseases caused by viruses, bacteria, and eukaryotes limit the productivity of aquaculture. In extreme cases, these types of infectious agents threaten the viability of entire aquaculture industries. This article describes the threats from infectious diseases in aquaculture and then focuses on one example (QX disease in Sydney rock oysters) as a case study. QX appears to be typical of many emerging diseases in aquaculture, particularly because environmental factors seem to play a crucial role in disease outbreaks. Evidence is presented that modulation of a generic subcellular stress response pathway in oysters is responsible for both resistance and susceptibility to infectious microbes. Understanding and being able to manipulate this pathway may be the key to sustainable aquaculture.

Highlights

During the latter part of the last century, aquaculture was seen as a key emergent food source needed to compensate for the world’s rapidly growing human population
A breakthrough in linking QX disease to environmental stress came from a study by Peters and Raftos (2003), which again tested a relationship between rainfall and disease, this time focusing on low salinity rather than altered pH
DIRECTIONS Infectious diseases are the main factors that limit the production of food and other products by aquaculture industries worldwide

Summary

INTRODUCTION

During the latter part of the last century, aquaculture (the farming of aquatic animals and plants) was seen as a key emergent food source needed to compensate for the world’s rapidly growing human population. The pathogens and parasites that affect aquaculture production around the world include viruses [e.g., ostreid herpes virus (OsHV1), white spot syndrome virus (WSSV), abalone viral ganglioneuritis], bacteria (e.g., Vibrio harveyi, Flexibacter columnaris, Aeromonas salmonicida), protozoans (e.g., Perkinsus species, Marteilia species, and Bonamia species), and multicellular parasites or pests (e.g., mud worms and platyhelminths) (Renault, 1995; Coelen, 1997). These infectious agents can be highly host specific (e.g., Marteilia sydneyi in Sydney rock oysters) or have a broad range of host species (e.g., Perkinsus olseni, WSSV, or Vibrio harveyi). Farmers implemented a “single seed” culture method, which involves spat being scraped off sticks after www.frontiersin.org

Microbial disease in oysters

Findings

CONCLUSIONS AND FUTURE DIRECTIONS