August 2005

Vibrio bacteria could be a risk to fish as well as humans

Press release based on a recent article published by Environmental Microbiology

About half of new marine vibrio bacteria discovered in the last five years, can kill fish and crustacea, according to researchers at Heriot-Watt University in Edinburgh.

The most common disease of vibrios is cholera, which has caused millions of cases of illness and fatality in humans. Recent interest in this genus of bacteria has led to the discovery of many new species, especially from seawater and marine animals.

New species have been found in a wide range of marine environments, including corals, sediments and rotifers. For example, Vibrio coralliilyticus has recently been described as a new cause of disease in coral.

Professor Brian Austin of Heriot-Watt University said that his research demonstrates that some of these new species are similar to existing fish and shellfish pathogens. The new species, Vibrio brasiliensis, seems to be related to Vibrio tubiashii, which has long been known to cause disease in oysters.

Professor Austin comments: "Having observed this, the question arose about whether any of these new species could have implications to the health of marine animals. The answer was that around half of the new species killed fish in laboratory conditions. Our research shows that marine vibrios could cause disease to fish and crustaceans. In some cases, only 100 bacterial cells from the pathogens were capable of causing disease. This means that the bacteria are extremely aggressive and could pose a great risk to sea animals, as disease is often caused by enzymes produced by bacteria."

It is not yet clear to what extent these new vibrios affect marine animals in the wild. The next thrust of the work by Professor Austin and his team is to devise methods to minimize the risk of these bacteria to animals and the environment.

Notes to editors

1. Pathogenicity of vibrios to rainbow trout (Oncorhynchus mykiss, Walbaum) and Artemia nauplii Brian Austin, Dawn Austin, Rowan Sutherland, Fabiano Thompson, Jean Swings

2.The species studied were: Vibrio brasiliensis, Vibrio coralliilyticus, Vibrio ezurae, Vibrio fortis, Vibrio kanaloaei, Vibrio neptunius and Vibrio rotiferianus

3. To view the full article, please follow these simple instructions:

4. For more information contact Brian Austin, Professor of Microbiology, School of Life Sciences, John Muir Building, Heriot-Watt University, Riccarton, UK. Email: [email protected]

5. Environmental Microbiology is published by Blackwell Publishing with the Society for Applied Microbiology. The journal is devoted to the study of microbial processes in the environment, microbial communities and microbial interactions.