Vibrio anguillarum

Introduction

Vibrio anguillarum is a Gram negative, curved rod bacterium with one polar flagellum. It is an important pathogen of cultured salmonid fish, and causes the disease known as vibriosis or red pest of eels.

The disease has been observed in the salmon, the bream, the eel, the mullet, the catfish and Tilapia amongst others.

The organism is most prevalent in late summer in salt or brackish water and transmission is mainly horizontal by direct contact. It is widely distributed across the world.

Clinical signs and diagnosis

There are multiple haemorrhages in the body and skin changes signifying systemic involvement. Splenomegaly may be evident in young fish.

Diagnosis relies on culture of V. anguillarum and the use of monoclonal antibodies.

Treatment and control

Various antibiotics such as ampicillin, chloramphenicol, nalidixic acid derivatives, nitrofurans, sulphonamides and trimethoprim can be used to treat the fish. Resistance is emerging however.

A vaccine against V. anguillarum is available.

References

• Vibriosis - Fish expert reviewed and published by Wikivet accessed 09/10/2011.