Toxic factors of Vibrio strains pathogenic to shrimp

[摘要] ABSTRACT: Vibriosis is a major disease problem in shrimp aquaculture. ŒSyndrome 93¹ is a seasonal juvenile vibriosis caused by Vibrio penaeicida which affects Litopenaeus stylirostris in grow-out ponds in New Caledonia. This study assessedthe toxic activities of extracellular products (ECPs) from V. penaeicida, V. alginolyticus and V. nigripulchritudo using in vivo injections in healthy juvenile L. stylirostris (= Penaeus stylirostris) and invitro assays on shrimp primary cell cultures and the fish cell line epithelioma papulosum cyprini (EPC). Toxic effects of ECPs were demonstrated for all pathogenic Vibrio strains tested both in vivo and in vitro, but for shrimponly; no effect was observed on the fish cell line. ECP toxicity for New Caledonian V. penaeicida was found only after cultivation at low temperature (20°C) and not at higher temperature (30°C). This points to the fact that ŒSyndrome 93¹ episodesare triggered by temperature drops. The assays used here demonstrate the usefulness of primary shrimp cell cultures to study virulence mechanisms of shrimp pathogenic bacteria.

[学科分类] 生物科学（综合）

[关键词] Vibrio;Vibrio penaeicida;Shrimp;Extracellular products;Temperature