Characterization of chitinolytic bacteria and histological aspects of Shell Disease Syndrome in European spiny lobsters (Palinurus elephas) (Fabricius 1787).
The present research reports the first description of Shell Disease Syndrome in European spiny lobsters Palinurus elephas (Fabricius 1787), which occurred in an experimental aquaculture facility in Sicily (Italy). Both bacterial characterization and histopathological examination of the exoskeleton at site of lesions was carried out. Infected specimens showed tail fan erosions, and in one case uropod ulceration and complete loss of periods. Identified species included: Listonella anguillarum 50.5%, Vibrio parahaemolyticus 27.5% and Vibrio alginolyticus 22%. Microscopic evaluation of lesions indicate the presence of inflammatory responses, which include melanization and pseudomembrane formation, similar to those described for other crustaceans affected by SDS.
First Episode of Shell Disease Syndrome in Carcinus aestuarii (Crustacea: Decapoda: Portunidae) in the Volturno River
In this study is reported the first episode of a Shell Disease Syndrome (SDS) in wild specimens of Carcinus aestuarii from the polluted Volturno River estuary. Collected crabs showed erosive and ulcerative “black spot” lesions on the exoskeleton; histologically the lesions ranged from a mild to extensive and severe damages and intense haemocyte infiltration. Bacterial isolation confirmed the presence of some marine bacterial species with chitinolytic activity. The authors suggest that the detection of sds in wild crabs living in polluted waters could be used to monitor the health status of this environment.
Pathogenicity of Vibrio parahaemolyticus in tiger prawn Penaeus monodon Fabricius: possible role of extracellular proteases
Abstract Tiger prawn, Penaeus monodon, were experimentally challenged with a virulent strain of Vibrio parahaemolyticus 25C, originally isolated from Penaeus orientalis in an outbreak of red leg disease at a shrimp farm in the People's Republic of China. The strain was found to be highly virulent to P. monodon with an LD50 value of 1×105 colony forming units (CFU)/prawn. The extracellular products (ECP) of the bacteria were also found to be toxic with an LD50 value of 8 μg protein/prawn. The strain was found to be a poor producer of hemolysins. Extracellular proteases present in the ECP were purified by Sephadex G-150 gel filtration and further analyzed by SDS-polyacrylamide gel electrophoresis. Two fractions viz., F I and F II, were obtained and both were found toxic to tiger prawns, but heat-inactivated fractions were not toxic.