Shellfish hatcheries are often affected by disease outbreaks. Three such episodes were investigated in different Galician hatcheries in order to establish the relationship between present microbiota and mortalities. Isolates were obtained from various parts of the hatcheries. Experimental tests for pathogenicity were carried out in microscale experiments using selected strains on Ostrea edulis larvae. The pathogenicity of 1 strain from each outbreak was demonstrated and shown to cause high mortalities (ranging from 98.5 to 100%) in 72 to 96 h after inoculation of larval cultures. All 3 strains belong to the genus Vibrio. One of the strains was identified as Vibrio neptunius and is the first description of this species as a molluscan pathogen. The other 2 strains showed low similarity with the Vibrio species analysed and may constitute new species within this genus. KEY WORDS: Flat oyster · Vibrio · Vibrio neptunius · Pathogenicity test · Shellfish hatchery Resale or republication not permitted without written consent of the publisherDis Aquat Org 67: [209][210][211][212][213][214][215] 2005 Tettelbach 1988, Lodeiros et al. 1992, Riquelme et al. 1995, Nicolas et al. 1996, Sáinz et al. 1998, Sugumar et al. 1998, Araya et al. 1999, Elston et al. 1999, Lacoste et al. 2001, Anguiano-Beltrán et al. 2004, Estes et al. 2004, Gay et al. 2004.In this paper, we present the results of bacteriological studies performed during 3 episodes of severe mortalities in 3 shellfish hatcheries in Galicia. The pathogenicity of isolated bacterial strains was tested in order to identify the aetiological agents. In addition, the first evidence of Vibrio neptunius as mollusc pathogen is presented. MATERIALS AND METHODS Description of facilities and bacterial isolation.The facilities where mortalities occurred are situated at different locations along the Galician coast in NW Spain (Fig. 1). Their management practices vary: one is a commercial hatchery beside a molluscan depuration facility (hatchery A); the second is a plant where molluscs and fishes are cultured (hatchery B); and the third is exclusively dedicated to molluscs (hatchery C). Two of the facilities (B and C) suffered mortalities in oyster larval stages and one (A) in post-larvae.Samples were taken in the different areas of the hatcheries: larvae, spat, broodstock, tank surfaces, phytoplankton and water. Larvae, spat and broodstock gonad (pieces excised aseptically) were washed, ground and homogenized in sterile seawater (SSW). Appropriate dilutions were made with these suspensions as well as with samples of water and phytoplankton used as larval feed. They were spread on Marine Agar (MA, Pronadisa) and Thiosulphate Citrate Bile Sucrose (TCBS, Oxoid). Samples taken directly from inner surfaces of the tanks containing the oysters were spread on the above mentioned media with sterile swabs.Plates were incubated at 22°C and selected colonies were isolated after 24 h (TCBS) or 7 d (MA) on MA, and further restreaked to purity. Pure cultures of strains were frozen at -8...

We have reviewed clinically, morphologically, and immunophenotypically a series of 14 Epstein-Bar virus (EBV)+ cutaneous natural killer cell (NK)/T-cell lymphoma from Peru. Most (11 out of 14) of these cases fit well into the category of Hydroa vacciniforme-like lymphoma (HVLL), but 3 have a different clinical presentation, without facial involvement. In all 14 cases, skin lesions present in both the sun-exposed and nonexposed areas exhibited a slowly progressive relapsing course, changing from edema, to blistering, ulceration, and final scarring. The immunophenotype had a cytotoxic T or NK-cell lineage. The mean time of disease before admission to hospital was 69 months (range, 6 mo to 31 y). Only 2 patients had fever, hepatosplenomegaly, systemic lymphadenopathy, and a high lactate dehydrodenage (LDH) level at the time of diagnosis, whereas 10 had facial swelling. After treatment, only 4 patients remain alive, although with persistent disease. Ten patients died after a mean follow-up of 11.6 months after the initial diagnosis (range, 1 to 32 mo), because of concurrent infections (4 cases), disease progression (4 patients) or both (2 patients). Endemic Epstein-Bar virus (EBV)-positive cutaneous NK/T-cell lymphoproliferative disorders in childhood and early adulthood are characterized by a protracted clinical course, eventually leading to an aggressive phase characterized by concurrent infections and disease progression.

Culture of native flat oysters Ostrea puelchana d'Orbigny in San Antonio Bay (San Matías Gulf, Argentina) began in 1995. After elevated mortality (33%) occurred in September 1996, 18 mo after immersion, histopathological analysis and evaluation of parasitic prevalence was carried out. In October 1997, after 31 mo of cultivation, cumulative mortality was 80%, and in December of the same year, when individuals reached marketable size, mortality was 95% and culture was discontinued. The present study describes the haemocytic parasitism that affected O. puelchana, and suggests that a Bonamia sp. was the etiological agent. This parasite should be considered as a different species from Bonamia sp. detected in Australia and New Zealand until more studies are made to determine the correct taxonomy. This work constitutes the first record of this haemocyte parasite in flat oysters from the Argentinean coast.KEY WORDS: Bonamia sp. · Oyster culture · Ostrea puelchana · Argentina Resale or republication not permitted without written consent of the publisherDis Aquat Org 63: [231][232][233][234][235] 2005 Aquaculture in Argentina is an emerging activity, as a new way to produce bivalve molluscs. A growing private interest concerning molluscan bivalve culture has stimulated research during the past century. Experimental farming of Mytilus edulis platensis, Aequipecten tehuelchus, and Ostrea puelchana has been carried out since 1980 (Pascual & Zampatti 1990, Zampatti 1990, Narvarte 1995, 2001.The native flat oyster Ostrea puelchana D'Orbigny is distributed from southern Brazil to northern Patagonia, Argentina (Castellanos 1957). Dense beds have been reported only in shallow subtidal waters of the NW San Matías Gulf (41 to 42°S, 63°30' to 65°W) ( Fig. 1) (Castellanos 1957). Research efforts concerning oyster culture have focused on spat collection and growout in the field (Pascual & Bocca 1987, Pascual & Zampatti 1990. Commercial flat oyster culture began in San Antonio Bay (Fig. 1), between March 1995 and December 1997, with the aim of exportation to the European Economic Community (EEC).Eighteen months after the beginning of the culture, the first abnormal mortality (33%) was recorded. After 31 months of culture, cumulative mortality was 80%, and 3 months later, when individuals reached marketable size, mortality was 95%. This prevented further commercial culture of Ostrea puelchana.The preliminary diagnosis, carried out on moribund oysters, indicated the presence of a 'Bonamia-like' haemocytic parasite which was the probable etiologic agent of the mortality (Kroeck 1997).The present study describes the haemocytic parasite that affected Ostrea puelchana. Histopathological analysis and evaluation of the parasitic prevalence were carried out during the course of commercial farming in San Antonio Bay. MATERIALS AND METHODSSan Antonio Bay (40°47' S to 64°62'W) is northwest of the San Matías Gulf (Fig 1). Oysters used for commercial culture were collected on artificial collectors placed on the oyster ground of Las Grut...

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Haplosporidian spores from Ostrea edulis, previously described as Minchinia armoricana, were reexamined by light and electron microscopy. These spores were either free among host cells or enclosed in sporocysts. They contained two long epispore cytoplasm extensions (ECE), each possessing cytoskeletal structures corresponding to the filaments. After lysis and degradation of the ECE, these extensions disappeared and the spores became devoid of membrane-bound extensions. However, 2 long filaments (approximately 130 microm long) persisted that were closely attached, in opposition to the spore wall, by a bundle of 9-13 fibers each. Thus, we propose a revised description of M. armoricana (= H. armoricana) to confirm its placement in the genus Haplosporidium as H. armoricanum.