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Abstract: Hemocytes are a critical component of the mussel defense system and the present study aims at investigating their spreading and oxidative properties during phagocytosis under in vivo experimental stress conditions. The spreading ability was measured by an automated cell analyzer on the basis of the circularity, a parameter corresponding to the hemocyte roundness. The oxidative activity was investigated by micromethod assay, measuring the respiratory burst as expression of the fluorescence generated by the oxidation of specific probe. Following the application of high temperature and exposure to air, there was evidence of negative modulation of spreading and oxidative response, as revealed by a cell roundness increase and fluorescence generation decrease. Therefore, the fall of respiratory burst appeared as matched with the inhibition of hemocyte morphological activation, suggesting a potential depression of the phagocytosis process and confirming the application of the circularity parameter as potential stress marker, both in experimental and field studies. [Copyright &y& Elsevier]

The article discusses a study on Bonamia-like microcell parasites such as Bonamia (B.) ostreae and B. exitiosa that were detected in the flat oyster Ostrea (O.) edulis L. from the Adriatic Sea in Italy. The O. edulis specimens that were collected and used as study subjects totaled to 750. The procedure of the study consisted of several steps such as microscopical examination, molecular analysis, and sequence determination and comparison. The results indicated the presence of B. ostreae throughout the Manfredonia Gulf since 1990.

The present study investigated the immunomodulatory activity of Ergosan, an algal extract containing alginic acid, and Macrogard, a yeast extract containing beta-glucans, on innate and specific immunity in sea bass (Dicentrarchus labrax). Four cycles of experimental feeding using normal fish feed formulation (control group) supplemented with Ergosan (0.5%) or Macrogard (0.1%) were performed at 60-day intervals (15 days of treatment+45 days of suspension). Serum complement, lysozyme, total proteins and heat shock protein (HSP) concentrations were measured at 15, 30 and 45 days from the end of the first 15-day feeding cycle (short term) and 45 days after the end of each feeding cycle over a 35-week period (long term). The percentage of B- and T-lymphocytes in peripheral blood leucocytes and gut were measured over long-term trial. Significant elevation (P < 0.05) in serum complement activity occurred in sea bass fed with alginic acid and glucans, at 15 days from the end of first cycle of treatment. Significant elevation (P < 0.05) in serum lysozyme, gill and liver HSP concentration were observed in the same experimental groups at 30 days from the end of treatment, whereas a significant increase (P < 0.05) of complement activity was only observed in fish that received an Ergosan diet. At 45 days from the end of treatment, complement, lysozyme and HSP concentration did not differ among groups. Over the long-term period, no significant differences were observed in innate and specific immune parameters, survival, growth performances and conversion index in treated and control fish. A dramatic decrease of both innate and acquired immune parameters was observed during the winter season in all groups, followed by a partial recovery when water temperature increased. Reduction in complement and lysozyme activities was significatively correlated (p < 0.01) to water temperature variation. The results suggested the potential of alginic acid and beta-glucans to activate some innate immune responses in sea bass, and particularly under conditions of immunodepression related to environmental stress.

Blood samples were collected from six captive bears and nine free-ranging Marsican brown bears (Ursus arctos marsicanus) in the Abruzzo National Park, Italy, between 1991 and 1995. Sera were tested for evidence of exposure to canine distemper virus (CDV), canine adenovirus type 2, canine coronavirus, and canine parvovirus type 2 (CPV-2). Serologic evidence of CDV and CPV-2-exposure was found in both captive and free-ranging bears. This may be the first report of CDV exposure in free-ranging bears.

Cats in the primary stage of Feline Immunodeficiency Virus (FIV) infection and FIV seronegative cats were vaccinated with a modified live Feline Panleukopenia virus vaccine (FPV-MLV). The FPV-MLV strain was not pathogenic for FIV seronegative cats, whereas in FIV infected cats it produced severe clinical signs, similar to those typically observed in cats naturally infected with field strains of FPV (fever, diarrhoea, leukopenia).