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A variety of bivalve mollusks (phylum Mollusca, class Bivalvia) constitute a prominent commodity in fisheries and aquacultures, but are also crucial in order to preserve our ecosystem’s complexity and function. Bivalve mollusks, such as clams, mussels, oysters and scallops, are relevant bred species, and their global farming maintains a high incremental annual growth rate, representing a considerable proportion of the overall fishery activities. Bivalve mollusks are filter feeders; therefore by filtering a great quantity of water, they may bioaccumulate in their tissues a high number of microorganisms that can be considered infectious for humans and higher vertebrates. Moreover, since some pathogens are also able to infect bivalve mollusks, they are a threat for the entire mollusk farming industry. In consideration of the leading role in aquaculture and the growing financial importance of bivalve farming, much interest has been recently devoted to investigate the pathogenesis of infectious diseases of these mollusks in order to be prepared for public health emergencies and to avoid dreadful income losses. Several bacterial and viral pathogens will be described herein. Despite the minor complexity of the organization of the immune system of bivalves, compared to mammalian immune systems, a precise description of the different mechanisms that induce its activation and functioning is still missing. In the present review, a substantial consideration will be devoted in outlining the immune responses of bivalves and their repertoire of immune cells. Finally, we will focus on the description of antimicrobial peptides that have been identified and characterized in bivalve mollusks. Their structural and antimicrobial features are also of great interest for the biotechnology sector as antimicrobial templates to combat the increasing antibiotic-resistance of different pathogenic bacteria that plague the human population all over the world.

The flat oyster Ostrea edulis L. is widespread along the Italian coasts. In particular, the Manfredonia Gulf (Adriatic Sea) represents an important site where natural beds subsist. Previous monitoring conducted in 1990 by light microscopy and ultrastructural studies revealed the presence of Bonamia-like microcell parasites in some flat oysters: following this observation, a new sampling of O. edulis was carried out at this location in 2007. Of 750 oysters collected, 3 showed the presence of uninucleated microcells (2 to 3 µm diameter) free or inside the haemocyte cytoplasm by cytology and histopathology. Molecular analysis confirmed that the microcells in 2 oysters were B. exitiosa, whereas in the third oyster the microcells were B. ostreae. Moreover, molecular studies were carried out to confirm the existence of Bonamia sp. in archived samples, confirming the presence of B. ostreae in the Manfredonia Gulf since 1990. KEY WORDS: Bonamia spp. · Ostrea edulis · Molecular analysis · Electron microscopy Resale or republication not permitted without written consent of the publisherDis Aquat Org 89: [79][80][81][82][83][84][85] 2010 Bonamia exitiosa infects Ostrea chilensis in New Zealand (Hine et al. 2001) and O. angasi in Australia (Corbeil et al. 2006) and has been recently reported in O. edulis in Spain (Abollo et al. 2008). B. roughleyi, previously called Mikrocytos roughleyi, infects Saccostrea glomerata in southeast Australia (Farley et al. 1988). B. perspora is a newly described protozoan species found in Ostreola equestris (North Carolina, USA) and represents the first Bonamia species producing a typical haplosporidian spore (Carnegie et al. 2006). Other B. exitiosa-like organisms have been described in O. chilensis from Chile (Kern 1993, Campalans et al. 2000, O. puelchana from Argentina (Kroeck & Montes 2005), and Crassostrea ariakensis from North Carolina ); these organisms have been subsequently declared B. exitiosa (Lopez-Flores et al. 2007).Previous studies have reported by microscopic and ultrastrustural means the occurrence in Italy of small parasites similar to Bonamia sp. in flat oysters collected from the southern (Tiscar et al. 1991) and northern Adriatic Sea (Tiscar et al. 2002). A small number of molluscs appeared infected by the parasites (1/161 from the southern and 8/600 from the northern Adriatic Sea, respectively). Nevertheless all the infected oysters showed high infection level of the haemocytes with the presence of numerous protozoans per cell (Tiscar et al. 1991(Tiscar et al. , 2002.Taking into account these previous reports, the aim of the present study was to investigate by cytology and histology the occurrence of microcell parasites in flat oysters Ostrea edulis newly collected from natural beds in the southern Adriatic Sea and to characterize the recovered parasites by molecular and ultrastructural analyses as well as to confirm and characterize the presence of Bonamia sp. in one positive sample collected during 1990 from the Manfredonia Gulf (Tiscar et al. 1991). MAT...

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Vector-borne diseases (VBDs) are globally widespread arthropod-transmitted diseases with a significant impact on animal and human health. Many drivers have recently spurred the geographic spread of VBDs in dogs. This study has evaluated the exposure to most important VBDs in dogs under different preventative treatments in different regions of Italy, i.e., Veneto, Friuli Venezia-Giulia, Umbria, Giglio Island (Tuscany), Abruzzo and Latium. Serological analyses were performed to detect antibodies against Leishmania infantum, Babesia canis, Anaplasma phagocytophilum/Anaplasma platys, Ehrlichia canis/Ehrlichia ewingii, Borrelia burgdorferi, Rickettsia conorii and the circulating antigen of Dirofilaria immitis. Dogs were categorized according to the treatment schedule usually received, and the association between seropositivity and possible risk factors was statistically evaluated. Overall, 124/242 (51.2%) dogs tested positive for at least one pathogen, while 34 (14.0%) were exposed to two or more pathogens. The most detected seropositivity was against R. conorii, followed by Anaplasma spp., L. infantum, B. canis, and the other pathogens under study. Significant statistical associations were found according to geographical provenance, history of tick infestation, lifestyle and inadequate prophylactic treatments. Random/irregular treatments have been identified as a clear risk factor. These results show that adequate prophylactic treatment protocols are overlooked by dog owners, despite the availability of several effective products, with possible implications in veterinary medicine and on public health.