Furthermore, new pathogens or new biovars of known bacterial species are frequently being reported ABT-263 (Mor-Mur & Yuste, 2010). The impact of most new pathogens on specific ecosystems and their pathogenicity are not known. Indeed, the traditional food inspection systems are insufficient, because knowledge of the emerging pathogens is incomplete. Furthermore,

the new techniques based on DNA analysis are not always applicable, in the absence of genetic data on these new biotypes. Therefore, to determine the concept of healthy food, it is crucially important that we expend efforts to comprehensive study of new emerging pathogens present in food products. Lactococcus garvieae is a pathogen that causes septicemia in fish and serious damage to fish aquaculture worldwide (Vendrell et al., 2006). However, the host range of L. garvieae is not limited to aquatic species. The pathogen has been found in domestic animals, in cows with mastitis and BKM120 mouse in various artisanal cheeses made with goat and cow raw milk, sometimes as a major component (Fortina et al., 2003; Foschino et al., 2006; Fernández et al., 2010). In addition, clinical cases associated with L. garvieae infection have been reported in humans (Li et al., 2008). Despite the growing importance of L. garvieae in both human and veterinary medicine, little research data are available on this pathogen in food matrices other

than fish products. The literature is mostly about epidemiological studies on fisheries and, in summary, as regards L. garvieae stressed two serotypes based on the presence of a capsule, which plays an important role in pathogenicity, and on a potential ability to produce intra- and extracellular toxins (Vendrell et al., 2006). High biodiversity also occurred depending see more on the geographical origin of the pathogen (Vela et al., 2000; Schmidtke & Carson, 2003; Eyngor et al., 2004).

Over the last few years, we collected a significant number of L. garvieae strains from different artisanal Italian raw milk cheeses (Fortina et al., 2003), which we compared with those isolated from fish (Fortina et al., 2007, 2009). The results emphasized a genetic difference among strains from the two ecological niches, particularly the presence in all dairy strains of the phospho-beta galactosidase gene (lacG), which was lacking in fish isolates. Recently, L. garvieae has been isolated from human, ruminant, and water sources (Aguado-Urda et al., 2010); in these strains, lacG seemed heterogeneously scattered. Lactococcus garvieae has also been isolated from different types of food, such as vegetables (Kawanishi et al., 2007) and meat (Santos et al., 2005) but only poorly characterized. In the present work, we monitored the population structure of L. garvieae strains from dairy products and fish included in original works (Fortina et al.