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Introduction:This research aimed to identify and quantify potentially pathogenic Vibrio from different cultivations of bivalve shellfi sh in the State of Santa Catarina, Brazil, and water regions in the South Bay, as well as correlate the incidence of these microorganisms with the physicochemical parameters of marine waters. Methods: Between October 2008 and March 2009, 60 oyster and seawater samples were collected from six regions of bivalve mollusk cultivation, and these samples were submitted for Vibrio counts. Results: Twenty-nine (48.3%) oyster samples were revealed to be contaminated with one or more Vibrio species. The Vibrio parahaemolyticus and Vibrio vulnifi cus counts in the samples ranged from < 0.5 log 10 Most Probable Number (MPN) g -1 to 2.3 log 10 MPN g -1 oyster and from < 0.5 log 10 MPN g -1 to 2.1 log 10 MPN g -1 oyster, respectively. Of the 60 seawater samples analyzed, 44 (73.3%) showed signs of contamination with one or more vibrio species. The counts of V. parahaemolyticus and V. vulnifi cus in the samples ranged from < 0.3 log 10 MPN·100mL -1 to 1.7 log 10 MPN·100mL -1 seawater and from < 0.3 log 10 MPN·100mL -1 to 2.0 log 10 MPN·100mL -1 seawater, respectively. A positive correlation between V. vulnifi cus counts and the seawater temperature as well as a negative correlation between the V. parahaemolyticus counts and salinity were observed. Conclusions:The results suggest the need to implement strategies to prevent vibrio diseases from being transmitted by the consumption of contaminated bivalve shellfi sh.

Ocurrence of Vibrio spp., positive coagulase staphylococci and enteric bacteria in oysters (Crassostrea gigas) harvested in the south bay of Santa Catarina island, Brazil IntroductionIn Brazil, bivalve mollusks production takes place mainly in Santa Catarina State, south Brazil, due to the excellent geographical conditions of this area for marine organism cultures, such as the presence of a large number of bays facilitating the establishment of mollusk farms (COELHO et al., 2003;CORRÊA et al., 2007;OLIVEIRA NETO, 2005). In 2007, about 11.000 t of mollusks were commercialized in Santa Catarina State, the largest producing region of oysters (Crassostrea gigas). The major production takes place in sea farms located in the South Bay of Santa Catarina Island (OLIVEIRA NETO, 2007).Oysters are filter-feeders that efficiently concentrate microorganisms from polluted habitats, and because they are often consumed raw, they pose a health risk to consumers (CORRÊA et al., 2007;LALOO et al., 2000; PEREIRA et al., 2006;SILVA et al., 2004). The enteric bacteria, originating from the contamination of water with human residues, can readily contaminate the fauna in marine environments, especially molluscan shellfish (CORRÊA et al., 2007, PEREIRA et al., 2006. To guarantee sanitary quality, mollusk cultures should be monitored for contamination by pathogenic microorganisms (CORRÊA et al., 2007).Vibrios are very common in marine and estuarine water environments and some may cause infections in humans that were exposed to seafood or sea water. Several Vibrio species are pathogenic to humans and may be present in raw or partially cooked shellfish (LHAFI; KÜHNE, 2007; PEREIRA et al., 2007a, b , para ambos os microrganismos, sugerindo um monitoramento tanto destas espécies quanto da temperatura das águas marinhas nas regiões de cultivo. Com base nos resultados das análises microbiológicas, as amostras analisadas mostraram qualidade bacteriológica aceitável, ou seja, dentro dos parâmetros estabelecidos na legislação brasileira. Palavras-chave: qualidade microbiológica; moluscos bivalves; filtradores; Escherichia coli; Vibrio parahaemolyticus; Vibrio vulnificus. AbstractThe aim of this study was to assess the contamination of oysters (Crassostrea gigas), harvested in six different regions of the South Bay of Santa Catarina Island, with Coliforms at 45 °C, Escherichia coli, Vibrio spp., positive coagulase staphylococci, and Salmonella sp. over a period of one year. One hundred eighty oyster samples were collected directly from their culture sites and analyzed. Each sample consisted of a pool of 12 oysters. All of the samples analyzed showed absence of Salmonella, 18 (10%) samples showed presence of Escherichia coli, 15 (8.3%) samples were positive for V. alginolyticus, and Vibrio cholerae was detected in 4 samples (2.2%). The counts of positive-coagulase staphylococci varied from <10 to 1.9 × 10 2 CFU.g , for both microorganisms. This suggests the need for monitoring these vibrios contamination in oysters. Based on the results of the ...