Ocurrence of Vibrio spp., positive coagulase staphylococci and enteric bacteria in oysters (Crassostrea gigas) harvested in the south bay of Santa Catarina island, Brazil

Abstract

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 ...

Occurrence of potentially pathogenic Vibrio in oysters (Crassostrea gigas) and waters from bivalve mollusk cultivations in the South Bay of Santa Catarina

“…In this study, more than half of the isolates were V. parahaemolyticus; this percentage of isolates is different from that previously observed in another study conducted in the same region 35 . The variability in the incidence of different species of Vibrio may be related to the fact that this study was conducted in the warmer spring and summer seasons, whereas the other study covered all four seasons.…”

“…Audemard et al 43 suggested that unexplored postharvest processing (PHP) methods to eliminate V. vulnifi cus from oysters, which use relaying to high salinity waters, could be an alternative strategy, considering that high salinities appear to negatively affect the survival of V. vulnifi cus. However, this study observed a negative correlation between salinity and V. parahaemolyticus, whereas no correlation was observed between salinity and V. vulnifi cus; this result is consistent with results obtained in other studies conducted in shellfi sh cultivation areas off the Brazilian coast 32,35 and in other parts of the world 41,44 . Although the V. parahaemolyticus and V. vulnifi cus counts observed in the waters can be considered as low, it is important to note that in fi ltering shellfi sh such as oysters and mussels, these microorganisms are concentrated in their guts and in other tissues, with levels reaching up to 10 6 bacteria per gram of shellfi sh…”

Genotypic and phenotypic characterization of Escherichia coli isolated from mollusks in Brazil and the United States

“…Since E. coli is a well‐known indicator of recent fecal contamination, and it was demonstrated that oysters can bioaccumulate fecal coliforms to a concentration four times greater than surrounding water (Burkhardt & Calci, ), isolation and characterization of E. coli from bivalve mollusks are essential. Moreover, some serogroups of E. coli can be highly pathogenic to humans (Ramos et al, ) and the development of antibacterial resistance is an important public health issue (Aitken, Dilworth, Heil, & Nailor, ). The search for antimicrobial‐resistant bacteria, their phylogenetic lineages and serogrouping is relevant and necessary.…”

“…Escherichia coli has been detected in bivalves from different parts of the world, and some pathogenic serotypes have been isolated (Balière, Rincé, Thevenot, & Gourmelon, 2015;Bennani et al, 2011;Gourmelon et al, 2006;Guyon et al, 2000) which enforces the importance of the study of E. coli isolates from mollusks. E. coli has been isolated from bivalve mollusks in different studies in Santa Catarina coast in Brazil (Pereira, Nunes, Nuernberg, Schulz, & Vieira Batista, 2006;Ramos et al, 2012) and in other states in Brazil (Forcelini, Kolm, & Absher, 2013;Ribeiro et al, 2016). In the United States, Montazeri et al (2015) reported E. coli isolated from oysters.…”

Pathogenicity and antibiotic susceptibility of two bacterial pathogens associated with the clam Tapes decussatus in some Egyptian fisheries

“…They are rich in proteins with essential amino acids and polyunsaturated fats with significant amounts of omega-3 fatty acids required for the growth and development of the human body (livestrong.com, 1969;Dong, 2010). However, due to feeding by filtering large volumes of water, bivalves can concentrate different types of pollutants including trace metals and microorganisms and exert health risks to consumers (Collin et al, 2008;Ramos, et al, 2012;Tubiash, 1975).…”