Microbiological quality assessment for oysters produced and traded in Paraná, Brazil

Oysters are filter-feeding bivalve molluscs that are associated with several foodborne illnesses, because they accumulate biotic and abiotic contaminants dispersed in the water. The state of Paraná in southern Brazil is distinguished by a high consumption of oysters, typically eaten raw, and this habit may present a risk to consumer health if the product is contaminated with pathogenic bacteria. This study intends to evaluate the microbiological quality of oysters produced and traded in Paraná, directly examining the localities of cultivation and trading of the product. The major sites for the trading of oysters in the state were identified and 52 dozen oysters (624 animals) were collected from these places, between April and December, 2013. The samples were subjected to analyses for total coliforms, Escherichia coli, Staphylococcus aureus, and Salmonella spp. No samples had results of microbial contamination above the limits established by Brazilian legislation. This study indicated that the microbiological quality of the oysters produced and traded in the state of Paraná is acceptable

Evaluation of the psychrotrophic specific signatures for cspA gene and 16S rDNA on the phenotype of Bacillus cereus sensu strictu

This study characterised the psychrotrophic genotypes and phenotypes behaviour of 63 strains of Bacillus cereus sensu stricto isolated from dairy products. The presence of the cspA gene signature and the 16S rDNA mesophilic and/or psychrotrophic specific signatures was evaluated. Among the strains, 25 (39.7%) had the cspA gene signature, 38 (60.3%) had both mesophilic and psychrotrophic 16S rDNA signatures, 24 (38.1%) had only mesophilic and one exhibited only psychrotrophic. No strain grew at 7 °C. The results indicate that the presence of psychrotrophic signatures for cspA gene or the 16S rDNA did not ensure a psychrotrophic behaviour on a B. cereus phenotype. © 2013 Society of Dairy Technology