Use of molecular techniques for the analysis of the microbiological quality of fish marketed in the municipality of Cuiaba, Mato Grosso, Brazil

The present study was stimulated by the growing demand for healthy food and the technology available for the detection and identification of microbial organisms in fishery products. Molecular tools were used to identify the bacterial community and detect the presence of pathogenic species in samples of farmed and wild-caught fish. Samples of muscle tissue were obtained from the local market in Cuiaba, Mato Grosso, Brazil. The 16S rDNA gene was used to detect 11 bacterial genera: Enterobacter (29.29%), Aeromonas (24.24%), Pseudomonnas (17.17%), Enterococcus (10.10%), Acinetobacter (6.06%), Citrobacter (4.04%), Bacillus (3.03%), Klebsiella and Lactococcus (2.02%), and Clostridium and Lysinibacillus (1.01%). High percentages of deleterious bacteria were recorded. Species-specific primers were used to detect the presence of Escherichia coli (35.71%), Staphylococcus aureus (12.5%), and Salmonella (7.14%), although Shigella was absent. These concentrations exceeded the limits established by the currently public health legislation. The molecular techniques used in the present study provide an alternative approach for the reliable diagnosis of contamination, which can be used on a large scale.