Padronização de PCR, cultura independente, para detecção de Salmonella Spp. em lavado superficial de tambaqui (Colossoma macropomum)

Abstract

Salmonella spp. is an enteric bacterium responsible for severe food poisoning, one of the main agents responsible for outbreaks reported in various countries, externalizing itself with some characteristics such as endemicity, morbidity and above all, the difficulty of adopting the measure of control. Traditional methods for isolation of Salmonella spp. in food is provided by Brazilian law, however, are made of extremely laborious manner and demand working days for confirmation of the genus. In this context, the PCR becomes an excellent alternative for rapid, sensitive and specific detection of Salmonella spp. in food, reducing the analysis time to a few days pathogen hours. Therefore, this research aims to standardize the PCR, independent culture, to detect the presence of Salmonella spp tambaqui (Colossoma macropmum). Was not possible to standardize the PCR technique by using reference strains of Salmonella spp. it was not possible to detect environmental contamination of Salmonella spp. fish in an artificial contamination was also performed. Two methods of DNA extraction by thermal lysis and comecial kit was evaluated. It was noted that the extraction (DNeasy mericon Food Kit) commercial kit Quiagen®, was more efficient and yielded a DNA of better quality compared to extraction by thermal lysis.The optimum conditions for the detection of Salmonella spp was reached and achieved the limit of detection was 101 CFU / mL. The PCR was as sensitive as conventional methods, with the advantage of reducing the analysis time of 7 days to approximately 4 hours of work.