COMPARISON OF A QUANTITATIVE POLYMERASE CHAIN REACTION ASSAY WITH A PLATE COUNT METHOD FOR THE QUANTIFICATION OF INOCULATED SALMONELLA COCKTAIL IN TURKEY BREASTS

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  • Presentation type: Pôster
  • Track: Food Science and Nutrition (CN)
  • Keywords: meat products; Foodborne; qPCR;
  • 1 Universidade Federal de Santa Catarina/Centro Tecnológico/Departamento de Engenharia Química e Engenharia de Alimentos
  • 2 Instituto Federal de Educação, Ciência e Tecnologia Goiano/Departamento de Tecnologia em Alimentos
  • 3 Federal University of Paraná/Department of Food Engineering
  • 4 Federal University of Santa Catarina/Department of Chemical Engineering and Food Engineering

COMPARISON OF A QUANTITATIVE POLYMERASE CHAIN REACTION ASSAY WITH A PLATE COUNT METHOD FOR THE QUANTIFICATION OF INOCULATED SALMONELLA COCKTAIL IN TURKEY BREASTS

Danielle de Sousa Severo

Universidade Federal de Santa Catarina/Centro Tecnológico/Departamento de Engenharia Química e Engenharia de Alimentos

Abstract

Salmonellosis is linked to the consumption of Salmonella-contaminated food products such as beef, pork, poultry meat, and other foods. The aim of this research was to establish a standard curve for comparing the quantitative polymerase chain reaction (qPCR) method and the plate count method, both used to quantify inoculated Salmonella cocktail (Typhimurium ATCC 14028, Enteritidis ATCC 13046, and Heidelberg isolated from a poultry industry) in turkey breasts. The chilled turkey breast slices (14 g) were inoculated with 0,1 mL of Salmonella cocktail (107 CFU/g), vacuum-packed, and then stored at 16 °C (temperature abuse storage). The initial sample count was 103 CFU/g. Salmonella growth curves were constructed by plating on Xylose Lysine Deoxycholate (XLD) Agar and Brain Heart Infusion (BHI) Agar until the stationary growth phase. The Salmonella invasion gene (invA) copy number was quantified by qPCR and converted to Salmonella cell concentration. Salmonella counts after 11 hours of the cultivation in XLD medium were not possible, while the Salmonella growth was quantified until the stationary growth phase (8.55 log CFU/g) in BHI medium. The standard curve showed a slope of -3.50, an R2 correlation coefficient of 0.99, and a reaction efficiency of 93%. From the standard curve, the quantification of the Salmonella concentration was possible to all growth phases. Salmonella growth showed a concentration of 3.84 log CFU/g by qPCR, while it was not visible on XLD plates at 27 hours of cultivation. These results highlight the importance of the quantification of foodborne pathogens by using new rapid methods. Therefore, it is proposed to assist the meat industry in understanding quantitative detection protocols to reduce the pathogen risk with greater precision and to ensure product safety.

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