Detection of Salmonella typhimurium on artificially contaminated milk by real time PCR using STM4497 and fljB primers

Abstract

Detection of food-borne bacterial pathogens was developed to overcome the limitations. The aim of this research was to develop Salmonella typhimurium detection by Real Time Polymerase Chain Reaction (RT-PCR) using two pairs of primers. The ability of primer pairs to detect S. typhimurium is seen from cycle threshold or Ct. Artificially contaminated milk sample with 24 ng each microliter can be detected with fljB (flagellin gene) primers on Ct 12,933 and with STM4497 (hypothetical protein code) primers on Ct 13,665. The specificity test of both primers showed that melting temperature (Tm) of fljB was 80,5 degree Celsius, and STM449 was 81,6 degree Celsius. FljB and STM4497 primers gave an average detection limit respectively of 11,75 Colony Forming Unit (CFU) each milliliter and 6,8 CFU each milliliter. The time needed throughout the detection process of S. typhimurium with fljB and STM4497 primers is faster than conventional methods. Based on the results it can be concluded that primers fljB and STM449 S. typhimurium can be applied to detection and quantification of S. typhimurium in milk samples.