By: Yulianingsih S1, Khotimah K1, Pusparini N1, Pangabean RIL1 and Rahayu WP1,2
1Research Center for Drug and Food, National Agency for Drug and Food Control
2Department of Food Science and Technology, Bogor Agricultural University)
Development method using Real Time Polymerase Chain Reaction (qPCR) is needed for identifying food borne pathogen such as SalmonellaTyphimurium due to its faster than conventional method. Isolation of Salmonella Typhimurium DNA from pasteurized milk as well as from fried rice was done by comparing two extraction methods: boiling and commercial kit. DNA isolate was amplified by specific primers invA. The result showed that regression coefficient and efficiency value of SalmonellaTyphimurium extracted by boiling method (0.93 and 109%) were better than by commercial kit (0.96 and 137%). In order to obtain detection limit of this pathogenic bacterium, SalmonellaTyphimurium was diluted in series (10-2-10-8) to isolate and create a standard curve. The resulting formula can be used to calculate the detection limit of SalmonellaTyphimurium in food samples. Detection limit of SalmonellaTyphimurium in laboratory media (2.3 cfu/ml) was relatively same with in pasteurized milk (2.2 cfu/ml) while in fried rice was higher (5.7 cfu/g).
Keywords: SalmonellaTyphimurium, Real Time Polymerase Chain Reaction, pasteurized milk, fried rice
Presented at The 4thInternational Seminar of Indonesian Society for Microbiology and IUMS-ISM Outreach Program on Food Safety, Denpasar-Indonesia.June22-24th2011.