Comparison of PCR and conventional culture for the detection of Salmonella in raw milk

Subject Areas : Journal of Comparative Pathobiology

M. Bonyadian, ¹ , تقی Zahraei salehi, ² , A. Mehrabani, ³

1 - گروه بهداشت و کنترل کیفی مواد غذایی، پژوهشکده بیماری های مش ترک انسان و دام، دانشکده [e-mail] . دامپزشکی، دانشگاه شهرکرد،
2 - استاد گروه میکروبیولوژی، دانشکده دامپزشکی، دانشگاه تهران،
3 - دانش آموخته دوره کارشناسی ارشد بهداشت و کنترل کیفی مواد غذایی، دانشگاه شهرکرد،

Received: 2014-11-28 Accepted : 2015-02-20 Published : 2015-07-23

Keywords: Salmonella, Raw Milk, Conventional Culture, PCR,

Abstract :

Salmonella is one of the authentic bacteria which cause illnesses, may exist in raw material andfood. The existence of these bacteria in food not only causes illnesses, but it also causes thedownfall of production quality and reduction of economic growth of the area and country. Inthis study, 150 bulk raw milk samples were examined to comparison of PCR and conventionalculture for the identification of Salmonella in raw milk. Firstly raw milk was cultured andexamined through the conventional method; afterwards its supplementary procedures forisolating Salmonella were carried out. Regarding to the results of the culture method, sixsuspicious isolates were selected to carry out by PCR using invA gene. The results showed thatnone of the isolates were salmonella. Secondly DNA extracted from raw milk and samples wereassessed utilizing the invA gene by PCR method. Regarding to the results 3 out of 150 examinedsamples were positive. Totally 2 percent of all samples were contaminated with Salmonella.The results of this study revealed that PCR is more potent than conventional culture methods toidentification of salmonella in raw milk.