Brazilian Journal of Microbiology Brazilian Journal of Microbiology
Braz J Microbiol 2018;49:320-8 - Vol. 49 Num.2 DOI: 10.1016/j.bjm.2017.09.001
Food Microbiology
Rapid detection of food-borne Salmonella contamination using IMBs-qPCR method based on pagC gene
Jiashun Wanga,1, Yi Lia,1, Jia Chena, Deping Huaa, Yi Lia, Hui Denga, Ying Lib, Zhixuan Liangb, Jinhai Huanga,,
a Tianjin University, School of Life Sciences, Tianjin, China
b Tianjin Center of Animal Disease Preventive and Control, Tianjin, China
Received 05 February 2017, Accepted 11 September 2017

Detection of Salmonella is very important to minimize the food safety risk. In this study, the recombinant PagC protein and PagC antibody were prepared and coupled with immunomagnetic beads (IMBs) to capture Salmonella cells from pork and milk samples. And then the SYBR Green qualitative PCR was developed to detect the pathogenic Salmonella. The results showed that the PagC polyclonal antiserum is of good specificity and the capture rate of 0.1mg IMBs for Salmonella tended to be stable at the range of 70–74% corresponding to the concentrations between 101 and 104CFU/mL. The method developed demonstrated high specificity for the positive Salmonella samples when compared to non-specific DNA samples, such as Escherichia coli, Staphylococcus aureus, Yersinia enterocolitica, and Yersinia pseudotuberculosis. The limit of detection of this assay was 18CFU/mL. Detection and quantitative enumeration of Salmonella in samples of pork or milk shows good recoveries of 54.34% and 52.07%. In conclusion, the polyclonal antibody of recombinant PagC protein is effective to capture Salmonella from detected samples. The developed pagC antibody IMBs-qPCR method showed efficiency, sensitivity and specificity for 30 Salmonella detection, enabling detection within 10h, which is a promising rapid method to detect Salmonella in emergency.

Salmonella, IMBs-qPCR, pagC gene, Detection
Braz J Microbiol 2018;49:320-8 - Vol. 49 Num.2 DOI: 10.1016/j.bjm.2017.09.001