Detection of Salmonella enterica serovars in shrimps in eight hours by multiplex PCR assay

Abstract

A rapid and sensitive multiplex PCR (MPCR)-based assay was developed for the detection of Salmonella serovars in shrimps within 8 h of pre-enrichment. Five sets of primers from different genomic sequences such as fimA, himA, hns, invA and hto genes were selected for the detection of serovars of Salmonella enterica such as S. Typhi, S. Paratyphi A, S. Typhimurium, S. Enteritidis and S. Weltevreden. The selected primers amplified products with sizes of 85 bp, 123 bp, 152 bp, 275 bp and 496 bp, respectively, for the genus Salmonella. The specificity and sensitivity of the assay were tested by contaminating shrimp homogenate artificially with viable cells of Salmonella. The MPCR assay could detect up to five Salmonella cells within 8 h. Amplification of DNA extracted from other genera, viz. Vibrio cholerae and Escherichia coli, yielded negative results. This assay allows for the cost effective and reliable detection of serovars of Salmonella enterica in one reaction tube from mixed bacterial communities occurring in products like shrimp. © Springer-Verlag and the University of Milan 2011.