Monitoring paneer for Listeria monocytogenes- A high risk food pathogen by multiplex PCR

Abstract

A multiplex polymerase chain reaction (PCR) assay was developed and applied to spiked and natural paneer samples to detect Listeria monocytogenes, a high risk food pathogen. The sensitivity of the assay on L. monocytogenes spiked paneer samples was 10⁴ cells prior to enrichment, was improved to 10³ cells after 4 h enrichment and one to 10 cells after 6 h enrichment as indicated by the amplification of 1.2 kb and 713 bp PCR products. The multiplex PCR assay when applied to 10 randomly sampled natural paneer products did not reveal any amplification products, indicating the absence of this organism from these samples.

Key words: Listeria monocytogenes, multiplex PCR, 16S rRNA, hemolysin, paneer products.