Simultaneous detection of food safety hazards (Salmonella enterica and Listeria monocytogenes) in table eggs using multiplex PCR

Abstract

Foods are analyzed for food safety hazards in order to comply with food safety standards. Among food-borne pathogens Salmonella enterica and Listeria monocytogenes are recognized as major foodborne pathogens of public health significance worldwide. In the present study, multiplex polymerase chain reaction (mPCR) was used to screen for S. enterica and L. monocytogenes in table eggs collected from different markets (840 eggs). Pooled egg samples categorized as commercial and backyard eggs based on the source of collection. Collected eggs were screened for S. enterica and L. monocytogenes using mPCR assays. Conserved regions viz. invA and prfA genes were targeted for the specific detection of S. enterica and L. monocytogenes, respectively. mPCR and conventional method showed same results, prevalence of S. enterica at 12.5 and 33.3 per cent in commercial and backyard eggs, respectively. While, L. monocytogenes was undetectable in commercial eggs; but, detected only in backyard table egg sample (8.3%). Present study indicated complete concordance between specific pre-enrichment mPCR and conventional cultural methods. Results of the study underscored mPCR as steadfast rapid tool for the screening of table eggs for listed food safety hazards S. enterica and L. monocytogenes in table eggs. Keywords: Eggs; Listeria; mPCR; Public Health; Salmonella