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Page No. : 73-79

ABSTRACT

In present work, Competitive ELISA (C-ELISA) and PCR were evaluated for their efficacy for rapid detection of Listeria monocytogenes from food. Cultural method was also used as standard test for comparison. Meat samples artificially inoculated with varying concentrations (1 to 107 cells/g) of L. monocytogenes were subjected to these three tests after one step enrichment in modified University of Vermont broth. Aliquots taken during different incubation periods when subjected to these three tests revealed that PCR and cultural methods were able to detect L. monocytogenes from samples spiked with as less as 10 cells/g after 36 h incubation time. However, 48 h incubation period was required for achieving similar detection levels with c-ELISA. A total of 90 market samples comprising goat meat -30, poultry meat -30 and milk-30 were also screened for the presence of L. monocytogenes by PCR, c-ELISA and cultural method. None of the samples were positive by PCR and cultural method. However, 5 samples (3 goat meat and 2 poultry meat) were positive by c-ELISA. Cultural examination of these samples revealed that they harboured either L. ivanovii or L. seeligeri.

Keywords: ELISA, Listeria spp., PCR, rapid detection