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Page No. : 97–101

ABSTRACT

A set of primers (Aer 1 and Aer 2) targeting aerolysin gene was employed to standardize PCR assay for detection of A. hydrophila from foods, which gave specific amplification of a 209 bp fragment. The minimum detection level with pure bacterial culture was found to be 5 organisms in 50 µl reaction mix. Experimental inoculation studies carried out over varied incubation schedule employing alkaline peptone water–cephalothin as selective enrichment broth revealed that earliest detection time by PCR of A. hydrophila from spiked milk was 12 h. There was good agreement between the results of PCR and cultural isolation. Examination of 45 naturally contaminated meat samples (30 chicken and 15 fish) revealed two chicken and 13 fish samples to be positive by PCR. The standardized one-step enrichment PCR protocol holds promise as a reliable and rapid method for the detection of haemolytic A. hydrophila from foods.

Keywords: A. hydrophila, PCR, sensitivity, specificity, spiking