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Page No. : 17-24

ABSTRACT

A total of 12 Aeromonas strains (A. hydrophila - 10 and A. sobria - 2) of diverse serotypes and 5 Vibrio strains were subjected to outer membrane protein (OMP) extraction followed by preparative sodium dodecyl sulfate-polyacrylamide gel electrophoresis for purification of 35 kD and 68 kD peptides. Antisera raised against these two peptides reacted specifically only with Aeromonas OMPs of corresponding molecular weight in immunoblotting. Standardization of indirect enzyme linked immunosorbent assay (ELISA) with these antisera revealed detection of 10⁵–10⁶ Aeromonas cells/ml. No cross-reactions were observed with 17 non-aeromonad organisms tested. The testing of ELISA to detect Aeromonas spp. after one step enrichment in cephalothin alkaline peptone water-10 from experimentally inoculated milk and meat samples with varying numbers of Aeromonas (6 to 6 × 10⁶ cells/ml) along with other related competing microflora revealed that the assay could detect Aeromonas spp. after enrichment in samples inoculated with as low as 6 Aeromonas cells/ml.

Keywords: Aeromonas, ELISA, Outer membrane protein, Rapid detection