Influence of multiple plating from fluid media on salmonella isolation from animal feeding stuffs

Abstract

SummaryThe influence of multiple plating of fluid cultures on salmonella isolation from animal feeding stuffs was examined. Four platings were made from broth culture after 24 h at 37 °C and four platings from selenite enrichment from 24 h at 43 °C. Selenite enrichment followed broth culture which was used as a pre-enrichment stage. Brilliant green MacConkey agar plates were employed for broth subculture and brilliant green MacConkey and desoxycholate citrate agars for selenite subculture. The eight brilliant green plates subcultured from broth and selenite were examined for salmonellas after incubation for 24 h at 37 °C. The four desoxycholate citrate agars after 24 h at 37 °C were used for motility enrichment. The food sample size was a single 100 g instead of 4 x 25 g cultured in an earlier study. This pooling of samples aimed at technical economy. Quadruple plating played an important part in salmonella isolation from 100 g specimens. The combination of multiple plating with motility enrichment was the most successful technique used.