Further studies on the screening technique for determining salmonella-negative samples of pasteurized dried egg.

Abstract A METHOD was described by Banwart et al. (1966, 1968) to detect Salmonella- negative samples of pasteurized dried egg products. The procedure included preparing tubes of mannitol purple agar and SIM agar and introducing them inverted into a lactose broth-egg mixture. During incubation, the mannitol was fermented or hydrogen sulfide (H2 S) was produced in the SIM agar if salmonellae were present. The determination of mannitol fermentation or H2 S production could be accomplished in tubes of media external to the lactose broth-egg system and would simplify the screening technique of Banwart et al. (1968). In the tests previously reported, lactose broth was the pre-enrichment medium. Nutrient broth was suggested as a replacement for lactose broth to pre-enrich food samples (Taylor et al., 1964). This research was conducted to determine if the mannitol-SIM inverted-tube system could be utilized in broths other than lactose and if tubes of mannitol and SIM inoculated external to…