Use of Rambach propylene glycol-containing agar for identification of Salmonella spp

Salmonella organisms isolated from patients and 54 of 62 (87.1%) Salmonella stock cultures produced a crimson-colored growth. Of the 14 clinical Salmonella isolates which displayed colors other than crimson, 8 were Salmonella typhi, 2 were Salmonella paratyphi A, and 4 belonged to other commonly isolated serotypes. All eight Salmonella stock cultures which failed to produce a crimson color belonged to rarely isolated serotypes. In contrast, of 83 non-Salmonella stock cultures distributed among 29 bacterial species, none produced a crimson color. These results suggest that while Rambach agar cannot preidentify S. typhi and S. paratyphi A, the medium can be used for the presumptive identification and can assist in the definitive identification of the overwhelming majority of Salmonella isolates. The separation of Salmonella spp. from other species of the family Enterobacteriaceae requires the determination of many biochemical properties, because no one biochemical property alone is sufficient to identify such organisms (2). Thus, Salmonella spp. usually do not ferment lactose and most often produce hydrogen sulfide, which is detected by precipitation with ferric compounds, but these two proper