Salmonella detection in marine waters using a short standard method

Abstract

A study was undertaken to compare two enrichment broths and to test a new plate medium, Rambach agar, for their suitability to detect Salmonella from marine recreational waters. The study shows that under conditions of low levels of fecal contamination, Salmonella spp was isolated more efficiently using NR10(10)/43 broth. While at higher levels of fecal contamination NR10/43 broth effectively limits the growth of accompanying flora. For the highest level of fecal contamination Rambach agar was less selective than Hektoen enteric agar but Rambach agar was shown to be better than Hektoen agar for the recovery of Salmonella strains from low contaminated waters. On Rambach agar the distinct color of salmonellas, seen in red, enhanced correct identification. Biochemical and serological confirmation of Salmonella isolates was performed using the API Z System and Oxoid Salmonella Rapid Latext test. The combination of enrichment broths (24 h at 42°C), isolation (24 h at 37°C) and identification systems described above (2 h or I min) allowed the detection of Salmonella from marine waters, with low or high levels of fecal contamination, in 48 h.