Use of selenite enrichment broth for the detection of Salmonella from stool: A report of one year experience at a provincial public health laboratory

Several references recommend that selenite enrichment be used only in stool cultures from suspect carriers, during outbreaks, and in other special circumstances. To determine the impact of such an approach, we examined results from 3977 specimens cultured by our laboratory. Epidemiological information was collected from physicians and the public health department. Salmonella spp. were identified in 74 specimens from 54 patients. Four Shigella spp. were recovered from four patients. Forty-seven of the 74 Salmonella spp. were recovered on both the primary xylose-lysine-deoxycholate (XLD) and after enrichment. No Salmonella or Shigella grew on the primary XLD only. Twenty-six Salmonella spp. were recovered only after selenite enrichment. Of these, 17 were from newly identified patients. The elimination of selenite enrichment would have significantly reduced our yield, whereas the elimination of the primary XLD would not have resulted in any fewer isolates and would have resulted in savings of approximately $4000 yearly.