EFFECTS OF CHOLATE AND SELENITE ON POLYMYXIN-CLOTH ENZYME-IMMUNOASSAY OF SALMONELLA STATICALLY CULTURED IN THE PRESENCE OF MICROFLORA FROM CHICKEN FECES

Selective enrichment of Salmonella using a combination of 0.3% selenite, 0.5% cholate and static incubation was examined for five common serotypes in she presence of Salmonella-free chicken faeces Enrichment cultures were then assayed by the polymyxin-cloth enzyme immunoassay (polymyxin-CEIA). This selective enrichment method was effective in suppressing large excesses of chicken faecal microflora, while permitting the growth of small numbers of Salmonella, which produced strong signals in the polymyxin-CEIA. When the medium contained no selective agents, the ability of the polymyxin-CEIA to detect Salmonella was greatly reduced in the presence of large excesses of chicken faecal microflora. The advantages of using static incubation and a dot-blot format for the polymyxin-CEIA are discussed for application in the hazard analysis critical control point programme. (C) 1995 Academic Press Limited