IMPROVED RAPID METHOD FOR ISOLATION AND ENUMERATION OF SALMONELLA FROM BIVALVES USING RAMBACH AGAR

Shellfish frequently host pathogenic bacteria involved in toxic food i nfections, in particular Salmonella whose surveillance has to be under taken carefully. The conventional method used for Salmonella detection is neither fast nor simple. A new rapid method reducing the duration of pre-enrichment and using Rambach agar has been compared with the co nventional method of detection. The comparison included 133 samples at duplicate temperatures of 37 degrees C and 42 degrees C. The new prot ocol appeared more efficient than the reference technique in recoverin g Salmonella from bivalves (respectively 28 and 17 positive results) a nd is faster and simpler. The sensitivity of the isolation step on Ram bach agar was satisfactory (under 10(5) Salmonella per ml). In additio n, the validity of this medium in direct enumeration of Salmonella fro m shellfish has been demonstrated.