Improved rapid method for isolation and enumeration of salmonella from bivalves using Rambach agar

Shellfish frequently host pathogenic bacteria involved in toxic food infections, in particular Salmonella whose surveillance has to be undertaken 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 conventional method of detection. The comparison included 133 samples at duplicate temperatures of 37°C and 42°C. The new protocol appeared more efficient than the reference technique in recovering Salmonella from bivalves (respectively 28 and 17 positive results) and is faster and simpler. The sensitivity of the isolation step on Rambach agar was satisfactory (under 10 5 Salmonella per ml). In addition, the validity of this medium in direct enumeration of Salmonella from shellfish has been demonstrated.