COMPARATIVE-STUDIES OF DIAGNOSTIC BACTERIOLOGICAL METHODS FOR THE RECOVERY OF SALMONELLA FROM FECAL SAMPLES FROM FLOCKS OF LAYERS

Several conventional culture procedures were compared for the recovery of Salmonella from faecal samples of layer flocks. The cultural media employed consisted of Rappaport-Vassiliadis and tetrathionate broth f or selective enrichment and three different plating media (Brilliant G reen, Xylose-Lysine-Desoxy-cholate and modified semisolid Rappaport-Va ssiliadis medium). The initial enrichment and plating procedures were repeated in a four-stage secondary enrichment. Selective enrichment in Rappaport-Vassiliadis or tetrathionate broth followed by plating on m odified semisolid Rappaport-Vassiliadis medium (selective motility enr ichment) resulted in a significantly higher isolation rate for Salmone lla from faecal samples of layers compared to Brilliant Green and Xylo se-Lysine-Desoxycholate medium. The selective enrichment yielded addit ional Salmonella isolates up to the second stage. Further enrichment d id not increase the isolation rate.