In this paper we first speculated and later on have proved that the increased number of Salmonella positive results, using the Salmonella Tek-Eiisa method as compared to the standard technique, was due to false positive results of the former method. We found out that the higher sensitivity of the former method was due to P.stuartii E. cloacae and E.coli bacteria (CRBs), which cross-reacted with the monoclonal antibodies of the method, giving rise to a higher number of Salmonella false positive results. The purpose of the present study was to identify the source of the higher sensitivity of the Elisa Tek technique and propose corrective steps.