Validation of a seminested PCR approach for rapid detection of Salmonella enterica subsp. enterica serovar Gallinarum

Salmonella enterica subsp. enterica serovar Gallinarum (S. Gallinarum) is the causative agent of fowl typhoid, one of the major causes of mortality and morbidity on poultry farms. Even though it has been substantially eradicated in many developed countries, the disease still remains endemic in Central and South America, in Africa and in the Mediterranean countries of Europe. This leads to the routine screening of flocks, mainly by cultivation and serological techniques, which are expensive, as well as time and labour-consuming. Here we describe a simple and specific PCR-based method for detecting S. Gallinarum. It relies on two seminested PCRs which use four pairs of primers designed on the basis of two genomic regions which appear to be exclusive to the pathogen. Furthermore, an internal positive control was devised in order to avoid any false negative results. We performed sensitivity and specificity tests, and our findings showed the cogency of the system and its potential effectiveness even for routine uses.