POLYMERASE CHAIN-REACTION FOR SALMONELLA VIRULENCE-ASSOCIATED PLASMIDGENES DETECTION - A NEW TOOL IN SALMONELLA EPIDEMIOLOGY

The important role of plasmid genes in assessing virulence for BALB/c mice in salmonella, and the difficulty of using standard techniques to detect them, led us to develop a detection method by gene amplificati on. One hundred and forty-three strains (71 serovars) of salmonella an d 35 strains of other species were tested using specific oligonucleoti de primers. The amplification products were identified by a specific o ligonucleotide probe. Forty-nine salmonella strains from ten serovars (S. abortus ovis, S. choleraesuis S. dublin, X. enteritidis, S. gallin arum/pullorum, S. hessarek, S. typhimurium, S. IIIa 48:z(4), z(23), X. IV 43:z(4), z(23):-, S. V 28:a:-) produced a positive and specific re sponse. Because of various origins of the strains possessing the gene sought and the diversity of the responses, both from one serovar to an other and in the same serovar, this search has its place among the epi demiological markers in general use. This method appears well suited t o the research and detection of plasmid genes associated with mouse vi rulence in salmonella.