Salmonella identification by the polymerase chain reaction

Polymerase chain reaction (PCR) primers for genus specific detection of Salmonella have been selected from a Salmonella-specific fragment of 2.3 kilobases (kb). Due to interserovar sequence diversity within this fragment, primer selection was based on DNA sequence alignment of sequences from 20 different Salmonella serovars. The specific PCR product of 429 base pairs (bp) was formed from 144 of 146 salmonella strains tested (116 of 118 serovars). The two false-negative strains belonged to two different serovars of the rarely isolated subspecies IIIa (monophasic S. arizonae). No product was produced in any of 86 non-Salmonella Enterobacteriacea strains tested, covering 41 species from 21 genera.