Direct and rapid detection by PCR of Erysipelothrix sp DNAs prepared from bacterial strains and animal tissues

A PCR method for rapid screening of Erysipelothrix spp. in the slaughterhou se was carried out by using four species-specific sets of oligonucleotide p rimers after initial amplification with the primer set MO101-MO102, which a mplifies the 16S rRNA sequences of all four Erysipelothrix species. The DNA sequences coding for the rRNA gene cluster, including 16S rRNA, 23S rRNA, and the noncoding region downstream of 5S rRNA, were determined in order to design primers for the species-specific PCR detection system. The homology among the 4.5-kb DNA sequences of the rRNA genes of Erysipelothrix rhusiop athiae serovar 2 (DNA Data Bank of Japan accession no. AB019247), E. tonsil larum serovar 7 (accession no. AB019248), E. rhusiopathiae serovar 13 (acce ssion no. AB019249), and E. rhusiopathiae serovar 18 (accession no. AB01925 0) ranged from 96.0 to 98.4%. The PCR amplifications were specific and were able to distinguish the DNAs from each of the four Erysipelothrix species. The results of PCR tests performed directly with tissue specimens from dis eased animals were compared with the results of cultivation tests, and the PCR tests were completed within 5 h. The test with this species-specific sy stem based on PCR amplification with the DNA sequences coding for the rRNA gene cluster was an accurate, easy-to-read screening method for rapid diagn osis of Erysipelothrix sp. infection in the slaughterhouse.