Title: Prevalence of slaughter house condemnation due to Erysipelothrix sp. and further characterization of isolates associated with these cases – NPB #07-072 Investigator:

The objective of this study was to confirm the presence and investigate the identity of Erysipelothrix spp. in condemned tissues obtained from a regional abattoir. Tissue specimens from 70 carcasses with macroscopic lesions suspect of swine erysipelas were collected at a regional abattoir in Iowa from October 2007 to February 2009. Erysipelothrix spp. culture isolation procedures were performed and recovered suspect isolates were confirmed to be Erysipelothrix spp. by standard laboratory methods. The genotype and the surface protective antigen (Spa) type of selected isolates (one from each positive case) were determined by multiplex real-time PCR assays. Erysipelothrix spp. was isolated from 84.3% (59/70) of the carcasses. All of the isolates recovered from the same carcass were the same serovar. In the culture positive carcasses the following serovars were identified: Serovar 1 (40.7%; 24/59), serovar 2 (49.2%; 29/59) and untypeable (5.1%; 3/59). Fifty-seven of the 59 isolates from positive carcasses were determined to belong to E. rhusiopathiae and 2/59 of the isolates were determined to be E. tonsillarum. Spa A was detected in 57/59 isolates and 2/59 isolates were negative for all Spa types. E. rhusiopathiae serovars 1a and 2 continue to be the most commonly isolated serovars in pigs condemned due to erysipelas. E. tonsillarum on the other hand, previously reported to be of low pathogenicity for swine was identified in a few cases and may be more important than currently assumed.