Occurrence of Erysipelothrix spp. in broiler chickens at an abattoir.

From September 1995 to August 1996, 750 chickens from 66 farms sent to an abattoir in Nagano Prefecture, Japan, were examined for the presence of Erysipelothrix spp. Erysipelothrix spp. were isolated from 118 (15.7%) of 750 skin samples, 27 (7.3%) of 372 hypoderm samples, 12 (1.9%) of 630 throat samples, 106 (59.2%) of 179 feather samples, and none of 257 spleen samples. Of 66 farms, 55 farms (83.3%) sent Erysipelothrix-positive chickens and 11 farms (16.7%) only negative ones. Of 297 Erysipelothrix isolates, 273 isolates were identified as Erysipelothrix rhusiopathiae and 24 as Erysipelothrix tonsillarum. E. rhusiopathiae isolates were serotyped into nine different serovars. Of the 273 E. rhusiopathiae isolates, 33 (11.1%) were serotyped to serovar 6; 22 (7.4%) were serovar 5; 19 (6.4%) were serovar 2; 15 (5.1%) were serovar 8; 2 (0.7%) were serovar 21; 4 each (1.3% each) were serovars 1b, 9, 12, and 19; and 178 (59.9%) were untypeable. Of 24 E. tonsillarum isolates, 15 (5.1%) were serotyped to serovar 3, and 9 (3.0%) were serovar 7. These findings indicate that chickens seem to be a potential reservoir of Erysipelothrix spp. in nature and to be a source of human Erysipelothrix infection.