Comparison of methods for detection of Erysipelothrix spp. and their distribution in some Australasian seafoods

For many years, Erysipelothrix rhusiopathiae has been known to be the causa tive agent of the occupationally related infection erysipeloid. A survey of the distribution of Erysipelothrix spp. in 19 Australasian seafoods was co nducted, and methodologies for the detection of Erysipelothrix spp. were ev aluated. Twenty-one Erysipelothrix spp. were isolated from 52 seafood parts . Primary isolation of Erysipelothrix spp, was most efficiently achieved wi th brain heart infusion broth enrichment followed by subculture onto a sele ctive brain heart infusion agar containing kanamycin, neomycin, and vancomy cin after 48 h of incubation. Selective tryptic soy broth, with 48 h of inc ubation, was the best culture method for the detection of Erysipelothrix sp p. with PCR. PCR detection was 50% more sensitive than culture. E. rhusiopa thiae was isolated from a variety of different fish, cephalopods, and crust aceans, including a Western rock lobster (Panulirus cygnss). There was no s ignificant correlation between the origin of the seafoods tested and the di stribution of E. rhusiopathiae. An organism indistinguishable from Erysipel othrix tonsillarum was isolated for the first time from an Australian oyste r and a silver bream. Overall, Erysipelothrix spp. were widely distributed in Australasian seafoods, illustrating the potential for erysipeloid-like i nfections in fishermen.