Avian wildlife reservoir of Campylobacter fetus subsp. jejuni, Yersinia spp., and Salmonella spp. in Norway.

Cloacal swabs from 540 wild-living birds were cultured for Campylobacter fetus subsp. jejuni, Yersinia spp., and Salmonella spp. The carrier rates detected were as follows: C. fetus subsp. jejuni, 28.4%; Yersinia spp., 1.2%; and Salmonella spp., 0.8%. All birds were apparently healthy when captured. C. fetus subsp. jejuni was isolated from 11 of the 40 bird species examined. Among birds inhabiting the city of Oslo, the highest isolation rate was found in crows (Corvus corone cornix) (89.8%), followed by gulls (Larus spp.) (50.0%) and domestic pigeons (Columba livia domesticus) (4.2%). The gulls and crows scavenge on refuse dumps. High carrier rates were also detected among the following birds from nonurban, coastal areas: puffin (Fratercula arctica) (51.3%), common tern (Sterna hirundo) (5.6%), common gull (Larus canus) (18.9%), black-headed gull (Larus ridibundus) (13.2%), and herring gull (Larus argentatus) (4.2%). The list of species harboring C. fetus subsp. jejuni also includes the Ural owl (Strix uralensis), goldeneye (Bucephala clangula), and reed bunting (Emberiza schoeniclus). The following five Yersinia strains were isolated: Y. kristensenii (two strains), Y. intermedia (two strains), and "Yersinia X2" (one strain). Four strains belonging to the genus Salmonella were isolated from three different species of gulls. These isolates were identified as S. typhimurium, S. indiana, and S. djugu. The results indicate that campylobacters are a normal component of the intestinal flora in several bird species, whereas Salmonella and Yersinia carriers are more sporadic.