Serotyping of and hippurate hydrolysis by Campylobacter jejuni isolates from human patients, poultry and pigs in the Netherlands.

Three hundred strains of Campylobacter jejuni, isolated from human patients, poultry and pigs were serotyped according to the Penner-Lauwers system and furthermore tested for hippurate hydrolysis. Serotyping showed a close relationship between human and chicken strains, whereas there was little relationship between human and pig strains. A similar conclusion was drawn from the results of the hippurate hydrolysis test: 86% of human and 94% of poultry strains were positive, whereas 91% of pig strains were negative. These data confirm the conclusions from epidemiological investigations, according to which poultry is a major source of human campylobacteriosis, while pigs are rarely so.