Plasmid profiles demonstrate that an upsurge in Salmonella berta in humans in England and Wales is associated with imported poultry meat.

Sixteen plasmid profile types have been identified in drug-sensitive isolates of Salmonella berta isolated from humans and human food in England and Wales in the ten-year period 1981-1990. Since 1988 six profile types of epidemiological importance have caused infections in widely-separated geographical areas and of these, four types have been identified in S. berta isolated from chicken carcasses imported from Denmark. The findings suggest that imported Danish poultry has substantially contributed to a recent upsurge of S. berta in humans in England and Wales.