More than one variant ofListeria monocytogenesisolated from each of two human cases of invasive listeriosis

Abstract

SUMMARYTwo variants ofListeria monocytogeneswere isolated from blood cultures from each of two patients with listeriosis. Each variant displayed a two-band difference in DNA profile from the other by pulsed-field gel electrophoresis. Although this difference in profile is insufficient to distinguish clearly between the variants, the possibility of co-infection with different strains ofL. monocytogenesneeds to be considered. We suggest that more than one colony should be selected for molecular typing to aid interpretation during investigation of the sources and routes ofListeriainfection.