Listeriosis and Milk

Abstract

The life cycle of Listeria monocytogenes seems to be inextricably intertwined with the monocyte. The species name was inspired by the curious ability of the organism to cause a monocytosis in the blood of infected laboratory animals. In 1929, Nyfeldt reported the first isolation from a human being, a boy with infectious mononucleosis, and three years later he described similar isolates from 3 of 10 patients with infectious mononucleosis. Although we now recognize that monocytosis is an uncommon manifestation of human listeriosis and that infectious mononucleosis is caused by the Epstein–Barr virus, the link between L. monocytogenes and the monocyte remains intriguing. The ability of this organism to parasitize the mononuclear phagocyte may explain not only the manifestations it produces but also whom it attacks and how it is transmitted.