Abstract
In the Kanto area a total of 245 wild rats were captured. All rats captured in Ikebukuro (110 rats) and 9 out of 41 rats in Yokohama were Rattus rattus, and all other 126 rats were Rattus norvegicus. In Kashima and Ikebukuro, listeria was isolated from 28 rats (77.8%) and 27 rats (24.5%), respectively, but in the other 4 areas listeria was isolated from 0-7% rats. Listeria monocytogenes was isolated from 12 fats (10.9%) captured in Ikebukuro and 2 rats in Kashima and Numazu. The frequent isolation of L.monocytogenes in buildings suggests the possibility of R.rattus as a reservoir of L.monocytogenes and the continual environmental contamination in buildings by L.monocytogenes.
