| relatedness of listeria monocytogenes isolates recovered from selected ready-to-eat foods and listeriosis patients in the united states. | pulsed-field gel electrophoresis and serotyping were performed for 544 isolates of listeria monocytogenes, including 502 isolates recovered from contaminated samples from 31,705 retail ready-to-eat (rte) food products and 42 isolates recovered from human cases of listeriosis. the isolates were from maryland (294 isolates) and california (250 isolates) and were collected in 2000 and 2001. the isolates were placed into 16 asci pulsogroups (level of relatedness within each group, > or =66%), 139 as ... | 2005 | 16332793 |