AEM
Home Help [Feedback] [For Subscribers] [Archive] [Search] [Contents]
This Article
Right arrow Full Text
Right arrow Full Text (PDF)
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Services
Right arrow Similar articles in this journal
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Right arrowReprints and Permissions
Right arrow Copyright Information
Right arrow Books from ASM Press
Right arrow MicrobeWorld
Citing Articles
Right arrow Citing Articles via HighWire
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Gray, M. J.
Right arrow Articles by Wiedmann, M.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Gray, M. J.
Right arrow Articles by Wiedmann, M.
Agricola
Right arrow Articles by Gray, M. J.
Right arrow Articles by Wiedmann, M.

 Previous Article  |  Next Article 

Applied and Environmental Microbiology, October 2004, p. 5833-5841, Vol. 70, No. 10
0099-2240/04/$08.00+0     DOI: 10.1128/AEM.70.10.5833-5841.2004
Copyright © 2004, American Society for Microbiology. All Rights Reserved.

Listeria monocytogenes Isolates from Foods and Humans Form Distinct but Overlapping Populations

Michael J. Gray,1 Ruth N. Zadoks,1 Esther D. Fortes,1 Belgin Dogan,1 Steven Cai,1,{dagger} Yuhuan Chen,2 Virginia N. Scott,2 David E. Gombas,2 Kathryn J. Boor,1 and Martin Wiedmann1*

Department of Food Science, Cornell University, Ithaca, New York,1 National Food Processors Association, Washington, D.C.2

Received 21 March 2004/ Accepted 21 June 2004

A total of 502 Listeria monocytogenes isolates from food and 492 from humans were subtyped by EcoRI ribotyping and PCR-restriction fragment length polymorphism analysis of the virulence gene hly. Isolates were further classified into genetic lineages based on subtyping results. Food isolates were obtained through a survey of selected ready-to-eat food products in Maryland and California in 2000 and 2001. Human isolates comprised 42 isolates from invasive listeriosis cases reported in Maryland and California during 2000 and 2001 as well as an additional 450 isolates from cases that had occurred throughout the United States, predominantly from 1997 to 2001. Assignment of isolates to lineages and to the majority of L. monocytogenes subtypes was significantly associated with the isolate source (food or human), although most subtypes and lineages included both human and food isolates. Some subtypes were also significantly associated with isolation from specific food types. Tissue culture plaque assay characterization of the 42 human isolates from Maryland and California and of 91 representative food isolates revealed significantly higher average infectivity and cell-to-cell spread for the human isolates, further supporting the hypothesis that food and human isolates form distinct populations. Combined analysis of subtype and cytopathogenicity data showed that strains classified into specific ribotypes previously linked to multiple human listeriosis outbreaks, as well as those classified into lineage I, are more common among human cases and generate larger plaques than other subtypes, suggesting that these subtypes may represent particularly virulent clonal groups. These data will provide a framework for prediction of the public health risk associated with specific L. monocytogenes subtypes.

* Corresponding author. Mailing address: Department of Food Science, 412B Stocking Hall, Cornell University, Ithaca, NY 14853. Phone: (607) 254-2838. Fax: (607) 254-4868. E-mail: mw16{at}cornell.edu.

{dagger} Present address: School of Medicine and Biomedical Sciences, State University of New York, Buffalo, New York.

Applied and Environmental Microbiology, October 2004, p. 5833-5841, Vol. 70, No. 10
0099-2240/04/$08.00+0     DOI: 10.1128/AEM.70.10.5833-5841.2004
Copyright © 2004, American Society for Microbiology. All Rights Reserved.



This article has been cited by other articles:



Home Help [Feedback] [For Subscribers] [Archive] [Search] [Contents]
J. Bacteriol. Microbiol. Mol. Biol. Rev. Eukaryot. Cell All ASM Journals

Copyright © 2004 by the American Society for Microbiology. All rights reserved.