In the fall of 2001, our laboratory at Cornell University was selected by the Technical Committee on Food Microbiology of ILSI North America to host the ILSI Listeria monocytogenes strains collection. This collection represents a unique resource that provides researchers with a standard set of L. monocytogenes isolates, thus allowing for comparison of data on Listeria physiological and genetic characteristics generated in different laboratories. Data generated with this strain collection will be linked through adding all references reporting data on these strains to our database, generating a large dataset that will improve our abilities to control L. monocytogenes contamination and infections throughout the food chain. In 2005, the ILSI NA Committee on Food Microbiology also decided to host the ILSI NA Enterobacter sakazakii collection at Cornell University. Strains are also distributed to other members of the research community, requests for strains and for more information should be directed to Dr. Martin Wiedmann; a fee to recovers costs of shipping, handling and strain preparation will be charged.
ILSI Listeria strain collection
The ILSI N.A. strain collection and database currently includes 44 L. monocytogenes isolates. These isolates are grouped into two separate sets, including one diversity subset (25 isolates) and one matched human and food isolate subset (21 isolates, 2 of which are also included in the diversity subset) representing isolates from human listeriosis outbreaks and cases. The diversity subset included in this collection provides a valuable reference strain set for evaluation of new L. monocytogenes detection method, determination of L. monocytogenes survival and growth characteristics in different foods, etc. The matched human and food isolate subset, particularly if used in conjunction with the diversity subset, provides a valuable reference collection for evaluation and validation of subtyping methods. In addition, both strain sets provide a unique resource for basic and applied studies on the physiology, ecology, evolution, and pathogenesis of different L. monocytogenes strains. A collection of L. monocytogenes mutants in various defined virulence genes has also been assembled. As soon as full permissions for distribution of these strains have been obtained from the laboratories that supplied these mutants, these strains will also be included in the ILSI N.A. Listeria strain collection and made available for distribution. A list of all isolates in the ILSI Listeria strain collection, including source information, year of isolation, serotype and ribotype information is available here. A detailed history of all isolates included in the ILSI Listeria strain collection is available here. A list of Listeria strains for which genome sequences have been completed or are in progress is available here. Additionally, a list of isolates representative of all listeriosis epidemics worldwide is available here. Collection isolates listed on this WWW page are also archived in the Cornell PathogenTracker database, which provides more complete information on these isolates. EcoRI ribotyping data and PFGE typing data are available for all isolates in the collection. Selected subsets of these isolates for specific applications have also been developed including: (i) 5 strain cocktail for challenge and survival studies in meat systems, click here.
The ILSI Listeria Strain collection was recently described in Fugett et al. 2006. J. Food Prot. Dec;69(12):2929-38. The citation and abstract for this article can be viewed in PubMed by clicking here
ILSI E. sak strain collection
The ILSI N.A. strain collection and database currently includes 30 E. sakazakii isolates. The collection includes isolates from human clinical cases (N = 10), foods (N = 10), and food environments (N = 10). A list of all isolates included in the ILSI N.A. E. sakazakii collection, including source, references, ribotype, and PFGE data is available here.
