Submitted to: Journal of Food Protection
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 5/15/2001
Publication Date: N/A
Interpretive Summary: Subtyping and identifying bacterial pathogens throughout food processing and production chains is key to the new HACCP based food safety plans. Manual serotyping remains the primary means of subtyping Salmonella isolates. Molecular biology techniques however, offer the promise of more rapid and sensitive subtyping of Salmonella. This study evaluates the potential of restriction enzyme PvuII followed by probing with the rRNA operon from E.coli to generate serotype specific DNA fingerprints. For 27 of the 32 identified serotypes there was a 100% correlation between the serotype as identified by USDA and the serotype as identified by the PVU II riboprint. There was an overall agreement in 217 of the 252 (86%) isolates tested between USDA serotyped identification and riboprint serotype identification. Most of the isolates that did not correlate were serotype identified as S. Montevideo which indicates that for this serotype there are multiple ribotypes. The greater than 85% correlation between both serotypes and isolates from this study indicate that the RiboPrinter could be added to manual serotyping as a rapid and reliable Salmonella subtyping method.
Technical Abstract: It is not enough to only know if Salmonella is present in a food sample. If effective intervention strategies are to be developed, implemented and evaluated, the specific identity of the Salmonella must be known. Manual serotyping is the current method of choice for identifying the over 2400 strains of Salmonella. Manual serotyping is slow and there is concern about the quality and availability of antisera to run the assays. This study evaluated an automated and highly reproducible system, the Qualicon Riboprinter with a specific set of reagents that are highly reproducible and should always be available. An excellent correlation of greater than 85% was seen between manual serotyping and the automated system. In some instances, the automated system gave even greater discrimination. This study indicate that the Riboprinter could be added to manual serotyping as a rapid and reliable Salmonella subtyping method.