IAFP 2009 Program Book and Abstract Book - AB39

6%) out of 6.25 g egg and 36% (RSD 19%) out of 6.25 g ice-cream. L. monocytogenes was recovered with 67% (RSD 26%) from 12.5 ml milk and for both pathogens real-time PCR quantification resulted in higher (1.5 to 2 fold) bacterial equivalent counts than with CFU determination. Significance: Application of ionic liquids permits the separation of foodborne bacterial pathogens from the food of interest for subsequent quantification with both real-time PCR and culture methods. Quantitative results can be obtained within one working day with the new buffer system. T4-07 A Novel, Automated, Large Volume Re-circulating IMS Sample Processing Device for Rapid Isolation of Specific Pathogens from Pre-enriched Pooled Food Samples Nicole Prentice, John Murray, Katarzyna Brzegowa, Paul M. Benton, Brooke V. Houston, Michael F. Scott, Christine M. Aleski, Marcie Van Wart and ADRIAN PARTON MATRIX MicroScience Ltd, Cambridgeshire, United Kingdom Introduction: Re-circulating IMS (RIMS) is well established as a robust and versatile approach to pathogen isolation from food and environmental samples, combining straightforward analysis of large, pooled pre-enriched samples, and removal of potential PCR inhibitory compounds with the ability to detect initially low levels of target pathogens. Utilizing the RIMS principle (the continuous flow and repeated passage of pre-enriched sample across a semi-permanent immobilized selective capture surface), PATHATRIX is widely employed in both routine food pathogen testing and outbreak investigations by regulatory agencies. Purpose: Recirculating IMS has many desirable characteristics but involves a series of manual steps to achieve washing and recovery of magnetic particles. While this labor is minimal, a degree of user interaction is required. The availability of an automated device employing the RIMS principle will enhance the sample handling and processing involved in food pathogen testing. This study describes the development, evaluation and validation of a large volume IMS device that automates the capture, wash, elution and bead concentration steps. The aim of this study is to demonstrate comparative or better performance than the current manual RIMS method. The ability to link the automated RIMS system to real time PCR was also investigated. Methods: A range of food samples, including several implicated in a significant number of food safety recalls and outbreaks during the past two decades (ground beef, peanut butter, chocolate, almonds and fresh produce) were inoculated (1 to 10 CFU/sample) with appropriate target pathogens (E. coli O157, Salmonella serovars, Listeria spp.). Samples were pre-enriched according to the standard RIMS protocols. Duplicate pooled samples of each food and pathogen combination were processed in parallel using automated RIMS alongside PATHATRIX . Both systems used immuno magnetic particles with the same magnetic properties, target specificity and inclusivity. Recovery of target pathogens after plating IMS beads onto selective agar plates was used as the detection methodology. Results: The detection of a range of target pathogens from pooled food samples by selective agar plating and real-time PCR was achieved using a novel, automated RIMS device. A 100% correlation between the recovery and detection of target organisms by the automated and manual RIMS systems was observed. Significance: The data presented in this study demonstrates that it is feasible to fully automate the RIMS procedure and employ standard PATHATRIX immuno-capture beads in this process with no loss of bead recovery or target pathogen capture functionality. T4-08 Evaluation of PremiTest Salmonella for Rapid Serotyping of Salmonella Strains Isolated from Broiler Farms in Southern Brazil Joao Paulo Zuffo, PRISCILLA KARINA V. KOERICH, Alceu Marafon and Ron van Santen Perdigao Agroindustrial S.A., Laboratorio Patologia Animal, Videira, Brazil Introduction: Salmonella serotyping plays an important role in Salmonella reduction programs, as it facilitates identification of the source of contamination. The conventional method for serotyping (Kauffmann-White scheme) is complex, labor intensive and time consuming, and therefore is only remotely available for many routine laboratories. The PremiTest Salmonella is a novel and rapid alternative test for Salmonella serotyping; it recognizes 78 of the most frequently encountered serotypes, is intended for routine use and can be completed within one working day. Purpose: The objective of this study was to evaluate the performance of the PremiTest Salmonella. Methods: A total of 100 Salmonella strains isolated from Brazilian broiler farms, comprising 21 different serotypes, was serotyped, using both the conventional and the alternative method. The alternative method uses multiplex PCR and a micro array to determine a genetic profile of the isolate (genovar). The accompanying software translates the genovar into a regular serotype. Results: The results indicate that 19 serotypes (n = 95) were recognized by the test; two serotypes (Corvalis and Rubislaw) were not present in the database, but were recognized with a distinct genovar code. From the 95 isolates, 85% was assigned to the right serotype (n = 81) and none of the strains was assigned to the wrong serotype. The remaining isolates (n = 14) yielded genovar scores that were not recognized by the software. Some of these scores were encountered for multiple strains and may be included in future versions of the software, thereby indicating the capabilities of the technique. Significance: The study indicates that the PremiTest Salmonella is a rapid and promising alternative to the regular Kauffmann-White scheme. It is easy to use and makes serotyping available to routine laboratories. As such, it is a valuable tool in Salmonella reduction programs. Abstract Book — 39 Technical

IAFP 2009 Program Book and Abstract Book

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