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Comparative evaluation of molecular based microarray tools for the rapid screening and assessment of Salmonella isolates - OZ0333

Project OZ0324 (New and emerging Salmonella serovars; epidemiological, risk-based and molecular approaches to their identification and control), laid the essential foundations to enable the success of this proposal. Project OZ0324 was always intended to be a rolling 5 to 6 year project and it was stated that it is a dependency upon funding beyond the first three years to assure success in meeting the stated goals. This proposal extends the original project, allowing developed molecular tools to be used as a rapid response to monitor, screen and assess Salmonella isolates for their pathogenicity and epidemicity using serotyping and structural analysis. The rapid tools used are designed to allow continual development, so as new genes and pathogenetic data are identified the screening platforms and methodologies can be updated and inform future analyses, and therefore novel or emerging serotypes.

The implementation of control measures for Salmonella is dependent upon the detection and detailed description of the causative organisms it is vital to maximize isolate details as quickly as possible with up to 99.9% accuracy (as required by EU legislation). By providing high levels of detail rapidly the emergence of an epidemic strain of Salmonella becomes clearer and quicker to identify. There is a strong requirement for development of these molecular tools in the area of veterinary surveillance. This is because to increase control and minimize the potential effects to the farming communities / public health, novel strains need to be identified before they are disseminated into the environment and the animal and/or human population. It is also important to identify, as soon as possible after the emergence of the strain, whether it is of public health significance. This requires knowledge of the key characteristics associated with specific Salmonella strains that are of public health importance.

The need to provide Defra with a Salmonella alerting system has been recognised. To achieve this the next step is to identify the rapid tools which adhere to the regulations stated in the EU directive and can be automated. Comparative analysis between the molecular assays needs to be performed and the selected array validated against the current gold standard. This proposal will contribute significantly to providing Defra with a rapid Salmonella alerting system, and is a step closer to providing “pen side” or real-time surveillance systems and will significantly contribute to the deciding of which factors are crucial in designing such a system.
Objective 1 : Select from commercially available DNA microarray assays that fulfill the criteria set by the EU

Objective 2: Perform a comparative analysis between the existing VLA system (Kauffmann White) and the commercially selected microarray(s)

Objective 3 : Perform comparative analysis of the chosen commercial microarray and the VLA developed microarray against the current Kauffmann White gold standard (validated to ISO16140 standard)

Objective 4 : Adapt the selected microarray to an automated system

Objective 5: Using the data obtained from objectives 2, 3 and 4 provide full validation up to test code status which also satisfies the ISO 16140 standard.
Project Documents
• EVID4 - Final project report : 20120530 OZ0333 final report   (481k)
Time-Scale and Cost
From: 2009

To: 2012

Cost: £317,692
Contractor / Funded Organisations
Veterinary Laboratories Agency
Animal Health              
Plants and Animals              
Fields of Study
Animal Health