Review of the Food-borne Zoonoses Research ... - ARCHIVE: Defra

Salmonella Research Projects
Project code: OZ0312
Project title: Development of a sensitive and
specific molecular typing
method for the epidemiological
study of Salmonella
Start date (dd/mm/yy): 03/01/2000
End date (dd/mm/yy): 31/01/2003
£228,700
Total cost:
Affiliation: LGC
Sub-contractor(s):
Abstract of research
Stobhill NHS Trust
Poultry Health Services
Bacterial pathogens such as Salmonella and Campylobacter are a major cause of
infection in the UK, and present a significant public health problem world-wide. Identifying
the source of infection is central to control the spread of disease, but can be hampered
by the inability to discriminate between isolates within the most common Salmonella
phage and serotypes using conventional typing methods. In this project the use of a
molecular typing method, fluorescent AFLP profiling (AFLP), as a tool for highly
discriminatory characterisation of food borne pathogens was evaluated, using Salmonella
as a model organism.
Until recently, conventional bacteriological methods such as serotyping and phage typing
have been used for the characterisation of Salmonella.
Molecular methods such as AFLP, plasmid analysis and macro-restriction fragment
polymorphism typing by pulsed-field gel electrophoresis (PFGE) can provide improved
discrimination and sensitivity in bacterial typing. AFLP analysis generates a detailed
genomic profile from an organism, consisting of a number of accurately sized DNA
fragments. The characteristic fragments within the profile are produced by selective PCR
amplification of total bacterial DNA, after initial restriction enzyme digestion. Profiles
produced from bacterial isolates are then be compared to assess the similarity of strains.
The genomic profiles provide a good indication of the relatedness of isolates, and
mathematical methods of evaluating evolutionary relationships from AFLP profiling data
have been developed.
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