News
17-September 2010 – LGC
supports food industry with new test for
Campylobacter
Novel molecular DNA identification approach from LGC
offers potential for improved foodborne bacteria
diagnosis
Research at LGC, the UK’s
designated National Measurement Institute
for chemical and bioanalytical measurement, has demonstrated proof
of principle for a novel molecular DNA diagnostic technique to
identify specific species of Campylobacter; a bacterium related to
foodborne illnesses.
Of the five major foodborne bacteria; Salmonella, Campylobacter,
E.coli 0157, Listeria monocytogenes and Clostridium perfringens,
Campylobacter is the most common cause of foodborne illness in the
UK. In 2008, there were 49,880 cases of Campylobacter infection in
England and Wales, compared with 9,867 of Salmonella*. Virtually
all cases of Campylobacter infection occur as isolated, sporadic
events, not as a part of large outbreaks.
The traditional method of identifying bacterial pathogens
associated with foodborne illnesses is examination via pour plate
technology with biochemical reactions and identification and
enumeration by microscopy. However, this approach could be
criticised as being time-consuming and somewhat subjective.
LGC’s research focuses on a more accurate and efficient approach
for species identification; LGC scientists have modified routine
polymerase chain reaction (PCR) methods to differentiate
successfully two of the most common Campylobacter species; C. coli
and C. jejuni, by their unique DNA profiles. Proof of principle for
LGC’s technique was demonstrated using Campylobacter DNA supplied
by ATCC via LGC Standards, the exclusive European distributor of
ATCC biological cultures and bioproducts.
Through expertise in refining PCR and the optimisation of
previously published methods, LGC’s scientists have reduced the
time taken to carry out the amplification step in the PCR process
by 50% and improved assay efficiency by decreasing both, reagent
volumes by 75% and the use of primers and enzymes by 85%. The
technique employs the novel use of a restriction enzyme which also
enables significantly improved experimental repeatability.
The FSA’s strategic plan for 2010 - 2015 sets one of its main
priorities as ensuring ‘Food produced or sold in the UK is safe to
eat’ and cites the reduction of foodborne disease, specifically in
tackling the incidences of Campylobacter in chicken as one of its
main objectives. Foodborne illness can be caused by the consumption
of food contaminated with bacteria and their toxins.
LGC’s molecular DNA technique demonstrates the potential to give
very specific identification of different Campylobacter species
based on unique DNA profiles. Whilst this approach is still in its
early stages of development, the technique has demonstrated the
potential to differentiate efficiently between species, and could,
in future, contribute to the Food Standards Agency (FSA) initiative
to manage the prevalence of Campylobacter in UK food sources.
* Source: HPA Centre for Infections. Provisional data.
- Ends -
Notes to
editors