International E.coli workshop reveals research gaps

Fifty nine of the world’s leading experts on EHEC - a group of E.coli that includes the serotypes E.coli O157, O26 and O104 - gathered for a workshop in Midlothian, Scotland, which was organised by FSA Scotland in conjunction with the Knowledge Transfer Network Biosciences and the University of Edinburgh.

Discussions centered around the factors that lead to EHEC colonisation in cattle, with a particular focus on the role of ‘supershedders’ - cattle that excrete high levels of the bacteria in their faeces - in the transmission of the infection to other cattle and humans.

Dr Jacqui McElhiney, who leads on the foodborne disease strategy within FSA Scotland, told Globalmeatnews.com: “Supershedders probably only make up around 8% of the herd of animals but they contribute around 99% of all the E.coli 0157 that is shed into the environment, so you can see that by targeting these particular animals we have really got a good option for a control measure for preventing the excretion of this pathogen.”​

Delegates agreed that “fundamental”​ research was needed to further understand the factors that cause E.coli to colonise the intestine of cattle, and whether cattle can only pick up the infection from each other, or if there are ‘environmental reservoirs’ of E.coli.

“We identified a need to know what is it about the cattle and what is it about the E.coli that make them interact. If we have a better understanding of the factors that cause that interaction we have a better chance of developing a control measure that can stop it from happening,”​ explained Dr McElhiney.

It was also agreed that international collaboration was needed to investigate how sequence based typing schemes can be used to investigate the evolution and virulence of strains. “We recognise that there is a lot of work that needs to be done to identify the different types of E.coli that circulate in the UK and compare that to partners in other countries in the world,”​ said Dr McElhiney.

Intervention strategies​

Another key aspect of the workshop was a discussion about control measures and intervention strategies. “This can include things like improved biosecurity on farms, looking at dietary interventions  - for example the use of probiotics or feed additives which can help to stop the E.coli colonising the cattle gut - and even looking at different types of feedstuff and how this can impact on bacteria in the cattle gut,”​ Dr McElhiney said.

Delegates agreed that further research was needed into the potential intervention strategies, and how effective they need to be to have an impact on human health. This was particularly important for countries in the EU, where intervention methods such as probiotics and E.coli vaccines have not yet been licensed for use.

“There is really a lack of evidence because a lot of the work that has been done to show how effective these vaccines and probiotics are has been done in other countries, particularly N.America, where they have very different farming systems to what we have in the UK,”​ explained Dr McElhiney.

FSA Scotland has produced a report on the workshop, which outlines its key findings and recommendations. McElhiney said that this would be used as a basis for formulating a future UK research strategy. “We are currently in the process of teasing out of those recommendations possible research programmes we can take forward in the future, both in the FSA and in collaboration with some of the other government funders. It has really been the first stage in developing a research programme in this area,”​ she said.