Mireille ANSALDI

As the project grows, we had more and more questions about our bacteriophage approach. Indeed, we wanted in the first place to use Xylella fastidiosa’s natural phages, but we met some difficulties. We went to see Ms ANSALDI, who directs the “phage cycle and bacteria metabolism” unity research in LCB, CNRS Marseille, France. As an expert in the field, she is an obvious choice to seek advice on the matter. She generously granted us time for an interview.

Thanks to her answers, we learned that Xylella fastidiosa certainly has some resistance mechanism, such as CRISPR and restriction enzymes. We had doubts about it, now we are fixed. She also told us that we could work on Xanthomonas campestris instead of Xylella fastidiosa since the binding proteins are similar. Indeed, the work on Xylella fastidiosa is not allowed in P1 or P2 labs, whereas Xanthomonas is allowed in P2 security labs. So we will use X.campestris instead, for more safety.

Finally, she also advises us to look about the prophages. By missing information about specific prophages of X.fastidiosa and the inducible toxicity by these phages, we let this approach aside. That’s why we end up with the phage-like particles approach, our final project.

To sum up, we question our phages approach with an expert opinion. Thanks to her, we change our mind about what we wanted to do. Now we are able to combine the phage’s specificity with the toxine’s efficiency.

Jacques VAN HELDEN

We contacted Jacques van Helden to help us find a strong Supernova promoter sequence and the consensus RBS consensus of the anti-shine Dalgarno of RNA polymerase. He sent us a "recipe" with the ingredients and how we should proceed with some valuable additional information. He also sent us a list of questions so that we could reflect on other important points concerning the specificity of the phage. Finally, he sent us a list of tracks of some other highly expressed genes and a detailed practical approach.

Marie-Agnès JACQUES