Closing day - The elephant in the red room
We need standardisation in order to have reproducible data but we can’t agree on standard methods
Phil Stewart, Tom Coenye and Bastiaan Krom led discussions on the need for standardised methods in biofilm research. Stewart started by giving a talk reminding us that without knowing important parameters such as dose response and biomass, we will never be able to treat biofilms effectively. Coenye then asked the important and provocative question, is lack of standardisation and uniform terminology hampering progress in biofilm research? He did this by quoting the famous Shakespeare line “That which we call a rose, by any other name would still smell as sweet”. He argued that although terminology might not be uniform, there are probably enough similarities among methods that we can still use for standardisation. However, this only works if we have enough data deposited with a method to make it clear exactly what happened. Without this, standardisation is a pipe dream. However, as reasonable as this sounds, it’s not easy to agree on what information should be included with each method, or even how we as a community can enforce it. Should we include dose responses every time? Should we report the biofilm thickness? Should we always measure the live/dead composition? This list goes on, and it seems that we are in a bit of a tight spot.
The floor opened to discussions which seemed focussed, at least in the beginning, on patching the holes in current standardisation techniques. Standardisation for animal experiments was discussed as well and including more realistic killing assays in which samples containing biological debris were considered. We also discussed how the 2 day MIC does not reflect clinical practice. Concerns were raised about the use of MIC’s pointing at drug concentrations that were systemically impossible to achieve. More criticism of the MIC followed which was ironic as it is arguably one of the most standardised methods we have, which is perhaps indicative of the uphill battle we are facing. Despite the concerns, MICs are still very important. As Coenye pointed out, they immediately tell us which antibiotics we cannot use, which is vital in the clinic.
Despite the enormity of the challenge ahead and the raft of problems levied against current standardisation techniques, two rays of light emerged from the discussion. The first was from Prashant Sharma who suggested that we include standard benchmark compound in biofilm assays. This is much easier to agree on that a standard method and would help us draw conclusions, even across diverse methods. The second point from Craig Williams was an observation that other fields accept that methods vary but they commit to standardisation in the analysis. It’s hard to see exactly how this would look in the biofilm field but if it works for other discipline, perhaps we should give it a try. Maybe we should start with COMSTAT?
Prior the discussion were two more parallel session and I was forced to abandon my PhD crush of social microbiology in the blue room. I stayed in the red room for my new loves, springs and dashpots, or mechanics and physics in biofilm. The session was lively and several of the talks built on one another which was nice and slowed the pace a little to give us more time to digest the information. We heard a lot about the viscoelastic properties of biofilm and surface stiffness and how these are poorly understood and yet critical for biofilm. We also heard about an interesting use for multiphoton microscopy to measure the penetration of drug delivery molecules into the biofilm and Paul Stoodley closed the session with his work on orthopaedic implants.