Microbial biofilms--the coming of age of a research field.

close to 300 participants coming from 30 different countries and more than 200 submitted abstracts, the meeting was very successful. It is clear that the field of microbial biofilms has come a long way since the early studies on biofilms (in the 1920s and 1930s, see the historical overview written by Niels Hoiby in this issue; Hoiby, 2014). The field has benefited dramatically from advances in our understanding of the molecular biology of microorganisms as well as from technological advances within microscopy techniques and methods for culture-independent investigation of microbial communities. While simple in vitro model systems are still very valuable to study fundamental aspects of the social behavior of microorganisms , we are gradually developing the capabilities of studying microbial biofilms under in vivo conditions. Results from these in vivo studies clearly indicate that the structure of many in vivo biofilms is very different from what is typically seen in in vitro biofilms and the use of in vivo models allows researchers to dissect the interplay between the host immune response and the microbial biofilm (Bjarnsholt et al., 2013). In addition, there is growing interest in and need for studying multispecies biofilms, both in in vitro and in vivo model systems (Burmølle et al., 2014). Particularly interesting in this regard are studies focusing on interactions between fungi (e.g. Candida albicans) and bacteria (e.g. Despite considerable progress in this area over the last decade, much still remains to be learned about resistance, tolerance, and persistence in microbial biofilms. Resistance , tolerance, and persistence all contribute to the frequent failure of antimicrobial therapy directed against biofilm-related infections. While a picture starts to emerge where protection against oxidative stress, expression of efflux pumps, and protection provided by matrix polysac-charides all contribute to the biofilm-specific phenotype (Van Acker et al., 2014), it is still not completely clear how these mechanisms are regulated in different bacteria and fungi. In addition, there is growing evidence that the outcome of antimicrobial therapy is also determined by the composition of the biofilm and the interactions between different organisms in a multispecies biofilms, and it is often observed that the simultaneous presence and interaction of different microorganisms in an infection can lead to failure of antimicrobial therapy (for example Perez et al., 2014). An important aspect of future biofilm research is the need for standardization, and in this regard, two European initiatives stand out. First, the Biofomics platform …