The medium is the messenger

Comment

Enteropathogenic Escherichia coli (EPEC) is an important category of diarrhoeagenic bacteria causing acute and chronic diarrhoea in young children in both developing and developed countries, and sporadic cases in adults.1 There has been rapid recent progress in understanding the early stages of EPEC pathogenesis and the events involved in the formation of the characteristic attaching–effacing (A/E) lesion,2 3 where EPEC attach to the mucosal surface and transform finger-like microvilli into a pedestal-like structure with which the bacterium makes intimate contact.4 5 The main reasons for this progress are the availability of in vitro cell culture models which reproduce the lesion,6 the ability to recognise easily the lesion by fluorescence and electron microscopy,7 and the existence of the “virtual” EPEC laboratory spanning several continents, where researchers from different institutes have shown a ready willingness to exchange ideas, bacterial strains and expertise. Just such a co-operative paper has been published by Knutton and colleagues, encompassing the UK, Israel and South America (with assistance from the USA). However, before commenting on the paper it is important to put it in the context of the rapidly changing field of EPEC research.

The genes needed for A/E lesion formation have been identified using in vitro cell culture models of virulence …