The prediction of virulence based on presence of virulence genes in E. coli may not always be accurate

Now that microbial whole genome sequencing is in reach of many researchers, it is common to infer virulent properties of a given bacterial isolate based on the presence of virulence genes. However, this may lead to inaccurate presumptions of virulence. Using the findings of a recent publication (Da Silva Santos et al. Gut Pathog 7:2, 2015) where virulence was inferred from a genome sequence and subsequently confirmed by in vitro analysis, we present an alternative view on the case described in that publication. Our alternative view point, which is further substantiated by whole genome sequencing of probiotic E. coli strains, may contribute to a more balanced vision on the interactions between pathogens and host.