Security and fidelity, two topics that are close to everyone's heart, are the subject of two Reviews in this month's issue of Nature Reviews Microbiology

On page 867, Vadim Agol and Anatoly Gmyl discuss the picornavirus leader (L), L* and 2A non-structural proteins, which flank the capsid precursor in the viral polyprotein and have previously been referred to as virulence factors. Agol and Gmyl argue that, although these proteins have no common structural or biochemical features, functional analysis indicates that they are specifically dedicated to counteracting host defences by switching off various aspects of host macromolecular synthesis and suppressing mechanisms involved in innate immunity, and so 'security proteins' would be a more fitting name.

On page 849, Michael Ibba and colleagues consider the topic of translational fidelity in bacteria, or how bacteria ensure that the correct amino acid is incorporated into the nascent polypeptide during translation. The authors review the molecular mechanisms involved in the different steps of translational quality control and show that mistranslation can have both positive and negative effects on bacterial growth and viability.

Last, the fifth in our series of supplements on evaluating diagnostics, which we are producing in conjunction with our partners at TDR, is supplied with this issue. The aim of the supplements is to provide practical, user-friendly guides that explain how to evaluate diagnostic tests for infectious diseases that mainly affect people in the developing world. The topic of this fifth supplement is the evaluation of diagnostics for dengue. The supplement can be accessed free online at http://www.nature.com/nrmicro/supplements.