Volume 9 Issue 4, April 2011

Our understanding of the role of the microbiota in our gut and other sites in our body is rapidly improving and can lead to many new and innovative approaches for health care.

Genetic analyses ofLactobacillus reuteristrains identifies factors that determine their host specificity.

A new FISH approach that greatly increases the number of microorganisms that can be distinguished in a single image.

Fusion of the outer membranes of bacteria allows exchange of periplasmic components

Modification of type IV pili with phosphoglycerol destabilizes these pili, allowing bacteria to separate from microcolonies and spread the infection.

The genome-packaging machinery of bacteriophage T4 is highly promiscuous and can translocate multiple DNA molecules into both immature and mature capsid heads.

Intercellular nanotubes can be formed between bacterial cells of the same and of different species to facilitate the exchange of cytoplasmic content.

Light-driven proton pumps of bacterial origin, or proteorhodopsins, are described for the first time in eukaryotes.

This month's Genome Watch looks at how recombination has providedStreptococcus pneumoniaewith the adaptability to overcome antibiotic and immune challenges.

Our monthly round up of infectious diseases news, which this month includes new influenza vaccines and potential antimalarials, hopeful news about HIV in Zimbabwe, and drug delivery using bacteria.

The use of antibiotics is making lasting alterations to the long-term relationship between a host and its microbiota. Willing, Russell and Finlay describe how these changes can result in the disruption of immune homeostasis and in increased susceptibility to disease.

Human skin is colonized by a diverse range of microorganisms. In this Review, Grice and Segre describe how molecular techniques are improving our understanding of our skin microbiota, the factors that affect its composition and its relationship with skin disorders.

Many diseases may be caused by the combination of a specific host genetic background and a viral infection. Here, Foxman and Iwasaki describe how viral infections may be involved in type 1 diabetes, asthma and inflammatory bowel disease.

The mucus barrier provides a crucial defence against commensal microorganisms and enteric pathogens. In this Review, McGuckin and colleagues describe the structure of the mucus barrier and discuss how the composition of the mucus layer is regulated under normal conditions and in response to infection.

In recent years, the composition of the gut microbiome has become the subject of intensive study. In this Review, Spor, Koren and Ley describe how host genetics and the environment shape the gut microbiome, both in health and in chronic disease.

The transcription factor nuclear factor-κB (NF-κB) plays a central part in the immune response to bacteria and viruses. To influence the host's immune response, many bacteria and viruses have devised ways of modulating the activity of NF-κB.

Mucosal surfaces are in direct contact with the external environment, making them the first point of contact between a host and an invading pathogen. Furthermore, mucosa are colonized by an array of commensal and beneficial microorganisms, meaning that the mucosal immune system must be able to differentiate between friend and foe. This Focus highlights the latest research providing insights into the composition of our mucosal microbial communities, the host and environmental factors that shape these communities, their interaction with the immune system and the impact of antibiotics on them.