Reviews & Analysis

This Progress article looks at recent developments in our understanding of the role of the host factor Alix in both retroviral and cellular membrane budding and fission events.

Accurately predicting the emergence of antibiotic resistance will be crucial to prolonging the clinical life of new antimicrobial molecules. Here, the authors propose methodological guidelines that should allow researchers to predict the development of resistance to an antibiotic before its therapeutic introduction.

The reduction in the incidence of poliomyelitis has stalled in the past 7 years, and an urgent re-assessment of the polio-eradication and post-eradication campaign strategies is needed. We propose that vaccination programmes are crucially important for the maintenance of high levels of population immunity against polio and should be continued into the foreseeable future.

Acinetobacterstrains have become a cause for concern — particularly among critically ill, hospitalized patients — owing to the spread of multidrug resistance and risk of epidemics. Here, the authors discuss the current knowledge of the genusAcinetobacter, with the emphasis on the clinically most important species, Acinetobacter baumannii.

Almost all bacteria can adapt efficiently to different nutritional environments by using global regulators that link gene expression to the available intracellular pools of a small number of key metabolites. Here, Abraham L. Sonenshein reviews howBacillus subtilisuses global regulators to manage traffic through two metabolic intersections that determine the flow of carbon and nitrogen to and from crucial metabolites.

How is it that biofilms are less susceptible to metal toxicity than exponentially growing planktonic cell populations? Here, Harrison and colleagues propose a multifactorial model of biofilm multimetal resistance and tolerance by which biofilms can withstand metal toxicity by an ongoing process of cellular diversification within the microbial population.

Owing to their ability to couple ion movement with ATP hydrolysis or synthesis, F-type and V-type ATPases constitute the cornerstone of cellular bioenergetics and are present in all three domains of life. In this Opinion, Eugene Koonin and colleagues use sequence and structural data to develop an evolutionary scenario for these ubiquitous molecular machines.

The Sec pathway, which transports proteins across membranes, is ubiquitous and essential for viability in all three domains of life. At the core of the pathway is the translocase, a dynamic nanomachine that catalyses transmembrane crossing. This Review considers the latest data on the structure and function of the bacterial Sec translocase.

The evidence suggests that a novel secretion system, which is unlike type I–VI secretion systems, exports proteins across the highly impermeable cell walls of mycobacterium. In this Opinion, Wilbert Bitter and colleagues propose to call this system, in line with the accepted nomenclature, type VII secretion.

Every year there are an estimated 500,000 new cases of visceral leishmaniasis (VL) and more than 50,000 deaths from the disease, a death toll that is surpassed among the parasitic diseases only by malaria. The epidemiology, clinical presentation and pathogenesis of VL are reviewed, along with the current control strategies and research challenges.

The complex life cycle ofMyxococcus xanthusincludes predation, swarming, fruiting-body formation and sporulation. The large genome of this bacterium contains eight chemotaxis gene clusters that define eight two-component chemosensory pathways, most of which have dedicated functions in motility or development.

The long-held belief that bacteria rely solely on homologous recombination for the repair of double-strand breaks was recently overturned by evidence that many bacterial genera contain a system for non-homologous end joining (NHEJ). Biochemical, structural and genetic studies are beginning to define an NHEJ pathway that has distinctive features and enzymatic components.

The deep-sea environment comprises a wealth of distinct ecosystems, such as hydrothermal vents, cold seeps and subsurface habitats. A multitude of bacteria and archaea live in these distant niches, and face challenges for growth at extremes of temperature, pressure and carbon limitation. This Review describes life in the deep-sea biosphere and discusses how microorganisms overcome the scarcity of energy resources, which is relevant to understanding the limitations to, and the diversity of, life on Earth.

In this Review, the authors discuss the benefits of thinking about the ocean in terms of microniches and advocate the study of global processes on a microscale. Farooq Azam and Francesca Malfatti stress the need to study oceanic microbiologyin situand to use this as a unifying basis for modelling the influence of microorganisms on the structure of marine ecosystems. This might lead to new insights into the regulation of primary production and carbon cycling.

Unlike prokaryotes, which do not leave a fossil trail, the patterns of change over evolutionary time of eukaryotic phytoplankton can be derived from microfossils. Here, Paul Falkowski and Matthew Oliver use the fossil record, resource competition theory and the physical principles of ocean dynamics to propose how climate might have affected phytoplankton populations in the past, and make predictions for the future.

David Karl provides a critical review of the exciting new discipline of microbial oceanography by discussing selected key advances. These include probing the metabolic balance in the oceans, the exciting discovery of bacterial proteorhodopsin, establishing a long-term ocean observatory, the unexpected role of marine Archaea, and attempts to understand the result of perturbing nutrient levels in the sea.