Friday, September 16, 2011

Hot off the presses! Oct 01 Nat Rev Microbiol

The Oct 01 issue of the Nat Rev Microbiol is now up on Pubget (About Nat Rev Microbiol): if you're at a subscribing institution, just click the link in the latest link at the home page. (Note you'll only be able to get all the PDFs in the issue if your institution subscribes to Pubget.)

Latest Articles Include:

  • - Nat Rev Microbiol 9(10):695 (2011)

  • - Nat Rev Microbiol 9(10):696 (2011)
  • Bacterial secretion: Coupled translation of effector–chaperone partners | PDF (193 KB)
    - Nat Rev Microbiol 9(10):697 (2011)
    Clustering of genes in operons enables the coordinated transcription of genes that encode functionally related products, so that these proteins are produced at the same time and in the same cellular location. Writing in Molecular Microbiology, Button and Gal now describe a type III secretion system (T3SS) effector and its cognate chaperone that are coupled not just at the level of transcription, but also during translation such that synthesis of the effector protein is dependent on the ongoing synthesis of its chaperone partner.
  • Symbiosis: Market economics in plant–fungus relationships | PDF (402 KB)
    - Nat Rev Microbiol 9(10):698 (2011)
    All relationships have the potential to turn sour, and this is true even of perhaps the world's most common pairing: the symbiotic relationship that exists between plants and arbuscular mycorrhizal fungi. As a single plant can be colonized by many fungal species, there is a risk that a fungus will cheat and benefit from plant nutrients without providing anything in return.
  • Microbial Ecology: First come, first served? | PDF (155 KB)
    - Nat Rev Microbiol 9(10):698 (2011)
    Bacterial communities are intricate collections of bacterial species that each provide functions which contribute to the stability of the community. In a recent issue of the Proceedings of the National Academy of Sciences USA, Thomas and colleagues show that in the bacterial communities that form on the surface of the alga Ulva australis, the gene content of the community is more constant than the phylogenetic content, a finding that has important implications for our understanding of how bacterial communities are formed.
  • Microbial ecology | Bacterial pathogenicity | Microbial ecology | PDF (110 KB)
    - Nat Rev Microbiol 9(10):698 (2011)
    Defining seasonal marine microbial community dynamics Gilbert, J. al. ISME J.18 Aug 2011 (doi:10.1038/ismej.2011.107)
  • Synthetic biology: Licensing bacteria to kill | PDF (140 KB)
    - Nat Rev Microbiol 9(10):699 (2011)
    The introduction of synthetic genetic systems into bacteria holds much promise for the production of drugs and biofuels and for the bioremediation of contaminated environments. With the design and testing of an engineered Escherichia coli strain that specifically targets Pseudomonas aeruginosa, Saeidi et al.
  • Biotechnology: Metal-like conductivity in microbial nanowires | PDF (269 KB)
    - Nat Rev Microbiol 9(10):700 (2011)
    The bacterium Geobacter sulfurreducens can obtain energy for growth by oxidizing organic compounds and transferring the resulting electrons through long filaments, known as pili or microbial nanowires, to the surface of iron oxide particles. However, it was unclear how the electron flow takes place, as the pili are composed of oligomeric pilin proteins, a material that was expected to be an electrical insulator.
  • Host response: Test of mettle for neutrophils | PDF (163 KB)
    - Nat Rev Microbiol 9(10):700 (2011)
    The abundant neutrophil protein calprotectin enhances host killing of Staphylococcus aureus by inhibiting the ability of the bacterium to respond to the neutrophil oxidative burst, according to a new publication in Cell Host & Microbe.
  • Expressions of individuality | PDF (192 KB)
    - Nat Rev Microbiol 9(10):701 (2011)
    This month, Genome Watch describes a new technique for single-cell transcriptomics that will allow the measurement of variations in transcript levels within a population.
  • In the news | PDF (192 KB)
    - Nat Rev Microbiol 9(10):702 (2011)
    Controlling dengue An open field trial in Australia has revealed that infecting mosquitoes with the endosymbiotic bacterium Wolbachia pipientis str. wMel has great potential to control the spread of dengue virus (DENV). Spread by the mosquito Aedes aegypti, DENV infects up to 50 million people worldwide each year and results in around 12,500 deaths. Previous work had indicated that it might be possible to control A. aegypti populations by infecting them with W. pipientis str. wMelPop-CLA, as this strain reduces the lifespan of the infected mosquito, thereby decreasing the potential of transmitting DENV. Unfortunately, the shortened lifespan also affected the ability of mosquitoes to pass on the bacterium to subsequent generations, hampering the use of this strain as a control agent. Two studies now reveal that using the avirulent wMel strain to infect mosquitoes has little effect on lifespan, reproductive rates and offspring viability. In an open field trial, 300,000 wMel-infected adult mosqui! toes were released into wild populations of A. aegypti in two remote areas of Australia. The bacteria spread rapidly through the population at both sites and after 5 weeks were found in nearly all mosquitoes tested. Furthermore, infection of female mosquitoes seems to block DENV transmission, although the mechanism behind this remains unclear. Nature/Washington Post/Science Mapping the spread of cholera Molecular epidemiological studies have identified at least three waves in the current Vibrio cholerae pandemic. Throughout history, there have been seven acknowledged cholera outbreaks, with the V. cholerae 'classical' biotype responsible for the first six and the 'El Tor' biotype responsible for the seventh, ongoing pandemic. A team from the Sanger Institute, UK, has mapped single-nucleotide polymorphisms in 154 whole genome sequences of V. cholerae isolates from around the world to show that the current pandemic spread from the Bay of Bengal in at least three independent, overlapping waves with a common ancestor in the 1950s. A separate study has used whole-genome sequence typing, pulsed-field gel electrophoresis and antimicrobial susceptibility testing to evaluate the potential Nepalese origin for the 2010 Haitian cholera outbreak. Twenty-four V. cholerae isolates from Nepal were found to belong to a single monophyletic group that also contained isolates from Bangladesh and Haiti, supporting the idea that cholera was spread to Haiti by Nepalese soldiers working as United Nations peacekeepers in the aftermath of the 2010 earthquake. Nature/mBio/BBC Microwaves and smelly socks Two very distinct approaches to tackle malaria have recently received funding for further development. The first aims to use microwaves to kill the parasites while they circulate in the host bloodstream. When the malaria parasite invades a red blood cell and digests haemoglobin, the iron released is stored in the parasite's feeding vacuole as an inert crystalline pigment called hemozoin. Jos Stoute from Pennsylvania State University, USA, and Carmenza Spadafora from the Institute for Advanced Scientific Studies, Panama, reasoned that microwave energy can be used to heat the hemozoin crystal until the food vacuole explodes, killing the parasite. Having shown that the approach can work in principle in a Petri dish, the project has been awarded US$1 million from the Bill & Melinda Gates Foundation to see whether the technique can be applied in mice. For the second approach, Fredros Okumu has received $775,000 from the Bill & Melinda Gates Foundation and Grand Challenges Canada to develop a toxic mosquito trap that attracts the insects using the scent of worn socks. Mosquitoes are most attracted to feet, but reproducing this scent chemically would be expensive. Instead, villagers wear cotton pads in their socks which will then be used to bait the traps. NY Times/LA Times Infectious trigger for narcolepsy The number of new cases of narcolepsy reported in China matches the seasonal patterns of infections such as influenza, according to a new study. Narcolepsy is an autoimmune disease that causes people to suddenly fall asleep and is thought to be caused by the death of brain cells that secrete the hormone hypocretin. Sufferers are thought to have a genetic predisposition to the condition, which may be triggered in these individuals by an environmental factor. Data collected from >900 patients with narcolepsy who were diagnosed in Beijing, China, between September 1988 and February 2011 revealed that an increase in the number of new cases occurred 5–7 months after a peak in cold and flu cases, suggesting that the response to such respiratory tract infections may trigger the onset of the condition. In 2010, an H1N1 influenza vaccine, Pandemrix, was found to be associated with a ninefold increase in the number of new narcolepsy cases in children in Finland. However, the authors! found that the rate of new narcolepsy cases in Beijing increased threefold following the 2009–2010 H1N1 influenza pandemic, despite fewer than 6% of patients having received a flu vaccination. Ann. Neurol./Telegraph/Independent Outbreak news Ehrlichiosis. New tests have confirmed that an outbreak of ehrlichiosis that affected 25 people in Minnesota and Wisconsin, USA, in 2009 was caused not by Ehrlichia chaffeensis or Ehrlichia ewingii, the two bacterial species known to cause the disease in the United States, but by a previously unreported species currently designated Ehrlichia Wisconsin HM543746. The new species is carried by the deer tick and is most closely related to Ehrlichia muris, which is commonly found in eastern Europe and parts of Asia. Wall Street Journal/N. Engl. J. Med. In the News was compiled with the assistance of David Ojcius, University of California, Merced, USA. David's links to infectious disease news stories can be accessed on his Twitter page (@Ojcius)..
  • Under the sea: microbial life in volcanic oceanic crust
    - Nat Rev Microbiol 9(10):703 (2011)
    Exploration of the microbiology in igneous, 'hard rock' oceanic crust represents a major scientific frontier. The igneous crust harbours the largest aquifer system on Earth, most of which is hydrologically active, resulting in a substantial exchange of fluids, chemicals and microorganisms between oceanic basins and crustal reservoirs. Study of the deep-subsurface biosphere in the igneous crust is technically challenging. However, technologies have improved over the past decade, providing exciting new opportunities for the study of deep-seated marine life, including in situ and cross-disciplinary experimentation in microbiology, geochemistry and hydrogeology. In this Progress article, we describe the recent advances, available technology and remaining challenges in the study of the marine intraterrestrial microbial life that is harboured in igneous oceanic crust.
  • Function, structure and mechanism of bacterial photosensory LOV proteins
    - Nat Rev Microbiol 9(10):713 (2011)
    LOV (light, oxygen or voltage) domains are protein photosensors that are conserved in bacteria, archaea, plants and fungi, and detect blue light via a flavin cofactor. LOV domains are present in both chemotrophic and phototrophic bacterial species, in which they are found amino-terminally of signalling and regulatory domains such as sensor histidine kinases, diguanylate cyclases–phosphodiesterases, DNA-binding domains and regulators of RNA polymerase σ-factors. In this Review, we describe the current state of knowledge about the function of bacterial LOV proteins, the structural basis of LOV domain-mediated signal transduction, and the use of LOV domains as genetically encoded photoswitches in synthetic biology.
  • Molecular insight into invasive group A streptococcal disease
    - Nat Rev Microbiol 9(10):724 (2011)
    Streptococcus pyogenes is also known as group A Streptococcus (GAS) and is an important human pathogen that causes considerable morbidity and mortality worldwide. The GAS serotype M1T1 clone is the most frequently isolated serotype from life-threatening invasive (at a sterile site) infections, such as streptococcal toxic shock-like syndrome and necrotizing fasciitis. Here, we describe the virulence factors and newly discovered molecular events that mediate the in vivo changes from non-invasive GAS serotype M1T1 to the invasive phenotype, and review the invasive-disease trigger for non-M1 GAS. Understanding the molecular basis and mechanism of initiation for streptococcal invasive disease may expedite the discovery of novel therapeutic targets for the treatment and control of severe invasive GAS diseases.
  • Growth of Candida albicans hyphae
    - Nat Rev Microbiol 9(10):737 (2011)
    The fungus Candida albicans is often a benign member of the mucosal flora; however, it commonly causes mucosal disease with substantial morbidity and in vulnerable patients it causes life-threatening bloodstream infections. A striking feature of its biology is its ability to grow in yeast, pseudohyphal and hyphal forms. The hyphal form has an important role in causing disease by invading epithelial cells and causing tissue damage. This Review describes our current understanding of the network of signal transduction pathways that monitors environmental cues to activate a programme of hypha-specific gene transcription, and the molecular processes that drive the highly polarized growth of hyphae.
  • Trichoderma: the genomics of opportunistic success
    - Nat Rev Microbiol 9(10):749 (2011)
    Trichoderma is a genus of common filamentous fungi that display a remarkable range of lifestyles and interactions with other fungi, animals and plants. Because of their ability to antagonize plant-pathogenic fungi and to stimulate plant growth and defence responses, some Trichoderma strains are used for biological control of plant diseases. In this Review, we discuss recent advances in molecular ecology and genomics which indicate that the interactions of Trichoderma spp. with animals and plants may have evolved as a result of saprotrophy on fungal biomass (mycotrophy) and various forms of parasitism on other fungi (mycoparasitism), combined with broad environmental opportunism.

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