Microbiology

Category: Microbiology

The oceans and other water bodies contain billions of tons of dissolved uranium. Over the planet's history, some of this uranium was transformed into an insoluble form, causing it to precipitate and accumulate in sediments. There are two ways that uranium can go from a soluble to an insoluble form: either through the action of live organisms - bacteria - or by interacting chemically with certain minerals. Knowing which pathway was taken can provide valuable insight into the evolution and activity of microbial biology over Earth's history. Publishing in the journal PNAS, an international team of researchers led by the Ecole Polytechnique Fédérale de Lausanne in Switzerland describes a new method that uses the isotopic composition of uranium to distinguish between these alternative pathways.

A University of Colorado Boulder and North Carolina State University-led team has produced the first atlas of airborne microbes across the continental U.S., a feat that has implications for better understanding health and disease in humans, animals and crops.

April 17, 2015 - A multicenter team of U.S. and Venezuelan scientists, led by researchers from NYU Langone Medical Center, have discovered the most diverse collection of bodily bacteria yet in humans among an isolated tribe of Yanomami Indians in the remote Amazonian jungles of southern Venezuela.

One of the immune system's most critical challenges is to differentiate between itself and foreign invaders -- and the number of recognized autoimmune diseases, in which the body attacks itself, is on the rise. But humans are not the only organisms contending with "friendly fire."


This image depicts the shape-shifting capabilities of the anti-HIV drug KP1212.
A newly developed spectroscopy method is helping to clarify the poorly understood molecular process by which an anti-HIV drug induces lethal mutations in the virus's genetic material. The findings from the University of Chicago and the Massachusetts Institute of Technology could bolster efforts to develop the next generation of anti-viral treatments.

It may come as a bit of a surprise to learn that bacteria have an immune system - in their case to fight off invasive viruses called phages. And like any immune system - from single-celled to human - the first challenge of the bacterial immune system is to detect the difference between "foreign" and "self." This is far from simple, as viruses, bacteria and all other living things are made of DNA and proteins. A group of researchers at the Weizmann Institute of Science and Tel Aviv University has now revealed exactly how bacteria do this. Their results were published online today in Nature.

Bacteria have traditionally been viewed as solitary organisms that "hang out on their own," says molecular biologist Kevin Griffith of the University of Massachusetts Amherst. However, scientists now realize that in fact, bacteria exhibit social behavior within groups.

Human cytomegalovirus (HCMV) is an extremely common virus, which as other members of the herpes virus family causes life-long infections in humans. Most individuals are exposed to HCMV during childhood, yet symptoms can be easily fought off by a healthy immune system. However, infections can be life-threatening for individuals with defective immunity, for instance newborn babies, people with AIDS, or those taking immunosuppressive drugs following organ transplantation. Scientists at École Polytechnique Fe?de?rale de Lausanne (EPFL) have discovered the molecular switch that allows HCMV to either lie dormant or reactivate its infection. The switch can be manipulated with simple drugs to force the virus out of dormancy, making it easy to target with antivirals. Published in eLife, the study shows how HCMV could be fought in high-risk patients and purged from organs before transplantation.


Pictured is Rachel Whitaker, Associate Professor of Microbiology, at the Carl R. Woese Institute for Genomic Biology at the University of Illinois at Urbana-Champaign.
The microbes could surrender to the harmless virus, but instead freeze in place, dormant, waiting for their potential predator to go away, according to a recent study in mBio.

New research from the University of Toronto has scientists re-thinking how a lethal fungus grows and kills immune cells. The study hints at a new approach to therapy for Candida albicans, one of the most common causes of bloodstream infections.


The scientists used the deep submergence vehicle Alvin to retrieve sea-floor samples.
The intraterrestrials, they might be called. Strange creatures live in the deep sea, but few are odder than the viruses that inhabit deep ocean methane seeps and prey on single-celled microorganisms called archaea.


Bacteria that cause many hospital-associated infections are ready to quickly share genes that allow them to resist powerful antibiotics. The illustration, based on electron micrographs and created by the Centers...
Antibiotic resistance is poised to spread globally among bacteria frequently implicated in respiratory and urinary infections in hospital settings, according to new research at Washington University School of Medicine in St. Louis.


This is an abstract representation of virus inducing enzyme to produce lipid envelope.
More than 60 percent of the world's population is infected with a type of herpes virus called human cytomegalovirus. The virus replicates by commandeering the host cell's metabolism but the details of this maneuver are unclear.

Proteins from salt-loving, halophilic, microbes could be the key to cleaning up leaked radioactive strontium and caesium ions from the Fukushima Dai-ichi Nuclear Power Plant incident in Japan. The publication of the X-ray structure of a beta-lactamase enzyme from one such microbe, the halophile Chromohalobacter sp. 560, reveals it to have highly selective cesium binding sites.

The composition of intestinal bacteria and other micro-organisms--called the gut microbiota--changes over time in unhealthy ways in black men who are prediabetic, a new study finds. The results will be presented Friday at the Endocrine Society's 97th annual meeting in San Diego.


Bacteria and archaea "remember " viral infections by inserting short spacer sequences (toe-tagged) of genetic information stolen from the invader between repeat elements (gray) of the host's genomic CRISPR loci.
A powerful genome editing tool may soon become even more powerful. Researchers with the Lawrence Berkeley National Laboratory (Berkeley Lab) have unlocked the key to how bacteria are able to "steal" genetic information from viruses and other foreign invaders for use in their own immunological memory system.

A new study demonstrates that sewage is an effective means to sample the fecal bacteria from millions of people. Researchers say the information gleaned from the work provides a unique opportunity to monitor, through gut microbes, the public health of a large population without compromising the privacy of individuals.


This image shows small yellow dots surrounding bright yellow cell nuclei in each cell are Wolbachia. The cytoskeleton (in red) allows seeing the shape of the cells.
We, as most animals, host many different beneficial bacteria. Being beneficial to the host often pays off for the bacteria, as success of the host determines the survival and spread of the microbe. But if bacteria grow too much they may become deadly. In a new study published in the latest edition of the scientific journal PLOS Biology*, a research team from Instituto Gulbenkian de Ciencia (IGC; Portugal) found that a single genomic change can turn beneficial bacteria into pathogenic bacteria, by boosting bacterial density inside the host.


Insect muscle cells are marked in red, cell nuclei (DNA) in blue and virus in green.
Insects can transmit viral diseases to humans. Therefore, understanding how insects cope with viral infection, and what immune mechanisms are triggered, can be important to stop diseases transmission. In a study published in this week's issue of the scientific journal PLOS Pathogens*, researchers from the Instituto Gulbenkian de Ciencia (IGC; Portugal) now show that the entry route of the virus changes how the insect host responds to it. Using the fruit flies as a model of study, they discovered an immune mechanism that is specifically effective when flies are infected through feeding.

A team of scientists has revealed how certain harmful bacteria drill into our cells to kill them. Their study shows how bacterial 'nanodrills' assemble themselves on the outer surfaces of our cells, and includes the first movie of how they then punch holes in the cells' outer membranes. The research, published today in the journal eLife, supports the development of new drugs that target this mechanism, which is implicated in serious diseases. The team brings together researchers from UCL, Birkbeck, University of London, the University of Leicester, and Monash University (Melbourne).

Microbiologists at NYU Langone Medical Center say they have what may be the first strong evidence that the natural presence of viruses in the gut -- or what they call the 'virome' -- plays a health-maintenance and infection-fighting role similar to that of the intestinal bacteria that dwell there and make up the "microbiome."

Filoviruses like Ebola "edit" genetic material as they invade their hosts, according to a study published this week in mBio®, the online open-access journal of the American Society for Microbiology. The work, by researchers at the Icahn School of Medicine at Mount Sinai, the Galveston National Laboratory, and the J. Craig Venter Institute, could lead to a better understanding of these viruses, paving the way for new treatments down the road.


Chimpanzees are shown in Gombe Stream National Park.
The microbes living in people's guts are much less diverse than those in humans' closest relatives, the African apes, an apparently long evolutionary trend that appears to be speeding up in more modern societies, with possible implications for human health, according to a new study.

A robust, broad spectrum antibiotic, and a gene that confers immunity to that antibiotic are both found in the bacterium Staphylococcus epidermidis Strain 115. The antibiotic, a member of the thiopeptide family of antibiotics, is not in widespread use, partly due to its complex structure, but the investigators, from Brigham Young University, Provo, Utah, now report that the mechanism of synthesis is surprisingly simple. "We hope to come up with innovative processes for large-scale production and derivitization so that new, and possibly more potent versions of the antibiotic can become available, says co-corresponding author Joel S. Griffitts. The research is published ahead of print in Journal of Bacteriology.

As the threat of antibiotic resistance grows, scientists are turning to the human body and the trillion or so bacteria that have colonized us — collectively called our microbiota — for new clues to fighting microbial infections. They've logged an early success with the discovery of a new antibiotic candidate from vaginal bacteria, reports Chemical & Engineering News (C&EN), the weekly newsmagazine of the American Chemical Society.

MicrobiologySeptember 15, 2014 05:20 PM


This is a ribbon diagram showing the tertiary structure with secondary-structure elements identified and labeled.
The current Ebola virus outbreak in West Africa, which has claimed more than 2000 lives, has highlighted the need for a deeper understanding of the molecular biology of the virus that could be critical in the development of vaccines or antiviral drugs to treat or prevent Ebola hemorrhagic fever. Now, a team at the University of Virginia (UVA), USA – under the leadership of Dr Dan Engel, a virologist, and Dr Zygmunt Derewenda, a structural biologist – has obtained the crystal structure of a key protein involved in Ebola virus replication, the C-terminal domain of the Zaire Ebola virus nucleoprotein (NP) [Dziubanska et al. (2014). Acta Cryst. D70, 2420-2429; doi:10.1107/S1399004714014710].

For multicellular life—plants and animals—to thrive in the oceans, there must be enough dissolved oxygen in the water. In certain coastal areas, extreme oxygen-starvation produces "dead zones" that decimate marine fisheries and destroy food web structure. As dissolved oxygen levels decline, energy is increasingly diverted away from multicellular life into microbial community metabolism resulting in impacts on the ecology and biogeochemistry of the ocean.

In contrast to their negative reputation as disease causing agents, some viruses can perform crucial biological and evolutionary functions that help to shape the world we live in today, according to a new report by the American Academy of Microbiology.

MicrobiologyJuly 16, 2014 06:37 PM

Scientists have discovered a new pathway the dengue virus takes to suppress the human immune system. This new knowledge deepens our understanding of the virus and could contribute to the development of more effective therapeutics.

Like human societies--think New York City--bacterial colonies have immense diversity among their inhabitants, often generated in the absence of specific selection pressures, according to a paper published ahead of print in the Journal of Bacteriology.

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