Monday, 27 June 2016 09:39

Small RNAs regulate Bacteroides nutrient use

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Just like you and me, bacteria have ‘favorite’ foods – though in the case of bacteria, 'favorite' translates to those which are energetically favorable or most accessible. Different bacteria have different preferences, based on their environments and the neighboring microbes that compete for or complement energy sources. Given a niche where many different carbohydrate resources are available, how do bacteria regulate their preferential food source? New research published in the Journal of Bacteriology shows a system of small RNAs help regulate polysaccharide usage in the human gut-residing Bacteroides genus.
Friday, 24 June 2016 09:34

Dispatches from ASM Microbe

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Things have been quiet on mBiosphere lately. We've been busy updating from ASM Microbe, covering some of the fascinating research presented there. The first Microbe meeting, which combines the former general meeting and ICAAC, was a whirlwind of poster presentations, lectures, seminars, book signings, career-building and networking events, Wikipedia editing, microbial sing-a-longs, and, of course, research talks. Many of these events were cataloged on our Facebook page, but these posts don't encapsulate the depth and richness of scientific endeavors discussed over the course of five days.
Last month’s announcement of an mcr1-bearing plasmid in a U.S. patient isolate caused quite a stir, and for good reason. This gene confers resistance to colistin, an antibiotic of last resistance, and its existence on a plasmid means relatively easy transfer between bacterial types. The possibility (or probability, given drug-resistant infection history) of colistin resistance spreading among other bacteria is one of the reasons this story received so much attention.
How do chronic infections change over time? This is the broad question addressed in recent research published in the Journal of Virology. In their study, a team of scientists headed by Fabio Luciani investigated a hepatitis B virus infection over a course of 15 years.
Thursday, 02 June 2016 16:43

New tools to detect new virus

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In fall 2015, a new human hepegivirus (HHpgV-1) was identified by using a novel, high throughput sequencing technique. Concerns were raised that this virus was found in blood to be used for transfusions, potentially passing on the infection. But without tools to test for its presence, there was no way to know how widespread HHpgV-1 infection is, or whether it is associated with human disease.
Tuesday, 31 May 2016 16:35

ASM holds Zika press conference

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Tomorrow begins a Special President’s Edition ASM Conference, hosted by the American Society for Microbiology in collaboration with the American Society for Virology. The conference, “What Does the Biology of Flaviviruses Tell Us About Zika: The Importance of Fundamental Virus Biology” highlights the value of fundamental virology. In this evening prior to the one-day conference, a panel of flavivirus experts convened before members of the press to briefly outline their research, its application to Zika virus and disease, and then opened the floor to questions related to recent research developments.
Friday, 27 May 2016 16:30

Predicting UTI antibiotic resistance

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By now, the news of a colistin-resistant E. coli isolate from a patient in the United States is widespread, with many major news sources covering the story. Most outlets highlighted the ease of future transfer of the plamid-borne mcr-1 gene between bacteria, the role of agricultural antibiotic use in generating resistant strains, and the looming antibiotic crisis once this gene spreads to carbapenem-resistant Enterobacteriaceae. This particular strain was identified as part of a routine screen for all extended-spectrum beta-lactamase (ESBL)-producing clinical isolates, and was found to harbor fifteen different resistance genes – but fortunately remained susceptible to carbapenem-class antibiotics, and…
Thursday, 26 May 2016 16:26

A microbial mystery in the Namib desert

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The Namib Desert is different than other deserts: it has an unusual geographic feature that differentiates it from most others. This desert (map, right) is where you can find ‘fairy circles,’ or circular areas absent of growth in an already plant-scarce environment. These deadened circles are surrounded by tall grass rings, a surprising sight in the arid land. This unexplained phenomenon has captured people’s imaginations, leading to mythological explanations for their origins. Scientists are also captivated by this geographic feature, and are working to discover what causes these unusual formations. A new study on the fairy circle microbial makeup, published…
Leonilde M. Moreira, PhD, has been studying the Burkholderia complex for 15 years. The bacteria, known for causing pneumonia or septicemia in some individuals, can survive for prolonged periods in moist environments. During the last 10 years, it has become one of the more predominant bacteria seen in cystic fibrosis patients.
Some of the most popular segments at conferences, such as Microbe 2016 coming up in in Jun, are those that give continuing medical education (CME) credit to participants. These CME credits are an important part of being an active medical professional: they keep participants current on best practices and inform practitioners about developing technologies.
In the 1960’s, the microbicide triclosan, was introduced in the United States, and soon after, human weight started to increase dramatically. For some time, researchers have wondered whether triclosan could have played a role in disrupting endocrine dysfunction and contributing to the obesity epidemic today.
Communication of experimental results via publishing is one of the most important steps of the scientific method; if you don’t share your results, how will knowledge within a field grow? A well-written article contextualizes the author’s data into a broader scientific landscape, which allows readers to develop questions based on the new data. Published articles are also a measure of a scientist’s contribution to their field, often used by search committees and in annual job reviews. As such, some authors suffer the temptation to cheat, as recently highlighted in a study of image duplication in biomedical research reports. Deliberately distorting…
This past fall, experts gathered at an American Academy of Microbiology Colloquium in Washington, D.C. to discuss an important topic relevant to many parts of society: the microbiology of built environments. A summary of the experts’ answers to important questions surrounding this topic is now available as an FAQ report.
Many components of our oral hygiene regimens are meant to keep cariogenic bacteria at bay: sodium fluoride in ACT interferes with electron transport and ATP synthesis, the essential oils in Listerine have antiseptic effects, and abrasives – small, insoluble particles in toothpaste – help remove plaque and calculus when you brush your teeth. Eliminating oral bacteria helps fight cavities, gingivitis, and periodontitis, but cavities (also called dental caries) aren’t caused by all oral microbes. The main culprit, Streptococcus mutans, causes caries by acidifying its environment, which demineralizes the enamel protecting our teeth.
In the year 2000, Kathleen Alexander, DVM, PhD, now a professor, at the Department of Fish and Wildlife Conservation, Virginia Tech, Blacksburg, Virginia, was working as a government veterinarian in Botswana, when a sickly banded mongoose wandered onto the grounds where she worked. When the mammal died, she determined the animal was infected with a novel tuberculosis (TB) pathogen, Mycobacterium mungi.
This past weekend, I went to visit a friend and meet his twin toddler boys for the first time. Though both boys eagerly ran around the playground we visited, one was just slightly less active. “He has asthma,” his dad explained to me, “but his brother doesn’t.” Why would two boys with the same environment and genetics have different disease manifestations?
The microbial world (much larger than even originally imagined, as demonstrated in the new Tree of Life) contains an extremely wide array of biochemical reactions that various organisms use to acquire energy, release waste products, and detoxify the surrounding environment. These broad abilities allow microbes to grow in some of the harshest conditions known on Earth – from sulphuric springs to frozen tundra, there are few places that are truly sterile in this world.
Thursday, 28 April 2016 15:47

Assessing gram stain error rates

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The gram stain, also known as the Gram stain for Hans Christian Gram, is one of the first techniques budding microbiology students learn in their introductory lab courses. It’s even a good exercise for younger students (with proper supervision, of course), due to its simplicity and the colorful, beautifully stained cells that result from the procedure. The protocol is often taught in tandem with lessons on bacterial structure, since the differential staining helps determine whether an isolate is a gram-positive or gram-negative bacterium.
Tuesday, 26 April 2016 15:44

A Microbial Ocean Feast: Who Ate What?

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Single-celled organisms called bacterioplankton spend their lives drifting in open ocean, visible to the naked eye only en masse. But don't be fooled by their slight size: These minuscule critters play a hefty role in the carbon cycle. Heterotrophic microbes, by some estimates, process half of the organic carbon in the ocean fixed by phytoplankton and other autotrophs through photosynthesis.
One of the most dangerous places for an infection to occur is in the bloodstream. Septicemia, when microbes are present in the blood, not only allows bacteria access to other internal organs through the highway of our circulatory system, but also can cause a massive inflammatory response, leading to septic shock. Conditions that increase risk of bloodstream infections, such as invasive surgery or implantation of an indwelling device, are carefully monitored and are sometimes accompanied by prophylactic antimicrobial drugs to prevent this very serious condition.