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Tuesday, 23 May 2017

Ebola death risen to 4 at Republic of Congo

Medical workers treating a patient suspected of having Ebola in the Democratic Republic of Congo in 2007 (Image: Getty Images)

The overall cases of Ebola rise at Republic of Congo from 29 to 37.

World Health Organization has reported that a forth reported person has possibly died of Ebola in a remote place at northeastern of Republic of Congo.

Since early May 37 cases has been reported with hemorrhagic fever with 2 confirmed Ebola cases,  3 with probable case (including recent death) and 32 are suspected.

Mobile laboratories have been dispatched to monitor around 416 people who are known to be in contact with the sufferers.

Sunday, 21 May 2017

The slow moving Microbes in deep down under the sea

Sea bed (Image: Pixabay)

The seabed is constantly filling with dead plankton, biological life and also brining down the bio-remnants from the shore. This is ultimately packing up all the ingredients that microbes need to sustain happily. But overtime new sources accumulate layer by layer on the previous sediments. So going deep under will unveil the past sources like moving back in time.

Deep down under the compressed time provides the evolutionary biologists huge difficulty to track genetic turn with community shifts in such a stable environment. In such no change in fluid movement can allow microbes to move or give back clues for horizontal gene transfer. Thus only chance that can happen is with any possible evolutionary changes or death. It has opened consequences that microbes still thrive as we go much deep down under the seabeds.

In a recent study that published in Proceedings of the National Academy of Sciences determined how microbial communities in sea behave as they are suffocated with newer biological layers and being captivated without any movement. Dr. Piotr Starnawski from Center for Geomicrobiology, Aarhus University led the study of seven top meters of Aarhus bay sediment. He along with his team collected sediments from different points, counting cells and sequenced full genomes. Using several factors like carbon use, cell count and how much carbon turns into biomass (assumed 8%), team calculated the rate of reproduction. They found that on the surface microbes divide every few months but those which are deep down under much slower which takes decades to divide. The energy starved microbes deep inside needs enough time to accumulate the essential carbon and energy to replicate.
Such lower rates give rare possibility for mutation in their genome and to mark for evolution. 

Researchers on calculation found a  rate of 10-5 of mutation rate per genome per generation of a single bacterial species. This has a frequency of almost 100times slower than the surface microbes. So when this mutation does take place is mostly “synonymous”, i.e. the change in DNA does not change the protein structure and function.

Journal Source:
Starnawski P, Bataillon T, Ettema T, Jochum L, Schreiber L, Chen X et al. Microbial community assembly and evolution in subseafloor sediment. Proceedings of the National Academy of Sciences. 2017;114(11):2940-2945.


Thursday, 4 May 2017

How does the immune system know friend from foe in gut bacteria?

Our guts are home to a complex community of more than 100 trillion microbial cells that play an important role in health and disease. These gut-resident microbes, or gut microbiota - which with their genetic material are known as the gut microbiome - influence metabolism, nutrition, and immune function. Scientists are discovering that disruption in the gut microbiota is linked to obesity, inflammatory bowel disease, and other gastrointestinal disorders. It has also been suggested that obesity’s effect on the gut microbiome may explain its strong link with type 2 diabetes. Others have likened the uniqueness of a person's gut microbiota to that of a "DNA fingerprint," raising potential privacy concerns for participants of human microbiome research projects. The new study concerns of cell called dendritic cells (DCs) that have evolved two distinctive - and what may appear to be opposite - roles in the human body, in that they can both promote and inhibit immune response. DCs help to activate the immune system in response to infection, but they are also involved in actively suppressing it in certain situations. They suppress immunity by triggering induced regulatory T cells (iTregs), a type of cell that controls the development of immune tolerance. As immunity inhibitors in the gut, DCs help to train the immune system to treat gut microbiota as friend rather than foe. They do this by internalizing proteins from the microbiota and migrating to lymph nodes associated with the gut.

As they travel to the lymph nodes, the DCs break down the internalized friendly bacteria proteins into smaller pieces that become similar to "identity badges" that they wear on their cell surfaces. These identity badges are displayed with specific binding proteins that iTregs recognize, with the effect that the iTregs do not promote immune responses against proteins wearing the identity badges. Prof. Brocker says: "We believe that these iTregs are specific for the proteins produced by natural gut bacteria." The team explains that the migration to lymph cells by the DCs - particularly those whose cell surfaces display a protein called CD103+ - is an important part of keeping the immune system updated on the composition of the gut microbiota. However, what the researchers wanted to discover was how this tolerance mechanism might be switched off in an emergency. Their investigation led them to another molecule that DCs display on their cell surfaces - known as CD40 - that behaves in a similar way to an alarm button. When activated, CD40 binds to a partner molecule on the surface of another type of T cell called effector T cells, which turns DCs from inhibitors of immune response to promoters.

In tests on mice, the researchers showed that animals whose CD40 signaling was permanently switched on developed severe colitis, but no other symptoms. They found that the affected dendritic cells still migrate to the lymph nodes from the gut lining, but when they get there they commit cell suicide (apoptosis) and thus deny the regulatory T cells the opportunity to sense the identity badges of the microbiota proteins that would normally protect them from immune attack.
This results in a generalized immune response in which T lymphocytes travel to the gut lining and cause inflammation. The team found that giving the mice antibiotics that killed their gut microbiota also reduced the inflammation, and the animals survived. The researchers now want to find out whether particular regulatory T cells are programmed for specific gut bacteria, as this study might suggest.

Written by Catharine Paddock PhD (Used without permission)

Wednesday, 3 May 2017

Depression in Mice Shown to be Reversed by Probiotics

Is it true that you are what you eat? Well, have some bacteria then and get happy. Actually it’s much more complex than that. New research from the University Of Virginia School Of Medicine has shown that depressive symptoms and behaviours in mice were reversed when the mice were given food containing lactobacillus, which is a probiotic bacteria found in yogurt that is made with live cultures. The research was even able to uncover the specific process for how these probiotics impacted mood. Finding a link that makes such a close connection between the gut microbiome and mental health is a major step forward in learning more about depression and how it can be treated.

Depression isn’t just feeling sad for a while, it’s a very real neurobiological illness. Major depressive disorder affects approximately 14.8 million American adults, or about 6.7 percent of the U.S. population age 18 and older, in any given year. As many as one in 33 children and one in eight adolescents have clinical depression. Depression also puts those who suffer with it at a higher risk for heart attacks, even if they have no other cardiovascular risk factors. Since depression can seriously hinder things like a person’s ability to have a rewarding career and a stable family life, research into treatments and causes are crucial.

Lead researcher on the study at UVA, Alban Gaultier, stated, “The big hope for this kind of research is that we won’t need to bother with complex drugs and side-effects when we can just play with the microbiome. It would be magical just to change your diet, to change the bacteria you take, and fix your health – and your mood. It’s a huge problem and the treatments are not very good, because they come with huge side-effects.”

So what exactly is the “gut microbiome?” It’s the living bacteria inside the intestinal tract that is responsible for, among other things, keeping the body in balance. It’s a popular target of researchers looking into all kinds of illnesses. Connecting it to mental illness or other neurological conditions has been difficult however. Since the mouse model is used in research because of its similarity to humans, Galtier’s team looked at mice that were subjected to stress since stress can cause depression. Of course in mice, it was more about observing how they acted and looking for “depressive like behaviors” and “despair behavior” since there is obviously no other way to judge mood in animals.

When the gut microbiome composition was examined in the mice, both before and after a period of stress there was one major change that stood out. The bacteria lactobacillus was reduced in correlation to the onset of depressive behaviors in the mice. When the researchers added lactobacillus cultures back to the food of the depressed mice, the behaviors stopped and they began to behave as they had before the stress was induced.

The research at UVA took it a step further and also investigated how exactly this mechanism of lactobacillus fluctuation worked. Their study revealed that amounts of Lactobacillus in the gut will impact levels of a metabolite in the blood called kynurenine which is known to fuel depression. When lactobacillus went down, kynurenine went up and the despair behaviors of the mice began. The team hopes that they can translate these results in humans. Graduate student Ioana Marin, a researcher on the study said, “There has been some work in humans and quite a bit in animal models talking about how this metabolite, kynurenine, can influence behavior. It’s something produced with inflammation that we know is connected with depression. But the question still remains: How? How does this molecule affect the brain? What are the processes?

Published first in Medical News

Friday, 28 April 2017

Rare Microbes Make a Critical Contribution to the Environment

New work published in Applied and Environmental Microbiology suggests that bacteria present at very small levels in the environment actually make a vital contribution to the health and stability of that environment. This research concerns microbes that don’t usually account for more than a tenth of a percent of the bacteria in the whole population. "The work aims to provide a fundamental understanding of how biodiversity contributes to ecosystem functioning," said the corresponding author of the work, Kostas Konstantinidis, PhD.

In the environment at large, these are low levels, but in individual communities there may be hundreds of them, actually therefore, composing 20 to 30 percent of specific bacteria in an aquatic group. Termed the rare biosphere, these uncommon species were found to harbor large amounts of genes capable of allowing for organic pollutant degredation. The abilities conferred by those microbes may be helping the entire microbial population remain stable in the face of environmental pressures and alterations. The investigators, a team from Georgia Institute of Technology, Atlanta, wanted to test this idea, so they created mesocosms, or laboratory environments, made up of 20 liters of water. These reservoirs were then inoculated with water samples taken from a local freshwater source, Lake Lanier. 

                                                     (c) Google Image
Three common organic chemicals, not present in the samples they took from the lake, were then dribbled into the mesocosms. The scientists wanted ot ensure that the microbes had not be acclimated to the presence of those pollutants in order to reveal as much as possible about the microbes’ abilities. "Also, the important environmental pollutants are generally at low concentration in most natural environments, similar to the organic compounds used here--except during major events such as oil spills" said Konstantinidis, the Carlton S. Wilder Associate Professor in the School of Civil & Environmental Engineering at Georgia Tech.

The pollutants used included 2,4-dichlorophenoxyacetic acid (2,4-D), a common herbicide that is a known endocrine disrupter and may be a carcinogen, according to the International Agency for Research on Cancer. The other compounds were caffeine (1,3,7-trimethyluric acid) and 4-nitrophenol (4-NP), used in fungicide production and one byproduct of pesticide breakdown.
"We chose these compounds because their biodegradation pathways and the underlying genes are known, which facilitated tracking which microbial populations encoded the proteins for the biodegradation of these organic compounds," explained Konstantinidis.

The researchers repeatedly assayed the bacterial levels in the mseocosms to find which ones grew more or grew less. "The results allowed us to rigorously test the hypothesis that low abundance species, as opposed to common species, provided the metabolic diversity that enabled the community to respond to the added compounds and the changing conditions," said Konstantinidis. The goal of the work was to improve our predictions of how microbial communities might react to future disruptions from stuff like oil, pesticides, or climate change, said Konstantinidis. We may learn a lot more about how microbes contribute to the function and resilience of our ecosystem, and the possible consequences microbes face due to contaminant spills or climate change.

Sources: AAAS/Eurekalert! Via American Society for Microbiology, Applied and Environmental Microbiology 

WHO Alerts the Globe to the 12 Deadliest Microbes.

Alarm bells have been ringing all over the world about drug-resistant superbugs, which are expected to pose a huge threat to human health in the coming decades. Years of overuse, misuse, and poor prescribing and purchasing habits has created a serious problem whereby humanity can no longer rely on the old standards that have been used to effectively treat bacterial infections for decades. The United Nations has identified the threat, now the World Health |Organization has produced a list of twelve microbes that are seen as major priorities for antibiotic development.

The WHO aims to promote research and development by publishing this list, and they have categorized the bacteria by how urgent the threat has been perceived to be - critical, high, and medium priority. The biggest problem is seen as the one that affects people already dealing with health issues - those infections that are primarily found in hospital, clinic and nursing home settings. In this group are Acinetobacter, Pseudomonas and the family of Enterobacteriaceae which includes Klebsiella, Proteus and the commonly known E. coli. Those bacteria often cause pneumonia and infections of the blood. Bacteria that have become resistant to virtually all antibiotic treatments are in this group. Carbapenems are seen as a last-resort treatment for various bacterial infections that are impervious to typical treatments, and some bacterial strains have gained resistance to those drugs (usually by gaining a piece of genetic material). The next categories include bacteria that are still very dangerous, resulting in illnesses like gonorrhoea and food-borne illness.

"This list is a new tool to ensure R&D responds to urgent public health needs," explained Dr Marie-Paule Kieny, WHO's Assistant Director-General for Health Systems and Innovation. "Antibiotic resistance is growing, and we are fast running out of treatment options. If we leave it to market forces alone, the new antibiotics we most urgently need are not going to be developed in time." There is global attention on this problem, which is planned to be discussed at a meeting of health experts in Berlin. "We need effective antibiotics for our health systems. We have to take joint action today for a healthier tomorrow. Therefore, we will discuss and bring the attention of the G20 to the fight against antimicrobial resistance. WHO’s first global priority pathogen list is an important new tool to secure and guide research and development related to new antibiotics," commented Mr Hermann Gröhe, the Federal Minister of Health.

The list was created by scientists at the Division of Infectious Diseases at the University of Tubingen, Germany, considering characteristics like how deadly resulting infections are, how treatable they are, how easily they spread, how preventable they are, etc. The list was then reviewed by international experts.
"New antibiotics targeting this priority list of pathogens will help to reduce deaths due to resistant infections around the world," said one researchers that helped to curate the list, Professor Evelina Tacconelli, who is Head of the Division of Infectious Diseases at the University of Tübingen. "Waiting any longer will cause further public health problems and dramatically impact on patient care."

Source WHO

Fight against Killer Superbugs

Last September, the United Nations gathered to recognize the serious threat that antibiotic resistance poses to the public. It is estimated that antibiotic resistance is responsible for the deaths of over 700,000 people worldwide annually. Only a few days ago, the World Health Organization released a list of the microbial pathogens that pose the biggest threat to human health. Needless to say, any progress in this fight is a benefit to people. Researchers have some good news in the face of all the warnings; it appears that a drug combination is effective against two of the three pathogenic bacteria identified by WHO as well as another dangerous pathogen, all of which are gram negative bacteria. These findings have been reported in Nature Microbiology.

Gram-negative bacteria have a impervious outer shell that serves as a shield against many commonly used, and usually effective bacteria. That makes for an especially tough bug, causing many deaths, especially in hospital settings.
"These pathogens are really hard nuts to crack, but we found a molecule that shreds that shell and allows antibiotics to enter and be effective," explained the senior author of the report, Eric Brown, a Professor of Biochemistry and Biomedical Science at McMaster's Michael G. DeGroote School of Medicine and a scientist of the Michael G: deGroote Institute for Infectious Disease Research.

                                               (c) Google Image
The researchers determined that an antiprotozoal drug called pentamidine breaks into the surface of even the most resistant Gram-negative bacteria. When this antifungal drug was used in combination with antibiotics, it was effective against multi drug resistant antibiotics. "These pathogens are really hard nuts to crack, but we found a molecule that shreds that shell and allows antibiotics to enter and be effective," said Brown.

When pentamidine was used with antibiotics it could combat enterobacteriaceae and Acinetobacter baumannii, two drugs on the list released by WHO. This combination of drugs was also effective against another dangerous pathogen, Pseudomonas aeruginosa. These results were modeled in rodents and in the lab, and now testing will have to investigate the side effects and safety for use in humans. Brown's lab continues to search for more therapies. "One of the things we want to pursue further is why this is working so well," he concluded.

Culled from LabRoots Inc. 

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