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campylobacter : microbiology   19

When Gut Bacteria Change Brain Function
Some of the most intriguing work has been done on autism. For decades, doctors, parents, and researchers have noted that about three-quarters of people with autism also have some gastrointestinal abnormality, like digestive issues, food allergies, or gluten sensitivity. This recognition led scientists to examine potential connections between gut microbes and autism; several recent studies have found that autistic people’s microbiome differs significantly from control groups. The California Institute of Technology microbiologist Sarkis Mazmanian has focused on a common species called Bacteroides fragilis, which is seen in smaller quantities in some children with autism. In a paper published two years ago in the journal Cell, Mazmanian and several colleagues fed B. fragilis from humans to mice with symptoms similar to autism. The treatment altered the makeup of the animals’ microbiome, and more importantly, improved their behavior: They became less anxious, communicated more with other mice, and showed less repetitive behavior.

Exactly how the microbes interact with the illness—whether as a trigger or as a shield—remains mostly a mystery. But Mazmanian and his colleagues have identified one possible link: a chemical called 4-ethylphenylsulphate, or 4EPS, which seems to be produced by gut bacteria. They’ve found that mice with symptoms of autism have blood levels of 4EPS more than 40 times higher than other mice. The link between 4EPS levels and the brain isn’t clear, but when the animals were injected with the compound, they developed autism-like symptoms.

Some subjects were fed 5.5 grams of a powdered carbohydrate known as galactooligosaccharide, or GOS, while others were given a placebo. Previous studies in mice by the same scientists had shown that this carb fostered growth of Lactobacillus and Bifidobacteria; the mice with more of these microbes also had increased levels of several neurotransmitters that affect anxiety, including one called brain-derived neurotrophic factor.

In this experiment, subjects who ingested GOS showed lower levels of a key stress hormone, cortisol, and in a test involving a series of words flashed quickly on a screen, the GOS group also focused more on positive information and less on negative.

Scientists have found that gut bacteria produce neurotransmitters such as serotonin, dopamine and GABA, all of which play a key role in mood (many antidepressants increase levels of these same compounds). Certain organisms also affect how people metabolize these compounds, effectively regulating the amount that circulates in the blood and brain. Gut bacteria may also generate other neuroactive chemicals, including one called butyrate, that have been linked to reduced anxiety and depression. Cryan and others have also shown that some microbes can activate the vagus nerve, the main line of communication between the gut and the brain. In addition, the microbiome is intertwined with the immune system, which itself influences mood and behavior.
microbiology  nutrition  mentalHealth  autism  health 
march 2019 by campylobacter
A Single Cell Hints at a Solution to the Biggest Problem in Computer Science
Keio University's solution is different from the typical algorithmic solutions produced by other researchers, because the scientists used an amoeba. Specifically, the Physarum polycephalum slime mold. Physarum polycephalum is a very simple organism that does two things: it moves toward food and it moves away from light. Millions of years of evolution has made Physarum abnormally efficient at both of these things.

The Keio University researchers used this efficiency to build a device to solve the traveling salesman problem. They set the amoeba in a special chamber filled with channels, and at the end of each channel the researchers placed some food. Instinctively, the amoeba would extend tendrils into the channels to try and get the food. When it does that, however, it triggers lights to go off in other channels.
microbiology  mathematics 
december 2018 by campylobacter
Deep beneath the Earth’s surface life is weird and wonderful
Gaetan Borgonie & Maggie Lau
19-24 minutes

The amount of water in the subsurface is considerable. Globally, the freshwater reservoir in the subsurface is estimated to be up to 100 times as great as all the available fresh water in the rivers, lakes and swamps combined. This water, ranging in ages from seven years to 2 billion years, is being intensely studied by researchers because it defines the location and scope of deep life. We know now that the deep terrestrial subsurface is home to one quintillion simple (prokaryotic) cells. That is two to 20 times as many cells as live in all the open ocean. By some estimates, the deep biosphere could contain up to one third of Earth’s entire biomass.
microbiology  waterSupply  biology 
december 2017 by campylobacter
Scientists Discover Some of the Oldest Signs of Life on Earth
In a rock formation called the Saglek Block, Yuji Sano and Tsuyoshi Komiya from the University of Tokyo found crystals of the mineral graphite that contain a distinctive blend of carbon isotopes. That blend suggests that microbes were already around, living, surviving, and using carbon dioxide from the air to build their cells. If the two researchers are right—and claims about such ancient events are always controversial—then this Canadian graphite represents one of the earliest traces of life on Earth.

The Earth was formed around 4.54 billion years ago. If you condense that huge swath of prehistory into a single calendar year, then the 3.95-billion-year-old graphite that the Tokyo team analyzed was created in the third week of February. By contrast, the earliest fossils ever found are 3.7 billion years old; they were created in the second week of March.
microbiology  evolution 
september 2017 by campylobacter
Weird Life Found Trapped in Giant Underground Crystals
Boston took samples from pockets of fluid trapped inside the crystals in 2008 and 2009, under the auspices of New Mexico Tech. Her team was able to "wake up" dormant microbes in that fluid and grow cultures, she revealed today at the meeting. The organisms are genetically distinct from anything known on Earth, according to her team’s analysis, although they are most similar to other microbes found in caves and volcanic terrain.

Previous work dated the oldest crystals in the cave at half a million years. Based on those calculations for the crystal growth rate, her team thinks the organisms they have growing in the lab had been inside their glittering cocoons for somewhere between 10,000 and 50,000 years.
biology  microbiology  geology  genetics 
february 2017 by campylobacter
Meet Luca, the Ancestor of All Living Things
A surprisingly specific genetic portrait of the ancestor of all living things has been generated by scientists who say that the likeness sheds considerable light on the mystery of how life first emerged on Earth.

This venerable ancestor was a single-cell, bacterium-like organism. But it has a grand name, or at least an acronym. It is known as Luca, the Last Universal Common Ancestor, and is estimated to have lived some four billion years ago, when Earth was a mere 560 million years old.

The 355 genes pointed quite precisely to an organism that lived in the conditions found in deep sea vents, the gassy, metal-laden, intensely hot plumes caused by seawater interacting with magma erupting through the ocean floor.
microbiology  evolution 
july 2016 by campylobacter
Was Tuberculosis Born Out of Fire?
To test this idea, Chisholm and Tanaka simulated the evolution of an ancient mycobacterium. They showed that even if that microbe needs just two mutations to become mildly transmissible between people, it’s very unlikely to accrue those under normal circumstances. But add fire to the mix—or more precisely, the increased social contact and damaged lungs that fire would cause—and the odds shoot up. It certainly wouldn’t be the first time that we wielded a new technology with unintended consequences.

For now, this is just a hypothesis. But it’s “really interesting and thought-provoking”, says Caitlin Pepperell, from the University of Wisconsin, Madison, who studies the evolution of human disease. “It’s plausible because smoke inhalation is so damaging to the lung’s innate immune system—our first line of defense against tuberculosis. Perhaps the bacteria that breached this defense had an easier time of it from that point on. Smoke inhalation also increases coughing and could enhance TB transmission.”
microbiology  evolution  anthropology 
july 2016 by campylobacter
1 Child Dies Every 21 Seconds From A Water-Related Disease. Here’s What You Can Do
Working in Ethiopia, Nepal, Thailand, Cambodia, Vietnam and China, Splash has set the ambitious goal of providing potable drinking water to at least 1 million children by 2020. But Splash’s ultimate goal is to enable these countries to independently develop their own clean water systems and hopes to be able to leave these countries behind by 2030 in self-sustaining situations.
The Water Project provides clean water to communities in need in the sub-Saharan Africa by providing training and financial support to construct water projects.
The only nonprofit of its kind, A Spring of Hope focuses on partnering with rural schools in Africa to bring kids fresh and clean water to school children and to promote social and economic development.
waterQuality  waterSupply  microbiology  parasitology  sustainability  bacteriology  virulogy  nonprofit 
april 2016 by campylobacter
Role of Campylobacter jejuni Infection in the Pathogenesis of Guillain-Barré Syndrome: An Update
C. jejuni infection is the predominant antecedent infection in GBS. It has been identified in 30%–50% of GBS patients and supposed as a potential predictor of poor outcome. Also about 20% of GBS patients are left with a functional disability and 60% report severe fatigue at 12 months. A more severe autoimmune response and greater axonal damage are mostly observed in C. jejuni-associated GBS. This is problematic in poorer countries where patients may have limited access to healthcare and treatment required for GBS. Therefore, the appropriate procedures must be developed to reduce the incidence of C. jejuni-associated GBS. The transmission of C. jejuni may be prevented by improving sanitation, well-cooked poultry products, disinfection of water, and public health warnings about hazards of raw milk consumption. The pathogenesis of the disease is believed to involve molecular mimicry between epitopes on C. jejuni LPS and neural gangliosides, resulting in immunologic damage to the peripheral nerve. Antibody- and cell-mediated immune responses are believed to produce degeneration of the nerve and interruption of neurotransmission. Studies should be made to investigate the emerging role of Th17 cells in reference to axonal and demyelinating subtypes, as well as infections particularly with C. jejuni. The infection is often associated with the presence of antibodies against GM1, which may target and injure the peripheral nerves resulting in the severity of the disease. Possibly to prevent C. jejuni-induced GBS, efforts should be directed towards markedly reducing the numbers of severely disabled survivors of GBS. Analysis of the expression of C. jejuni genes involved in LOS biosynthesis should be helpful in designing drugs useful in treating these conditions. For continued advancement in this field, researchers will need to work in a collaborative effort to dissect the mechanisms of molecular mimicry and immune-mediated nerve damage.
campylobacter  microbiology  disability 
march 2016 by campylobacter
Scientists film death of white blood cell for first time and discover alert system
Cell biologist Georgia Atkin-Smith was co-leader of the team to capture the process, which she said shows cell death comprised three stages; bulging, exploding and breaking apart.

“So when the cell starts to die it forms these lumps which push outwards and when the cell then explodes, it shoots out long ‘beaded’ protrusions which look like a necklace, which then breaks apart into individual ‘beads’,” she said.

“The cells around them can easily engulf these smaller pieces. But we also think there are certain molecules in the beads that, when eaten by a live cell, can signal back a warning to other white blood cells cells to say ‘Look out, there may be a pathogen coming to get you’.”
microbiology  immunology 
june 2015 by campylobacter
Scientists Capture a White Blood Cell’s Death For the First Time
...These protrusions have been deemed “beaded apoptopodia.” The team believes that some molecules in the beads may contain a chemical warning that, when eaten by a live cell, can tip off other white blood cells around that a pathogen—a virus or infection—is looming close by.
microbiology  immunology 
june 2015 by campylobacter
Children’s cells live on in mothers
Cells from my daughters are knitted into my body and bones and brain. I also carry cells from my mom, and quite possibly from my grandma. I may even harbor cells from my older brother, who may have given some cells to my mom, who then gave them to me. It means my younger brother just might have cells from all of us, poor guy. This boundary blurring invites some serious existential wonder, not least of which might involve you wondering if this means your family members really are in your head.

Microchimerism also has implications here for women who have lost pregnancies, an extremely common situation hidden by the taboo of talking about miscarriages. Fetal cells seem to migrate early in pregnancy, meaning that even brief pregnancies may leave a cellular mark on a woman.
biology  stemcells  microbiology  pregnancy 
may 2015 by campylobacter
Medieval potion kills antibiotic-resistant MRSA superbugs
- garlic
- onion or leek
- wine
- oxgall (bile from a cow's stomach)
...must be brewed in a brass vessel, strained and then left to sit for 9 days before use

The remedy proved effective at killing bacteria in a test tube, so the researchers decided to try it on MRSA biofilms – tightly packed, sticky coatings of bacteria found all over surfaces in places like hospitals.
microbiology  medicine  bacteriology 
april 2015 by campylobacter
Microbes on keyboards can be used to identify typists
A paper in Proceedings of the NAS showed that scientists were able to successfully predict who owned which keyboard and mouse based on the bacteria left behind on the keys. Each of us carries a wealth of micro-organisms (you've got 100 times more non-human cells in your body than human cells!) and that microbial nation is distinctive -- maybe as distinctive as a fingerprint. Wired talked to a microbiologist who wasn't impressed with the technique for criminal forensics (we don't know yet if microbial nations are static or if they change over time, nor how unique each one truly is), but they do note that microbes are useful in forensically distinguishing between identical twins.
biology  microbiology  forensics  science 
march 2015 by campylobacter
Woman's stool transplant leads to 'tremendous weight gain'
A woman has dramatically gained weight after a stool transplant from her daughter, doctors report.

It is a genuine medical procedure to transplant healthy bacteria into a diseased gut, but US doctors think it may have affected her waistline.

She quickly gained 36lb (16kg) and is now classed as obese, the case report in Open Forum Infectious Diseases says.

A UK expert said the link between gut bugs and obesity was still unclear.

A faecal microbiota transplant - also referred to by some as a "transpoosion" - is like an extreme version of a probiotic yogurt.

The aim is to introduce good bacteria into the gut and it was officially backed by the UK health service last year.
food  microbiology 
february 2015 by campylobacter
MEASLES: A Dangerous Illness
Measles encephalitis caused the death of Roald Dahl's daughter Olivia in 1962. He became an ardent supporter of measles vaccination as a result of the tragic loss of his daughter. He wrote a letter to parents encouraging them to get their children vaccinated [which is reproduced here].
microbiology  biology  vaccine 
february 2015 by campylobacter
Biologists discover electric bacteria that eat pure electrons rather than sugar, redefining the tenacity of life
Some intrepid biologists at the University of Southern California (USC) have discovered bacteria that survives on nothing but electricity — rather than food, they eat and excrete pure electrons.
bacteriology  microbiology 
january 2015 by campylobacter
Campylobacter Infection: The Danger Lurking in Factory Farmed Chickens - Homesteading and Livestock - MOTHER EARTH NEWS
British researchers have established that chickens raised in a stressful environment are more likely to transmit campylobacter infections to human consumers.
campylobacter  microbiology  foodsafety  factoryfarming 
november 2014 by campylobacter

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