Monday 21 October 2019

Lifestyle is a threat to gut bacteria: Ötzi proves it, study shows

The intestinal microbiome is a delicate ecosystem made up of billions and billions of microorganisms, bacteria in particular, that support our immune system, protect us from viruses and pathogens, and help us absorb nutrients and produce energy.

The industrialization process in Western countries had a huge impact on its content. This was confirmed by a study on the bacteria found in the intestine of Ötzi, the Iceman who, in 1991, emerged from the ice of the Ötztal Alps, where Italy borders with Austria. Scientists of Eurac Research examined samples of the mummy's bacteria, confirming the findings of the researchers of the University of Trento who had analyzed the genome of intestinal microorganisms of over 6500 individuals from all continents.
Previous studies by the University of Trento had demonstrated that there is a connection between the microbiome's bacterial content and the increase, in Western countries, of obesity, autoimmune and gastrointestinal diseases, allergies and other complex conditions. In the study that appeared today in Cell Host & Microbe, researchers from Cibio of the University of Trento and Eurac in Bolzano/Bozen demonstrated that the differences between Western and non-Western or prehistoric microbiome lie in the decrease of some types of bacteria that process complex and vegetal fibers in the intestine.
That may have been caused by the Westernization process. Changes in diet, which is now higher in fat and low in fibers, a sedentary lifestyle in an urban setting, the development of new hygiene habits and the widespread use of antibiotics and other medical products have, with no doubt, made our life safer, but impacted the delicate balance of our microbiome.
About the study
The scientists of Eurac Research in Bolzano/Bozen sequenced the Iceman's DNA and were able to identify his set of bacteria, while the researchers of the University of Trento compared it with the microbiome of contemporary non-Westernized populations (from Tanzania and Ghana in particular), which are not used to processed food and have non-Westernized hygiene practices and lifestyle. Their findings were surprising.
The study focused, in particular, on Prevotella copri, a microbe that, when is found in our intestine, is usually the most represented. P. copri is present in 30% of Western individuals.

"First of all, we found out that P. copri it is not a monotypic species but is composed of four distinct but similar clades," explained Nicola Segata, coordinator of the study with Adrian Tett of Cibio of the University of Trento. "We then noticed that at least three of these four clades are almost always present in non-Westernized populations, but are much less prevalent in Westernized individuals. And when it is so, there usually is only one of the four clades. We postulated that the complex process of Westernization had a considerable impact on the gradual disappearance of this bacterium. Our hypothesis was confirmed by the analysis of ancient samples of DNA that were made available by Frank Maixner of the Institute for Mummy Studies at Eurac Research. The Iceman's guts contained three of the four clades of P. copri. And the four clades were also co-present in fossilized stool samples from Mexico that are more than one thousand years old. We still do not know what are the biomedical consequences of these changes of the microbiome which has evolved considerably in recent decades while the human body it colonizes has remained genetically practically unchanged for centuries,"

"Through these 'ancient' samples," continued Tett, "we were able to study the evolution of these clades and now we know that they genetically delineated with the human species and before the initial human migrations out of the African continent."

The study is the result of close collaboration with the research group of Albert Zink and Frank Maixner at Eurac Research in Bolzano/Bozen. Their team was responsible for the collection and pre-analysis of the Iceman's DNA samples. "The relation between the evolution of the human species and the diversity of intestinal microorganisms, as a field of research, is still rather unexplored, but can yield important results in the future through the analysis of ancient DNA. For this reason, finding more advanced and less invasive techniques to obtain and analyze DNA from human remains is one of the major areas of research at Eurac" concluded the microbiologist of Eurac Research Frank Maixner.

Monday 14 October 2019

What do you need to know about Toxic Shock Syndrome?

What do you need to know about Toxic Shock Syndrome?

Toxic shock syndrome is a rare multisystem disease with many widespread symptoms. It is caused by a toxin that is produced and secreted by the bacterium Staphylococcus Aureus. Often staphylococcus aureus is blamed for toxic shock syndrome but it also can happen due to group A streptococcus (strep) bacteria. These bacteria are commonly found in some areas on our bodies such as nose, armpit, skin, groin, or vagina of every one in three people and they usually don’t cause any problems, but they make toxins that in rare cases can enter in our blood stream which leads to Toxic shock syndrome. The underlying mechanisms involves the production of super antigens during invasive streptococcus infection or a localized staphylococcus infection. In both TSS and TSLS, disease progression stems from a super antigen Toxin 1 from staphylococcus aureus or TSST-1 secreted as single polypeptide chain. The gene encoding toxic shock syndrome toxin is carried by a mobile genetic element of S. aureus and the SAPi family of pathogenicity islands. The toxin causes the non-specific binding of MHC II, on professional antigen presenting cell, with T-cell receptors, on T cells. In typical T-cell recognition, an antigen is taken up by an antigen-presenting cell, processed, expressed on the cell surface in complex with class II major histocompatibility complex in a groove formed by the alpha and beta chains of class II MHC, and recognized by an antigen-specific T-cell receptor. This results in polyclonal T-cell activation. Super antigens do not require processing by antigen-presenting cells but instead interact directly with invariant region of the class II MHC molecule. In patients with TSS, up to 20% of the body’s T-cells can be activated at one time. This polyclonal T-cell population causes a cytokine strom, followed by multisystem disease. Most cases of toxic shock syndrome occur in menstruating females in association with the use of tampons. It has been associated with the superabsorbent tampons. Toxic shock syndrome can effect anyone child, male and female possible cause can include, high fever, accompanied by low blood pressure. Malaise and confusion, which can rapidly progress to stupor, coma, and multiple organ failure. The severity if the disease often needs hospitalization. Admission to the intensive care unit is often necessary for supportive care (for aggressive fluid management, ventilation, renal replacement therapy and inotropic support), particularly in the case of multiple organ failure.Treatment includes removal or draining of the source of infection often tampon and draining of abscesses. Outcomes are poorer in patients who do not have the source of infection removed. 

Antibiotic treatment should cover both S pyogenes and S aureus. This may include a combination of cephalosporin’s, penicillin’s or vancomycin. The addition of clindamycin or gentamycin reduces oxin production and mortality. 

A significant number of cases of TSS involve tampon use and especially super absorbent tampons. Soft tissues injuries that can also lead to TSS include the complications of childbirth, an injury or burn, a localized infection, such as a boil, or the use of a contraceptive sponge. Tampon use is implicated in 55 percent of cases, but another 15 percent are linked to childbirth and infected wounds. From December 2015 to March 2016, five cases of menstrual-related TSS were reported in Michigan State. Four of the women were using super absorbency tampons. The bacteria that cause TSS are not uncommon. Between 20 percent and 30 percent of all humans carry S. aureus on their skin and nose usually without complications. Most people have antibodies to protect them. It may be that some people do not develop the necessary antibodies. One possibilities are that super absorbent tampons, the ones that stay inside the body for the longest time become breeding grounds for bacteria. Another is that tampon fibers scratch the vagina, making it possible for bacteria to get through and into the bloodstream. Either the action or the composition of the tampons combined with preexisting staphylococcal bacteria in the vagina, probably triggering the disease. 

Preventing toxic shock syndrome
The following things can reduce your risk to toxic shock syndrome 
Treat wounds and burns quickly and get medical advice if your notice signs of an infection, such as swelling, redness and increasing pain
Always use a tampon with the lowest absorbency suitable for your period
Alternate between tampons and a sanitary towel or panty liner during your period 
Wash your hand before and after inserting tampon 
Change tampons regularly- as often as directed on the pack (usually at least every 4 to 8 hours) 
Never have more than one tampon in your vagina at a time 
When using a tampon at night, insert a fresh tampon before going to bed and remove it when you wake up.
Remove a tampon at the end of your period 
When using female barrier contraception, follow the manufacturers instruction about how long you can leave it in 
It’s a good idea to avoid using tampons or female barrier contraception of you has TSS before.
Precaution is always better than a cure.

Friday 11 October 2019

Prehistoric humans ate bone marrow like canned soup 400,000 years ago

Tel Aviv University researchers, in collaboration with scholars from Spain, have uncovered evidence of the storage and delayed consumption of animal bone marrow at Qesem Cave near Tel Aviv, the site of many major discoveries from the late Lower Paleolithic period some 400,000 years ago.

The research provides direct evidence that early Paleolithic people saved animal bones for up to nine weeks before feasting on them inside Qesem Cave.
The study, which was published in the October 9 issue of Science Advances, was led by Dr. Ruth Blasco of TAU's Department of Archaeology and Ancient Near Eastern Civilizations and Centro Nacional de Investigación Sobre la Evolución Humana (CENIEH) and her TAU colleagues Prof. Ran Barkai and Prof. Avi Gopher. It was conducted in collaboration with Profs. Jordi Rosell and Maite Arilla of Universitat Rovira i Virgili (URV) and Institut Català de Paleoecologia Humana i Evolució Social (IPHES); Prof. Antoni Margalida of University of Lleida, University of Bern, and the Institute for Game and Wildlife Research (IREC); and Prof. Daniel Villalba of University of Lleida.

"Bone marrow constitutes a significant source of nutrition and as such was long featured in the prehistoric diet," explains Prof. Barkai. "Until now, evidence has pointed to immediate consumption of marrow following the procurement and removal of soft tissues. In our paper, we present evidence of storage and delayed consumption of bone marrow at Qesem Cave."

"This is the earliest evidence of such behavior and offers insight into the socioeconomics of the humans who lived at Qesem," adds Dr. Blasco. "It also marks a threshold for new modes of Paleolithic human adaptation."
"Prehistoric humans brought to the cave selected body parts of the hunted animal carcasses," explains Prof. Rosell. "The most common prey was fallow deer, and limbs and skulls were brought to the cave while the rest of the carcass was stripped of meat and fat at the hunting scene and left there. We found that the deer leg bones, specifically the metapodials, exhibited unique chopping marks on the shafts, which are not characteristic of the marks left from stripping fresh skin to fracture the bone and extract the marrow."

The researchers contend that the deer metapodials were kept at the cave covered in skin to facilitate the preservation of marrow for consumption in time of need.

The researchers evaluated the preservation of bone marrow using an experimental series on deer, controlling exposure time and environmental parameters, combined with chemical analyses. The combination of archaeological and experimental results allowed them to isolate the specific marks linked to dry skin removal and determine a low rate of marrow fat degradation of up to nine weeks of exposure.

"We discovered that preserving the bone along with the skin, for a period that could last for many weeks, enabled early humans to break the bone when necessary and eat the still nutritious bone marrow," adds Dr. Blasco.
"The bones were used as 'cans' that preserved the bone marrow for a long period until it was time to take off the dry skin, shatter the bone and eat the marrow," Prof. Barkai emphasizes.
Until recently, it was believed that the Paleolithic people were hunter gatherers who lived hand-to-mouth (the Stone Age version of farm-to-table), consuming whatever they caught that day and enduring long periods of hunger when food sources were scarce.

"We show for the first time in our study that 420,000 to 200,000 years ago, prehistoric humans at Qesem Cave were sophisticated enough, intelligent enough and talented enough to know that it was possible to preserve particular bones of animals under specific conditions, and, when necessary, remove the skin, crack the bone and eat the bone marrow," Prof. Gopher explains.

According to the research, this is the earliest evidence in the world of food preservation and delayed consumption of food. This discovery joins other evidence of innovative behaviors found in Qesem Cave including recycling, the regular use of fire, and cooking and roasting meat.
"We assume that all this was because elephants, previously a major source of food for humans, were no longer available, so the prehistoric humans in our region had to develop and invent new ways of living," concludes Prof. Barkai. "This kind of behavior allowed humans to evolve and enter into a far more sophisticated kind of socioeconomic existence."

Lifestyle is a threat to gut bacteria: Ötzi proves it, study shows

The intestinal microbiome is a delicate ecosystem made up of billions and billions of microorganisms, bacteria in particular, that support ...