The Theory of Disappearing Microbiota and the Epidemics of Chronic Diseases.

In the present era, medical scientists have been confounded by the increasing incidence of multiple diseases across the world, beginning first in developed countries, and gradually spreading to other areas as they develop. These include the rises in cases of obesity, asthma, hay fever, food allergies, inflammatory bowel disease, juvenile (type 1) diabetes and autism, among many others. Are these diseases, which affect different body systems, unrelated or can a unified theory explain the increased incidence of all of these?

I believe that the latter possibility is true, and that the central theory to explain why these diseases have arisen and by what mechanism is based on modern changes in early life events that are related to the human microbiome. According to this theory, the microbiome of humans and of other animals is not accidental, but has been selected over long time periods to optimize host reproductive success through interactions between the microbiota and host physiology. Early life is the crucial period during which the adult microbiome becomes established, and development of the host and of the microbiota occur together in a conjoined manner through a dynamic equilibrium that follows a well-choreographed path. In early life, the context is set for the important developmental decisions that are required for the immune system to distinguish between what is self and what is not self, for metabolic organs to partition how much energy to expend or to save, and for the brain to determine how to respond socially to a person who might be either a friend or a foe.

Read more: The theory of disappearing microbiota and the epidemics of chronic diseases

Figure 1: A model for the interaction of the inherited microbiota with
early life immunological development in past and present children.

Source: NATURE REVIEWS IMMUNOLOGY

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Heterogeneity in Tuberculosis.

Infection with Mycobacterium tuberculosis, the causative agent of tuberculosis (TB), results in a range of clinical presentations in humans. Most infections manifest as a clinically asymptomatic, contained state that is termed latent TB infection (LTBI); a smaller subset of infected individuals present with symptomatic, active TB. Within these two seemingly binary states, there is a spectrum of host outcomes that have varying symptoms, microbiologies, immune responses and pathologies. Recently, it has become apparent that there is diversity of infection even within a single individual. A good understanding of the heterogeneity that is intrinsic to TB — at both the population level and the individual level — is crucial to inform the development of intervention strategies that account for and target the unique, complex and independent nature of the local host–pathogen interactions that occur in this infection. In this Review, we draw on model systems and human data to discuss multiple facets of TB biology and their relationship to the overall heterogeneity observed in the human disease.

Read more: Heterogeneity in Tuberculosis.

Figure 1: A classical tuberculosis granuloma. The hallmark tuberculosis
granuloma is a highly organized collection of immune cells that aggregate
around a central necrotic core.

Source: NATURE REVIEWS IMMUNOLOGY

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Why Is My Urine Bright Yellow? Colors Changes and Causes

Normal urine should be a pale yellow color. It should be clear, without cloudiness or particle deposits.

"Why is my urine bright yellow?" is a question that can be answered if the meaning of bright yellow is clear.

This page will explain the full range of possible colors of urine and why they change. If bright yellow means neon yellow, this has a specific cause.

Read more: Why Is My Urine Bright Yellow? Colors Changes and Causes

If anyone has concerns about urine, it is recommended that they visit a doctor. Some drugs may turn

the urine orange, brown, or green. Urine color may be used to work out hydration levels.

Source: MedicalNewsToday

Blood test for Tuberculosis

Together with AIDS, tuberculosis ranks among those infectious diseases with the highest global mortality rate, claiming the lives of between 1.5 and two million people every year. However, not everyone infected with the bacterium develops tuberculosis. In fact, fewer than ten percent of those infected go on to manifest the disease. An international team of scientists, including researchers from the Max Planck Institute for Infection Biology in Berlin, have now developed a tuberculosis test that can reliably predict whether an individual will develop active tuberculosis. Doctors may be able to use this test in future to predict the progression of the disease and initiate medical care early.

In future, molecules from blood samples can tell physicians if somebody will develop tuberculosis.

Read more: Blood test for Tuberculosis

Source: cli-online

How Hepatitis C Spreads

You may have heard of hepatitis C (HCV or hep C), the potentially deadly virus that causes liver inflammation. HCV often produces no symptoms until it reaches an advanced stage, which makes it hard to know you’ve been infected. However, if you understand the ways in which hep C spreads, you can take precautions to reduce your risk of contracting this virus.

What is hepatitis C?

Hepatitis, in general, refers to liver inflammation. Many things can cause liver inflammation, including toxic chemicals, medications and drug or alcohol abuse. These types of hepatitis sometimes clear up on their own and may not even require treatment.

Read more: How Hepatitis C Spreads

Source: healthguides.healthgrades

Video: What is hepatitis C?

Antimicrobial resistance: a collection of reviews and research papers from Nature journals

Resistance to antimicrobials is a global problem of increasing importance. Pathogens rapidly develop mutations that render current treatments ineffective. For example, resistance to carbapenems, one of the ‘last lines’ of antibiotics, is widespread and has been observed in numerous countries; resistance to artemisinin, the gold standard in malaria treatment, has also emerged. Our current arsenal of antimicrobial agents thus has a limited lifespan and new drugs are urgently needed. Tackling this resistance will require a deep understanding of microbial infections and the mechanisms through which resistance arises, as well as concerted efforts between academia and industry aimed at developing novel antimicrobial agents.

This collection consists of Reviews, Research articles, and News and Comment articles from several Nature journals, describing how antibiotic resistance emerges and detailing strategies through which new antimicrobial compounds are being discovered.

Read more: Antimicrobial resistance: a collection of reviews and research papers from Nature journals

Source: nature

Lab Automation: Renewed Vigor Under Pressure

Over the years, automation in clinical labs has made sizable gains toward improving efficiency and productivity, and delivering timely and accurate results to improve patient outcomes. But automating the many processes used in microbiology departments has been laboratories’ “last frontier,” according to Brad Banks, worldwide marketing manager for lab automation at BD Diagnostics–Diagnostic Systems, Sparks, Md.

Because of the nation’s aging population, the volume of assays performed by US labs is continuing to increase. Yet, at the same time, the number of available techs is decreasing, says Nilam Patel, senior product manager for automation solutions at Sysmex America Inc, Lincolnshire, Ill. Coupled with an increased emphasis on quality and patient outcome initiatives, these trends are leading clinical laboratories to seek automation that provides quality clinical information, maximizes operational efficiency, and minimizes “sample touch points.”

Read more: Lab Automation: Renewed Vigor Under Pressure

Automating the microbiology laboratory is the last frontier

Source: clpmag

The superbug that doctors have been dreading just reached the U.S.

For the first time, researchers have found a person in the United States carrying bacteria resistant to antibiotics of last resort, an alarming development that the top U.S. public health official says could mean “the end of the road” for antibiotics.

The antibiotic-resistant strain was found last month in the urine of a 49-year-old Pennsylvania woman. Defense Department researchers determined that she carried a strain of E. coli resistant to the antibiotic colistin, according to a study published Thursday in Antimicrobial Agents and Chemotherapy, a publication of the American Society for Microbiology. The authors wrote that the discovery “heralds the emergence of a truly pan-drug resistant bacteria.”

Read more: The PhD journey: A guide to applying, starting and succeeding

Source: washingtonpost

Not unexpectedly, a new drug-resistant ‘superbug’ pops up in the United States

For years, public health experts have warned us that deadly bacteria are developing resistance to all our available antibiotics. This week, researchers reported the first known U.S. case of an Escherichia coli infection resistant to colistin, a harsh drug seen as a last resort to knock out stubborn infections. The finding, described in the American Society for Microbiology journal Antimicrobial Agents and Chemotherapy, is no big surprise to researchers tracking the rise of resistant bacteria. The resistance gene, known as mcr-1, was discovered in E. coli in China last year, and has since cropped up in Europe.

As the United States crosses the same ominous milestone, research to understand resistance and develop new drugs is surging ahead. As Science reported earlier this month, evolutionary biologists have recently revisited old dogma about how best to prescribe antibiotics—revealing that trusted strategies such as using a high dose may not actually help prevent resistance.

Read more: Not unexpectedly, a new drug-resistant ‘superbug’ pops up in the United States

E. coli bacteria growing in a dish.

Source: sciencemag

'Millions will die' from antimicrobial resistance unless we act now

From helping humans live longer and hacking our performance, to repairing the body and understanding the brain, WIRED Health will hear from the innovators transforming this critical sector.

Ten million people around the world will die each year by 2050 if more is not done to tackle the growing threat of antimicrobial resistance, Jim O'Neill, commercial secretary to the treasury, has said.

Speaking at WIRED Health, O'Neill said the rise in resistance needs to be "embraced by policy makers around the world".

If it isn't then the number of people dying from antimicrobial resistance (AMR) will increase dramatically.

Read more: 'Millions will die' from antimicrobial resistance unless we act now

Staphylococcus Aureus

Source: Getty Images / BSIP

MacConkey Agar (MAC): Composition, preparation, application and colony characteristics

MacConkey agar was developed in 20th century by Alfred Theodore MacConkey. It was the first formulated solid differential media. MacConkey Agar is a selective and differential culture media commonly used for the isolation of enteric Gram-negative bacteria. It is based on the bile salt-neutral red-lactose agar of MacConkey. Crystal violet and bile salts in incorporated in MacConkey Agar to prevent the growth of gram-positive bacteria and fastidious gram-negative bacteria, such as Neisseria and Pasteurella. Gram-negative enteric bacteria can tolerate to bile salt because of their bile-resistant outer membrane.

MacConkey Agar is selective for Gram negative organisms, and helps to differentiate lactose fermenting gram negative rods from Non lactose fermenting gram negative rods. It is primarily used for detection and isolation of members of family enterobacteriaceae and Pseudomonas spp.

Composition of MacConeky Agar:

Enzymatic Digest of Gelatin, Casein and Animal tissue: provides nitrogen, vitamins, minerals and amino acids essential for growth.

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MacConkey Agar (MAC): Composition, preparation, application and colony characteristics

LF and NLF colonies in MacConkey Agar

Source: microbeonline

Emerging Blood-Borne Bacteria Detected in Blood Donors

Bartonella species cause chronic and intermittent intra-erythrocytic bacteremia and infect endothelial cells of both incidental and natural reservoir hosts. The establishment of chronic, stealth infection is achieved by evasion of innate immune responses.

In humans, Bartonella species have been detected from sick patients presented with diverse disease manifestations, including cat scratch disease, trench fever, bacillary angiomatosis, endocarditis, polyarthritis, or granulomatous inflammatory disease.

An international team of scientists, led by those at the Western University of Health Sciences, Pomona, CA, USA), collected blood from 500 apparently healthy Brazilian voluntary blood donors in a cross sectional study. Bartonella species infection from the bloodstream was detected based on enrichment blood culture in a liquid growth medium (Bartonella alpha-Proteobacteria growth medium-BAPGM), coupled with isolation in solid medium. Bartonella-specific DNA was amplified by polymerase chain reaction (PCR), followed by DNA sequencing to confirm species identification. Of the ten Bartonella species that are believed to produce infection in humans, the most commonly encountered are B. henselae, B. quintana, and B. bacilliformis. The latter causes Oroya fever and Verruga peruana.

Read more: Emerging Blood-Borne Bacteria Detected in Blood Donors

Electron micrograph of Bartonella henelae, Gram-negative bacteria that causes cat scratch fever

Source: Prokaryotes

Acid-Fast Stain Identifies Schistosoma Eggs

Schistosomiasis, also known as snail fever, is a disease caused by parasitic flatworms called schistosomes. The urinary tract or the intestines may be infected and signs and symptoms may include abdominal pain, diarrhea, bloody stool, or blood in the urine.

Microscopic identification of eggs in stool or urine is the most practical method for diagnosis. Stool examination is performed when infection with Schistosoma mansoni or S. japonicum is suspected, and urine examination should be performed if S. haematobium is suspected. Eggs can be present in the stool in infections with all Schistosoma species.

Scientists at the University of Lisbon examined whether the Ziehl–Neelsen (ZN) stain, also known as the acid- fast stain, would be helpful in detection and identification of Schistosoma eggs. In histological sections, S. mansoni eggshells appear as ZN positive and S. haematobium shells as ZN negative. The staining target of the responsible ZN component (carbolfuchsin) in the shell is unknown and because carbolfuchsin is supposed to stain mycolic acids in the mycobacterial cell wall, unidentified substances in the eggshell were proposed as target. Fuchsin is a known nucleic acid stain, and it was already shown that mycobacteria with insufficiently retained carbolfuchsin may be invisible in bright-field microscopy; yet, they can be easily detected because of a strong red fluorescence when excited with green light.

Read more: Acid-Fast Stain Identifies Schistosoma Eggs

Positive staining of Schistosoma mansoni eggs

Source: ganfyd

Microbes and Cancer.

Understanding cancer’s relationship with the human microbiome could transform immune-modulating therapies.

In 2013, two independent teams of scientists, one in Maryland and one in France, made a surprising observation: both germ-free mice and mice treated with a heavy dose of antibiotics responded poorly to a variety of cancer therapies typically effective in rodents. The Maryland team, led by Romina Goldszmid and Giorgio Trinchieri of the National Cancer Institute, showed that both an investigational immunotherapy and an approved platinum chemotherapy shrank a variety of implanted tumor types and improved survival to a far greater extent in mice with intact microbiomes. The French group, led by INSERM’s Laurence Zitvogel, got similar results when testing the long-standing chemotherapeutic agent cyclophosphamide in cancer-implanted mice, as well as in mice genetically engineered to develop tumors of the lung.

The findings incited a flurry of research and speculation about how gut microbes contribute to cancer cell death, even in tumors far from the gastrointestinal tract. The most logical link between the microbiome and cancer is the immune system. Resident microbes can either dial up inflammation or tamp it down, and can modulate immune cells’ vigilance for invaders. Not only does the immune system appear to be at the root of how the microbiome interacts with cancer therapies, it also appears to mediate how our bacteria, fungi, and viruses influence cancer development in the first place.

Read more: Microbes and Cancer.

Source: © Istock/Kateja_FN/Frank Ramspott

Gut microbes regulate nerve fibre insulation.

Far from being silent partners that merely help to digest food, the bacteria in your gut may also be exerting subtle influences on your thoughts, moods, and behaviour. And according to a new study from researchers at University College Cork, your gut microbes might affect the structure and function of the brain in a more direct way, by regulating myelination, the process by which nerve fibres are insulated so that they can conduct impulses properly.

The surprising new findings, published today in the journal Translational Psychiatry, provide what is perhaps the strongest evidence yet that gut bacteria can have a direct physical effect on the brain, and suggest that it may one day be possible to treat debilitating demyelinating diseases such as multiple sclerosis, and even psychiatric disorders, by altering the composition of the gut’s microbial menagerie in some way or another.

Gut microbe research has exploded in the past 10 years, and in that time, it has become increasingly clear that there is a two-way line of communication betweengut bacteria and the brain. The human gut microbiome seems to play important roles in health and disease, and alterations in its composition have been implicated in a wide range of neurological and psychiatric conditions, including autism, chronic pain, depression, and Parkinson’s Disease, although the links still remain somewhat tenuous.

Read more: Gut microbes regulate nerve fibre insulation.

Scanning electron micrograph showing E. coli bacteria.

Source: Wikimedia Commons

Metabolic Diseases Could be Promoted by 'Unhealthy' Microbiomes.

Trillions of bacteria surround us, permeate us, and bind our bodies together. They affect our immune systems and our brains, they shift and change with our diet, and some researchers suspect that these microbial multitudes may be an important link between our modern lifestyle and ongoing epidemics of diseases such as asthma, obesity, and diabetes.

Leading microbiome researchers recently came to UC San Francisco to share the newest insights about how improving our relationship with our bodies’ microbial ecosystems could be the next big breakthrough in treating metabolic disease. One major theme of the symposium – hosted by theUniversity of California Sugar, Stress, Environment, and Weight (SSEW) Center – was the question of whether the troubling modern epidemic of metabolic disease may arise in part because our civilization has not been kind to our microbes.

“In Western industrialized nations, we have dramatically changed our interaction with microbes in last several decades,” said Susan Lynch, PhD, who studies links between the microbiome and chronic inflammatory diseases at UCSF. “Particularly in urbanized areas, we have less contact with the soil and with animals. We have changed our diets dramatically and waged war on our microbes with antibiotics.”

Read more: Metabolic Diseases Could be Promoted by 'Unhealthy' Microbiomes.

Source: ucsf.edu

Mother's microbiome influence her offspring's immune system during gestation.

During gestation, a mother's microbiome shapes the immune system of her offspring, a new study in mice suggests. While it's known that a newborn's gut microbiota can affect its own immune system, the impact of a mother's microbiota on her offspring has largely been unexplored.

Here, Mercedes Gomez de Agüero et al. infected the guts of pregnant mice with E.coli engineered to dwindle over time, allowing the mothers to become germ-free again around the time they gave birth.

This temporary colonization of E.coli in the mother affected the immune system of her offspring; after birth, the offspring harbored more innate lymphoid and mononuclear cells in their intestines compared to mice born to microbe-free pregnant mothers. Similar results were seen when pregnant mothers were temporarily colonized with a cocktail of eight other microbes.

An RNA analysis of offspring born to gestation-only colonized mothers compared with controls revealed greater expression of numerous genes, including those that influence cell division and differentiation, mucus and ion channels, and metabolism and immune function.

By transferring serum from bacteria-colonized pregnant mice to non-colonized pregnant mice, the researchers found that maternal antibodies likely facilitate the transmission and retention of microbial molecules from a mother to her offspring.

Read more: Mother's microbiome influence her offspring's immune system during gestation.

Shaping of the immune system starts with the maternal microbiota.

Source: sciencedaily

Tweaking Gut Bacteria Could help Prevent Brain Strokes

Recent research has shown how fundamentally important the bacteria in our gut are to the rest of our mental and physical health, affecting everything from our appetite to our state of mind.

Now a new study suggests that our gut bacteria could even play a role in protecting us from brain damage, with an experiment involving mice showing that certain types of stomach microbes can actually help reduce the severity of strokes.

"Our experiment shows a new relationship between the brain and the intestine,"said neuroscientist Josef Anrather from the Feil Family Brain and Mind Research Institute at Cornell University. "The intestinal microbiota shape stroke outcome, which will have an impact [on] how the medical community views stroke and defines stroke risk."

Anrather and his colleagues analyed two groups of mice – one received a combination of antibiotics that tweaked their gut microbiota, and the other acted as a control group, with no alterations made to their gut microbiota over the course of the experiment.

Read more:
Tweaking Gut Bacteria Could help Prevent Brain Strokes

Source: anufrench