Microbes That Cause UTIs Use Hooks to Hold On While We Pee

Microbes

Urinary tract infections are typically caused by a bacterium that somehow manages to creep its way into the bladder, despite the intense pressures exerted by urination. It turns out these microbes use hooks to cling on in desperation while we pee.

As anyone who has ever had a UTI knows, such infections are supremely uncomfortable. They are caused by the intestinal bacterium Escherichia coli,which makes its way from from the urethra to the bladder. Nearly one in every two women will experience a UTI at some point during her life, but men can get them too (though less frequently).

Scientists have wondered how these microbes are capable of withstanding urinary flow, but new research from the University of Babel and ETH Zurich shows these tiny critters have evolved a rather clever trick in the form of built-in grappling hooks.

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Source: Knorre/Shutterstock

Gut Bacteria And The Brain: Are We Controlled By Microbes?

Although the interaction between our brain and gut has been studied for years, its complexities run deeper than initially thought. It seems that our minds are, in some part, controlled by the bacteria in our bowels.

The gut has defenses against pathogens, but, at the same time, it encourages the survival and growth of "healthy" gut bacteria.

The vast majority of these single-celled visitors are based in the colon, where no less than 1 trillion reside in each gram of intestinal content.

Estimating the number of bacterial guests in our gut is challenging; to date, the best guess is that 40 trillion bacteria call our intestines home - partially dependent on the size of your last bowel movement (poop's major ingredient is bacteria).

Read more: Gut Bacteria And The Brain: Are We Controlled By Microbes?

How much sway can a microbe hold? Bacterial influence over human psychology is slowly coming
into focus.

Source: medicalnewstoday

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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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

Food Pathogen Detection via Handheld 'Nanoflower' Biosensor

At present, harmful pathogens in food are mostly only discovered when people get sick. Earlier detection - preferably before food reaches consumers - could prevent many cases of foodborne illness and save the cost and effort involved in food recalls. Now, a team working toward solving this problem has developed a portable biosensor based on "nanoflowers" that detects harmful bacteria.

The new technology is the work of researchers at Washington State University (WSU) in Pullman, who describe how they developed and tested it in a paper published in the journal Small.

Even tiny amounts of harmful bacteria and other microbes can give rise to serious health risks, but the available sensor technology is unable to detect them easily and quickly in small quantities.

The key challenge in solving this problem is finding a way to detect the faint chemical signals that the harmful microbes emit at the molecular level.

Read more:  Food Pathogen Detection via Handheld 'Nanoflower' Biosensor

The nanoflower biosensor detects tiny chemical signals emitted by bacteria and amplifies them so they
can be picked up easily with a simple handheld pH meter.

Source: medicalnewstoday

'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

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