[Press release] Among gut microbes, strains, not just species, matter

From the 29 January 2015 University of Washington press release

First large-scale analysis completed of intra-species genetic variation in gut’s resident organisms

By Leila Gray  |  HSNewsBeat  |  Updated 9:00 AM, 01.29.2015

Posted in: Research

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  Gut microbiomes from different people can contain similar microbial species, but different strains, as this cartoon illustrates.Dana C, Thomas

A large community of microorganisms calls the human digestive tract home.  This dynamic conglomerate of microscopic life forms – the gut microbiome – is vital to how people metabolize various nutrients in their food, how their immune systems react to infection, and how they respond to various medications.  Moreover, imbalances in the microbiome are thought to play a significant role in many human diseases.

The collection of species occupying the gut is known to be quite personalized, and people may differ considerably in the set of species they harbor. Now new research suggests that the differences between people may go even deeper. In a paper published Jan. 29 in Cell, researchers at the University of Washington show that even when people share microbes in common, the exact strains each carries might be very different.

“Knowing more about these strain-level variations,” said Elhanan Borenstein, the senior author of this paper and an associate professor of genome sciences at the University of Washington, “is crucial for understanding the complex relationship between the composition of the community of microbes living in the human gut and its influence on health and disease.”

Read the entire article here–http://hsnewsbeat.uw.edu/story/among-gut-microbes-strains-not-just-species-matter

 

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[News article] Designer viruses could be the new antibiotics | Ars Technica

Designer viruses could be the new antibiotics | Ars Technica.by Luc Henry Oct 16 2014, 11:30am EDT

From the news article

https://www.flickr.com/photos/creative_stock/3473950631

Bacterial infections remain a major threat to human and animal health. Worse still, the catalog of useful antibiotics is shrinking as pathogens build up resistance to these drugs. There are few promising new drugs in the pipeline, but they may not prove to be enough. Multi-resistant organisms—also called “superbugs”—are on the rise, and many predict a gloomy future if nothing is done to fight back.

The answer, some believe, may lie in using engineered bacteriophages, a type of virus that infects bacteria. Two recent studies, both published in the journal Nature Biotechnology, show a promising alternative to small-molecule drugs that are the mainstay of antibacterial treatments today.

From basic to synthetic biology

Nearly every living organism seems to have evolved simple mechanisms to protect itself from harmful pathogens. These innate immune systems can be a passive barrier, blocking anything above a certain size, or an active response that recognizes and destroys foreign molecules such as proteins and DNA.

An important component of the bacterial immune system is composed of a family of proteins that are tasked specifically with breaking down foreign DNA. Each bug produces a set of these proteins that chew the genetic material of viruses and other micro-organism into pieces while leaving the bacterial genome intact.

In vertebrates, a more advanced system—called the adaptive immune system—creates a molecular memory of previous attacks and prepares the organism for the next wave of infection. This is the principle on which vaccines are built. Upon introduction of harmless pathogen fragments, the adaptive immunity will train specialist killer cells that later allow a faster and more specific response if the virulent agent is encountered again.

Crisp news

Until recently, people thought bacteria were too simple to possess any sort of adaptive immunity. But in 2007, a group of scientists from the dairy industry showed that bacteria commonly used for the production of cheese and yogurts could be “vaccinated” by exposure to a virus. Two years earlier, others noticed similarities between repetitive sections in bacterial genomes and the DNA of viruses. These repetitive sequences—called CRISPR for “clustered regularly interspaced short palindromic repeats”—had been known for 20 years, but no one could ever explain their function.

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Do our medicines boost pathogens?

Do our medicines boost pathogens?

From the 21 December 2011 Science News Today article

Scientists of the Institute of Tropical Medicine (ITG) discovered a parasite that not only had developed resistance against a common medicine, but at the same time had become better in withstanding the human immune system. With some exaggeration: medical practice helped in developing a superbug. For it appears the battle against the drug also armed the bug better against its host.

“To our knowledge it is the first time such a doubly armed organism appears in nature,” says researcher Manu Vanaerschot, who obtained a PhD for his detective work at ITG and Antwerp University. “It certainly makes you think.”…

 

Read the entire news article