Posts about National Geographic

Search for Antibiotic Solutions Continues: Killing Sleeper Bacteria Cells

Killing Sleeper Cells and Superbugs with Assassin Janitors

Discovered in 2005 by scientists from Bayer Healthcare in Germany, ADEP4 killed a variety of different bacteria and cured lethal infections in mice and rats.

Here’s how it works. Proteins need to fold into very precise shapes to do their jobs, and misfolded proteins are wastes of space. Bacteria dispose of these useless molecules with ClpP—a janitorial protein that digests other proteins. It works with a partner, which recognises misfolded proteins, unfolds them, and threads them through a hole in the middle of ClpP so they can be broken down. But ADEP4 opens ClpP up so it no longer needs its partner. The janitor now becomes an assassin, running amok and chopping up any protein it comes across, misfolded or not.

The Bayer scientists showed that ADEP4 can force fast-growing cells to self-destruct, but Lewis suspected that it would do the same to persisters. Afterall, ClpP’s partner requires energy to do its job, but ClpP itself doesn’t. Once ADEP4 opens it up, it should go about its fatal business even in a dormant cell.

Lewis’ team found that ADEP4 did effectively kills persister populations of Staphylococcus aureus, but the bacteria bounce back. ClpP isn’t essential, so the bacteria just inactivated it to evolve their way around ADEP4. This, says Lewis, is why Bayer stopped working on the drug.

His solution was to pair ADEP4 with another antibiotic called rifampycin. ADEP4 would kill off the majority of the persisters, and if any of the rest started growing again, rifampycin would finish them off. He predicted that the double-whammy would leave very few survivors, maybe just a thousand cells or so.

“That’s not what we saw,” he says. “What we saw was complete sterilisation.”

This is a very nice effort. As our efforts fail to find “magic bullet” antibiotics fail and antibiotic resistance increases combo drug solutions offer some hope. While this is good news, the overall state of our ability to treat bacterial infections continues to decline as our misuse of antibiotics has greatly increased the speed at which antibiotic resistance has developed in bacteria.

This solution only works on gram positive antibiotics. ADEP4 is too big to pass through the extra outer layers of the gram-negative bacteria like ecoli and salmonella.

Related: Entirely New Antibiotic Developed, Platensimycin (2006) (2013 update: Platensimycin is a very effective antibiotic in vivo when continuously administered to cells, however this efficacy is reduced when administered by more conventional means. Efforts continue to find a way to create delivery options that are successful in treating people.) – New Family of Antibacterial Agents Discovered (2009)Potential Antibiotic Alternative to Treat Infection (2012)

People are Superorganisms With Microbiomes of Thousands of Species

In a recent article in National Geographic Carl Zimmer has again done a good job of explaining the complex interaction between our bodies and the bacteria and microbes that make us sick, and keep us healthy.

The damage done by our indiscriminate use of antibiotics is not just the long term resistance that we create in bacteria (making the future more dangerous for people) that I have written about numerous times but it also endangers the person taking the anti-biotics in the short term. Sometimes the other damage is a tradeoff that should be accepted. But far too often we ignore the damage taking antibiotics too often does.

When You Swallow A Grenade

While antibiotics can discriminate between us and them, however, they can’t discriminate between them and them–between the bacteria that are making us sick and then ones we carry when we’re healthy. When we take a pill of vancomycin, it’s like swallowing a grenade. It may kill our enemy, but it kills a lot of bystanders, too.

If you think of the human genome as all the genes it takes to run a human body, the 20,000 protein-coding genes found in our own DNA are not enough. We are a superorganism that deploys as many as 20 million genes.

Before he started taking antibiotics, the scientists identified 41 species in a stool sample. By day 11, they only found 13. Six weeks after the antibiotics, the man was back up to 38 species. But the species he carried six weeks after the antibiotics did not represent that same kind of diversity he had before he took them. A number of major groups of bacteria were still missing.

They found that children who took antibiotics were at greater risk of developing inflammatory bowel disease later in life. The more antibiotics they took, the greater the risk. Similar studies have found a potential link to asthma as well.

The human body contains trillions of microorganisms — outnumbering human cells by 10 to 1. Because of their small size, however, microorganisms make up only about 1% to 3% of the body’s mass, but play a vital role in human health.

Where doctors had previously isolated only a few hundred bacterial species from the body, Human Microbiome Project (HMP) researchers now calculate that more than 10,000 microbial species occupy the human ecosystem. Moreover, researchers calculate that they have identified between 81% and 99% of all microorganismal genera in healthy adults.

“Humans don’t have all the enzymes we need to digest our own diet,” said Lita Proctor, Ph.D., NHGRI’s HMP program manager. “Microbes in the gut break down many of the proteins, lipids and carbohydrates in our diet into nutrients that we can then absorb. Moreover, the microbes produce beneficial compounds, like vitamins and anti-inflammatories that our genome cannot produce.” Anti-inflammatories are compounds that regulate some of the immune system’s response to disease, such as swelling.

“Enabling disease-specific studies is the whole point of the Human Microbiome Project,” said Barbara Methé, Ph.D., of the J. Craig Venter Institute, Rockville, MD, and lead co-author of the Nature paper on the framework for current and future human microbiome research. “Now that we understand what the normal human microbiome looks like, we should be able to understand how changes in the microbiome are associated with, or even cause, illnesses.”

Read the full NIH press release on the normal bacterial makeup of the body

Related: Tracking the Ecosystem Within UsWhat Happens If the Overuse of Antibiotics Leads to Them No Longer Working?Antibacterial Products May Do More Harm Than GoodAntibiotics Too Often Prescribed for Sinus Woes

Elephant Underpass in Kenya

photo of elephant preparing to walk under a highway

Elephant Underpass Reuniting Kenya Herds

The first of its kind for elephants, the underpass will ideally provide a safe corridor for the large mammals to move throughout the Mount Kenya region, where highways, fences, and farmlands have split elephant populations…

Without the underpass, animals that try to move between isolated areas often destroy fences and crops—leading to conflicts with people.

Since its completion in late 2010, the underpass has been a “tremendous success”—hundreds of elephants have been spotted walking through the corridor, according to the conservancy.

It is great to see such solutions put into place. Animals that come into conflict with people (whether it is farmers in Africa, ranchers in the USA or villagers in India) often lose. There is a reason humans dominate the globe. We might be easy to beat in a one on one battle when we can prepare. But when we get frustrated and decide it is time to take action, that is bad news for most mammals (bacteria are only in trouble with our scientists and manufacturers get together and even then the bacteria might not lose).

What we need to do is find ways for the animals to live without too severely impacting people. Because if we don’t eventually the people will take action.

I have been to the game parks in Kenya twice, it is amazing.

Related: Monkey Bridge in KenyaInsightful Problem Solving in an Asian Elephantunderwater highway bridgeA Group of Wild Mountain Gorillas Strolling Through Camp Observing Humans Observe the Gorillas

Critter Cam: Sea Lion versus Octopus

Octopus vs. Sea Lion – First Ever Video

Sea lions fitted with GPS trackers and a National Geographic Crittercam are taking scientists on amazing journeys to previously unknown marine ‘hot spots.’ These areas are important not only for providing the sea lions’ food, but also for maintaining fish populations.

The Crittercams were deployed at Dangerous Reef in Spencer Gulf, a rocky island the size of a football field, and home to the biggest Australian sea lion colony.

Dr. Page says, “One important discovery is that the sea lions always feed on the sea floor” and they don’t eat open ocean fish, known as pelagic. “This is critical information because the marine parks are being set up to protect sea floor habitats,” a move that the scientists can now confirm will protect critical sea lion resources.

In one of the more spectacular pieces of Crittercam video so far, we can see this female working hard to handle a challenging prey item – a large octopus. Too big to swallow in one gulp, she drags it to the surface where she can breathe while she works at breaking it down into bite-size pieces.

Related: Orcas Create Wave to Push Seal Off IceOctopus Juggling Fellow Aquarium OccupantsWater Buffaloes, Lions and Crocodiles Oh MyCat and Crow Friends

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