The Catastrophe of Antibiotic Resistance

March 17, 2015 by

March 6, 2015

By Medical Discovery News

The Catastrophe of Antibiotic Resistance

The World Health Organization has categorized antibiotic resistance as “a major global threat” and multidisciplinary research teams estimate it could lead to 10 million deaths each year by 2050. Bacteria that cause disease in humans can become resistant to the drugs used to treat them, and this poses a growing problem to public health.

Antibiotics were first introduced in the 1940s with the discovery and development of penicillin and saved many people from otherwise life-threatening infections. This one class of drugs has had an incredible impact on decreasing the severity of infections and saving lives.

Lately antibiotics have become overused and misused, which has allowed bacteria to mutate in ways that render antibiotics relatively powerless. Bacteria were one of the earliest life forms on Earth and remain one of the most successful, present everywhere from Arctic glaciers to geothermal springs. Because they are masters of adaptation, exposure to antibiotics causes the bacteria to accumulate mutations that will allow them to ignore the action of the antibiotics. That’s why doctors should only prescribe an antibiotic in the likelihood of a bacterial infection, and why it’s important to take all of the prescribed doses of an antibiotic. Otherwise, you can give the bacteria enough contact with the antibiotic to mutate but not enough to kill them, and they can come back stronger.

Half the use of antibiotics does not come from a doctor’s office or hospital, but a farm. Chickens, pigs, cows, and other livestock raised for food production are fed antibiotics to prevent infections and for faster weight gain. Many countries now ban this practice, and in 2013 the U.S. Food and Drug Administration (FDA) asked pharmaceutical companies to voluntarily curtail the sale of antibiotics directly to famers. Today, 26 pharmaceutical companies will only issue antibiotics for animals with a veterinarian’s prescription.

Infections by drug-resistant bacteria can be twice as likely to result in hospitalization and death. And while some bacteria are resistant to a single antibiotic, others are resistant to many. Methicillin-resistant Staphylococcus aureus (MRSA), multi-drug-resistant Neisseria gonorrhea, and multi-drug-resistant Clostridium difficile are superbugs taking a devastating toll worldwide. Some bacteria have mutated against all forms of antibiotics normally used to treat them, leaving no effective treatment options. Such infections are occurring around the globe in both rich and developing countries.

Legislation in the U.S. Congress proposes to permanently ban antibiotics that are used in humans from being used in livestock as well.  However, some argue that there is not a clear link between the antibiotic-resistant bacterial strains generated in livestock practices and those seen in human disease, which requires more intense research to answer. Whatever the outcome, the emergence and spread of antibiotic-resistant bacteria must be stopped. We also desperately need to develop new antimicrobials human use.

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Sponges for Toxins

September 6, 2013 by

Sept. 6, 2013

By Medical Discovery News

People reach to sponges for soaking up messes, washing the dishes, and cleaning appliances. But sponges can also clean up toxins – inside the body, no less.

For years, scientists have worked to develop methods to remove toxins that destroy cells and tissues. This has been a challenge due the variety of infectious agents and poisons that produce toxins. Recently, a significant advance using nanosponges could lead to the removal of many life-threatening toxins from the bloodstream. 

Nanosponges, developed by bioengineers at the University of California-San Diego, work much like their name implies – they are designed to absorb specific substances. These nanoparticles can remove toxins produced by bacteria such as the common skin infection Staphylococcus aureus, even the antibiotic-resistant MRSA strain. These bacteria produce something called pore-forming toxins. These toxins attack cells by inserting themselves in the cell membranes, creating holes in the surface of the cell, and allowing cell contents to leak out or large amounts of external water to rush in.

In either case, this causes the cell to die. Significant or rapid loss of cells results in the damage seen during disease processes. Nanosponges work by absorbing dangerous toxins, thereby preventing them from destroying cells. To work at this level, nanosponges must be super small – 85 nanometers in diameter, about 90 times smaller than a red blood cell.  

A major issue with all drugs delivered by the bloodstream is how to prevent the immune system from removing them. Since the immune system’s job is to remove foreign agents, it is a challenge to thwart its attacks long enough for a drug to do its job. Nanosponges can overcome this with a clever technique called cloaking. Just like the enchanted invisibility cloak Harry Potter uses, nanosponges become “invisible” to the immune system by blending in with their surroundings. The nanosponge is coated with pieces of the membranes of red blood cells. This makes them look like smaller versions of red blood cells and not foreign invaders to the immune system. Cloaking is so effective that the nanosponges can still be detected in the blood 72 hours after injection, long enough to remove pore-forming toxins in the blood before the nanosponge is removed by the liver. And since they are much smaller than human cells, it’s safe to use a large dose where nanosponges outnumber red blood cells. 

The pore-forming toxins usually attack red blood cells, but when they attach to a nanosponge in disguise, they are trapped by the nanosponge’s core, which is made of a polymer called poly lactic co-glycolic acid. Each nanosponge can trap about 30 – 900 toxin molecules, depending on the type of toxin. A remarkable 90 percent of animals survived a lethal dose of MRSA toxin when they received nanosponge injections. 

MRSA is just the beginning. With this platform technology, scientists can jump into using nanosponges with other toxins as well, even bee venom. If the clinical trials in humans have similar results, nanosponges could revolutionize the way doctors treat these diseases. 

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Overuse of Antibiotics on Farms

August 2, 2012 by

By Medical Discovery News

July 21, 2012

 

 

 

Resistance to antibiotics has become a crisis that is overall alarmingly ignored. Some scientists believe without new antibiotics, medicine as practiced now will have to fundamentally change. Doctors struggle to control bacterial infections that continually evolve into lethal killers because current antibiotics are useless against them.

Bacteria have grown resistant because antibiotics have been overprescribed for the past 50 years and patients often quit taking antibiotics as soon as symptoms go away, giving bacteria an introduction to the antibiotic without killing them. Several bacteria are now considered super bugs, meaning they’re resistant to multiple antibiotics. Recent numbers show these super bacteria killed nearly 100,000 Americans in one year alone.

While doctors in the U.S. are becoming more aware and restrained in prescribing antibiotics, they account for less than 20 percent of the antibiotics used. The rest, more than 80 percent (28 million pounds), go to agriculture. But this massive amount of antibiotics is not being used to treat sick animals. Instead, subtherapeutic levels are routinely injected or added to animal water and feed to boost livestock weight and compensate for the unsanitary, packed conditions of commercial American farms.

These conditions create the perfect petri dish to produce resistant bacteria. As bacteria multiply in these tight, unsanitary conditions, the animals such as chickens, turkeys, pigs and cattle are treated with common human antibiotics that include streptomycin, kanamycin, and millions of pounds of penicillin. Studies show long-term subtherapeutic levels of antibiotics may be more conducive to producing resistant bacterial strains than the short-term, high-level antibiotic treatments of humans.

These bacteria, which thrive in the intestinal tract of animal, can contaminate human food  during slaughter, processing, and food preparation. The result is that more people die from foodborne illnesses. Looking at outbreaks caused by antibiotic-resistant bacteria over the past several decades, the Center for Science in the Public Interest concluded the responsible bacteria were resistant to 14 different antibiotics. Of those, seven are classified by the World Health Organization as critically important to human medicine and eight as highly important.

The issue has become critical enough that the EU banned the use of penicillin for animal growth, then in 2006 banned the use of all antibiotics for animal growth on farms. Though the Food and Drug Administration tried at one time to follow the EU’s move by banning penicillin use, farm lobbyists prevailed. Now the FDA is asking pharmaceutical companies to voluntarily limit the sale of antibiotics to farms to just medical treatments and only through a veterinarian (they are now available through retail stores open to the public).

This pits the FDA against the powerful agriculture industry, which defends the practice as a proven way to produce economical animal-based food products. They argue that banning antibiotics will raise food costs astronomically.

But follow-up studies in countries such as Sweden and Denmark show better handling of farm animals led to a decrease in the need for antibiotics, and retail prices on meat did not rise dramatically. Denmark cited just a one percent rise in pork prices.

Ignoring the problem is not an option as people continue to die from bacterial infections that can’t be treated by existing antibiotics, especially since many drug companies have stopped developing new, more powerful antibiotics.

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