Friday, May 27, 2011

Antibiotic Resistance: Bacteria are winning the battle against antibiotics faster than we can invent them.

Resistant bacteria
Antibiotics are a class of drugs meant to kill bacteria. Since their development and widespread use around the time of World War II, antibiotics have been used globally in battling bacterial illnesses. They have been shown to be powerful tools against dangerous and life threatening bacteria. Unfortunately, antibiotics are often overused or used inappropriately leading to the increasingly serious and alarming problem of antibiotic resistance.

Bacteria and other microorganisms that cause infections behave like every other living organism on the planet... they evolve through genetic mutation. The problem with bacteria is that they can divide and reproduce themselves very quickly (they can actually double in number every few hours). Every time a bacteria divides there is a chance that a genetic mutation will occur during the process of cell division. Over the course of this population explosion, a few of these bacteria can develop a mutation that renders them immune to a given antibiotic. Thus, with enough cell divisions these bacteria will eventually mutate the genes necessary to resist the antibiotic being used. Once resistance occurs, that antibiotic becomes useless and a new more powerful antibiotic must be tried against this, now more hardy and, resistant strain of bacteria.

If this picture isn't frightening enough, the genes responsible for antibiotic resistance can even be transferred between entirely different species of bacteria through a process called "horizontal gene transfer". This can lead other bacteria to develop resistance to antibiotics even if they have never been exposed to an antibiotic themselves.

Staphylococcus bacteria - the type responsible for MRSA.
Antibiotic resistant strains of many bacterial infections are becoming an increasing concern in medicine. You may have heard of MRSA (Methicillin Resistant Staphylococcus Aureus) which is an infection that is extremely dangerous and can lead to necrotizing pneumonia (flesh killing pneumonia) and severe sepsis (a blood infection), which are rapidly progressive and often fatal. Streptococcus Pneumoniae resistance is also on the rise worldwide, which can lead to meningitis and death. Salmonella and E. Coli are responsible for many people being hospitalized every year. These two common pathogens may be found in contaminated food and roughly 80% of these strains are resistant to at least one or more antibiotics used in their treatment.

The prevalence of antibiotic resistant bacteria is a result of antibiotics which have been used both for humans and for animals. In fact, the use of antibiotics on animals makes up a vast majority of total worldwide antibiotic use. While you might imagine that this use is for treating illness, it is actually almost entirely used to prevent illness and as a means to fatten animals faster for slaughter. In 2001, the Union of Concerned Scientists estimated that greater than 70% of the antibiotics used in the US are given to food animals (for example, chickens, pigs, and cattle) in the absence of disease.

In humans, there are many factors that can contribute to the development of resistant bacteria. When people get sick, they sometimes ask their doctor for antibiotics, despite the fact that their illness is not caused by bacteria. A third of people, for example, mistakenly believe that antibiotics are effective for the common cold, which is in fact caused by a virus. Regardless of whether or not you are sick, even a single course of an antibiotic leads to a greater risk that you will develop bacteria in your body that will become resistant to that antibiotic for up to a year after you take them.

Additionally, many people do not finish their full course of antibiotics, primarily because they start to feel better. This is dangerous because the harmful bacteria may not have been properly eliminated, allowing some of these to have developed resistance to the antibiotic to remain. Once the antibiotic is removed these bacteria are allowed to multiply freely, causing your illness to return, but this time with a resistant strain of bacteria. At this point, if you try to restart the same antibiotic you were taking, it will now no longer be effective and you will be faced with starting a different, possibly more dangerous, antibiotic as treatment. This also increases the risk of multiple resistant strains of bacteria developing.

Newer antibiotics are increasingly harder to find and
develop. This chart shows the trend of antibiotic discovery.
The risks of antimicrobial resistance are serious and increasing as we struggle to find new antibiotics capable of battling them. Since the 1940s, when penicillin was discovered, myriad new antibiotics have been developed and used. However, in recent years, we are having an increasingly difficult time developing new antibiotics to keep pace with resistance. Due in part to horizontal gene transfer, as a bacteria develops immunity to new antibiotics, it may transfer this resistance to other bacteria species. Much research is being aimed at discovering and developing new antibiotic drugs, but we need to do what we can to prevent resistant strains from developing in the first place.

There are some steps we can all take to battle this threat. If you are prescribed antibiotics for a diagnosed bacterial infection, take the entire course of medication even, and especially, if you start to feel better. Don’t ask for antibiotics unless your doctor has confirmed a bacterial infection; antibiotics are only for bacteria and are useless against viruses and fungal infections. Ask your doctor if there are other ways to help relieve your symptoms, especially, if you do not have a bacterial infection.

Furthermore, when it comes to antibiotic resistance, any type of antibiotic released into the environment, is of concern to us all. When disposing of antibiotics, do so responsibly; don’t flush them down the toilet where they get into the water supply and can cause antibiotic resistance in animals and humans who ingest the antibiotic laden water"downstream".

Don't use antibacterial soaps; while there is, so far, no direct evidence linking anti-bacterial hand soap (usually containing triclosan) to the development of resistant bacteria, you should be aware of other potential concerns with its use. First and foremost, triclosan has been shown to be an endocrine disruptor in some animals, which means that it may alter your body’s hormonal balance (for which it is currently under review by the FDA). Secondly, when we use triclosan containing soaps they are washed down our drains, and then exposed to the environment where it has been found concentrated in animals. Triclosan is toxic to many aquatic bacteria and even prevents photosynthesis in diatom algae (which are responsible for a large part of photosynthesis on Earth). Finally, and most shocking, is that ordinary soap is just as effective as consumer-grade antibacterial soap (with triclosan) in both preventing illness and removing bacteria from the hands. So there is virtually no benefit to using triclosan in soaps, but several risks, including the potential of bacterial resistance.

In recent years, many retailers have started carrying meats with no added antibiotics. Raising animals without the use of antibiotics may be helpful toward reducing the number and frequency of antibiotic resistant bacteria (notably, E. coli and Salmonella) in these meat products. By purchasing meats from producers who are not using antibiotics, you are helping to prevent the overuse of antibiotics in farm animals and supporting responsible farming practices while decreasing you risks of contracting a resistant bacteria.

While avoiding overuse and misuse of antibiotics is a key factor in reducing the development of resistant bacteria, it is important to know when antibiotics are not only needed but essential. In these cases, antibiotics could be life saving and it is important to act quickly. Pay particular attention if you or a family member have a high fever (over 102 degrees F) or a fever with shaking chills, extreme fatigue (with lethargy or confusion), any severe sore throat especially with difficulty swallowing, rapid labored breathing or wheezing, shortness of breath, persistent or severe chest pain, stiff neck or severe headache, unusual rash or skin pallor, or cold-like symptoms that last for longer than 2 weeks. Any of these symptoms or signs could indicate a serious life threatening bacterial illness and it is important that you immediately seek medical attention from your physician or nearest emergency department.

In any discussion of infection, it is also worth keeping the health of your immune system in mind. Keeping your immune system healthy, through healthy lifestyle choices, is the best way to give yourself a fighting chance against infection, without the the need for antibiotics (or antimicrobials). Making efforts to live a healthy lifestyle helps your body to maintain a healthy immune system. A healthy immune system is capable of fighting off most types of infections (bacterial,viral, fungal, etc.) much more efficiently and effectively, often without the need for any outside assistance from antibiotics or antimicrobials of any kind. After all, humans (and animals) have survived and thrived on this planet for millennia. We have done so right along with bacteria and viruses before the age of antibiotics. Our immune systems fought our battles for us along with some help from immune boosting herbal remedies that our ancestors discovered to help us along the way. Clearly, antibiotics have helped us fight the more deadly and dangerous battles and given humans the upper hand in this fight. Unfortunately, we are losing the fight against resistant bacteria as we cannot create effective antibiotics fast enough to utilize against the rapidly emerging, new strains of resistant bacteria. After all, bacteria have the evolutionary advantage because they can mutate faster than we can invent!

So help yourself and our planet by reducing the overuse of antibiotics. Keep yourself healthy by living a healthy lifestyle, don't ask for antibiotics if you don't have a serious infection that is caused by bacteria, choose antibiotic free meats and poultry, avoid antibiotic soaps, don't flush your antibiotics down the drain, finish your full course of antibiotics when prescribed. Working together, we can seriously impact the increasing problem of antibiotic resistance and hopefully reserve the effectiveness of antibiotics for as long as possible.
Follow Up Reading:
Health Briefs: Antibiotic Resistance from Chickens?

Researched and written by Dr. Rebecca Malamed, M.D. with assistance from Mr. Malcolm Potter.

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