How We Can Help Stop Antibiotic Resistance
Antibiotics are compounds that either:
1. kill bacteria directly (bacteriocidal)
2. hamper their ability to grow and reproduce (bacteriostatic)
When you are fighting off a bacterial infection, your immune system can be overwhelmed by the invading bugs. Antibiotics are thrown into the fray to mount a defense against the invaders until your immune system can recover and finish off the remaining bacteria.
How do antibiotics stave off bacterial growth? Antibiotics stop or
interfere with a number of everyday cellular processes that bacteria
rely on for growth and survival, such as:
* crippling production of the bacterial cell wall that protects the cell from the external environment
* interfering with protein synthesis by binding to the machinery that builds proteins, amino acid by amino acid
* wreaking havoc with metabolic processes, such as the synthesis of folic acid, a B vitamin that bacteria need to thrive
* blocking synthesis of DNA and RNA Antibiotics stop working because bacteria come up with various ways of countering these actions, such as:
* Preventing the antibiotic from getting to its target
When you really don’t want to see someone, you might find
yourself doing things like hiding from them or avoiding their phone calls.
Bacteria employ similar strategies to keep antibiotics at bay. One
effective way to keep a drug from reaching its target is to prevent it
from being taken up at all. Bacteria do this by changing the
permeability of their membranes or by reducing the number of channels available for drugs to diffuse through. Another strategy is to create the molecular equivalent of a club bouncer to escort antibiotics out the door if it gets in. Some bacteria use energy from ATP to power pumps that shoot antibiotics out of the cell.
* Changing the target
Many antibiotics work by sticking to their target and preventing it from interacting with other molecules inside the cell. Some bacteria respond by changing the structure of the target (or even replacing it within another molecule altogether) so that the antibiotic can no longer recognize it or bind to it.
* Destroying the antibiotic
This tactic takes interfering with the antibiotic to an extreme. Rather than simply pushing the drug aside or setting up molecular blockades, some bacteria survive by neutralizing their enemy directly. For example, some kinds of bacteria produce enzymes called beta-lactamases that chew up penicillin.
How do bacteria pick up these drug-fighting habits? In some cases, they don’t. Some bacteria are simply making use of their own inherent capabilities. However, there are many bacteria that didn’t start out resistant to a particular antibiotic. Bacteria can acquire resistance by getting a copy of a gene encoding an altered protein or an enzyme like beta lactamase from other bacteria, even from those of a different species. There are a number of ways to get a resistance gene:
* During transformation – in this process, akin to bacterial sex, microbes can join together and transfer DNA to each other.
* On a small, circular, extra chromosomal piece of DNA, called a plasmid – one plasmid can encode resistance to many different antibiotics.
* Through a transposon – transposons are “jumping genes,” small pieces of DNA that can hop from DNA molecule to DNA molecule. Once in a chromosome or plasmid, they can be integrated stably.
* By scavenging DNA remnants from degraded, dead bacteria.
Unfortunately, if a bacterium gets a resistance gene stuck into its
chromosomal DNA or picks one up in a free-floating plasmid, all of its progeny will inherit the gene and the resistance it confers. Why do resistance genes persist and spread throughout bacterial populations?
It’s basically just Darwin’s idea of the survival of the fittest,
reduced to a microscopic level — bacteria with these genes survive and outgrow susceptible variants. And our own less than judicious use of antibiotics actually selects for these resistant types! Here’s how we contribute to the problem:
* Ignoring the brightly colored labels on the pill bottle and the doctor’s admonitions to take all of the medicine that you get, even if you start to feel better. If you stop taking your medicine too early, your immune system may not be capable of killing off the stragglers, and any resistant bacteria left unscathed will be able to proliferate and spread to other people.
* Insisting on getting antibiotics from the doctor to treat a cold or the flu. Antibiotics are completely ineffective against viruses, so you actually accomplish nothing by popping a pill. Worse yet, antibiotics can’t discriminate between bacteria that are good for us and bacteria that cause disease. Our preoccupation with cleanliness notwithstanding, we actually peacefully co-exist with a wide variety of bacteria each day. For example, our intestines are lined with bacteria that break down foods that we can’t digest. Whenever you take antibiotics, you kill off some of these beneficial bugs. Using antibiotics indiscriminately can blow away most of the bacteria normally in your body, opening the door for more sinister strains to establish themselves in their place.
* Stockpiling leftover antibiotics and trying to medicate ourselves – not every antibiotic will work for every infection.
Your doctor prescribes a specific drug for you based on what kind of
infection you have. He or she also selects a specific dose and length
for your treatment. The old antibiotic you have may not work at all
against the infection you have, so it’s best to seek a doctor’s advice
before trying to treat yourself.
Antibiotic Resistant Bacteria and What we can Do
— It’s a troubling issue:
Many bacteria are becoming resistant to antibiotics. As governmental agencies take action to curb overuse of antibiotics in livestock, consumers and physicians are also taking responsibility.
Too many people are asking doctors for antibiotics — it’s as simple as
that, says Richard Besser, MD, pediatric and medical epidemiologist in the National Center for Infectious Diseases at the CDC.
Here’s the crux of the problem: “If you acquire a bacteria that is
resistant to antibiotics, then it becomes much more difficult to treat
your infection,” Besser tells WebMD. “If you take an antibiotic, it
will kill off the bacteria that are happily living in your nose and are
sensitive — and allows those that are resistant to multiply.”
Even if you’re judicious about antibiotic use, the guy sitting next to
you could be a problem. “You can get resistant infection by acquiring
it from someone else sitting next to you who has been taking a lot of
antibiotics,” says Besser. “You’re at risk from your own use but also
from use by everyone else in your community.”
So what can you do?
“If your doctor prescribes an antibiotic, ask questions,” Stuart B.
Levy, MD, director of the Center for Adaptation Genetics and Drug
Resistance at Tufts University School of Medicine, tells WebMD. “Do I
need it? What are we treating here? Make sure they’re treating a
bacterial infection.” If it’s a virus — as with colds and flu —
antibiotics won’t help. You’ll just have to let it run its course.
“Tell your doctor you can really do without it for few days, that you
just want to let him see you,” he says. “The patient can then call in a
few days if still not feeling well. The doctor can decide then whether
or not — or maybe never [to prescribe the antibiotic].”
* Only use antibiotics from a new prescription.
Don’t ever use antibiotics left over from a previous prescription. They
may not be the right kind of drug, and there certainly won’t be enough to kill all the bacteria causing your illness. The bacteria that come back will actually be stronger because they are likely to be more resistant.
* If you do take antibiotics for a bacterial infection, be sure to take
all of the pills — even if you feel better before they’re all gone. It’s important to kill off the last remaining bacteria because they are the most drug resistant.
* Don’t overuse household products containing antibacterial agents, because your house can become a breeding ground for drug-resistant bacteria.
* Use regular soap and water in your home instead of antibacterial products.
“There’s no evidence that antibacterial cleansers do any more than soap and water,” Levy tells WebMD. Whether antibacterial cleansers cause more illnesses, he says, “We don’t know. The point is that we have evolved with certain bacteria that our systems know well, and by trying to destroy that world, we raise the possibility of changing the bacteria that are threatening to us.”
Children’s immune systems need to be exposed to “normal” amounts of germs in order for their immune systems to develop, says Levy.
And if you do get a prescription for antibiotics, make sure you know
what to expect, he advises. Antibiotics are generally safe, but they
can have side effects — such as triggering allergic reactions and
interfering with birth control pills and other medications, says Levy.
A few tips:
* Know why you are taking the particular
antibiotic and what it is supposed to do.
* Ask about side effects — and ways to prevent
them. Because antibiotics kill “good” bacteria as well as “bad”
bacteria, they can upset your system and cause nausea, diarrhea,
vaginal yeast infections, and other problems.
* Should the drug be taken at a specific time —
with or without food? Does this drug interfere with the effectiveness
of other medication (such as birth control pills)? Should you avoid
alcohol or other foods?
* Tell your doctor about any allergic reactions
you have had to previous antibiotics. Be sure to tell your doctor about adverse drug reactions, special diets, allergies, health problems, or if you are pregnant.