Why you are resistant to antibiotics (and why that’s a good thing)
Superbugs pop up in the news regularly and doctors are no longer the figures of authority they once were. Therefore, patients increasingly discuss their proposed treatments. There’s often a vague fear of resistance among patients, and increased discussions about whether to take medication or not.
But there’s much confusion about the terminology in these discussions. So before I can attempt to defend the good of the chemicals that heal and help us, the following needs to be cleared up: what’s the difference between resistance, immunity, and tolerance?
“Resistance”
This is a term for pathogens only, like bacteria. Antibiotics are designed to kill bacteria (or to stop them from multiplying, but let’s stay on topic). If antibiotics should be distributed in the body, most effective way is by bloodstream. This means antibiotics encounter nearly all cells of the patient’s body (except the brain, but that’s also a story for another time).
So if a drug reacts to the cell membrane (the outside layer) of bacteria to damage it, it must be incapable of interacting this way with the human cells, which have similarities in their cell membranes. Antibiotics are chemicals, and so they either react or they don’t, there’s no intention involved.
The human cells must be completely resistant, or the antibiotic is a poison instead of a cure.
So human cells are resistant to antibiotics, but — hopefully — the bacteria in your wound, bladder, or blood aren’t.
However, when some of the bacteria are lucky (by random mutation) and resist the antibiotic’s mechanism, they survive and copy their resistant selves. In reality, this always happens a little bit. But if the infection has become small enough, the body itself can succeed in exterminating the leftover bacteria through other mechanisms than the one they resisted. But if, for instance, too little of the antibiotics reach the infection, more and more bacteria survive that are all a little better at resisting.*
So taking too little antibiotics is more harmful than helpful.
These survivers can grow into a big infection again, but now they’re unaffected by the drug that was used to battle them.
Bonus: how to become a superbug
Besides getting lucky with mutations, bacteria can exchange these survival skills to other bacteria alongside them (exchanging DNA through “bacterial conjugation”). Now imagine some very densely populated areas (with mammals and accompanying pathogens) where antibiotics can be bought and used by everyone without knowledge, or consultation with a doctor. It’s superbug dreamland. Besides, you can begin to understand what poor hygiene can accumulate to, in a hospital full of infections being treated with all sorts of antibiotics. All the handy bacteria are being selected by Darwin’s law, and they exchange their skills among themselves. And when everyone is super, bacteria are all extra super.
“Immunity”
This is a term for bodies. Immunity occurs when bodies become so well prepared for pathogens that they don’t get sick from them anymore. This occurs after certain diseases, or after vaccination.
Vaccinations contain non-dangerous parts or versions of a pathogen, like an inactivated virus (not dead, cause they never lived). They’re combined with an irritating substance that causes the immune system to be signaled extra strongly (the adjuvant). The immune system cleans up the site and activates its own memory system, making a future response quicker and more effective because the pathogen is quickly recognized.
This is what makes the difference between health and disease.
It’s what makes a body immune.
“Tolerance”
Also a term for bodies. Tolerance is when a body has seen so much of a drug that it doesn’t respond to it as strongly as it should. So this doesn’t apply to antibiotics, as the human cells shouldn’t respond to it at all. (Of course the body as a whole will respond to the changing bacterial community, mainly in the gut.) Tolerance occurs in long-term (weeks to months) drug users and abusers.
If you take a painkiller or other drug over a long period of time, you can become less sensitive, and increasingly tolerant to it.
In other words: you have to take increased amounts to get the same response.
If there’s a constant presence of the drug in your blood, the receptors that start the body’s reaction can eventually lessen in number, and each give off a weaker signal. Withdrawal from the drug can reinstate the sensitivity wholly or partly, depending on the length and intensity of the use.
Keep calm and carry on
So there you have it. Yes, resistant bacteria can be dangerous, but following your doctor’s advice and prescription will minimize the risk. And this downside of antibiotics has nothing to do with the possible tolerance for other drugs.
You can still question your treatment and fear superbugs, but hopefully you’ll do so with a little extra knowledge. Besides, you can use the right words now. Yay!
* A lot of factors can play a role in reaching insufficient levels of antibiotics, or reaching them for too short amounts of time, e.g. when a patient stops treatment too soon, often the moment they feel better, but in fact the infection hasn’t shrunken enough yet. Or in the case of limited blood flow in a (pus-filled) wound.
Source: study in Veterinary Medicine and a spell checker. Spell check. Spelling check. Spell checking device.
