Belief Listing Project: Antibiotics |
August 20th, 2011 |
| antibiotics, current_beliefs, health |
An antibiotic will kill bacteria. Most bacteria. Unfortunately, the ones not killed will have little baby bacteria that also know how to survive this antibiotic. Over time, each antibiotic goes from being extremely effective to nearly useless because bacteria have evolved resistance.
No matter what we do, an antibiotic doesn't last forever. There are some really foolish things we're doing, however, that are letting bacteria evolve resistance much faster than they have to. The biggest thing is prescribing a particular antibiotic when it is not called for. Antibiotics are on a continuum from the ones for which there is widespread resistance to the super powerful new ones we save for the most dire cases of multi-antibiotic-resistant disease strains. When treating a patient with antibiotics, the right thing to do is to use a low tier antibiotic unless there is evidence that this will be insufficient. Doctors, however, are responsible for individual patients, not global health, and suffer no penalty for prescribing an antibiotic more powerful than required. This dynamic leads to prescribing antibiotics that we should instead by holding in reserve, visibly increasing outcomes for patients but invisibly increasing resistance. The long term result is more people dying.
Patients are also at fault here in at least two ways. Because antibiotics are so effective when used properly to treat bacterial infections, patients demand them when they are suffering from viral infections upon which they will have no effect. Doctors can sometimes convince their patients that this will not help, but others capitulate and the patient gives whatever bacteria are around a chance to evolve better resistance to whatever antibiotic was prescribed. The other big problem with patients is not finishing the prescribed dose. Patients take the antibiotics as directed, but stop taking them once they feel better. This doesn't make them get sick again, but because not enough bacteria have been killed they can go on to infect other people. And it's not just any bacteria going on to do that: it's the ones most resistant to the antibiotics the patient was taking.
We also use antibiotics in factory farming, often relying on them to keep the animals healthy instead of giving them enough room or proper sanitation. I've heard people claim this is increasing antibiotic resistance, but I'm not sure how much of a problem this is because we're only feeding the animals low-tier antibiotics, not daptomycin.
While we do continue to develop new antibiotics, we're slowing down. Looking at wikipedia's list of when antibiotics were released, we can see that new releases are falling:
| decade | new antibiotic releases |
|---|---|
| 1910s | 2 |
| 1920s | 0 |
| 1930s | 4 |
| 1940s | 10 |
| 1950s | 12 |
| 1960s | 15 |
| 1970s | 22 |
| 1980s | 41 |
| 1990s | 20 |
| 2000s | 6 |
Future medical breakthroughs may save us, but there's a good chance they won't. We need to stop wasting valuable antibiotics on conditions that do not need them, and make sure future generations get to live with antibiotics too.
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If this fever doesn't break by tomorrow I'll probably need to go to the hospital for a round of IV antibiotics. I've still got my own personal IV pole from the first time. I suspect it's one of the weird symptoms of PKD (same thing Dan Perl has).
Is it possible that, given enough time, antibiotics which are no longer effective could become effective again? If we stopped using them once they weren't effective, it seems like it could happen. Not that I'm banking on this, just musing.
I think one thing that should also be pointed out is that doctors often prescribe antibiotics without confirming if an infection is viral or bacterial. This has happened to me - and I tried to argue with the doctor, but she wouldn't listen. Additionally, sometimes the drugs are prescribed prophylactically - hoping to prevent the onset of a possible bacterial infection (ie. preventing the development of bacterial pneumonia after fighting off a persistent cold, which is viral in nature). I haven't decided yet if I agree with the use of antibiotics prophylactically. I think it might depend on how healthy, or at risk, the patient is for developing the possible bacterial infection. Any thoughts on that?
You point out that patients not being strict with their antibiotic regiments can lead to the spread of resistant bacteria to other people. It's also important to note that that infected individual may ALSO become ill again. Clostridium difficile is a great example of this. Although, part of the reason C. difficile can survive antibiotic treatment is its ability to form spores, which is not an transferrable resistance marker.
@Todd I think that you raise a good point. If we were to stop using certain antibiotics, it is possible that the genes encoding antibiotic resistance would be lost when the pressure to keep them around was removed. However, the genes for antibiotic resistance have been around since well before we started using antibiotics - they are a natural defense mechanism against bacteria/fungus that secrete the antibacterial toxins. So, they aren't going to disappear completely.
I don't have any concept of how long we would have to stop using a particular antibiotic in order to allow for a drastic reduction of the resistance genes in the bacterial population. Additionally, we've reached a point where bacteria have started to utilize resistance mechanisms that protect them from more than one type of antibiotic - these are mainly pumps that pump the drugs out the bacterial cells before they can function. Therefore, I think we would have to stop use of ALL antibiotics in order to decrease the percentage of resistant bacteria - and that just isn't practical.
@EmilyKate "I think we would have to stop use of ALL antibiotics in order to decrease the percentage of resistant bacteria"
Wouldn't it be possible to stop using a type of antibiotic, if the issue is that bacteria are adapting to a specific type?
We might be unlucky, however, and find that general antibiotic resistance is also a (very minor) survival advantage for bacteria, helping them against fungi or something. Then bacteria would not lose their antibiotic resistance once they had gained it.
@BDan I agree with you if we are talking about resistance markers present in the chromosome, which is true for some resistances (ie. resistance to Rifampacin is due to a mutation in the beta subunit in RNA polymerase). However, if the resistance gene is maintained on a plasmid (extrachromosomal DNA), it will quickly be lost. It takes a lot of energy to maintain a plasmid, and because of that it is disadvantageous to a bacterium to keep it around unless there is pressure to do so. We see this phenomenon quite frequently in lab...
HOWEVER, I do stand by what I said before, that we would have to stop use of all antibiotics... Yes, @Jeff Kaufman , it is true that there are different types of antibiotics - and some resistance genes only provide resistance to certain types or classes of antibiotics. However, there are some resistance genes that work against many types/classes of drugs...mainly pumps.
I've been prescribed antibiotics prophylactically, to prevent infection after oral surgery.
@Josh Do you have a congenital heart condition of some sort, or something else that increases your risk from infections? Most people I know who get prophylactic antibiotics for dental work have septal defects or other heart issues that make infections more dangerous.
@EmilyKate I think that it would take a very long time for resistance genes in the population to be significantly reduced. Unless they had some negative influence on survival out of the presence of the antibiotics, or were associated with something that did, there would be no pressure for them to be eliminated. Look at all the useless stuff that humans are still dragging around.
BDan: Nope; I assumed it was just because the mouth is full of bacteria, and things are more likely to heal cleanly if you're on antibiotics for that first week.