Live data from Hacker News

Dr. Arjun Srinivasan: We’ve Reached “The End of Antibiotics, Period”

pbs.org

221–230 of 414 posts

Re: Dr. Arjun Srinivasan: We’ve Reached “The End of Antibiotics, Period”

#221
post #94

Earlier quoted context omitted.

I think it's a bit pedantic to argue about his usage of "desire". Evolution is a blind watchmaker. The bacteria are reacting to selective pressures. Large populations of bacteria around the world are getting exposed to different kinds of antibiotics. It's not a matter of "if" they will acquire resistance, but "when", and we're seeing this happening right now. The fact that lines of bacteria go extinct does nothing to…

I have never heard of bacteriophages before. Doing some light research, I found their protein/body structures to look almost machine-like. Very fascinating stuff. From Wikipedia's Bacteriophage page: "Medical trials were carried out, but a basic lack of understanding of phages made these invalid". I seriously hope alternatives like bacteriophages are being revisited and reconsidered within the medical community, as i…

Phages have been, and are, being revisited and reconsidered.

The early days of 'phage therapy' were pretty bad - because we really didn't understand what was going on, the "purified" phage solutions still had bits of bacterial cell membranes and the like in them, including endotoxins. People died.

But phages were still being looked at for most of the antibiotic period, especially in countries without quite such widespread access to antibiotics. The Soviet Union had a very active program in Georgia, which was ongoing before the trouble there a few years back, I don't know the status of it now.

It's a promising avenue, and there's some decisive advantages phages have over antibiotics. But it's also quite hard, and right now we lack a generalizable form of phage therapy - it tends to be a bespoke solution to specific intractable cases. But the incentives might increase as antibiotics become less and less effective.

For awhile I wanted to work on phage research before I realized wet-lab Biology was not my forte.

Re: Dr. Arjun Srinivasan: We’ve Reached “The End of Antibiotics, Period”

#222

Earlier quoted context omitted.

> Now we have no weapons; we're helpless and the world is again going to be a scary place where a cut or a scrape can land you in a hospital or in a mortuary. Perhaps most terrifying is that the mere act of hospitalization will likely be the highest vector of transmission of nearly untreatable infections. Go in for a routine procedure and end up in the isolation ward due to some highly infectious, deadly disease.

> Perhaps most terrifying is that the mere act of hospitalization will likely be the highest vector of transmission of nearly untreatable infections. Go in for a routine procedure and end up in the isolation ward due to some highly infectious, deadly disease. This is one reason to avoid hospitals at all cost. It's also why hospitals are terrible as a first treatment option for the poor. I can't recall a family hospit…

> This is one reason to avoid hospitals at all cost.

I think generally, everyone avoids hospitals at all costs.

Re: Dr. Arjun Srinivasan: We’ve Reached “The End of Antibiotics, Period”

#223
post #86

The anthropomorphism of bacterial evolution makes the article hard to follow for the layman (me). Can someone familiar with bacterial evolution please explain to me how the use of antibiotics leads to superbugs? I am clearly misunderstanding something. I was under the impression that in a population of bacteria, genes express themselves in any number of random ways. If we expose the bacterial culture to antibiotics,…

My guess: before the antibiotic, the minority resistant bacteria have to compete with the majority non-resistant. After, they can proliferate freely. Repeat with the next antibiotic, and soon all the ones we see are resistant to all the antibiotics we have.

You pretty much nailed it in a very succinct manner.

That's why it's so important to complete a course of antibiotics rather than stopping once you feel better. Once you've started antibiotics, you're basically enriching the population in bacteria that aren't affected by the antibiotic. This is normally a very small population, but if you stop half-way, the pressure on those bacteria from other bacteria (the ones that died) is lower, allowing the resistant population to flourish.

If you finish a course of antibiotics, you not only kill the susceptible bacteria, but you also give your own immune system a chance to take down the few remaining bacteria that are resistant.

Re: Dr. Arjun Srinivasan: We’ve Reached “The End of Antibiotics, Period”

#224
post #100

Earlier quoted context omitted.

You are completely right in that bacteria don't have the ability to "want" things since they don't have any kind of brain. However, desire is a useful way for the general public to understand what is happening. It's like saying "Water wants to flow to the lowest point of a room" or "The arrow wants to follow the path of least air resistance"

Yes, the talk of desire is clearly personification that's not meant to be taken literally.

Inability to understand figurative language seems a common malady on certain parts of the internet.

Re: Dr. Arjun Srinivasan: We’ve Reached “The End of Antibiotics, Period”

#225

The interviewed expert has very good credentials and clinical experience to be talking about what he is talking about, and his warnings should be taken seriously. But even at that, the fallacious teleological language he uses about biological evolution by natural selection suggests a way out of this problem. When he says, "Bacteria, like any living organism, want to survive," and "So anything that we do to try and ki…

For someone who opens complaining of teleology, your third paragraph relies heavily on the assumption that science will march forward. Where is the skepticism aimed at the assumption that we will be able to surgically genocide _all harmful bacteria_ faster than they can evolve?

Re: Dr. Arjun Srinivasan: We’ve Reached “The End of Antibiotics, Period”

#227
post #152

Earlier quoted context omitted.

Clearly, everyone needs to stop washing their hands, or bacteria will develop soap immunity. And then what will we do?

Killing bacteria is easy. The trick is killing bacteria without harming ourselves. Soaps can be massively more "brutal" in terms of the mechanisms that destroy bacteria than what antibiotics can, and so the evolutionary steps that would have to occur for resistance are vastly larger, and would mean changing them in many different directions. E.g. it does not help if a bacteria can survive a soap if it is still physic…

Handwashing with soap doesn't actually kill bacteria, it mechanically dislodges the oils and debris that bacteria are embedded in on your skin and rinses them down the drain. So bacteria have no defense.

Re: Dr. Arjun Srinivasan: We’ve Reached “The End of Antibiotics, Period”

#228

The interviewed expert has very good credentials and clinical experience to be talking about what he is talking about, and his warnings should be taken seriously. But even at that, the fallacious teleological language he uses about biological evolution by natural selection suggests a way out of this problem. When he says, "Bacteria, like any living organism, want to survive," and "So anything that we do to try and ki…

General reply to express thanks for and respond to the several replies my first comment here received. First of all, I wrote in the original reply, "his warnings should be taken seriously," so I am by no means disagreeing with the quoted CDC expert about his general policy recommendations. Indeed, I am on record here on HN[1] saying that I'd like to see the United States follow the lead of the EU immediately in banning antibiotics used in human medicine (especially last-line antibiotics used for antibiotic-resistant human disease) from use on farms. That seems like a sensible way to segregate the ecosystems in which microorganisms develop antibiotic resistance by haphazard evolution through natural selection.

I respectfully note the disagreement of several participants here have with me. They disagree with my disagreement with the interviewed expert's casual language about thoughtful agency by bacteria. Noting your statements that this is just everyday conversational usage, I stand by my objection to that fallacious manner of speaking. Most people in the English-speaking world think erroneously about biological evolution and especially about the implications of evolution for human medicine. I am not alone in thinking that popular thinking about biology needs to be improved by rejecting the idea of organismal agency in evolution,[2] although it is remarkably hard to find this kind of careful thinking by a Google search amid the flood of webpages that specifically assert a purpose or intention to evolution by natural selection. Ernst Mayr, mentioned in one reply to my first comment here, is indeed a rare example of a reliable author on that issue. Human beings have a cognitive bias of attributing agency to inanimate objects,[3] and the reactions to my first comment suggest how deep-seated that cognitive bias is.

The entire revised introduction to the thirtieth anniversary edition of Richard Dawkins's book The Selfish Gene[4] appears to be available for free online reading, and Dawkins writes explicitly about what level of analysis can be useful when pretending that genes have intentions and goals while thinking about problems in evolutionary theory. The University of California Berkeley website about evolution has a good page about antibiotics[5] that makes helpful medical practice and public policy suggestions with more cautious language.

There is a testable prediction here of course: either bacteria outrun human antibiotic development or they do not. I'm confident that more bacterial lineages will be wiped out before human medicine is seriously compromised by natural selection of bacteria that are resistant to most antibiotics used in human medicine. The precautionary principle suggests that we follow the quoted expert's policy recommendations, but meanwhile conduct research for a deeper understanding of the biochemistry of harmful microorganisms and their ecology.

[1] https://news.ycombinator.com/item?id=5674781

[2] http://whyevolutionistrue.wordpress.com/2011/02/21/natural-s...

[3] http://cogsci.stackexchange.com/questions/3951/is-there-a-co...

[4] http://books.google.com/books?id=koaD_Aod_V0C&printsec=front...

[5] http://evolution.berkeley.edu/evolibrary/article/medicine_03

Two other comments at this level express the nub of the argument:

I'm slightly bugged by "desire" type language because it does actually cause problems in how laymen think about evolution. It's not uncommon to hear them make the mistake of thinking evolution will "think ahead". But the bigger problem I have with it is the "anything we do ... bacteria will eventually discover".

Some problems are just very difficult to evolve around, and it's hard to predict what they'll be even if you have a complete working knowledge of an organism's genome and biological workings. If the problem space doesn't contain a solution that can be climbed toward without sacrificing fitness in the short term, it is unlikely that it will ever be found by evolution.

Evolution is actually a really crappy optimization algorithm. The reason it has worked so well is not that it is so effective, but because it's the only game in town.

That is very well put, and deserves your upvote.

At what point do we start designing RNA with a delivery mechanism that attaches itself to a specific bacterial type and eliminates it?

A good question. It is an empirical question about the future, so it has no definite answer yet, but that is the general research direction to follow to get around the legitimate problem mentioned in the article kindly submitted here.

Re: Dr. Arjun Srinivasan: We’ve Reached “The End of Antibiotics, Period”

#229
post #119

Earlier quoted context omitted.

You've been voted down but there is actually a school of thought that excess use of antibacterials and generally going "overboard" (whatever that means exactly) with preventing children from being exposed to natural flora can potentially result in weakened immune systems. There's a lot of pseudo-science in these claims but that doesn't mean there's absolutely no truth to them. It would probably be hard to do a study…

Ignoring the snark (of the parent comment), I've often wondered why it was bad to use anti-bacterial soap (and antibiotics in general), but not regular soap, since both leave some amount of bacteria behind, which presumably have genetics making them more resistant to the pressure. I think part of the answer is that its just not possible to evolve resistance to any amount of soap and hand washing, unlike resistance to…

I'll take a stab at this - I'm an infectious disease epidemiologist that works on hospital infections mostly.

The thing with anti-bacterial soaps is not that the use of the soap is bad. The problem is the anti-bacterial part. It puts amounts of a broad spectrum antibiotic into the environment (be it your hands, your countertop, or the water system) in concentrations that aren't enough to do much, but are enough to put a little bit of selective pressure on the organisms and promote resistance.

It's also not particularly effective - soap and water, through a combination of both mechanical action and how soap disrupts cell membranes, works swimmingly. So there's a cost, and no benefit.

The answer to 'why isn't there a resistance to soap' is that soap, as a chemical, is absurd overkill. It's hellish on lipids of all sorts (tough on grease...and lipid cell membranes), and there's nothing to evolve a resistance to. Not expressing a particular protein, or expressing an enzyme that does a number on an antibiotic compound is effective - to evolve a resistance to soap, you'd somehow have to develop an entirely new type of compound to build cell membranes out of.

And while evolution is rather magnificent, that's asking a little much.

Re: Dr. Arjun Srinivasan: We’ve Reached “The End of Antibiotics, Period”

#230

The interviewed expert has very good credentials and clinical experience to be talking about what he is talking about, and his warnings should be taken seriously. But even at that, the fallacious teleological language he uses about biological evolution by natural selection suggests a way out of this problem. When he says, "Bacteria, like any living organism, want to survive," and "So anything that we do to try and ki…

I share your distaste of when evolution is personified or otherwise represented to be anything other than a powerful but passive process. That being said, I have no problem with the statement that bacteria want to survive. They most certainly have mechanisms that are engaged actively in order to increase chances of survival. Horizontal gene transfer ( http://en.wikipedia.org/wiki/Horizontal_gene_transfer ) allows bac…

[deleted]
Post reply on HN