Why can't antibiotics kill a virus?

[pie]

[Dookus]

1. because

a virus is a very different critter than a bacterium. Very, very different.

[pie]

6. I know that. But what are the particulars?

[atommom]

10. Read this...

http://www.drjaygordon.com/faqs/virusbact.htm

http://www.betterhealthchannel.com.au/bhcv2/bhcarticles.nsf/pages/Infections_bacterial_and_viral?OpenDocument

[Warpy]

14. Antibiotics kill by attacking

the cell wall or the metabolic processes of a bacterium. A bacterium is a living organism, capable of all the things we use to define it: eating, elimination, reproduction. Antibiotics kill them directly.

A virus is a different thing entirely, a packet of DNA contained inside a lipid coating. The lipid coating merges with the phospholipid coating on a body's cell, the DNA migrates inside the cell, and hijacks the cell to replicate copies of itself until the cell ruptures, sending more virus into the body. Since virues can't be properly defined as alive, they can't really be killed. What the body eventually does is recognize the particular DNA pattern as foreign, and neutralizes the virus's ability to enter the cells via antibodies that affix themselves to the lipid coating and prevent contact with the cell wall.

What vaccines do is mimic the virus enough (or even use part of that virus, itself) to trigger an immune response so that the body already has a template for those particular antibodies should a virus take hold.

This is a very basic explanation of the difference between the two. It gets ridiculously complicated, but basically you can't kill something that isn't alive, and viruses aren't alive in any sense that we recognize.

[pie]

23. very good

[msmcghee]

33. It's posts like this that make me realize . .

. . how valuable it is belonging to DU. There are some pretty smart folks here.

Thanks Warpy.

[DenaliDemocrat]

34. Viruses

are encapsulated with protiens, not lipids.

[asthmaticeog]

2. Because they're not antivirals.

[XemaSab]

32. Love the pictures!

n/t

[asthmaticeog]

37. Thanks! n/t

[trotsky]

3. Viruses aren't alive.

Antibiotics generally work by interfering with bacteria's process of subdivision. Viruses can't self-replicate - they need a host cell to manufacture copies of themselves.

[pie]

8. I did not know that. Can a virus cause cancer?

[trotsky]

12. Theoretically, yes.

The DNA it injects into a host cell could have that consequence.

On edit: Actually, I should correct that - I think viruses only use RNA, not full DNA.

[Warpy]

15. Most viruses are DNA viruses

The main problem they had in recognizing HIV for what it was is that they'd rarely seen any sort of an infective RNA virus, although they'd long been known to exist.

[MAlibdem]

24. HIV is awful

I have a final on it partially tomorrow. I'll pretend giving you a description from memory counts as studying.

HIV starts its life cycle by binding to a cell wall and incorporating itself into the cell.

Its RNA is then reverse transcripted with reverse transcriptase (creates a double-stranded DNA molecule from a single stranded RNA). This is possible because it is also has a tRNA molecule bound to the RNA near its 5' end and this serves as a primer from reverse transcriptase. After replication in the 3' to 5' direction (unusual) and reaching the end, the whole complex of reverse transcriptase, tRNA, and the synthesized DNA then migrate to the 3' end of the viral RNA and DNA reverse transcription resumes. Then some complicated stuff im not responsible for happens, and the viral DNA is the product.

Then transcription of the DNA begins. RNA polymerase cannot bind very well to the viral DNA, and so has many abortive attempts. Finally, it will transcribe enough to produce the TAT protein, which binds to the TAT binding site on the viral RNA transcript and recruits the TAF protein, which phosphorilizes the RNA polymerase and increases its efficiency dramatically.

Then its just a matter of normal transcription, etc. Though REV proteins must be able to be produced to bind to the REV binding site to allow for alternate splicing of the mRNA product (i think). Also, it is interesting that the viral protein product are written overlapping in different reading frames (3 nucleotides code for a single amino acid, there can thus be 3 reading frames). There is a point in the GAG protein where there is a slip site so that the ribosome slips into the -1 reading frame (from the 0 reading frame) and it then can translate the POL, PROT, and INT polyprotein.

When the viral protein and DNA (now in RNA form once more) is replicated, it then moves to the cell membrance, and pushes outward.

Oh yeah, this is all in T cells. Safe. A little more studying, perhaps...uggggggggh.


Oh, and in making decisions, firm want MB=MC...and from there, all sorts of crap explodes <--- i have and econ final as well.

[pie]

29. Nothing simple about that, now is there

I loved/hated cramming for exams.

[Warpy]

30. Virology's a bugger, no?

HIV is diabolical. I have to laugh at people who think the CIA made it in some lab. I don't think we're smart enough to come up with something that has a 15 year prodromal period followed by certain death. We certainly don't have the technology for it.

[MAlibdem]

38. another important point...

is the inherent crappiness of the reverse transcriptase enzyme. instead of working properly, and thus producing low levels of mutation, it makes on average 4 mistakes per reverse transcription (which is a really bad rate for an 18kb long molecule). so that means the body cannot possibly create antibodies for all the variants and vaccinations are wicked hard to come up w/ b/c the virus can mutate around them.

[Hoping4Change]

36. Thanks for that overview. Goodluck on your exams.

:hi:

[Dogmudgeon]

19. Human Papilloma Virus (HPV) causes uterine cancer

This has been well-established for a couple years now.

A lot of cancers appear to have viral causes, but the scientific work required to make the case is extremely difficult, so it has been slow going. I was actually pleasantly surprised that it took so little time to track down HIV and describe it as well.

--p!

[amazona]

28. and cervival cancer NT

.

The conservation movement is a breeding ground of communists
and other subversives. We intend to clean them out,
even if it means rounding up every birdwatcher in the country.
--John Mitchell, US Attorney General 1969-72

[atommom]

13. Yes, some do, by altering the host cell's DNA.

[Heddi]

39. Hepatitis B can cause Liver Cancer

and that's why the HepB Vaccine is considered to be the first "Anti-Cancer" vaccine.

As someone else mentioned, Genital Warts (Human Papilloma Virus) can cause Cervical Cancer as well

AIDS can cause an increased risk of certain cancers, although it's not the AIDS virus directly that causes the cancers, but rather the very low immune system that increases susceptability to cancers (and other problems like pneumonia, etc)

[Massacure]

4. Bacteria are living creatures and viruses are not.

Hence a virus cannot be "killed".

[MAlibdem]

21. but they can be taken apart or digested

but not by antibiotics

[LeftCoast]

5. Antibiotics disrupt cell function

Viruses (virii) don't have cell functions for the most part. They're really quite different from bacteria.

[atommom]

7. A virus is really just a piece of genetic code, stuck in a protein

envelope. Bacteria are much more complex, and there are many ways we can mess with their defenses, especially their cell membranes.

[pie]

9. How does a virus attack human cells?

[atommom]

11. Receptors on the virus bind to receptors on the human cells, and

the viral DNA or RNA is injected into the cell. The virus can then hijack the human cell and use it to make more viruses.

[pie]

27. very good

[Dogmudgeon]

16. Viruses are almost like little gene robots

You need complex cytoplasm to use an antibiotic. They disrupt the cytoplasm, as a rule.

There is a small class of drugs called "antibiotics" which work by disrupting mitochondria, the cell's power plants. They are very toxic, but often save lives when everything else has failed. Chloramphenicol is one such drug, IIRC.

And some viruses actually may be killed by antibiotics, but it's a coincidental effect. Antibiotics usually have a certain amount of general toxicity to which a virus may be sensitive. A scientist could tell you more about the details.

Fun Fact: H3 stomach histamine blockers, like Tagamet, are potentially very good anti-virals, and several studies are underway to determine what viruses they are best used against. AIDS/HIV is one virus that it kills -- studies are available, but I don't have any citations.

I suspect you are concerned about the recent bird flu, in no small part a result of my fear mongering. The best way to deal with influenzae is to stock up on specially-made antiviral meds, like Tamiflu or Symmetrel. Symmetrel is available generically as amantadine, and is effective against Influenza A.

Vitamin C may also be effective, but it has not been well-studied; since it is cheap and safe, it is also worth looking into. But most of the more exotic alternative cures are poorly studied, so avoid any that have significant side-effects.

As for my fear mongering, I stand behind it. There is far too much complacency about the real risks we, as a civilization, are up against. The cure starts with individual empowerment -- which is one of the reasons DU exists.

Be well. Be active.

--p!

[pie]

26. These are difficult concepts to wade thru

I figure this might be a good time to learn something
about this whole business. It won't be fear mongering when
thi damn thing is all around us.

[Warpy]

31. Your fearmongering and mine, I guess

although I still don't suggest getting a bunch of credit cards and charging them up 'cause we're all gonna die tomorrow.

The good sign is the detection of avian flu antibodies in people whose symptoms weren't severe enough for them to be considered as having been infected with it at the time. It leads me to believe those 70% mortality stats were way off.

The bad news is that it's crossed into swine and a large reservoir in wild waterfowl is out there. We're next.

The really bad news is that we've got Fuckwit in the White House. While other countries (most notably in Scandinavia) are already beginning to stock up on antiviral drugs, the US is stocking up on faith healers.

[LisaL]

17. Because antibiotics work on bacteria, not virus.

[DulceDecorum]

18. The scientists here might not totally agree with this

but think of it this way.

Bacterium - car.
Virus - car-driver.
Antibiotic - gasoline shortage.

The gas shortage will ground all the cars
but the car-drivers will be just fine,
and if the cardrivers find a car with gasoline
they will simply take it over and drive it away.

The car-driver and the car are completly different.
the gas shortage has no appreciable effect on the health or wellbeing of the car-driver.

OK, its weird
but I hope it makes it a bit more clear.

[pie]

25. I can ponder that over coffee

[MAlibdem]

20. Ugggh, im taking genetics right now...

viruses aren't really "alive," they are just DNA in a protein shell capable of infection, replication, and lysing the bacterial (or other) host's cell wall or membrane to infect more cells.

Bacteria and other targets of antibiotics are living organisms that are much more complex.

So what can kill a virus? Antibodies and the immune system OR bacteria-produced restriction enzymes that cut viral DNA (and have been adapted as tools for genetics).

[Speck Tater]

22. Same reason mosquito repellant won't repel giraffe's

Different body chemistry. Viruses and bacteria work completely differently.

[Dookus]

35. I dunno...

I've used mosquito repellant and I've never seen a giraffe around afterward. :P