Systemic Fungicides - How often do you rotate ?

[Arne]

I never thought I had to use a fungicide but then the Aerangis luteo-alba v. rhodosticta entered my collection. It seems to get both fungal and bacterial infections all the time. Since one year back I use one single remedy. I know, however, that I have to change sooner or later. Fungus, but even more so bacteria (and virus is the worst), tend to become resistant to one single treatment.

[sciencegal]

Fungus, but even more so bacteria (and virus is the worst), tend to become resistant to one single treatment.

There aren't any treatments for a viral infection so they can't become resistant.

[Arne]

I meant virus in general. The HIV-1 virus gets resistant in three months or less. I'm working with it on a daily basis.

[sciencegal]

I meant virus in general. The HIV-1 virus gets resistant in three months or less. I'm working with it on a daily basis.

Resistant to what?

[Arne]

Resistant to what?

I don't understand what you mean. Unless it is an 'abrasive' general agent like ethanol, these fungi/bacteria/virus get resistant to anything.

[sciencegal]

Viruses live inside of cells. They cannot survive on their own outside of another living cell. In general there is nothing that will destroy viruses inside the cell. If you want to kill a virus you have to kill the cell it is hiding in. The host may not appreciate it. If they spend a short time outside of a cell - then the immune system can destroy or incapacitate them. Or if they are on a surface like a table top they can usually be killed by a disinfectant. Therefore viruses spend little time outside of their safe haven in a cell. They are often carried from one plant to another safely inside an insect vector.

When you say that an organism becomes resistant it means that the agent you are using no longer becomes effective at killing them because the bacteria or fungi or insect or parasite has developed a way around it. Many times there was always a small fraction of the population that had the resistant factor and they took over when the non resistant ones died off. There are other complex mechanisms of developing resistance.

Viruses are simply a package of genes. They have no way of becoming "resistant" to anything. Fungicides or bacteriocides interfere with some part of the life cycle of the fungi or bacteria. Viruses don't have a life cycle except to get inside a cell and use the cell's machinery to make more copies of themselves. The main damage they cause is by destroying the host cell when they exit it in huge numbers to go on and infect other cells.

[Arne]

Viruses live inside of cells. They cannot survive on their own outside of another living cell. In general there is nothing that will destroy viruses inside the cell. If you want to kill a virus you have to kill the cell it is hiding in. The host may not appreciate it. If they spend a short time outside of a cell - then the immune system can destroy or incapacitate them. Or if they are on a surface like a table top they can usually be killed by a disinfectant. Therefore viruses spend little time outside of their safe haven in a cell. They are often carried from one plant to another safely inside an insect vector.

When you say that an organism becomes resistant it means that the agent you are using no longer becomes effective at killing them because the bacteria or fungi or insect or parasite has developed a way around it. Many times there was always a small fraction of the population that had the resistant factor and they took over when the non resistant ones died off. There are other complex mechanisms of developing resistance.

Viruses are simply a package of genes. They have no way of becoming "resistant" to anything. Fungicides or bacteriocides interfere with some part of the life cycle of the fungi or bacteria. Viruses don't have a life cycle except to get inside a cell and use the cell's machinery to make more copies of themselves. The main damage they cause is by destroying the host cell when they exit it in huge numbers to go on and infect other cells.

I mean the best when I'm saying this now Karin: You can talk to the audience in this forum but you cannot teach me. You just cannot. And you are actually wrong, totally. These viruses get resistant in no time, the HIV-1 virus in less than three months. I have been active as a biophysicist for more than 20 years and written at least 50 papers on this particular subject. The last one I wrote together with the NIH Vaccine Research Center will be published in Nature shortly. It is about the absolute latest HIV-1 entry inhibitor currently in Phase III clinical trials. That will be the first clinically approved inhibitor of HIV-1 entry that targets the virus, not any human target. There will be resistance to this inhibitor within 3 months or so but we all know that. The trick is to combine the treatments in order to break the vitality of the virus. The virus can only be resistant to a certain number of antivirals before it loses the resistance to another antiviral, which then suddenly becomes effective.

[sciencegal]

Okay. I did ask the question - resistant to what - and now you have explained. However we do not routinely use anti-virals on orchids. I will go away now.
Posted via Mobile Device

[Arne]

I just want to take a moment to say this:

For anyone out there infected with the HIV virus, please remember that the virus can only be resistant to a certain number of antivirals before it loses the resistance to another antiviral, which then suddenly becomes effective again. Also, the side effects are not too bad now for many of the treatments. You will stay alive as long as you want.

[oile]

I use fungicides only when needed, use those specific for each problem, if and when manifest