Anyone with biology knowledge: boiling or baking to kill Mycobacteria/Fish TB?

[FlyingShawn]

The short version of the story is that my fish are confirmed to be infected with Mycobacterium Marinum (aka "Fish TB") and I'm looking at a full-system teardown and nuke. For the tank and filter system, I'll be using a chemical warfare protocol (high-concentration bleach, then Lysol, then 70% isopropyl alcohol), but am afraid a chemical strategy would be damaging to decorations/lava rock/driftwood. Will heat work?

It seems to be an accepted procedure to sanitize driftwood by boiling or baking it, but I have not been able to find a reliable answer on if it'll work on Mycobacteria.

By Googling "heat kill mycobacterium" or "heat killed mycobacterium marinum" I can find a number of scholarly articles (example: The efficacy of the heat killing of Mycobacterium tuberculosis), but they primarily seem to focus either on heat-killing laboratory samples in a way that doesn't damage their DNA or "heat inactivation," where they aren't dead, but also aren't able to reproduce.

Either of the above answers would seem to imply that my heat strategy would be effective, but my biology knowledge is extremely limited and I need input from people who might actually know what they're talking about or at least have the background to properly interpret articles like the one above.

I've posted some of these questions in the thread detailing the full-saga of this problem (UPDATE: IT'S FISH TB. ...Help me diagnose this disease that's killing my fish), but I'm hoping that this thread will get some fresh input on the matter. Thanks!

[OverStocked]

The decorations/lava rock/wood will be fine with the chemicals. I highly recommend Metricide 14, as well, which is used as an excel replacement by many here. It is a surgical disinfectant

Metricide 14 has a TB kill time of 3 minutes. Any parts you're not attached to should be disposed of. Substrate, for instance.

[FlyingShawn]

Originally Posted by OverStocked

The decorations/lava rock/wood will be fine with the chemicals. I highly recommend Metricide 14, as well, which is used as an excel replacement by many here. It is a surgical disinfectant

Metricide 14 has a TB kill time of 3 minutes. Any parts you're not attached to should be disposed of. Substrate, for instance.

Wow, that stuff is PRICEY!! While the 3 minute TB kill time is certainly attractive, I simply can't justify $28/gal when I have this much to clean (52gal main tank, plus multiple smaller tanks)

Regardless of which chemical I use, I'm still concerned about it soaking into driftwood or the lava rocks and either taking excessively long to soak back out or potentially being toxic to the tank.

The substrate is MTS capped with Flourite. Seachem actually recommends boiling Flourite as a way of sterilizing it. So, if I can confirm that heat-killing will work, doing so would save me a substantial amount on replacing enough Flourite for a 52gal tank!

[OverStocked]

In a spray bottle that 1 gallon woudl last you all day. Look it up on dealmed. Boiling sanitizing, but does not sterilize. It requires an autoclave to sterilize.

[FlyingShawn]

Originally Posted by OverStocked

In a spray bottle that 1 gallon woudl last you all day. Look it up on dealmed. Boiling sanitizing, but does not sterilize. It requires an autoclave to sterilize.

For cleaning the tanks themselves, a spray bottle would work. However, I wouldn't trust a spray-application for getting into all of the little pores of lava rock or the driftwood. Regardless, I'd still be concerned about toxic chemicals remaining in the rocks and driftwood after I was done.

After doing a little reading, it seems that dry heat also works for sterilizing, which takes me back to the other option I mentioned of using the oven to bake these materials.

[FlyingShawn]

unissuh said this in the original thread:

Originally Posted by unissuh

Heat will probably knock it off - marinum is a low temp bug, not as temp tolerant as some others in the genus AFAIK. Boil it for a while and it will probably be fine. Wood and rocks are fine with this or soaking in alcohol, I'd ditch your substrate and plants or keep them in a known contaminated system because I don't think it's worth the effort of disinfecting to a satisfactory degree.

I've bolded the key part: as far as he (and I) know, marinum is a low-temp bug. At least on my part, that's only a semi-educated guess, so I'm really hoping to find someone on here who can confirm that with some confidence/authority.

Please chime in if you have any of the education/knowledge to help me figure this out!

[mistergreen]

http://en.wikipedia.org/wiki/Mycobacterium_marinum

The inhibition of growth of M. marinum at 37°C

I'm pretty sure 100°C will kill it.

[Sindawe]

Originally Posted by mistergreen

http://en.wikipedia.org/wiki/Mycobacterium_marinum



I'm pretty sure 100°C will kill it.

A quick search turns up this article that indicates Mycobacterium marinum is a spore forming organism.

http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2705590/

Its been awhile since I worked in the Biosciences, but IIRC you're going to need to autoclave soft materials like drift wood at 121 Celcius, 15 PSI pressure for not less than 20 minutes to get effective sterilzation of spores.

[mistergreen]

We're not going to find an autoclave cheaply. Try a pressure cooker.

[mistergreen]

Originally Posted by FlyingShawn

Regardless of which chemical I use, I'm still concerned about it soaking into driftwood or the lava rocks and either taking excessively long to soak back out or potentially being toxic to the tank.

It's also toxic to you. You need training to handle the stuff.

[Chlorophile]

Originally Posted by mistergreen

It's also toxic to you. You need training to handle the stuff.

And let me tell you those training videos are awful.
I had to get my pesticide handler/worker training a few weeks ago and then I decided never to handle pesticides because they made it clear that you're going to get sick and get cancer and get nerve damage =[

[kwheeler91]

I would ditch all things except the tank and filter housings, sterilize tank and filters, replace media and everything else including substrate, wood, plants, fish. I know its a pain but I have heard fish tb can be contracted by humans. Even if thats not the case you dont want a reoccurence once you get set up again. There are many generous members here who might be able help you get back on your feet.

[DogFish]

Originally Posted by OverStocked

....Any parts you're not attached to should be disposed of. Substrate, for instance.

I'd bleach out the tank & filter. I can't believe much would survive a boil or a bake at 200 degrees.

Sometimes practical is the better path than OCD. If you need to spend $30 in meds& chemicals to save a $3 pc of drift wood, the math on that really doesn't make much sense.

[mallorieGgator]

Unfortunately, heat as in boiling or baking won't work. You would have to autoclave everything (121.21 degrees celcius) for about 90 minutes to be 100% sure you killed it. If it forms spores, you will have to be careful about even using chemicals as some bacteria's spore can actually resist things such as bleach and alcohol. I know with bacillus bacteria they form spores and contaminate a lot of things in the micro lab I used to work in. If we heated a sample to less than 81 celcius, then bacillus would live in a spore form but everything else that was non-spore forming would die.

[DogFish]

Originally Posted by mallorieGgator

Unfortunately, heat as in boiling or baking won't work.

This seems to contradict that http://textbookofbacteriology.net/control_3.html

I can understand the consistency & effectiveness of the autoclave. I don't understand without documented study of how to destroy Mycobacterium marinum, how can we say that Boiling at 220 or heat in a oven at 200 is absolutely not going to work?