Experimenting with in-tank antibiotic treatments for Brown Jelly Disease

[Futuretotm]

Just observations
I returned home after two weeks of vacation to see a few colonies receding and torches/hammers not happy.
I decided to throw 250mg of cipro in the sump after lights out for 3-4 days

Not sure if Cipro made things better, or things just got better themselves, but noted a marked improvement in the next few days. Other things that changed: stopped the autofeeder(flakes/pellets), restarted frozen food/frozen clams

 

[tundraguy1106]

Just observations
I returned home after two weeks of vacation to see a few colonies receding and torches/hammers not happy.
I decided to throw 250mg of cipro in the sump after lights out for 3-4 days

Not sure if Cipro made things better, or things just got better themselves, but noted a marked improvement in the next few days. Other things that changed: stopped the autofeeder(flakes/pellets), restarted frozen food/frozen clams

Cipro is really good in my experience. Helped me beat BJD. I use it to dip anything that looks off using the KFC dip method. I’ll also do a 10 day display tank treatment if I suspect anything in my main tank. Have not observed any issues in dosing it so far.

 

[nomad6]

Had a couple of aussie torches bj due to an indo beating on them at night, broke a 2 h Aussie hammer, tried saving it by gluing it it back together lived for 6 days and on 7th bj’d. Chain reaction aussie bj’d then torches have a fully stocked tank w wall to wall euphyllia, had a few other frags start showing signs of infection and in an effort to halt the spread I dosed h2o2 at 0.75ml/ gal, plunged orp (die off) but next day those frags were fully extended some showing a burn here and there on tentacles but recovered within a few days. I’ve been keeping a close eye on my tank and keeping up w beneficial bacteria dosing but have also noticed that like all bacteria it’s opportunistic. After dosing dr Tim’s or brightwells I notice a slight decline in health of those sick coral. After dosing h2o2 they bounce back and depending on severity an iodine dip max dose max time with a rinse bath 1ml/gal h2o2. I do have a hospital tank but I mainly use it when coral are on the fritz. Side effect, slight tissue recession im thinking due to stress of the oxidation effect but I feed every other day so tissue regenerates pretty quick. Main reason I don’t do antibiotics is due to the fear of creating a super strain in my tank and effectively wiping out all my stock. Not against Cipro but I’ve seen hydrogen peroxide plus iodine dips to halt bjd spread/ infection. I have used antibiotic dips to halt stn on some acros and know they’re effective. Just wanted to add and share an alternative to Cipro. Also, wipes algae and cyano out. Will spike nutrients a bit for sure but nothing good husbandry can’t handle.

 

[Atlantis3199]

Brown Jelly Disease (BJD) is an issue many reefers have run into. Like most coral diseases, the pathogen causing BJD has not been conclusively determined. Here I will share some observations and test results supporting the idea that its caused by a bacterial pathogen, and so may be treatable with antibiotics.

I'm sure this is not the first time someone's tried antibiotics against BJD, but I havent previously come across a DNA based study of the results. This is a preliminary investigation based on observations made on my home tanks spanning a few months. It is not conclusive, and is not intended to put the discussion to rest; far from it. It's just another piece of the puzzle as we figure out how to deal with this disease.

Overall my finding suggest that:

• Infection with a specific bacterium in the genus Arcobacter contributes to BJD.
• This infection can be safely treated in the aquarium with low doses of a commonly used aquarium antibiotic.
• This treatment doesn't appear to damage the microbial community, but may actually improve it.

Here is the story, including the single case study so far of a tank treated in this way.

A Specific Bacterium Associated with Brown Jelly Disease
Over the last 6 months I've seen several cases where newly imported Euphyllia developed Brown Jelly Disease shortly after I received them. It had all the signs of an infectious disease. A newly imported colony would dissolve in BJD, and several other frags Euphyllia in the tank would also develop BJD if I didn't remove the affected corals quickly enough.

These corals aren't cheap, so my instinct was initially to try to save them (with no success) rather than conduct experiments. But after losing a few Euphyllia from different orders and suppliers my curiosity got the better of me. So the next two corals that developed early signs of BJD (a Hammer Coral E. ancora, and a Grape Coral E. cristata), I let it develop. Once they were in full-blown BJD, I sacrificed and sampled them.

Both of these samples were dominated by a single type, an unclassified bacterium in the genus Arcobacter. To clarify what I mean by that: this is a type that has been seen before, it's a perfect match to a sequence record in public DNA sequence databases. But, like so many microbes found in environmental samples, the species has not been formally described and named.

Identifying it to the genus can be pretty useful, though. The genus Arcobacter includes several known pathogens of humans and other animals, including A. butzleri, which is a food-borne pathogen that presents a serious risk to human health. When you sequence samples of two different diseased corals, and find them both dominated by a genus known to contain pathogens, it's worth noting.

It also gives us a good guess at the likely physical description and lifestyle. These are rod-shaped to helical, non-spore forming, and swim in a corkscrew motion using their single flagellum. These occur in association with animals, and also free living in waste water, seawater, and other aquatic habitats.

This information can also be useful in developing treatment strategies, since the members of a Bacterial genus often share characteristic sensitivities to the same antibiotics. We'll get to that.

Infecting a Euphyllia Garden with BJD
Who would intentionally do such a thing?? Not me.

What happened was this. I continued to buy Euphyllia, a fraction of them continued to develop BJD, and I was experimenting with short antibiotic dips. (This approach never yielded much success for me, but there is more work to be done on that front. )

Then one batch of especially nice corals started to BJD within 24 hours after arrival, and I panicked. I decided my Frag Tank must have the BJD pathogen, and I needed to get them out of it. I triaged the new corals, sacrificing the worst cases and transferring a couple that I thought were clean into a different tank... my Euphyllia Display Tank.

This was not my smartest move ever. They were so pretty, I acted irrationally

Next thing you know, both of the new Euphyllia and 4 of my existing Euphyllia in the tank were showing early signs of stress. They all showed oddly deflated tentacles that were not fully extended, and I could the beginnings of some of the characteristic Brown Jelly stuff on the two new corals. I removed these plaguebearers, pretty though they were, from the tank.

So I sampled the water at this point... after introducing the new corals, at the earliest signs of stress. What I found: exactly the same bug (Acrobacter sp., sv1103) at unusually high levels. I found 92 sequences matching this perfectly, representing >1% of the total community. (These were never found in biofilm samples, this analysis is based only on water samples)

Treating BJD with antibiotics, in the aquarium
What to do? I could remove all the Euphyllia and try a dip, but I hadn't been having much success with dips. So I looked at the tank and realized, the only corals I cared about in this tank were the Euphyllia. Fish are easy to move to another tank if something goes wrong, I have plenty of tanks running with room for a fish or two.

So I decided to take the plunge and treat my whole tank with the antibiotic. Although it's often repeated on the internet that adding antibiotics to your tank will kill the good bacteria, I hadn't seen any evidence of that.

Meanwhile I had evidence an Arcobacter species was associated with BJD, published reports of the antibiotic sensitivity of these bugs, and a tank full of Euphyllia on the verge of succumbing to BJD. So I dosed the tank.

I chose Ciprofloxacin because it is effective at the lowest doses, reasoning that in this way, I could minimize collateral damage. I based this decision on this study because it had a nice comparison of dosage trials for a wide range of antibiotic; I saw several other studies that also supported the use of Ciprofloxacin to treat Arcobacter infections.

I used Ciprofloxacin at 0.125 mg / L. To achieve this I dissolved a 500 mg pill in 50 ml of RODI water, producing a 10 mg / ml solution (which I subsequently stored in the fridge). The aquarium system has 70 gal volume altogether (~265 L), so I added 3.3 ml of this solution to achieve 0.125 mg / L. I repeated this dose every 2 days for 3 doses altogether.

Within 24 hours of the first dose, all of the affected corals showed signs of improvement. Their tentacles inflated again, although the remained not full extended. Within 48 hours they were fully extended and looked perfectly healthy again.

A few days after the final dose, I sampled the aquarium again. Like samples taken from the same aquarium a month prior to introducing the diseased Euphyllia, Arcobacter sp. (sv1103) was again not detected. Introducing the diseased animals introduced the bacterium, and the antibiotic treatment appears to have knocked their populations down substantially.

I should emphasize that since there are no controls, or photographs, for the effects of this treatment on the corals it's entirely possible they simply got better on their own. We can have a little more confidence in the effects of the treatment on the Arcobacter themselves, though. Here we have a measurement of the effect, although not replicated in multiple tanks.

In a future experiment I will address both issues -- this was an experimental trial born of desperation.

But doesn't that kill the good bacteria too?
This is of course a reasonable concern. There's a wide range of views on how to achieve the right microbial community, and how much the various parts of the community even matter. But I think few experienced reefers would say the bacterial community doesnt matter at all. So it makes sense to be cautious about adding antibiotics to the tank and potentially killing off whatever parts of the community you think are important.

But of course the dose makes the poison, and remember that I chose this antibiotic specifically because it was effective against this genus at the lowest dosage of any antibiotics tested.

The system has a moderate bioload with 4 fish in a 40 gallon DT with 30 gallons of sump volume, along with a bunch of corals. There is no algal refugium or macroalgae. So if the nitrifying community were to die, I would expect to see an explosion in nutrients and algal growth. This didnt happen. (I confess, I didnt measure nutrients this time around. I base this conclusion on the lack of algal growth that would be fueled by a rise in nutrients)

More directly, I compared the aquarium microbiome before and after the treatment. Here's a table summarizing the major stats we look at in comparing aquarium microbial communities:

	T-1 month (before BJD)	T+1 day (during BJD)	T+10 days (after treatment)
Diversity Score (percentile)	552 (91st)	438 (69th)	532 (87th)
Balance Score (percentile)	0.5 (76th)	0.18 (50th)	0.51 (83rd)
Ammonia-oxidizing microbes (%)	Present (5.5%)	Present (2.3%)	Present (0.9%)
Nitrite-oxidizing bacteria (%)	Present (0.08%)	Not detected	Present (0.05%)

Did the treatment damage the microbial community? Not at all. If it had any effect at all, it was to restore the community to its previous state by selectively knocking out a few susceptible bacteria.

If all a person cares about is the nitrifying community, that was not removed. There was a slight decrease in AOM while NOB were restored from undetectable to a more typical level.

If a person is interested in the microbial functions of the community more broadly, the summary statistics of Diversity and Balance scores were also improved by the treatment rather than harmed. The introduction of diseased corals lowered both scores, and the antibiotic treatment increased both scores.

This point about the broader microbial community can be illustrated most easily with a barplot showing the community over time. In these plots, each color represents a different microbial family.

The figure shows that the microbial community was fairly typical before BJD, became atypical during BJD, and was restored to something like its previous state following the antibiotic treatment.

A skeptical reader may point out that since there are no replicates here, we can't be confident attributing the changes to the treatment. It could be coincidence. Perhaps the corals recovered on their own and the microbial community resumed its previous structure after a transient disturbance caused by adding diseased corals. Based on my previous efforts to save Euphyllia with BJD I find this a little unlikely, but certainly not impossible.

Ultimately that objection would be correct and in the future I will do a properly replicated experiment to test this. What I've shown here is a just hypothesis with some preliminary evidence supporting it.

How Common is this Bacterium in Saltwater Aquaria?
In a set of 148 aquariums I've sampled (this is not the entire database, its the "high quality" database made up of normal, healthy tanks with good sequencing coverage), Arcobacter sp. sv1103 is not detectable in a majority of tanks.

We can express this same idea a few different ways. For the majority oftanks, this sequence was not detected at all (80%). For nearly all tanks (95%), this bacterium was absent or extremely rare (<0.00006%).

This context makes the comparison with my BJD infected tank even more stark. That 1.2% is huge in comparison with the typical levels observed across a large number of aquaria.


Summary
Based on what I've reported here, I hypothesize that infections with Arcobacter sp. (sv 1103) contribute to Brown Jelly Disease in LPS corals, and that these infections can be safely and effectively treated in the aquarium with low doses of Ciprofloxacin. Depending on the results of further tests, this could be a useful tool for the hobbyist community in the fight against BJD.

Important disclaimer: if anyone reading this feels inspired to treat their own tank, I specifically take no responsibility for the results. This is an experimental treatment, and if you run experiments on your own tank you take all the responsibility for the results.

But I know some of you, like me, enjoy running experiments on your own tanks. Many of us have a bottle of Cipro sitting around. And anybody who keeps Euphyllia is likely to encounter BJD at some point. Anybody want to test this? I'll throw in the microbiome testing before and after if so...

Thanks for reading and may your tanks stay free of Brown Jelly!


[unless you're the kind of person inclined to run experiments with antibiotics on your tanks, so you can help me duplicate this ]

Great reading. I have a system of 2000 litres.
I ship in euphyllia every 2 weeks and want to keep cipro in my system all the time. What dosage would you recommend for a 2000 litre system.

Kind regards Mark
07834349830
[email protected]

 

[Tired]

That seems like a good way to potentially make your corals and/or yourself sick with an antibiotic-resistant pathogen of some sort.

 

[Tina22]

any other sources. When I go to order it says out of stock see alternatives.

Fish Flox Forte Ciprofloxacin 500 mg | Fish Antibiotics

Fish Flox and Fish Flox Forte are Manufactured in the USA with USA-sourced ingredientsand and are both Pharmaceutical Grade Fish Antibiotics , Free Shipping on Every Order of Fish Antibiotics !

www.fishick.com

My fish are doing fine. I thought I had lost them. A great product at a great price

 

[TheSheff]

I know this is a thread mentioning ciprofloxacin but could there be a potential that a UV sterilizer could reduce the population of arcobacter?

 

[FlyPenFly]

Making sure I did the math right but if I'm using 150mg pills in 50ml water, to achieve .125mg/l for 151L I should be using 6ml?

 

[KrisReef]

Making sure I did the math right but if I'm using 150mg pills in 50ml water, to achieve .125mg/l for 151L I should be using 6ml?

6.29 ml

150mg/50ml = 3mg/ml treatment solution

0.125mg/l x 151l = 18.875mg/ treatment

18.875 mg/treatment / 3mg/treatment solution = 6.29 mls

I hope you have a 10ml syringe laying around (I have extras for my Hanna Checkers).

 

[KrisReef]

I know this is a thread mentioning ciprofloxacin but could there be a potential that a UV sterilizer could reduce the population of arcobacter?

I think it might impact microbes, but I am not sure if it reduces arcobacter?

I know that a UV will impact ciprofloxacin. It is light sensitive and a tank with a UV should light needs to cut the power off during treatment.

 

[MartinM]

I know this is a thread mentioning ciprofloxacin but could there be a potential that a UV sterilizer could reduce the population of arcobacter?

It makes sense it would in the water column if utilized properly, but it wouldn’t cure an active infection in an animal.

 

[eyesolator]

I had a branching hammer for over 10 years that was literally bullet proof. Big time alkalinity , calcium and magnesium swings. NO3 and PO4 through the roof and then nonexistent. Yep I have done everything imaginable to kill coral and have done pretty good job of it. But the branching hammer always survived and thrived. For the last several years things have been very stable until I added some new LPS.

Since I gave a lot of coral to my local LFS they allowed me to get coral at wholesale pricing just split shipping. Great deal so I got pictinia, parascolmyia and a trachy. Not long after adding them my bullet proof hammer had a head BJ, then a torch did the same and it would randomly happen for no apparent reason ever now and again? The trach just never looked good and is in the landfill. Same with the para however I was able to save the para using every dip imaginable but not the pictinia. It’s skin has been shrunk tightly to its skeleton since about a month after I got it and despite several dips it just kept receding. I was ready to give up and just toss it.

Then I came across this thread. Got some aqua cipro and starting dosing the system per AquaBiomics instructions mainly to prevent any BJ on my hammer and torches. Not sure what to expect the next day after the first dose but when the lights came on I was shocked, astounded!! The pictinias flesh was puffed up and looked normal?? All other LPS looked a little better as well. This is crazy!

While the pictinia looks horriable I confident that in time it will make a full recovery. In the future nothing will go into my tanks without a couple days of cipro quarentine.

When I first got it.

Now

 

[CaptainSupersonic]

I am dosing using the OP math but for six nights. On the forth night and everything is looking great. For anyone else worried of detrimental effects, I haven't seen any.

 

[FlyPenFly]

I did a 2x or maybe more overdose A few weeks ago.

Had an amazingly huge Dino breakout shortly after. I think it caused a big bacterial imbalance and Dinos took advantage of it. All my torches closed up extremely tight.

Thankfully, had a second display tank to move everything over while I fought off the Dino’s. It was the worst case of Dino’s I’ve ever seen. When sucked out to a bucket And let standing for a few hours, they formed crystalline alien looking spirals. It was messed up.

Anyway, don’t overdose.

 

[CaptainSupersonic]

I did a 2x or maybe more overdose A few weeks ago.

Had an amazingly huge Dino breakout shortly after. I think it caused a big bacterial imbalance and Dinos took advantage of it. All my torches closed up extremely tight.

Thankfully, had a second display tank to move everything over while I fought off the Dino’s. It was the worst case of Dino’s I’ve ever seen. When sucked out to a bucket And let standing for a few hours, they formed crystalline alien looking spirals. It was messed up.

Anyway, don’t overdose.

Good advice. I am dosing at the recommended daily dose but doing it for six straight nights.

 

[MartinM]

I've actually dosed as high as 6.25mg/L in one of my displays to cure an anemone dominated display system. I had some dinos but nothing nearly that crazy. They went away when I added the carbon back. SPS, LPS, clams, sponges, etc were all fine.

 

[Marinexx]

Brown Jelly Disease (BJD) is an issue many reefers have run into. Like most coral diseases, the pathogen causing BJD has not been conclusively determined. Here I will share some observations and test results supporting the idea that its caused by a bacterial pathogen, and so may be treatable with antibiotics.

I'm sure this is not the first time someone's tried antibiotics against BJD, but I havent previously come across a DNA based study of the results. This is a preliminary investigation based on observations made on my home tanks spanning a few months. It is not conclusive, and is not intended to put the discussion to rest; far from it. It's just another piece of the puzzle as we figure out how to deal with this disease.

Overall my finding suggest that:

• Infection with a specific bacterium in the genus Arcobacter contributes to BJD.
• This infection can be safely treated in the aquarium with low doses of a commonly used aquarium antibiotic.
• This treatment doesn't appear to damage the microbial community, but may actually improve it.

Here is the story, including the single case study so far of a tank treated in this way.

A Specific Bacterium Associated with Brown Jelly Disease
Over the last 6 months I've seen several cases where newly imported Euphyllia developed Brown Jelly Disease shortly after I received them. It had all the signs of an infectious disease. A newly imported colony would dissolve in BJD, and several other frags Euphyllia in the tank would also develop BJD if I didn't remove the affected corals quickly enough.

These corals aren't cheap, so my instinct was initially to try to save them (with no success) rather than conduct experiments. But after losing a few Euphyllia from different orders and suppliers my curiosity got the better of me. So the next two corals that developed early signs of BJD (a Hammer Coral E. ancora, and a Grape Coral E. cristata), I let it develop. Once they were in full-blown BJD, I sacrificed and sampled them.

Both of these samples were dominated by a single type, an unclassified bacterium in the genus Arcobacter. To clarify what I mean by that: this is a type that has been seen before, it's a perfect match to a sequence record in public DNA sequence databases. But, like so many microbes found in environmental samples, the species has not been formally described and named.

Identifying it to the genus can be pretty useful, though. The genus Arcobacter includes several known pathogens of humans and other animals, including A. butzleri, which is a food-borne pathogen that presents a serious risk to human health. When you sequence samples of two different diseased corals, and find them both dominated by a genus known to contain pathogens, it's worth noting.

It also gives us a good guess at the likely physical description and lifestyle. These are rod-shaped to helical, non-spore forming, and swim in a corkscrew motion using their single flagellum. These occur in association with animals, and also free living in waste water, seawater, and other aquatic habitats.

This information can also be useful in developing treatment strategies, since the members of a Bacterial genus often share characteristic sensitivities to the same antibiotics. We'll get to that.

Infecting a Euphyllia Garden with BJD
Who would intentionally do such a thing?? Not me.

What happened was this. I continued to buy Euphyllia, a fraction of them continued to develop BJD, and I was experimenting with short antibiotic dips. (This approach never yielded much success for me, but there is more work to be done on that front. )

Then one batch of especially nice corals started to BJD within 24 hours after arrival, and I panicked. I decided my Frag Tank must have the BJD pathogen, and I needed to get them out of it. I triaged the new corals, sacrificing the worst cases and transferring a couple that I thought were clean into a different tank... my Euphyllia Display Tank.

This was not my smartest move ever. They were so pretty, I acted irrationally

Next thing you know, both of the new Euphyllia and 4 of my existing Euphyllia in the tank were showing early signs of stress. They all showed oddly deflated tentacles that were not fully extended, and I could the beginnings of some of the characteristic Brown Jelly stuff on the two new corals. I removed these plaguebearers, pretty though they were, from the tank.

So I sampled the water at this point... after introducing the new corals, at the earliest signs of stress. What I found: exactly the same bug (Acrobacter sp., sv1103) at unusually high levels. I found 92 sequences matching this perfectly, representing >1% of the total community. (These were never found in biofilm samples, this analysis is based only on water samples)

Treating BJD with antibiotics, in the aquarium
What to do? I could remove all the Euphyllia and try a dip, but I hadn't been having much success with dips. So I looked at the tank and realized, the only corals I cared about in this tank were the Euphyllia. Fish are easy to move to another tank if something goes wrong, I have plenty of tanks running with room for a fish or two.

So I decided to take the plunge and treat my whole tank with the antibiotic. Although it's often repeated on the internet that adding antibiotics to your tank will kill the good bacteria, I hadn't seen any evidence of that.

Meanwhile I had evidence an Arcobacter species was associated with BJD, published reports of the antibiotic sensitivity of these bugs, and a tank full of Euphyllia on the verge of succumbing to BJD. So I dosed the tank.

I chose Ciprofloxacin because it is effective at the lowest doses, reasoning that in this way, I could minimize collateral damage. I based this decision on this study because it had a nice comparison of dosage trials for a wide range of antibiotic; I saw several other studies that also supported the use of Ciprofloxacin to treat Arcobacter infections.

I used Ciprofloxacin at 0.125 mg / L. To achieve this I dissolved a 500 mg pill in 50 ml of RODI water, producing a 10 mg / ml solution (which I subsequently stored in the fridge). The aquarium system has 70 gal volume altogether (~265 L), so I added 3.3 ml of this solution to achieve 0.125 mg / L. I repeated this dose every 2 days for 3 doses altogether.

Within 24 hours of the first dose, all of the affected corals showed signs of improvement. Their tentacles inflated again, although the remained not full extended. Within 48 hours they were fully extended and looked perfectly healthy again.

A few days after the final dose, I sampled the aquarium again. Like samples taken from the same aquarium a month prior to introducing the diseased Euphyllia, Arcobacter sp. (sv1103) was again not detected. Introducing the diseased animals introduced the bacterium, and the antibiotic treatment appears to have knocked their populations down substantially.

I should emphasize that since there are no controls, or photographs, for the effects of this treatment on the corals it's entirely possible they simply got better on their own. We can have a little more confidence in the effects of the treatment on the Arcobacter themselves, though. Here we have a measurement of the effect, although not replicated in multiple tanks.

In a future experiment I will address both issues -- this was an experimental trial born of desperation.

But doesn't that kill the good bacteria too?
This is of course a reasonable concern. There's a wide range of views on how to achieve the right microbial community, and how much the various parts of the community even matter. But I think few experienced reefers would say the bacterial community doesnt matter at all. So it makes sense to be cautious about adding antibiotics to the tank and potentially killing off whatever parts of the community you think are important.

But of course the dose makes the poison, and remember that I chose this antibiotic specifically because it was effective against this genus at the lowest dosage of any antibiotics tested.

The system has a moderate bioload with 4 fish in a 40 gallon DT with 30 gallons of sump volume, along with a bunch of corals. There is no algal refugium or macroalgae. So if the nitrifying community were to die, I would expect to see an explosion in nutrients and algal growth. This didnt happen. (I confess, I didnt measure nutrients this time around. I base this conclusion on the lack of algal growth that would be fueled by a rise in nutrients)

More directly, I compared the aquarium microbiome before and after the treatment. Here's a table summarizing the major stats we look at in comparing aquarium microbial communities:

	T-1 month (before BJD)	T+1 day (during BJD)	T+10 days (after treatment)
Diversity Score (percentile)	552 (91st)	438 (69th)	532 (87th)
Balance Score (percentile)	0.5 (76th)	0.18 (50th)	0.51 (83rd)
Ammonia-oxidizing microbes (%)	Present (5.5%)	Present (2.3%)	Present (0.9%)
Nitrite-oxidizing bacteria (%)	Present (0.08%)	Not detected	Present (0.05%)

Did the treatment damage the microbial community? Not at all. If it had any effect at all, it was to restore the community to its previous state by selectively knocking out a few susceptible bacteria.

If all a person cares about is the nitrifying community, that was not removed. There was a slight decrease in AOM while NOB were restored from undetectable to a more typical level.

If a person is interested in the microbial functions of the community more broadly, the summary statistics of Diversity and Balance scores were also improved by the treatment rather than harmed. The introduction of diseased corals lowered both scores, and the antibiotic treatment increased both scores.

This point about the broader microbial community can be illustrated most easily with a barplot showing the community over time. In these plots, each color represents a different microbial family.

The figure shows that the microbial community was fairly typical before BJD, became atypical during BJD, and was restored to something like its previous state following the antibiotic treatment.

A skeptical reader may point out that since there are no replicates here, we can't be confident attributing the changes to the treatment. It could be coincidence. Perhaps the corals recovered on their own and the microbial community resumed its previous structure after a transient disturbance caused by adding diseased corals. Based on my previous efforts to save Euphyllia with BJD I find this a little unlikely, but certainly not impossible.

Ultimately that objection would be correct and in the future I will do a properly replicated experiment to test this. What I've shown here is a just hypothesis with some preliminary evidence supporting it.

How Common is this Bacterium in Saltwater Aquaria?
In a set of 148 aquariums I've sampled (this is not the entire database, its the "high quality" database made up of normal, healthy tanks with good sequencing coverage), Arcobacter sp. sv1103 is not detectable in a majority of tanks.

We can express this same idea a few different ways. For the majority oftanks, this sequence was not detected at all (80%). For nearly all tanks (95%), this bacterium was absent or extremely rare (<0.00006%).

This context makes the comparison with my BJD infected tank even more stark. That 1.2% is huge in comparison with the typical levels observed across a large number of aquaria.


Summary
Based on what I've reported here, I hypothesize that infections with Arcobacter sp. (sv 1103) contribute to Brown Jelly Disease in LPS corals, and that these infections can be safely and effectively treated in the aquarium with low doses of Ciprofloxacin. Depending on the results of further tests, this could be a useful tool for the hobbyist community in the fight against BJD.

Important disclaimer: if anyone reading this feels inspired to treat their own tank, I specifically take no responsibility for the results. This is an experimental treatment, and if you run experiments on your own tank you take all the responsibility for the results.

But I know some of you, like me, enjoy running experiments on your own tanks. Many of us have a bottle of Cipro sitting around. And anybody who keeps Euphyllia is likely to encounter BJD at some point. Anybody want to test this? I'll throw in the microbiome testing before and after if so...

Thanks for reading and may your tanks stay free of Brown Jelly!


[unless you're the kind of person inclined to run experiments with antibiotics on your tanks, so you can help me duplicate this ]

Are you still looking to replicate and offering two kits for follow-up analyses?
confirmed Arcobacter sp / Aquabiomics test results 1001788_Microbiome May 9, 2023.
I have Chewy delivering Cipro flora in hopefully tomorrow. I spect I can wait, TSA Lime Surprise Torch is retracting but slowly. Hammers and Goniaporas are still doing fine.
However, SCTLD has already affected Pectinia, a single corrallite on a favites and also affecting montipora and chalice. Will Ciprofloxacin effectively treat SCTLD?

 

[drbark]

Just my two cents with Cipro treatments. I have a great number of Torches and Hammers so after a couple of heads appeared to have died from brown jelly, I decided to do the tank treatment route. I have dipped them in the past in Cipro with minimal results. I made a 50 mg/ml solution and stored it in the fridge in a dark glass container. Then treated the tank to a final concentration of 0.125 mg/L at night at 8 PM and then another dose at 8 AM. I did it for 5 days straight. I obviously removed carbon from the system and took off the skimmer reservior. I didn't turn off the skimmer becaue I draw air from outside with the skimmer for pH control. That was a month ago. Not only I have not lost a single head since, but my other torches are open even more with more vibrant colors than before. I was pleasantly surprised and terrified at the same time when I was doing a whole tank treatment.

I have many Acanthophyllias, and expensive torches so if they didn't make it I figured my marriage might be in jeopordy.

 

[FlyPenFly]

Really hope Cipro remains effective and we’re not encouraging a super bug strain that can wipe out Euphyllia.

 

[taricha]

It seems this treatment will become an increasingly large part of the hobby toolbox.

Apparently, the same arcobacter species that is the central character of this thread is also a likely cause behind Brown Jelly in goniopora, and RTN in millepora. Would not have guessed that these diseases in these different corals are the same disease - but it seems at least likely that they can all be caused by the exact same pathogen. See vid below.

Dr. Eli Meyer from AquaBiomics and Dr. Andrew Bouwma (29:30 - 31:45 in video)

Dr. Bouwma also mentions that another antibiotic may be more sensible choice as it acts like cipro, but is not a human-use antibiotic.