Brown Jelly Disease: Under The Microscope!
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Backreefing
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Have you tryed Chemiclean? It works against cyano ( I know it’s much different) but it may work??
Backreefing
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Also you wrote that BJD seems to not exist in the dark areas of the aquarium. Which leads me to ask has anyone tried a total aquarium blackout at first sight of the disease?
OP
OP
I'm sorry, I can't recall saying this? In any event, that certainty hasn't been my observation. We've sucsessfully been "culturing" the organisms associated with BJD in both light and dark and have not observed any difference between the two samples.
Yes, we will be posting the results of chemiclean shortly.
OP
OP
Hydrogen Peroxide
Hydrogen peroxide is a powerful oxidizer that is readily available to hobbyists. Hydrogen peroxide has been used in the hobby with various degrees of sucsess as a coral dip, dosed for dinoflagellates, and used as a point treatment for certain macro algaes including green hair algae. The concentrations of each treatment differ wildly, so a large serial dilution was employed for treatments. For these series of experiments, 3% hydrogen peroxide was utilized.
Concentrations (Hydrogen peroxide to saltwater): 1:100,000, 1:10,000, 1:1,000, 1:100, 1:10, 1:4, 1:2
Time Course: 30 seconds, 60 seconds, 2 minutes, 5 minutes
Results:
Ciliates were unaffected at 1:100,000, 1:10,000 and 1:1,000 concentrations. A reduction in ciliate activity was noticed at 5 minutes at the 1:100 concentration.
Two- and five-minute dips of 1:10 concentration: many of the ciliates were motionless or almost motionless with faint twitching. Of those that were moving, their cilia beat in what appeared to be a non-coordinated manner which produced a rotational movement. The ciliates that rotated continued to do so for hours and never recovered. Most perished hours later.
[Ciliates exposed to 1:10 hydrogen peroxide concentrations after 5 minutes]
[Another example of the uncoordinated movement following exposure]
Dips of 1:4 and 1:2 concentrations were completely lethal to the ciliates for dips lasting more than 60 seconds.
Three infected specimens of C. furcate were rinsed in clean saltwater to remove as much of the brown jelly as possible before being treated with a 1:10 concentration of 3% hydrogen peroxide for 5 minutes. The treated specimens were then rinsed with fresh saltwater and placed in separate experimental tanks utilizing a mature biological filter from a non-infected tank. All water parameters were identical to their original tank. Two of the three specimens of C. furcate survived treatment and did not display any further symptoms consistent with BJD after 7 days. These specimens eventually made a full recovery. One specimen is still under observation, but preliminary observations suggest the specimen will likely perish.
Takeaway:
As a strong oxidizer and antiseptic, hydrogen peroxide was the first agent that was able to effectively disrupt ciliate activity without killing the host coral. That being said, only three specimens of a single species (C. furcate) were tested. Further tests will be necessary to determine whether disruption of ciliates by hydrogen peroxide is associated with a meaningful mortality benefit to infected corals. Further tests are being designed to investigate additional time points, concentrations, and treatment of other species in order to determine optimal dosing. At present, these tests only suggest hydrogen peroxide is a useful target for further experimentation. As control tests have not been carried out to test the safety of such concentrations on healthy specimens, it is premature to suggest hydrogen peroxide be used as a coral dip for BJD.
Right now, we are currently investigating the MIC and minimum contact time of hydrogen peroxide to try and provide more information concerning efficacy and a possible safety profile.
Hydrogen peroxide is a powerful oxidizer that is readily available to hobbyists. Hydrogen peroxide has been used in the hobby with various degrees of sucsess as a coral dip, dosed for dinoflagellates, and used as a point treatment for certain macro algaes including green hair algae. The concentrations of each treatment differ wildly, so a large serial dilution was employed for treatments. For these series of experiments, 3% hydrogen peroxide was utilized.
Concentrations (Hydrogen peroxide to saltwater): 1:100,000, 1:10,000, 1:1,000, 1:100, 1:10, 1:4, 1:2
Time Course: 30 seconds, 60 seconds, 2 minutes, 5 minutes
Results:
Ciliates were unaffected at 1:100,000, 1:10,000 and 1:1,000 concentrations. A reduction in ciliate activity was noticed at 5 minutes at the 1:100 concentration.
Two- and five-minute dips of 1:10 concentration: many of the ciliates were motionless or almost motionless with faint twitching. Of those that were moving, their cilia beat in what appeared to be a non-coordinated manner which produced a rotational movement. The ciliates that rotated continued to do so for hours and never recovered. Most perished hours later.
[Ciliates exposed to 1:10 hydrogen peroxide concentrations after 5 minutes]
[Another example of the uncoordinated movement following exposure]
Dips of 1:4 and 1:2 concentrations were completely lethal to the ciliates for dips lasting more than 60 seconds.
Three infected specimens of C. furcate were rinsed in clean saltwater to remove as much of the brown jelly as possible before being treated with a 1:10 concentration of 3% hydrogen peroxide for 5 minutes. The treated specimens were then rinsed with fresh saltwater and placed in separate experimental tanks utilizing a mature biological filter from a non-infected tank. All water parameters were identical to their original tank. Two of the three specimens of C. furcate survived treatment and did not display any further symptoms consistent with BJD after 7 days. These specimens eventually made a full recovery. One specimen is still under observation, but preliminary observations suggest the specimen will likely perish.
Takeaway:
As a strong oxidizer and antiseptic, hydrogen peroxide was the first agent that was able to effectively disrupt ciliate activity without killing the host coral. That being said, only three specimens of a single species (C. furcate) were tested. Further tests will be necessary to determine whether disruption of ciliates by hydrogen peroxide is associated with a meaningful mortality benefit to infected corals. Further tests are being designed to investigate additional time points, concentrations, and treatment of other species in order to determine optimal dosing. At present, these tests only suggest hydrogen peroxide is a useful target for further experimentation. As control tests have not been carried out to test the safety of such concentrations on healthy specimens, it is premature to suggest hydrogen peroxide be used as a coral dip for BJD.
Right now, we are currently investigating the MIC and minimum contact time of hydrogen peroxide to try and provide more information concerning efficacy and a possible safety profile.
OP
OP
Fluoroquinolones
Fluoroquinolones are a group of broad spectrum antibiotics that are effective in a concentration-dependent manner. Although recently falling out of favor in human medicine due to their side-effect profile, their unique mechanism of action makes them a target for possible study. Much like the macrolides, these antibiotics are unlikely to be available to most hobbyists. For these experiments, we utilized the second generation fluoroquinolone, Ciprofloxacin and the third generation fluoroquinolone, Levofloxacin.
Concentrations: Based on limited toxicity information in marine environments, a large serial dilution was employed in these experiments. Concentrations of 1mg/gallon, 10mg/gallon, 100mg/gallon, 1g/gallon, and 10g/gallon were tested.
Time Course: 1, 5, 15, 30, 60, 240 minutes
Results:
Ciliates were completely unaffected of both levofloxacin and ciprofloxacin at doses up to 1g/gallon at all time points. At levofloxacin concentrations of 10g/gallon, the samples became opaque and foul smelling. Ciliates did not seem to be moving at this dose, although no organisms could be seen to be moving. It remains unknown whether the observations are due to the opacity of the water, direct action of the fluoroquinolone on the ciliates, or secondary to antimicrobial activity that affected the water chemistry. Further trials of levofloxacin at 10g/gallon all demonstrated similar findings.
Two specimens of infected Duncanopsammia axifuga were dipped for 1 hour in 100mg/gallon and 1g/gallon concentrations of levofloxacin. The treated specimens were then rinsed with fresh saltwater and placed in separate experimental tanks utilizing a mature biological filter from a non-infected tank. All water parameters were identical to their original tank. One specimen (treated in 1g/gallon) perished within 18 hours, the other specimen (100mg/gallon) died within 36 hours.
Takeaway:
Unlike time dependent antibiotics such as the beta-lactams (to be written up) or macrolides (detailed above), the fluoroquinolones kill via a concentration dependent manner. Even at extremely high concentrations (26mg/dL), the antibiotic had no effect on ciliate activity. Although only tested on two specimens, both specimens treated with 100mg/gallon and 1g/gallon continued to demonstrate symptoms consistent with the unabated spread of BJD and died within 36 hours. At present, it does not appear the fluoroquinalones are an effective antimicrobial for treating the ciliates associated with BJD.
Fluoroquinolones are a group of broad spectrum antibiotics that are effective in a concentration-dependent manner. Although recently falling out of favor in human medicine due to their side-effect profile, their unique mechanism of action makes them a target for possible study. Much like the macrolides, these antibiotics are unlikely to be available to most hobbyists. For these experiments, we utilized the second generation fluoroquinolone, Ciprofloxacin and the third generation fluoroquinolone, Levofloxacin.
Concentrations: Based on limited toxicity information in marine environments, a large serial dilution was employed in these experiments. Concentrations of 1mg/gallon, 10mg/gallon, 100mg/gallon, 1g/gallon, and 10g/gallon were tested.
Time Course: 1, 5, 15, 30, 60, 240 minutes
Results:
Ciliates were completely unaffected of both levofloxacin and ciprofloxacin at doses up to 1g/gallon at all time points. At levofloxacin concentrations of 10g/gallon, the samples became opaque and foul smelling. Ciliates did not seem to be moving at this dose, although no organisms could be seen to be moving. It remains unknown whether the observations are due to the opacity of the water, direct action of the fluoroquinolone on the ciliates, or secondary to antimicrobial activity that affected the water chemistry. Further trials of levofloxacin at 10g/gallon all demonstrated similar findings.
Two specimens of infected Duncanopsammia axifuga were dipped for 1 hour in 100mg/gallon and 1g/gallon concentrations of levofloxacin. The treated specimens were then rinsed with fresh saltwater and placed in separate experimental tanks utilizing a mature biological filter from a non-infected tank. All water parameters were identical to their original tank. One specimen (treated in 1g/gallon) perished within 18 hours, the other specimen (100mg/gallon) died within 36 hours.
Takeaway:
Unlike time dependent antibiotics such as the beta-lactams (to be written up) or macrolides (detailed above), the fluoroquinolones kill via a concentration dependent manner. Even at extremely high concentrations (26mg/dL), the antibiotic had no effect on ciliate activity. Although only tested on two specimens, both specimens treated with 100mg/gallon and 1g/gallon continued to demonstrate symptoms consistent with the unabated spread of BJD and died within 36 hours. At present, it does not appear the fluoroquinalones are an effective antimicrobial for treating the ciliates associated with BJD.
OP
OP
Beta Lactams
The beta lactam antibiotics are a diverse group of antibiotics all containing a beta lactam ring in their structure. The beta lactams interact with specific proteins and disrupt cell wall synthesis and integrity. While not all beta lactams are available to hobbyists (e.g. carbapenems), certain products are available to the hobbyist (e.g. Fish Mox).
For the purposes of this test, we utilized Amoxicillin, and the first generation cephlasporin, cephalexin. At the time of this writing, we have not tested any 3rd generation cephlasporins which have increased gram negative activity.
Concentrations were based around FishMox dosage of 250mg per 10 gallons of water. The tested concentrations were: 250mg/10 gallons, 250mg/1 gallon, 2.5g/1 gallon, 25g/1 gallon.
Time course: 5, 10, 30, 60, 240 minutes
Results:
Ciliates were completely unaffected of both amoxicillin and cephalexin at doses up to 25g/gallon at all time points. Selected samples were observed 24 hours post treatment and all ciliates were still motile and behaving appropriately.
[Ciliate activity 24 hours post treatment with 2.5g Amoxicillin/gallon for 240 minutes]
Four specimens of infected Duncanopsammia axifuga were dipped for 1 hour in 250mg/gallon and 2.5g/gallon concentrations of Amoxicillin and Cephalexin (two specimens per agent). The treated specimens were then rinsed with fresh saltwater and placed in separate experimental tanks utilizing a mature biological filter from a non-infected tank. All water parameters were identical to their original tank. Three of the four specimens continued to show signs consistent with the progression of BJD and died within 48 hours. One specimen (2.5g/gallon Amoxicillin), had a cessation of tissue loss after 12 hours and remained consistent for the next 36 hours. That specimen eventually perished after 7 days. It is unknown whether the specimen ultimately succumbed to BJD or died from an infection secondary to the damage of the BJD.
Takeaway:
Unfortunately, both beta lactams tested have good coverage of gram-positive organisms, but poor coverage of gram negative coverage. Further tests could look at 3rd or 4th generation cephlosporins to see what effect this broader spectrum of activity has on coral/ciliate mortality. At present, it does not appear the beta lactams are an effective antimicrobial for treating the ciliates associated with BJD.
The beta lactam antibiotics are a diverse group of antibiotics all containing a beta lactam ring in their structure. The beta lactams interact with specific proteins and disrupt cell wall synthesis and integrity. While not all beta lactams are available to hobbyists (e.g. carbapenems), certain products are available to the hobbyist (e.g. Fish Mox).
For the purposes of this test, we utilized Amoxicillin, and the first generation cephlasporin, cephalexin. At the time of this writing, we have not tested any 3rd generation cephlasporins which have increased gram negative activity.
Concentrations were based around FishMox dosage of 250mg per 10 gallons of water. The tested concentrations were: 250mg/10 gallons, 250mg/1 gallon, 2.5g/1 gallon, 25g/1 gallon.
Time course: 5, 10, 30, 60, 240 minutes
Results:
Ciliates were completely unaffected of both amoxicillin and cephalexin at doses up to 25g/gallon at all time points. Selected samples were observed 24 hours post treatment and all ciliates were still motile and behaving appropriately.
[Ciliate activity 24 hours post treatment with 2.5g Amoxicillin/gallon for 240 minutes]
Four specimens of infected Duncanopsammia axifuga were dipped for 1 hour in 250mg/gallon and 2.5g/gallon concentrations of Amoxicillin and Cephalexin (two specimens per agent). The treated specimens were then rinsed with fresh saltwater and placed in separate experimental tanks utilizing a mature biological filter from a non-infected tank. All water parameters were identical to their original tank. Three of the four specimens continued to show signs consistent with the progression of BJD and died within 48 hours. One specimen (2.5g/gallon Amoxicillin), had a cessation of tissue loss after 12 hours and remained consistent for the next 36 hours. That specimen eventually perished after 7 days. It is unknown whether the specimen ultimately succumbed to BJD or died from an infection secondary to the damage of the BJD.
Takeaway:
Unfortunately, both beta lactams tested have good coverage of gram-positive organisms, but poor coverage of gram negative coverage. Further tests could look at 3rd or 4th generation cephlosporins to see what effect this broader spectrum of activity has on coral/ciliate mortality. At present, it does not appear the beta lactams are an effective antimicrobial for treating the ciliates associated with BJD.
OP
OP
RO Water
Readily available to hobbyists, RO water has been used to varying degrees of success as a coral dip for zoas in the past. Due to the osmotic pressure gradient between saltwater organisms and the RO water, organisms associated with brown jelly disease may undergo osmotic lysis. Unfortunately, the same stress would also affect the host coral. Therefore, test dips are aimed at investigating whether the effect of osmotic lysis would be selective for the pest compared with the host tissue.
RO water (TDS 0) was heated to 78 degrees to match the host water. Additionally, a second sample of RO water was chilled to 50 degrees after one user requested that I investigate the protocol of a cold water dip.
Time course: 10, 30, 60, 120, 300 seconds
Results:
Ciliates exposed to 78 degree water were unaffected by the 10 second dip. The 30, 60, and 120 second dip seemed to “stun” about 1/3 of the ciliates. About half of those ciliates that were unmoving following the dip began to move again and the other half seemed to die. All ciliates were dead or not moving by 300 seconds.
[Ciliates following exposure to 5 minute dip of warmed RO water]
The specimens exposed to the 50 degree RO water were all dead or not moving at all time points after 10 seconds.
A single specimen of infected Duncanopsammia axifuga was dipped for 2 minutes in warmed RO water. The treated specimen was then rinsed with fresh saltwater and placed in a separate experimental tank utilizing a mature biological filter from a non-infected tank. All water parameters were identical to its original tank. The specimen did not show signs consistent with the spread of BJD, but still died within 48 hours.
A healthy specimen of Acanthastrea echinate was exposed to RO water (temperature 78 degrees) for 2 minutes. It was then rinsed with fresh saltwater and placed in a separate experimental tank utilizing a mature biological filter from a non-infected tank. All water parameters were identical to its original tank. The specimen began to bleach shortly after the dip and died within 10 days.
No specimens were tested with the 50 degree RO water.
Takeaway:
A freshwater dip with warmed RO seems to be effective at killing the ciliates associated with BJD, but is only effective at time points that also killed a healthy specimen. The single infected specimen treated with RO water did seem to suggest a slowing of the brown jelly, however the coral ultimately died. It is unknown whether additional specimens might uncover a mortality benefit of RO dips. That being said, while it is possible that further testing might uncover a time point that selectively kills the ciliates without harming the host coral, based on the present observations, it does not seem like RO water is a promising avenue for treating the ciliates associated with BJD.
Readily available to hobbyists, RO water has been used to varying degrees of success as a coral dip for zoas in the past. Due to the osmotic pressure gradient between saltwater organisms and the RO water, organisms associated with brown jelly disease may undergo osmotic lysis. Unfortunately, the same stress would also affect the host coral. Therefore, test dips are aimed at investigating whether the effect of osmotic lysis would be selective for the pest compared with the host tissue.
RO water (TDS 0) was heated to 78 degrees to match the host water. Additionally, a second sample of RO water was chilled to 50 degrees after one user requested that I investigate the protocol of a cold water dip.
Time course: 10, 30, 60, 120, 300 seconds
Results:
Ciliates exposed to 78 degree water were unaffected by the 10 second dip. The 30, 60, and 120 second dip seemed to “stun” about 1/3 of the ciliates. About half of those ciliates that were unmoving following the dip began to move again and the other half seemed to die. All ciliates were dead or not moving by 300 seconds.
[Ciliates following exposure to 5 minute dip of warmed RO water]
The specimens exposed to the 50 degree RO water were all dead or not moving at all time points after 10 seconds.
A single specimen of infected Duncanopsammia axifuga was dipped for 2 minutes in warmed RO water. The treated specimen was then rinsed with fresh saltwater and placed in a separate experimental tank utilizing a mature biological filter from a non-infected tank. All water parameters were identical to its original tank. The specimen did not show signs consistent with the spread of BJD, but still died within 48 hours.
A healthy specimen of Acanthastrea echinate was exposed to RO water (temperature 78 degrees) for 2 minutes. It was then rinsed with fresh saltwater and placed in a separate experimental tank utilizing a mature biological filter from a non-infected tank. All water parameters were identical to its original tank. The specimen began to bleach shortly after the dip and died within 10 days.
No specimens were tested with the 50 degree RO water.
Takeaway:
A freshwater dip with warmed RO seems to be effective at killing the ciliates associated with BJD, but is only effective at time points that also killed a healthy specimen. The single infected specimen treated with RO water did seem to suggest a slowing of the brown jelly, however the coral ultimately died. It is unknown whether additional specimens might uncover a mortality benefit of RO dips. That being said, while it is possible that further testing might uncover a time point that selectively kills the ciliates without harming the host coral, based on the present observations, it does not seem like RO water is a promising avenue for treating the ciliates associated with BJD.
OP
OP
Chemiclean
Chemiclean is widely available to hobbyists and has been used for the treatment of cyanobacteria. While the active ingredients in chemiclean have not been publicly disclosed by the company, many believe the active ingredient is a compound containing erythromycin. Although erythromycin was shown to be ineffective (tested under macrolides) at treating the ciliates associated with BJD, chemiclean will be tested separately.
Per the manufacturer’s instructions, the dosage for chemiclean is 1 level scoop per 10 gallons of water. This works out to approximately 6.67mg per gallon of water (252mg/dL).
Concentrations tested: 1 scoop/10 gallons, 5 scoops/10 gallons (5x), 1 scoop/gallon (10x), 5 scoops/gallon (50x), 10 scoops/gallon(100x).
Time course: 5, 10, 30, 60, 240, 1440 minutes.
Results:
The ciliates were unaffected at all concentrations and every time course up to 240 minutes. A reduction in ciliate activity was noticed in those ciliates exposed to 5 scoops/gallon and 10 scoops/gallon for 1440 minutes (24 hours).
[Ciliate activity following exposure to 10 scoops/gallon for 240 minutes]
No infected coral specimens were exposed to chemiclean.
A healthy specimen of Duncanopsammia axifuga was dipped in 1 scoop/gallon chemiclean for 240 minutes in warmed saltwater water. The treated specimen was then rinsed with fresh saltwater and placed in a separate experimental tank utilizing a mature biological filter from a non-infected tank. All water parameters were identical to its original tank. The specimen did not show any ill effects from the treatment.
Takeaway:
Based on the exposure dosages in the macrolide tests, it is unsurprising that even at concentrations 100 times the recommended dose, the ciliates were largely unaffected by chemiclean. The reduction in ciliate activity 24 hours post exposure may suggest a time-dependent mechanism (consistent with erythromycin), however given the rapid spread of brown jelly disease noted in the controls, it is my belief that any treatment that would take several days to act is unlikely to be an effective treatment in the preservation of an infected coral. To what extend a treatment might be effective in reducing/preventing the spread of BJD when manual excision of an infected coral is not possible is beyond the scope of the current experiments. Therefore, based on the limited data, it does not appear that chemiclean is an effective agent in targeting the ciliates associated with BJD.
Please note: Although chemiclean is advertised as an in-tank treatment, all tests investigated its use as a coral dip. As such, concentrations far higher than those that would be administered into a reef tank were used. Please do not exceed the manufacturer’s dosage recommendations for in tank treatments.
Chemiclean is widely available to hobbyists and has been used for the treatment of cyanobacteria. While the active ingredients in chemiclean have not been publicly disclosed by the company, many believe the active ingredient is a compound containing erythromycin. Although erythromycin was shown to be ineffective (tested under macrolides) at treating the ciliates associated with BJD, chemiclean will be tested separately.
Per the manufacturer’s instructions, the dosage for chemiclean is 1 level scoop per 10 gallons of water. This works out to approximately 6.67mg per gallon of water (252mg/dL).
Concentrations tested: 1 scoop/10 gallons, 5 scoops/10 gallons (5x), 1 scoop/gallon (10x), 5 scoops/gallon (50x), 10 scoops/gallon(100x).
Time course: 5, 10, 30, 60, 240, 1440 minutes.
Results:
The ciliates were unaffected at all concentrations and every time course up to 240 minutes. A reduction in ciliate activity was noticed in those ciliates exposed to 5 scoops/gallon and 10 scoops/gallon for 1440 minutes (24 hours).
[Ciliate activity following exposure to 10 scoops/gallon for 240 minutes]
No infected coral specimens were exposed to chemiclean.
A healthy specimen of Duncanopsammia axifuga was dipped in 1 scoop/gallon chemiclean for 240 minutes in warmed saltwater water. The treated specimen was then rinsed with fresh saltwater and placed in a separate experimental tank utilizing a mature biological filter from a non-infected tank. All water parameters were identical to its original tank. The specimen did not show any ill effects from the treatment.
Takeaway:
Based on the exposure dosages in the macrolide tests, it is unsurprising that even at concentrations 100 times the recommended dose, the ciliates were largely unaffected by chemiclean. The reduction in ciliate activity 24 hours post exposure may suggest a time-dependent mechanism (consistent with erythromycin), however given the rapid spread of brown jelly disease noted in the controls, it is my belief that any treatment that would take several days to act is unlikely to be an effective treatment in the preservation of an infected coral. To what extend a treatment might be effective in reducing/preventing the spread of BJD when manual excision of an infected coral is not possible is beyond the scope of the current experiments. Therefore, based on the limited data, it does not appear that chemiclean is an effective agent in targeting the ciliates associated with BJD.
Please note: Although chemiclean is advertised as an in-tank treatment, all tests investigated its use as a coral dip. As such, concentrations far higher than those that would be administered into a reef tank were used. Please do not exceed the manufacturer’s dosage recommendations for in tank treatments.
OP
OP
I will finish writing up the remaining tests tomorrow, but the following is a list of agents that were tested and I was not planning on doing full write ups of. The same serial dilutions and experimental protocols were used. In addition to those agents already detailed above, the following agents were found to be ineffective:
- Fluconazole
- Coral Rx
- Tea Tree Oil
- Ivermectin
- Hyposalinity (1.012)
- Hypersalinity (1.035, 1.045)
- Flatworm Exit
- Prazi Pro
- Vinegar
- Fenbendazole
- Povidone Iodine
OP
OP
Doxycycline
Doxycycline, a tetracycline family an antibiotic, exerts its antimicrobial activity in both a time and concentration dependent manner (concentration-dependent kinetics at high doses). Doxycycline has a broad spectrum of activity against both gram positive and negative bacteria as well as key parasites. Doxycycline seems to be available to most hobbyists though either fish pharmaceuticals or products like API’s Fin and Body Cure (250mg Doxycycline Hyclate tablets).
Because a starting dosage was unknown a wide serial dilution was employed. The tested concentrations were: 100mg/10 gallons, 250mg/10 gallons, 100mg/gallon, 1g/gallon, 10g/gallon.
Time course: 5, 10, 30, 60, 240 minutes
Results:
Ciliates were unaffected at all time points up to 1g/gallon. At 10g/1gallon, ciliate activity was decreased. Further observations of the ciliates demonstrate that they are motile and behaving appropriately (consuming coral tissue), but seem to be “slowed”. Samples of tissue were still consumed by samples treated with 10g/1 gallon for 240 minutes.
[Ciliate activity post treatment with 1g/gallon Doxycycline for 4 hours]
Two specimens of infected Duncanopsammia axifuga (Duncans) were dipped for 1 hour in 10g/gallon doxycycline. The treated specimens were then rinsed with fresh saltwater and placed in separate experimental tanks utilizing a mature biological filter from a non-infected tank. All water parameters were identical to their original tank. Both specimens demonstrated signs consistent with the spread of brown jelly disease and perished within 48 hours.
A healthy specimen of Duncanopsammia axifuga (Duncan) was dipped for 1 hour in 10g/gallon doxycycline. The treated specimen was then rinsed with fresh saltwater and placed in separate experimental tanks utilizing a mature biological filter from a non-infected tank. All water parameters were identical to their original tank. The specimen slimed heavily and was withdrawn for the next 96 hours, but ultimately made a full recovery within 14 days.
Takeaway:
In previous experiments run by @taricha (post #37), they observed a reduction in microbial activity and very little brown jelly following doxycycline administration (concentration unknown). Unfortunately, it is unknown how to interpret these results in light of the current experiments. Confounding variables include the dosage of doxycycline administration between the two experiments, contact time (it appears the ciliates were exposed overnight to the doxycycline solution in the experiments run by @taricha), the use of softy vs LPS corals, and possibly other experimental differences (e.g. temperature, oxygenation, pH). In light of @taricha 's observations, further investigations into the use of doxycycline may be warranted. While the current set of experiments were unable to demonstrate an effective reduction in the ciliates associated with Brown Jelly Disease, additional experiments might uncover a role for doxycycline administration.
Doxycycline, a tetracycline family an antibiotic, exerts its antimicrobial activity in both a time and concentration dependent manner (concentration-dependent kinetics at high doses). Doxycycline has a broad spectrum of activity against both gram positive and negative bacteria as well as key parasites. Doxycycline seems to be available to most hobbyists though either fish pharmaceuticals or products like API’s Fin and Body Cure (250mg Doxycycline Hyclate tablets).
Because a starting dosage was unknown a wide serial dilution was employed. The tested concentrations were: 100mg/10 gallons, 250mg/10 gallons, 100mg/gallon, 1g/gallon, 10g/gallon.
Time course: 5, 10, 30, 60, 240 minutes
Results:
Ciliates were unaffected at all time points up to 1g/gallon. At 10g/1gallon, ciliate activity was decreased. Further observations of the ciliates demonstrate that they are motile and behaving appropriately (consuming coral tissue), but seem to be “slowed”. Samples of tissue were still consumed by samples treated with 10g/1 gallon for 240 minutes.
[Ciliate activity post treatment with 1g/gallon Doxycycline for 4 hours]
Two specimens of infected Duncanopsammia axifuga (Duncans) were dipped for 1 hour in 10g/gallon doxycycline. The treated specimens were then rinsed with fresh saltwater and placed in separate experimental tanks utilizing a mature biological filter from a non-infected tank. All water parameters were identical to their original tank. Both specimens demonstrated signs consistent with the spread of brown jelly disease and perished within 48 hours.
A healthy specimen of Duncanopsammia axifuga (Duncan) was dipped for 1 hour in 10g/gallon doxycycline. The treated specimen was then rinsed with fresh saltwater and placed in separate experimental tanks utilizing a mature biological filter from a non-infected tank. All water parameters were identical to their original tank. The specimen slimed heavily and was withdrawn for the next 96 hours, but ultimately made a full recovery within 14 days.
Takeaway:
In previous experiments run by @taricha (post #37), they observed a reduction in microbial activity and very little brown jelly following doxycycline administration (concentration unknown). Unfortunately, it is unknown how to interpret these results in light of the current experiments. Confounding variables include the dosage of doxycycline administration between the two experiments, contact time (it appears the ciliates were exposed overnight to the doxycycline solution in the experiments run by @taricha), the use of softy vs LPS corals, and possibly other experimental differences (e.g. temperature, oxygenation, pH). In light of @taricha 's observations, further investigations into the use of doxycycline may be warranted. While the current set of experiments were unable to demonstrate an effective reduction in the ciliates associated with Brown Jelly Disease, additional experiments might uncover a role for doxycycline administration.
OP
OP
A quick update on an interesting finding. @Reefer1978 was generous enough to send me some additional BJD samples. Over the years, the ciliates associated with BJD have had a consistent size and shape. This is the first sample to contain a ciliate with a distinctly different morphology (pictured below). These "new" ciliates appear to have shorter cilia and the body contains a distinctive coil of filamentous matter. If possible, I'll try and subject these samples to the same battery of testing, but it's interesting to consider whether this supports the idea that the ciliates are simply filling the scavenger role or if this suggests a larger group of ciliates comprise the pathognomonic jelly.
Thank you @Reefer1978 - what an unexpected finding!
Thank you @Reefer1978 - what an unexpected finding!
Awesome, glad I could help!!!
OP
OP
I only tested a 1:2 and 1:4 concentration on the ciliates.
In another experiment, I tested a 1:5 dilution of hydrogen peroxide (3%) on some LPS, but I moved away from that testing as I was worried about the smaller margin of safety.
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