For what it is worth, I found the following 'cures' for fish TB in
*Diseases of Fishes* by C. van Duijn, 1967.
1a) 1.8mg terramycin per g food
feed 3% body weight for 8 days.
1b) Terramycin 13mg/l (pure)
3 3day treatments with a water change on the 4th day and brief
pause (1 to 2 days) between treatments.
2) Streptomycin: 10mg/l
3) 3-5mg/l iso-nicotinic acid hydrazide (INH, Isoniazid, Nidaton....)
Kannamycin and Tetrachloromycin should also be effective (the
latter also being effective against Discus plague). However, all of
these are strong, regulated antibiotics which dou to there broad
range activity will pose a real battle getting hold of.
If you do manage to twist some ones arm, use these drugs
properly!
They also have a tendency to turn toxic after a few days and
hence the need for a 100% water change. If the fish do die during
treatment, over dose the tank just to make sure all the bacteria are
dead so as to prevent the possibility of resistant strains being bred.
As for human infections: Streptomycin should work well there too,
being a broad range antibiotic and one developed specifically for
Mycobacterium sp.
In regard to the immunology behind the disease: the fish's
immunesystem, regardless of specie, should be able to deal with
the intracellular parasite itself providing the fish comes under no
stress.
The Mycobacterium infests the fish's macrophages upon
phagocytosis there the fish's T-lymphocytes then go into action to
trigger the macrophages antibacterial measures or simply trigger
the death of the macrophage setting the bacterium free to be
destroyed by other macrophages as well as to be bound by
antibodies for easier targetting.
As this is an acquired immune response, there can be NO truth in
the idea that rainbows are less resistant to fish TB than other fish.
All fish, if given the chance will be able to cope with the infection
and generate immunity. The problem with rainbow fish is that we
take a fish which is used to large bodies of open water and cram it
into a small fishtank which equates to a pathogenic soup and then
expect the fish to handle a constant series of attacks by various
pathogens. As a result the immune system comes under serious
stress and then can no long cope with the infection.
By the time we notice the fish is sick it is already to late to help it
with anything other than antibiotics.
If you want to maintain healthy fish, don't crowd them and keep the
water clean by regular large water changes.
In regard to the possible cross infection between fish and man.
Fish TB can only gain access through lesions in the skin or mouth.
If you feel really paranoid about it wear gloves or NEVER stick a
wounded appendage in the aquarium. As for syphoning by mouth:
I've been doing it for years with no problems. The mucosal
surfaces of the mouth along with the rest of the digestive system
are constantly secreting IgA (immunoglobin A, an antibody) of high
polyvalency which then to bind and inactivate most bacteria before
they can do any harm.
If you are interested in learning a bit more on immunology see
*Essential Immunology* by E. Roitt.
Regards
Tyrone
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"Jesus is Lord! Creation's voice proclaims it!"
-David J. Mensell