Join Date: May 2012
Location: Texas.. where else IS there.. lol
Here goes... it is too long so going to come in pieces...
What is Mycobacteria?
Mycobacteriosis is a disease caused by several bacterial species within the genus Mycobacterium. Some of these bacteria can cause serious diseases in humans. The species that cause Mycobacteriosis in fish are referred to as non-tuberculous bacteria. They do not tend to cause major disease in normal and healthy people.
Non-tuberculous mycobacteria are fairly common bacteria found in the environment. This means you do not have to have fish or other living tissue for them to survive. They have been found in drinking water supplies, swimming pools, coastal waters, and aquatic facilities.
Mycobacteriosis is of concern in fish for several reasons. First, it slowly destroys the fish as it causes a chronic wasting condition. It should be suspected when fish are in poor condition but also have scale loss, skin ulcers, or a history of reproductive problems. At times you will see deep hemorrhagic skin lesions in addition to the more common superficial lesions. The mortility level is continuous low to moderate within the affected population. This can result in significant loss of fish.
The second reason is the disease is considered non-treatable once established in the fish host. Unfortunately, Mycobacterial diseases of fish are common. Though some species seem to be at greater risk than others, all fish are susceptible. The disease has been found in a broad range of fish and from freshwater to marine. Fish in the families Anabantidae (bettas and gouramis), Characidae (tetras), Cyprinidae (barbs, danios, koi and goldfish), and some members of the Cichlidae (including freshwater angelfish) may be more prone to the infection. This disease is also of concern in recirculating systems and once established can be difficult to eradicate. High organic loads, water quality characteristics common in intensive systems, and very crowded populations can all exacerbate the infection.
And if that is not enough, Mycobacterium infected fish do have the potential to cause disease in humans. Mycobacterial infections of fish are zoonotic, which means the organisms can cause disease in humans. Considering how prevelant the organisms are, these infections are relatively rare. Infections in people are usually associated with cleaning aquaria or from and injury resulting from contact with fish. The most common symptom in human patients is skin lesions that develop on the hands or extremities where broken skin may have come into contact with infective material. These lesions are often called “fish tank granuloma” or “fish handler’s disease.” Lesions in humans may develop from 3 weeks to 9 months after contact with infective material. Typically, mycobacterial lesions in humans are restricted to the extremities, particularly the skin though deep lesions into musculature and tendons have been reported. Rarely, systemic disease has occurred in immunocompromised individuals.
Environmental Conditions That Favor Mycos
Mycobacteria thrive under certain environmental conditions. They like warm water temperatures, low dissolved oxygen levels, acidic pH, high soluble zinc, high fulvic acid, and high humic acid. Investigators have found a much higher prevalence of mycobacteria in swamps as they have the desired environmental conditions of low levels of dissolved oxygen, low pH, high organic loads and warm water. Another investigation found a high amount of non-tuberculous mycobacteria associated with low salinity. All these conditions can be easily found in freshwater aquaculture systems. Trace amounts of certain minerals, particularly zinc and iron, have also been associated with greater numbers of mycobacteria in an environment. In addition to being present in infected fish, mycobacterial organisms also live in filter media and biofilms.
Although these mycobacteria are common in aquatic environments, it has been found that the disease in fish may be associated with certain strains rather than with the environmental conditions. Poor water conditions and husbandry, chronic stress and anything that impairs the immune system of the fish will increase the chance an infection will develop. Because some bacteria are more pathogenic than others it is critical to eliminate these specific stains from a fish room. It is the only way of stopping disease progression and death. Culling sick fish or completely destroying fish is usually recommended. Less pathogenic species of mycobacterium can be controlled by creating a less favorable environment for the organism
Basement Bettas ~ Breeder of Show Bettas
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