Mycobacterium marinum

 What is Mycobacterium Marinum?

Mycobacterium marinum (M. marinum) is a contagious deadly fish disease that even humans can catch. It is also known as tuberculosis or fish TB. Below are some images which show you signs to look out for so that you can spot it in its early stages. The wrist and the hand are affected in about 50% of the cases. It may cause skin and soft tissue infections after skin abrasion. This Mycobacterium marinum disease often occurs following the cleaning of fish tanks. 

Some clinical Findings of this disease involves:- 

1. The hand and wrist are commonly involved.

2. There will be painful swelling of the hand.

3. Subcutaneous granules, masses, nodules, ulcers, non-caseating granulomas.

4. It may present as chronic tenosynovitis of the hand.

5. It also affects the extensors more than the flexors.

This disease is a very slow-growing bacteria that is mainly found in bodies of fresh or saltwater aquarium tanks. Most infections occur after skin exposure to bacteria through small cuts or eroding the skin. The first signs of infection with M. Marinum include reddish or brown skin lumps called a granuloma. Very less, commonly, String or batch of small reddish lumps appear in the area of ​​the body that is open in a classic pattern called sporotrichosis lymphangitis. Mycobacterium marinum infection is very rare to be seen in well-maintained swimming pools because of the protection provided by proper chlorination. It does not typically grow at normal body temperature, which is why it remains localized to the cooler skin surface.

In this article, we are going to discuss, how to avoid your fish from Mycobacterium marinum disease in your aquarium tank.

This disease can catch any aquarium fish in your tank. If you noticed closely to your fish, back muscles are actually quite reduced in thickness giving it an angular look and also reduced activity levels and has loss of body coloration. These two are the major signs which confirmed as being infected with fish tuberculosis. Most of the other fishes in the tank appear to be happy and healthy. This disease is more commonly found in freshwater tropical fish.  

How to avoid your fish from Mycobacterium marinum disease?

This bacteria disease grows at low temperatures. So, it is recommended to increase your aquarium temperature to around 32 degrees. Change water every week at around 30-40% depending upon the size of your aquarium. Rinse and wash all your aquarium toys or any decorative items with the tap running water. Do not use any detergent or any soap.

How to treat aquarium fish from Mycobacterium marinum disease?

It is very important to treat your fish for this disease otherwise your fish will die in a few days. Below are some steps to treat your fish

1. Provide some oral antibiotics such as Clarithromycin with ethambutol.

2. It is very rarely surgical treatment may be required.

Medical treatment remains the primary and preferred treatment for nearly all cases. 

If you see some signs of this disease on your fish then it is highly recommended that you should remove the fish from your main tank and put it into another emergency tank for treatment. However, there is no specific treatment, but in most cases, this disease is treated with Kanamycin and Vitamin B-6 depending on the severity of the disease. You can find this medicine at your local pet store or any pharmacy. Add a drop of liquid in 5 gallons of aquarium water during the treatment. Overcrowding of the fish is the main culprit of this disease. So, it is recommended that we should keep the fish according to the size of the aquarium. After the disease breaks out, clean all the accessories, and disinfected properly. 

How can I prevent this infection?

The following steps may help to protect you from contracting an infection with M. marinum:

1. Do not clean the aquarium if you have any open cuts, scrapes, or sores on your skin.

2. If you have a weak immune system, you can easily reduce the risk of infection by covering the cuts.

3. Wear gloves while cleaning the aquarium tank. Wash hands with soap and running water after cleaning the tank, even if gloves were worn.