El Flexibacter columnaris It is a bacterial disease that can seriously affect our fish, especially in poorly maintained or overpopulated aquariums. Its main characteristic is the appearance of putrefaction in the mouth and the presence of cottony white spots around the body of the fish, in addition to the fraying of fins and tail.
What is Flexibacter Columnaris?
El Flexibacter columnaris it's a bacterium Gram-negative which can be easily confused with fungal infections due to the similarity in the lesions it causes, such as white spots on the skin and in the mouth of the fish. However, unlike fungi, which usually grow on dead tissue, Flexibacter Columnaris affects live fish, and is transmitted mainly through the water contamination or contact with other sick fish.
Although the symptoms may seem similar, one key difference is that Flexibacter Columnaris is spread between live fish, while fungal infections are usually triggered when dead tissue is already present in the fish.
Risk factors and causes of Flexibacter Columnaris
This bacteria is quite common in aquariums, but it only attacks fish under conditions of high stress and weakness. Healthy fish are usually not affected, but when the aquarium environment is not optimal, the bacteria can proliferate. Among the main risk factors for the development of Flexibacter Columnaris in fish are:
- Poor water quality: An aquarium with poor maintenance, which does not receive regular water changes, is the perfect place for this bacteria to spread.
- Overpopulation: Too many fish in a small space not only increases stress, but also makes it easier for disease to be transmitted from one fish to another.
- Low oxygen levels: Poorly oxygenated aquariums create a favorable environment for the proliferation of bacteria such as Flexibacter Columnaris.
- High levels of nitrites: The accumulation of organic waste and uneaten food generates an increase in nitrites which, combined with poor oxygen levels, can weaken fish and make them more susceptible to infections.
Transmission and diagnosis
El Flexibacter columnaris It spreads rapidly in aquariums where a single bacterium can infect several fish in a matter of days. direct transmission It occurs when fish eat contaminated food, or share the same contaminated water space. It is also common for the infection to spread through other objects in the aquarium such as plants, decorations, or undisinfected equipment.
The most common symptoms Symptoms of this infection include the appearance of cottony patches in the mouth, fraying of the fins and ulcers on the body of the fish.
Treatment for Flexibacter Columnaris
There are different approaches to treating this disease, but it depends a lot on the degree of advancement of the infectionIf caught in the early stages, it is possible to improve water conditions by increasing regular changes and keeping the aquarium well oxygenated to help reduce infection.
In more advanced cases, the use of antibiotics and oxytetracycline, tetracycline or kanamycinThese antibiotics can be administered through impregnated food with the compounds, or directly in the aquarium water.
In addition, it is important to note that Flexibacter Columnaris is often resistant to some antibiotics such as ormetoprim and sulfadimethoxine, which makes its treatment more complicated if the diagnosis is not made in time.
Antibacterial Treatment Protocol
- Maintaining water quality: Perform partial water changes regularly and make sure the biological filter is working properly.
- Use of antibiotics: If the infection has already occurred, use antibiotics such as oxytetracycline o kanamycin, which are effective against bacteria. These are best administered in food.
- Isolation of infected fish:Place sick fish in a hospital tank where you can better control the infection without putting other fish at risk.
- Constant monitoring of behaviors: Observe any changes in the color, appetite and behavior of the fish.
Prevention
Although treatment is essential once the disease appears, it is best to keep the aquarium in conditions that prevent infection. To avoid the Flexibacter columnaris in the aquarium:
- Performs partial water changes frequently to prevent bacteria build-up.
- Avoid the overpopulation in the aquarium.
- Keep optimal oxygen levels using a high quality aeration system or filter.
- Make sure that no food unconsumed remains in the water for a long time.
- Limits stresses on the fish, such as sudden changes in temperature or water quality.
Environmental Factors and Their Influence on Disease
It is important to mention that the Flexibacter columnaris thrives in temperatures higher than 25°CTherefore, one of the recommended steps to reduce their proliferation is to reduce the temperature of the aquarium slightly, to around 24°C, which helps to slow the growth of the bacteria. However, this procedure must be carried out carefully so as not to cause additional stress to the fish.
Antibiotic Resistance and Complementary Treatments
One of the challenges in dealing with the Flexibacter columnaris is that the bacteria has developed resistance to certain antibiotics, such as ormetoprim and sulfadimethoxineTherefore, it is important to use a combination of approaches to effectively treat the disease.
A study has suggested that adding One tablespoon of salt for every 4 liters of water to the aquarium can reduce mortality rates by up to 30%, as it helps reduce the bacteria's ability to adhere to the fish's body.
In addition, the introduction of acriflavine o nitrofurazone in therapeutic baths has shown favorable results. In addition, the use of antibacterials such as phenoxyethanol It is also effective when applied in the early stages of the disease.
Relationship between stress and the incidence of Columnaris in fish
As with many bacterial diseases in fish, Stress plays a key role in the emergence of Flexibacter ColumnarisFish that are subjected to sudden changes in temperature, an overcrowded environment or poor water quality tend to develop these infections more frequently. Therefore, it is essential to minimize sources of stress in the aquarium.
Stress also weakens the immune system of fish, making them more susceptible to disease. To mitigate the risk, it is important to keep water parameters stable, perform frequent partial water changes, and not introduce sick fish into the aquarium without first quarantining them.
Columnaris in Different Fish Species
While all freshwater fish are potentially susceptible to Flexibacter columnaris, some species, particularly the viviparous Like guppies and mollies, they are more prone to contracting the disease. This is because many of these fish are bred in dense conditions in commercial aquariums, which increases their exposure to pathogens and stressful conditions.
It is essential to monitor these species more closely, as any early signs of infection must be treated quickly to prevent the disease from spreading throughout the aquarium.
Even scaleless fish, such as catfish, are susceptible to the disease and present reddish ulcers with swollen edges that must be treated immediately to prevent them from getting worse.
It is important to point out that the newly imported fish or acquired are particularly vulnerable to this disease due to transport and overcrowding conditions. For this reason, it is always advisable to use a quarantine tank before introducing new fish into an already established aquarium.
Finally, small changes in aquarium maintenance and care can make the difference between a healthy environment and an outbreak of Flexibacter columnaris endangering all fish. It is essential to remain vigilant for any symptoms and to treat fish at the slightest sign of illness.