Bacteria are common pathogens that can cause several diseases in fish. The document lists 7 common bacterial diseases: furunculosis caused by Aeromonas salmonicida, columnaris caused by Flexibacter columnaris, dropsy caused by Pseudomonas punctata, vibriosis caused by Vibrio anguillarum, tuberculosis caused by Mycobacterium piscium, bacterial gill disease caused by Myxobacteria, and fin/tail rot also caused by Myxobacteria. The diseases are treated through antibiotics, disinfectants like copper sulfate or potassium permanganate, or removing infected fish. Proper water quality, nutrition, and sanitation are important for prevention.

2. • Unicellular or Single celled microscopic
organisms.
• Cell membrane made up of cellulose and
chitin.
• Vacuoles
• Gram- positive and negative.
• Lack nuclie and other organized cell
structure.
• Some bacteria are pigmented.
BACTERIA

5. Bacterial diseases in fish
1. Furunculosis
2. Columnaries
3. Dropsy
4. Vibriosis
5. Tubercolosis
6. Bacterial gill
disease
7. Fin rot/ tail rot

6. Common symptoms
Lethargic swimming
Loss of appetite
Respiratory distress
Jumping from the water
Colour of gill changed
Fins become frayed

7. CAUSE
 Poor water quality
 Fluctuation in temperature
 Improper nutrition
 Access waste deposition

8. Furunculosis
• Causative agent - Aeromonas salmonicida
• Furunculosis is highly contagious disease that affects fish of all ages.
• The infection causes high mortality in salmonids, though some other
species of fish are affected.
• Horizontal transmission occurs via the water column, but also
through direct fish-to-fish contact and animal vectors.

9. Pathological sign
1) Furuncles (or boils) involving
skin and/or muscle progressing
to lesions.
2) Hemorrhages on the skin, mouth
and fin bases.
3) Darkening of body colour and
pale gills.
4) Bloody discharge from nares
and/or vent.
5) Stomach filled with mucus,
blood.

11. TREATMENT
• To drain the pond and treat it with slaked lime.
• Treatment is done by removing the severely infected fishes
from the pond and by supplying food containing antibiotics
like introfurans or sulphonamids etc.
• Disinfection may be done. It is most recommended ones
owing to its relatively lesser toxicity compared to other
disinfectants.
• Iodine is used to decontaminate the surface of fertilized
eggs to prevent vertical transmission (passage of infection
from parent to offspring).

12. columnaris (cotton mouth)
• Causative Organism: Flexibacter
columnaris/Chondrococcus columnaris
• Often mistaken for a fungal infection
because of its mold-like lesions.
• Columnaris is a common bacterial
infection in aquarium fish, particularly
livebearing fish and catfish.

13. Symptoms
• White spots on mouth, edges of scales,
and fins.
• Fins disintegrate beginning at the edges.
• 'Saddleback' lesion near the dorsal fin.

15. Treatment
• Add antibiotic in water .
• Normally used antibiotics
include the chloramphenicol ( 10
ppm. repeated at 2-5 days interval
) and furance ( o.1 – 0.3 ppm ) in
which the infected fishes with
cotton mouth disease are kept for
a long time bath.

16. Infectious Dropsy
• Causative agent- Pseudomonas punctata
• Dropsy is an old medical term that was once used
to describe swelling due to accumulation of fluids in
the tissues or body cavities, such as the abdomen.
Fish suffering from Dropsy often have a hugely
swollen belly.
• It was the most feared disease in carp culture

17. Symptoms
• • Swollen belly.
• • Scales stand out.
• • Eyes bulge.
• • Anus becomes red and swollen.
• • Internal organs are affected, most
notably the liver and kidneys.
• • Spine may become curved.
• • Fish hangs near the surface

18. Treatment
• Removal and complete destruction of fishes ,
followed by draining , drying and disinfecting the
fish pond with quicklime is suggested to prevent
spread of the disease.
• The infected fishes may be cured by a two
minutes dip in 5 mg / KMnO4 sol.
• Resistant strains bacteria may be killed by
applying streptomycin or chloromycetin or
oxytetracyclin along with supplementary food or by
injecting the severely infected fishes .

19. vibriosis
• Causative agent – Vibrio anguillarum
• This is comma shaped bacterium.
• It enters the animal via their food and attacks
the gastrointestinal tract.
• found in all species in saltwater
• It multiplies in the skin of salmonids, but the
toxins produced act on the circulating blood cells
causing severe anaemia.
• This disease occurs more than readily at
temperture above 11°c.

20. symptoms
Large bright colour body lesions
in the skin and muscles.
Gills may bleed with slightly
pressure.
Inflammation of intestinal tract.
Eye problems with cloudy eye,
leading to pop- eye and finally eye
loss.

21. Treatment
• Dip treatment in copper sulphate
sol. and application of antibiotics with
artificial food may be considered as
curative measures for vibrosis

22. TUBERCULOSIS
• Causative agent- Mycobactrium piscium.
• A bacterium closely related to Mycobacterium
tuberculosis called Mycobacterium piscium can
be present in wild caught as well as captive
bred fish and stay lurking in our aquariums
without us ever realizing it.
• Fish can be treated with the same drugs as
humans get when they become infected by
Mycobacterium piscium, e.g. Kanamycin.

23. SYMPTOMS
 Fin rot , waxy coat on body ,
ulcer on body. o Nodules in
the internal organs
 loss appetite
 Loss body weight
 Loss of scales
 Loss of colours

24. Treatment
• Dip treatment for one minute in 1 : 2000
copper sulphate sol. for 3-4 days may be
useful.
• Alternatively the fishes may be destroyed
and the pond sterized with KMnO4 or with
soaked lime restocking .

25. Bacterial gill disease
• Causative agent- Myxobacteria
• The colonization of damaged gills by these
organisms in the condition known as
“BACTERIAL GILL DISEASE”
• This reduces the ability of the gills to
supply oxygen to the blood and results in
mortality if left unchecked.

26. Symptoms
Swelling in gill lamellae.
 Change in gill colour.
Treatment
• Application of antibiotics like neomycin
chloramphenicol etc. may be useful in treatment of
bacterial gill disease in fishes .

27. Fin rot / tail rot
Causative agent- Myxobacteria
• Fin Rot is one of the most common.
• It is caused by several types of bacteria
and often occurs concurrently with other
diseases.

28. SYMPTOMS
• Fin edges turn white
• Fins fray
• Bases of fins inflamed
• Entire fin may rot away
TREATMENT
• Move sick fish to a hospital tank.
• Feed fresh high quality foods.
• Treat with antibiotics(MARACYN-2, a ten day course
is ideal for ensuring the infection is eradicated)

29. • Terramycin has proven to be quite
effective both as a bath, and when
used to treat foods for internal
infections.
i. Perform regular water changes.
ii. Keep the tank clean.
iii. Clean the filter regularly.
iv. Avoid overcrowding the tank.
v. Use flake foods within one month of
opening.
vi. Use disinfect nets and other
equipment.
• If the tank is well maintained, and
the fish fed a healthy diet, outbreaks
of any bacterial disease are unlikely..

30. FOR LISTENING