BACTERIAL CAUSES OF FIN ROT IN SOME FRESH WATER FISHES. Enany,, M. E., El Sayed,, M. E., Diab.. A. S., Hassan,, S. M., and El Gamal,, R.M.** *Department of Microbiology, Faculty of Vet. Medicine, Suez Canal University. ** Central Lab. For aquaculture, Agr.. Research Center; Abbessa
70 naturally infected fishes (90 tilapia spp., 50 Clarias lazera and 30 Commen carp) with fin rot revealed clinically progressive erosions, congestion and hemorrhages of the body fins especially the caudal and dorsal fins with edema and sloughing in some cases.
naturally infected fishes revealed the presence of 46 bacterial isolates related to bacterial genera and species. A. hydrophila (9) P. fluorescens (0) Streptococcus sp.(36) F. columnaris (36) Klebsiella sp. (4) E. coli (4) Proteus sp() And Shig ella sp. ()
Table (): Collective data of bacterial isolates from examined naturally infected fish species. Fish species of infected fishes with fin rot Aeromon as species Pseudomo nas species Flecibacte r species Klebsiella species Streptoco c species E. Coli Proteus species Shegella Total % Tilapia 90 05 (4.6%) 54 (.95%) 9 (7.73%) 5 (0.6% 0.6%) (7.3%)) 0 (4.06%) (3.5%) 7 (.5%) 46. Clarias 50 59 (43.3%) 30 (.06%) (.09%) 4 (0.9% 0.9%) 9 (6.6%) 6 (4.4%) 3 (.%) 4 (.94%) 36 0.0 Carp 30 34 (39.53%) (0.93%) 6 (6.9%) 9 (0.47% 0.47%) 9 (0.47%) (9.30%) (.6%) (.6%) 6 6.3 Total 70 9 (4.3) 0 (.) 36 (7.7) 4 (0.3) 36 (7.7) 4 (5.) (.6) (.6) 46 34.4 N. B.: % was calculated according to total number of isolates of each species. Total was calculated according to the total number of the samples.
Table (): Distribution of Bacterial isolates among various tissues and organs of naturally infected fish species with tail and fin rot. 50.00 50.00 3 6.67 6.67 33.33 33.33 6 Carp Carp.. 45.45 45.45 5 36.36 36.36 4 Clarias Clarias 36.4 36.4 7 3.5 3.5 6 3.5 3.5 6 9 9 Tilapis Tilapis F. F. columnaris columnaris 6.67 6.67 3.. 5.56 5.56 7.7 7.7 5 6.67 6.67 3.. 4 Carp Carp 6.67 6.67 3.33 3.33 6.67 6.67 3.00 3.00 9 0.00 0.00 6 33.33 33.33 0 0 30 30 Clarias Clarias.96.96 7 5.56 5.56 3 5.56 5.56 3 9.63 9.63 6 6 6.67 6.67 9 9.63 9.63 6 6 54 54 Tilapis Tilapis Ps Ps. fluorscence fluorscence s.94.94 4.7 4.7 5 5. 5. 0.59 0.59 7.76.76 4 4.7 4.7 5 9.4 9.4 0 0 34 34 Carp Carp 3.39 3.39 6.77 6.77 4 0.7 0.7 6 6.77 6.77 4.64.64.46.46 5 0.39 0.39 5.4 5.4 5 5 59 59 Clarias Clarias 3. 3. 4 6.67 6.67 7.37.37 3 3 5.70 5.70 6 7.4 7.4.59.59 9.. 9 9 37.6 37.6 9 9 05 05 Tilapis Tilapis A. A. hydrophila hydrophila % % % No No. % N o. % % No No. % % isolate isolate s Species Species Ascitic fluid Ascitic fluid Ovaries Ovaries Muscle Muscle Spleen Spleen Gills Gills Kidney Kidney Liver Liver Fin & tail Fin & tail lesions lesions Total Total Fish Fish Isolates Isolates
Fig. () Tilapia nilotica showing progressive erosions of body fins, especially caudal and ventral fin, focal to diffuse necrosis of muscle and detachment of scales.!
Fig. () Tilapia nilotica showing erosions of body fins, detachment of scales and skin congestion.!
Fig.(3) Clarias lazera showing erosions and congestion of the body fins.!
The postmortem changes of naturally infected fishes were abdominal ascitis, enlargement and congestion of the liver, kidneys, spleen and intestine with distension and congestion of the gall bladder.
Fig.(4) Common carp showing congestion of! internal organs specially liver as well as inflamed muscle
Fig. (5)Common carp showing detachment of! scales, erosion of caudal fin, congestion of internal organs & bloody ascitic fluid.
Fig. (6) Muscles showing extensive necrosis and! focal replacement to the necrotic muscles by edema, hemorrhage, and mononuclear leukocytes
Fig. (7) Gills showing edema, congestion, and hemorrhage in the gill arch, necrosis and desquamation in the gill lamellae along with mononuclear leukocytic infiltration!
Fig. () Kidney showing wide spread necrosis of the renal tubules along with interstitial edema, hemorrhage and mononuclear leukocytes!
Fig. (9) Liver showing extensive vacuolar! degeneration and focal areas of coagulative necrosis
The pathogencity of isolated strains revealed that A.hydrophila appeared to be highly virulent ( 700%) mortality in injected groups followed by P.fluorescens (50%) and F.columnaris (37.5%)
Table (3):Route of infection and pattern of mortality in armout catfish experimentally inoculated with fish pathogenic isolated bacteria. Fish group fish Infected organism Route of inf. 3 4 5 6 7 9 0 3 4 5 Total % I A. ydrophila I/P 3 00 II P.fluorescens I/P 4 50 III F. olumnaris I/M 3 37.5 IV A. ydrophila & P.fluorescens I/P 7 7.5 V A. ydrophila & F.columnaris I/M 00 VI P.fluorescens & F.columnaris I/P 5 VII A. ydrophila & P.fluorescens & F.columnaris I/M 7 7.5 VIII Sterile broth I/P IX Cytophaga I/M fish inoculated
Sensitivity test of isolated strains showed that kanamycin and nalidexic acid were the drugs of choice used for control and treatment of fin rot disease.
Table(4): Antibiotics sensitivity of Bacteria isolated from naturally infected fish Isolates Fish Antibiotics Species AM X C CL D E K NA N S G TE SXT A. hydrophila ( Tilapia (05 isolates + _ + ( Claris (59 isolates + + + ( Carp (34 isolates + + + Ps. fluorscences ( Tilapia (54 isolates ( Claris (30 isolates + + + + ( Carp ( isolates + + F. columnaris ( Tilapia (9 isolates + + + ( Claris ( isolates + + + + + ( Carp (66 isolates + AMX= Amoxicillin E= Erythromycin G= Sulfonamides C= Chloramphincol K= Kanamycin NA= Nalidixic acid CL= Colistin N= Neomycin SXT= Trimethoprim sulfonamides D= Doxycycline S= Streptomycin Te= Tetracycline
Thank You