PATHOGENECITY OF Edwardsiella ictaluri TO DIFFERENT KINDS OF FISH. World Aquaculture Society Bali Conference, May 9-13, 2005

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1 PATHOGENECITY OF Edwardsiella ictaluri TO DIFFERENT KINDS OF FISH BY : NOVITA PANIGORO 1), MELIYA BAHNAN 1) EDY BARKAT KHOLIDIN 1), and KEI YUASA 2,3) World Aquaculture Society Bali Conference, May 913, ) FRESHWATER AQUACULTURE DEVELOPMENT CENTER JAMBI 2) JAPAN INTERNATIONAL COOPERATION AGENCY 3) NATIONAL RESEARCH INSTITUTE OF AQUACULTURE, FISHERIES RESEARCH AGENCY OF JAPAN INTRODUCTION a) Outbreaks of E. ictaluri infection in the world b) Outbreaks of the infection in Indonesia c) Characteristics of the infection in the field (Mortality, clinical signs, causative agent, host range) d) Control measures (diagnostic and treatment methods)

2 a) Outbreaks of E. ictaluri infection in the world Mass mortality of channel catfish showing enteric septicemia spread in USA and the causative agent was identified and newly named as Edwardsiella ictaluri (1981) Edwardsiella ictaluri infection was observed in walking catfish in Thailand (1987) Mass mortalities due to Edwardsiella ictaluri infection occurred at striped catfish farms in Vietnam (1992). b) Outbreaks of the infection in Indonesia First report of the infection: January 2002 in Jambi, Sumatra Type of culture systems: 1. Inland pond, floating net cage, floating wood cage (culture period) 2. Aquarium, concrete tank (nursery period). Figure 1. Inland pond Figure 2. Floating net cage Figure 3. Floating wood cage

3 c) Characteristics of the infection in the field 1. Mortality : Accumulative mortality reached % 2. Clinical signs : a. Hemorrhages around anus, mouth, abdomen and basal fins b. White patches on kidney, liver, and spleen c. Anemia on gill. 3. Causative agent : Edwardsiella ictaluri 4. Host range : Small fish (0.02 g) until young fish (300 g). Figure 4. Affected stripped catfish fingerling with hemorrhages around anus and mouth Figure 5. Hemorrhages around abdomen and basal fins Figure 6. Anemia observed on gill Figure 7. White patches on spleen and liver of affected fish

4 Figure 9. Smear preparation from spleen stained with Giemsa Figure 8. White patches on spleen of fish with artificial infection Figure 10. E. ictaluri stained with Gram d) Artificial infection for prelimary studies 1. Artificial infection conducted by injection and bathing method 2. Injection was conducted by intramuscular and intraperitoneal 3. For injection, number of bacteria inoculated into fish was is 2.2 x 10 8 cells and 2.2 x 10 6 cells 4. Each fish was injected with 0.05 ml bacterial suspension

5 5. For bathing, number of bacteria suspension was 10 6 cells and 10 4 cells fish used in artificial infection with total length was 10 cm 7. Each fish group was kept in 10 L tank with aeration for 10 days without food 8. Water temperature during the course of experiments was C. Accumulative mortality (%) Days Intramuscularly inj. with 2.2 x 108 cells Intramuscularly inj. with 2.2 x 106 cells Intraperitoneally inj. with 2.2 x 108 cells Intraperitoneally inj. with 2.2 x 106 cells Bathing with 106 cells Bathing with 104 cells Figure 11. Accumulative mortality of each artificial infection method

6 Table 1. Accumulative mortality in each infection methods Intramuscularly injection Intraperitoneally injection Bathing Methods Number of bacteria (cells) 2.2 x x x x Accumulative mortality (%) e) Control measure 1. Diagnostic 1) Clinical signs 2) Identification (morphology and biochemical characteristics) 3) Coaglutination test with anti serum (rapid and confirmatory diagnosis) 2. Treatment Oral administration of several kinds of antibiotic such as : 1) 10% OTC : 50 mg/kg fish/day for days 2) 10% Sodium nifurstyrenate : 50 mg/kg fish/ day for days 3) Oxolinic acid : 1030 mg/kg fish/day for days 4) Enrofloxacin HCl : 1020 mg/kg fish/day for days.

7 OBJECTIVES 1. Pathogenicity to seven kinds of fishes were conducted by artificial infection test. 2. To determine host range of Edwardsiella ictaluri isolated from diseased striped catfish to seven kinds of fishes. MATERIALS AND METHODS 1. Fishes used in artificial infection 1) Striped catfish/patin siam ( (Pangasius hypophthalmus) 2) Patin jambal ( (P. djambal) 3) Walking catfish/lele (Clarias batrachus) 4) Green catfish/baung baung (Mystus nemurus) 5) Common carp/mas (Cyprinus carpio L) 6) Tilapia ( (Oreochromis sp) 7) Kissing gouramy/tambakan (Helostoma temminckii).

8 Figure 12. Striped catfish Figure 13. Patin jambal Figure 14. Green catfish Figure 15. Common carp Figure 16. Tilapia Figure 17. Walking catfish Figure 18. Kissing gouramy 2. E. ictaluri isolated from a diseased striped catfish was used for artificial infection. 3. The number of bacteria inoculated into fish was 2.6 x 10 7 cells and 2.6 x 10 5 cells. 4. Each fish was intraperitoneally injected with 0.1 ml bacterial suspension. 5. Each fish group was kept in 10 L tank with aeration for 10 days without food. 6. Water temperature during the course of experiments was C.

9 Table 2. Fishes* used on this study No Fishes Striped catfish/patin siam (P. hypophthalmus) Patin jambal ( (P. djambal) Walking catfish/lele lele (C. batrachus) 4 Green catfish/baung (M. nemurus) 5 Common carp/mas (C. carpio L) 6 Tilapia ( (Oreochromis sp) 7 Kissing gouramy/tambakan (H. temminckii) *10 fish were used in each experiment **Average body weight (g) and total length (cm) BW** 7.8 g TL** 6.2 cm , RESULTS Striped catfish Mortality (%) Figure Days after injection Patin jambal Walking catfish Green catfish Tilapia Common carp Kissing Accumulative mortality in each fish injected with 2.6 x 10 7 cells

10 M o rtality (% ) Days after injection Striped catfish Patin jambal Walking catfish Green catfish Tilapia Common carp Kissing gouramy Figure 20. Accumulative mortality in each fish injected with 2.6 x 10 5 cells Table 3. Pathogenicity to fishes injected with 2.6 x 10 7 cells of E. ictaluri Fishes Accumulative mortality (%)( Clinical signs Reisolated of E. ictaluri Striped catfish Patin jambal Walking catfish Green catfish 70 Tilapia 70 Common carp 40 Kissing gouramy 0

11 Table 4. Pathogenicity to fishes injected with 2.6 x 10 5 cells of E. ictaluri Fishes Accumulative mortality (%)( Clinical signs Reisolated of E. ictaluri Striped catfish Patin jambal 90 Walking catfish 90 Green catfish 20 Tilapia 40 Common carp 0 Kissing gouramy 0 CONCLUSIONS 1. Pathogenicity to each fish of Edwardsiella ictaluri as follows : 1. Striped catfish died % with typical clinical signs 2. Patin jambal and walking catfish died 90% without clinical signs 3. Green catfish and tilapia died 2070% without clinical signs 4. Common carp and kissing gouramy did not die and no clinical signs were found. Mortality was occurred in common carp caused by another factor.

12 2. Edwardsiella ictaluri have a possibility to affect another fish such as : 1) Patin jambal 2) Walking catfish 3) Green catfish 4) Tilapia But, naturally E. ictaluri infection not yet occurred in another fish beside striped catfish ( (Pangasius hypopthalmus). Acknowledgement Authors would like to grateful to : Prof. Kishio Hatai Yoshitetsu Nukiyama DR. Kunika Wakita Ir. Ceno Harimurti Adi, M.Si (Nippon Veterinary and Animal Science University, versity, Japan) (Japan International Cooperation Agency) (Jambi Freshwater Aquaculture Development Center)