Patogenitas Aeromonas hydrophila Isolat Bali pada ikan Koi (Cyprinus carpio)

ARITONANG, Anna Haryati, drh. Kurniasih, MV.Sc.,Ph.D

2004 | Tesis | S2 Sain Veteriner

Penelitian bertujuan untuk mengetahui gambaran patogenisitas Aeromonas hydrophila isolat Bali pada ikan koi (Cyprinus carpio) meliputi gejala penyakit, perubahan makroskopik dan mikroskopik agar dapat digunakan sebagai salah satu acuan dalam mendiagnosa penyakit ikan di karantina ikan. Ikan Koi (Cyprinus carpio) yang digunakan berasal dari Bali dengan ukuran 6-8 cm (berat rata-rata 5 gram) yang diinfeksi Aeromonas hydrophila, koleksi laboratorium Stasiun Karantina Ikan Kelas 1 Ngurah Rai Denpasar. Uji pendahuluan untuk mengetahui kisaran konsentrasi yang akan digunakan pada uji utama dengan menggunakan sebanyak 40 ekor ikan koi ukuran 6-8 cm dengan berat rata-rata 5 gram diberi perlakuan yaitu satu kelompok /kontrol = tanpa diinfeksi bakteri, 3 kelompok yang diinfeksi A. hydrophila masing-masing 102, 108 dan 1012 sel/ml. Uji utama untuk mengetahui perubahan patologi dengan menggunakan ikan koi sebanyak 150 ekor yang dibagi dalam 5 kelompok dengan 3 kali ulangan yaitu A (kontrol = tanpa diinfeksi bakteri), B (diinfeksi bakteri 102 sel/ml), C (diinfeksi bakteri 104 sel/ml), D (diinfeksi bakteri 106 sel/ml) dan E (diinfeksi bakteri 108 sel/ml). Kepadatan/jumlah bakteri dihitung dengan agar plate method dan pengujian infeksi bakteri terhadap ikan secara rendaman. Pengamatan yang meliputi gejala, dan kematian ikan dilakukan setiap 6 jam sehingga 96 jam setiap perlakuan uji utama dilakukan pemeriksanan patologi anatomi meliputi makroskopik dan mikroskopik. Kelangsungan hidup ikan perlakuan dianalisa secara rancangan acak lengkap dan gejala klinis yang tampak dianalisa dengan uji chi square, sedangkan perubahan histopatologi dianalisa secara deskriptif. LD50 dari A. hydrophila pada ikan koi adalah 4,37x106 sel/ml. Daya kelangsungan hidup ikan koi (Cyprinus carpio) makin menurun seiring dengan meningkatnya konsentrasi A. hydrophila. Ikan koi yang sakit mengeluarkan lendir, bintik hitam dan seperti abu-abu pada mata, pelekatan dan bintik putih pada insang, usus kosong, ginjal membesar, hati pucat, sekitar mulut, sirip ekor, punggung dan dada kemerahan. Pada infeksi ringan menyebabkan congesti hati, ginjal, pankreas, insang. Pada infeksi berat terlihat radang kulit, hemoragi ginjal dengan enteritis hemoragika.

The purpose of this research is to know description of pathogenicity Aeromonas hydrophila from Bali on Koi fish (Cyprinus carpio) such as clinical symptom, macroscopic and microscopic sign in order to be used as the one way in diagnosis fish disease of fish quarantine. Koi fish originally was from Bali and it length was 6 -8 cm (about 5 gr) it was infected by Aeromonas hydrophila which were laboratory collection of the first degree fish quarantine station in Ngurah Rai Denpasar. The preliminary test is conducted to figure out the range of infection concentration that will be used in the main experiment. Experiment was done by using 40 pieces of koi, size range 6-8 cm, weight average 5 gram through the treatment i.e. one group/control=without bacteria infection and three groups was immersed with Aeromonas hydrophila threat as 102, 108 and 1012 cell/ml. The main experiment is conducted to observed pathological effect of infection on 150 koi fish sample which divided into 5 groups with 3 replication. First group was control (without bacterial infection), second group was immersed with 102 cell/ml of Aeromonas hydrophila, third group was immersed with 104 of Aeromonas hydrophila, fourth group was immersed with 106 cell/ml of Aeromonas hydrophila, and fifth group was immersed with 108 cell/ml of Aeromonas hydrophila. Bacterial density rate is counted with agar plate method. Diagnostic of clinical symptom and mortality of fish was checked every 3 hours until 96 hours, each treatments in the main experiment was checked by pathological method macroscopically and microscopically. The analyze method of treatment bacteria infection to fish survival rate is completely randomiaze design (CRD) and analyze method of clinical symptom is chi square experiment, whereas histopathology analyze is description. LD 50 Aeromonas hydrophila on Koi reached 4,37 . 106 cell/ml. The survival rate of koi fish ( Cyprinus carpio) will decreased along with the increase of Aeromonas hydrophila concentration. Clinical symptom of koi fish infected with Aeromonas hydrophila were excreted mucus, black spot and grayish eyes, white spot and sticky gills, empty intestine, swollen kidney, pale liver, rash around caudal, abdominal, pectoral fin and mouth. Light infection shown liver, kidney, pancreatic and gill congestion. Severe infection shown skin lesion, hemorrhage kidney with hemorrhage enteritic.

Kata Kunci : Penyakit kan Koi,Aeromonas Hydrophila Isolat Bali, Koi fish (Cyprinus carpio), Aeromonas hydrophila, histopathology