Efektivitas antibiotik terhadap Vibrio alginolyticus pada kerapu macan (Epinephelus fuscogutattus)

YUWONO, Heri, drh. Syarifuddin Tato, SU

2006 | Tesis | S2 Sain Veteriner

Penelitian ini bertujuan untuk mengetahui sensitifitas V. alginolyticus terhadap berbagai antibiotik secara in vitro dan efektivitas antibiotik terpilih untuk pengobatan vibriosis pada kerapu macan secara in vivo. Penelitian tahap ke-satu yaitu uji sensitifitas V. alginolyticus streptomycine, amoxyciline, enrofloxacine, chloramphenicol dan doxycycline menggunakan metode disc diffusion Kirby-Bauer. Nilai MIC (Minimum Inhibitory Concentration) dari antibiotik yang terpilih dilakukan dengan metode tabung berseri. Penelitian tahap ke-dua adalah menginfeksikan V. alginolyticus pada kerapu macan secara rendaman dengan dosis LC50 (106 sel/ml) hingga timbul gejala klinis. Ikan uji kemudian diberi antibiotik terpilih dengan dosis 1 MIC (2 μg/ml), 2 MIC (4μg/ml), 4 MIC (8 μg/ml), 8 MIC (16 μg/ml) dan 16 MIC (32 μg/ml) selama 2 jam secara rendaman 5 hari berturut-turut. Pengamatan ikan dan kualitas air dilakukan setiap 6 jam sampai dengan hari ke-10. Kualitas air hasil pemeriksaan adalah suhu 25-26oC, salinitas 34-35 ppt, pH 7,2-7,5 dan DO 5,3-6,2 ppm. Antibiotik yang terpilih adalah enrofloxacine. Pengobatan dengan enrofloxacine dosis 4 MIC (8 μg/ml) efektif untuk kesembuhan ikan akibat vibriosis. Ikan kerapu macan yang terinfeksi V. alginolyticus tampak gerakan renang lemah, sering ke permukaan air, reaksi terhadap rangsangan kurang, nafsu makan menurun, mulut hemoragi, insang pucat, sirip geripis, jumlah lendir berlebihan dan kulit pucat. Perubahan histopatologi tampak radang pada kulit, insang, ginjal, jantung dan mata, kongesti pada insang, ginjal, otak dan mata, degenerasi melemak pada hati dan adesi lamela pada insang. Ikan yang diinfeksi V. alginolyticus dan diobati dengan enrofloxacine dosis 4 MIC secara rendaman selama 2 jam 5 hari berturut-turut tampak kongesti pada otak, sedangkan kulit, insang, hati, ginjal, jantung dan mata normal.

The study aims at investigating the sensitivity of V. alginolyticus to various antibiotics and the effectiveness of the selected antibiotics at the treatment of fibrosis in kerapu macan fish (E. fuscoguttatus). The first step of the study is the sensitivity test of streptomycine, amoxyciline, enrofloxacine, chloramphenicol and doxycycline using Kirby-Bauer’s disk diffusion method. The Minimum Inhibitory Concentration (MIC) value of the selected antibiotics is determined using serial tubes. The second step of the study is to infect the fishes with Vibrio alginolyticus using rendemen method with the concentration at the dose LC50 (106 cell/ml) for 2 days till clinical symptom emerges, and then they are tested by giving them the selected antibiotics at the doses 1 MIC (2 μg/ml), 2 MIC (4 μg/ml), 4 MIC (8 μg/ml), 8 MIC (16 μg/ml) and 16 MIC (32 μg/ml) for 2 hours with rendemen method in 5 successive days. The observation of the fishes and water quality is conducted every 6 hour till the 10th day. The results of the water quality test show that the temperature of the water is 25-26 oC, the salinity 34-35 ppt, pH 7.2-7.5 and DO 5.3-6.2 ppm. The results of the water quality test show that its temperature is 25-26 oC, its salinity is 34-35 ppt, its pH is 7.2-7.5 and its DO is 5.3-6.2 ppm. The selected antibiotic is enrofloxacine. The treatment with the enrofloxacine at the dose 4 MIC (8 8 μg/ml) is effective to recover the fishes from the vibriosis. The kerapu macan fishes infected by V. alginolyticus swim weakly, thier appetite decreases, a hemorrhage tooks place in their mouth cavity, pale gills, seriously wounded fins, excessive mucus excretion and pale skin. The histopathologic changes are clearly observed in the inflamation of skin, gills, kidney, heart and eyes, gills, kidney, cerebrum congestions and eyes, the degeneration becomes weak in lever and lamela adhesion takes place in the gills. The fishes infected by the V. alginolyticus is treated with the enrofloxacine at the dose 4 MIC using rendemen method for 2 hours in 5 successive days and they show cerebrum congestion, while their skin, gills, lever, kidney, heart and eyes are normal.

Kata Kunci : Penyakit Ikan,Vibrio Alginolyticus,Antibiotika, Kerapu macan fish (E. fuscoguttatus), V. alginolyticus, enrofloxacine, effectiveness