Penggunaan Probiotik, Prebiotik dan Kombinasinya untuk Meningkatkan Respon Imun dan Resistensi Ikan Nila Oreochromis Niloticus terhadap infeksi Streptococcus agalactiae

Abstract

Tilapia have been cultured to meet increasing market demand on fish. Some efforts have been done to increase tilapia production. However, some parasitical and bacterial diseases often caused mass mortality in fish culture. One of the bacterial disease that recently attacked tilapia is streptococcosis caused by Streptococcus agalactiae. In this study, fish feed supplemented with probiotic, prebiotic and synbiotic were applied to enhance the immune response and fish resistance against Streptococcus agalactiae infection. Treatments used in this study, were as follows : feed containing 1% (v/v) of probiotic, feed containing 2% (v/v) of prebiotic and feed containing mixed of 1% (v/v) of probiotic + 2% (v/v) of prebiotic (defined as synbiotic). In controls (positive and negative controls), fish were fed by fish feed without containing neither probiotic and prebiotic. In this study, we used all male (monosex) red tilapia with the average of body weight of ± 13 gram. Fish were fed by supplemented feed within the first 30 days before challenge test by injection of 109 CFU/ml of Streptococcus agalactiae. The results demonstrated that the survival rate of the fish challenged by Streptococcus agalactiae in control group (+) was lowest (50%) than others. The survival rate of the fish fed by supplemented feed containing probiotic, prebiotic and synbiotic were 76%, 76% and 80%, respectively. These results were statistically different compared to that of control (50%) (P<0.05). The results demonstrated that addition of probiotic, prebiotic and synbiotic in fish feed could increase immune response and survival rate against Streptococcus agalactiae infection. Keywords : tilapia, probiotic, prebiotic, synbiotic, Streptococcus agalactiae ABSTRAK Ikan nila telah banyak dibudidayakan oleh masyarakat untuk memenuhi peningkatan permintaan pasar. Beberapa upaya telah dilakukan untuk meningkatkan produksi tilapia. Tetapi penyakit akibat prasit dan bakteria masih sering menyebabkan kematian masal pada ikan budidaya. Salah satu penyakit bakterial yang akhir-akhir ini banyak menyerang ikan nila adalah streptococcosis yang disebabkan oleh bakteri Streptococcus agalactiae. Pada penelitian ini, ikan diberi pakan yang mengandung probiotik, prebiotik dan sinbiotik yang diduga dapat meningkatkan respon imun dan ketahanan ikan terhadap Streptococcus agalactiae. Pakan yang diberikan adalah pakan yang mengandung probiotik 1% (v/v), prebiotik 2% (v/v) dan probiotik 1% (v/v) + prebiotik 2% (v/v) (sinbiotik). Ikan kontrol (kontrol positif dan kontrol negatif) diberi pakan yang tidak mengandung probiotik maupun prebiotik. Pada penelitian ini, digunakan ikan nila merah monoseks (all male) dengan ukuran bobot rata-rata 13 gram. Ikan tersebut diberi pakan perlakuan selama 30 hari sebelum diuji tantang dengan disuntik Streptococcus agalactiae dengan kepadatan 109 CFU/ml. Hasil yang diperoleh menunjukkan bahwa tingkat kelangsungan hidup ikan setelah diinfeksi Streptococcus agalactiae memberikan pengaruh yang berbeda nyata (P<0,05) pada perlakuan A (kontrol +) sebesar 50% terhadap semua perlakuan lain, yaitu perlakuan C (probiotik), D (prebiotik) dan E (sinbiotik) yang masing-masing sebesar 73%, 76% dan 80%. Penambahan probiotik, prebiotik dan sinbiotik pada pakan ternyata dapat meningkatkan respon imun dan tingkat kelangsungan hidup ikan terhadap infeksi Streptococcus agalactiae. Kata kunci : ikan nila, probiotik, prebiotik, sinbiotik, Streptococcus agalactiae