Evaluation of single and multispecies probiotic applications for the prevention of Motile Aeromonads Septicaemia in gourami, Osphronemus gourami

The aim of this study was to evaluate single and multispecies probiotic applications for the prevention of Motile Aeromonads Septicaemia (MAS) disease in gourami, Osphronemus gourami. The experiment consisted of the in vitro inhibition test and the in vivo application of probiotics in gourami. The in vivo assay, consisted of five treatments and five replicates, namely: negative control (K-); positive control (K+); (B) fish fed with supplementation of 1% (v/w) probiotic Bacillus NP5 RifR cells and challenged with Aeromonas hydrophila RifR; (L) fish fed with supplemention of probiotic Lactobacillus plantarum CipR 1% (v/w); challenged with A. hydrophila RifR; (BL) fish fed with mixture supplementation of Bacillus NP5 RifR 0.5% (v/w)+L. plantarum CipR 0.5%; infected with A. hydrophila RifR. Fish (29.57 ± 1.00 g) were reared in a 45 L volume aquaria with a rearing density of 10 fish/m3 for 50 days, with feeding trial three times a day. The challenge test was conducted by intramuscular injection with pathogenic A. hydrophila RifR cells (106 CFU/mL) on day 41st. In vitro test results showed that single and multispecies probiotics significantly (P<0.05) inhibited A.hydrophila RifR. In vivo experiment showed that probiotic supplementation treatments improved the growth performance, and microbiota diversity in the gut. The immune responses, fish resistance to A. hydrophila RifR and gourami survival rate in all treatments of supplemented feed were significantly higher compared to the positive control. The best treatment, multispecies probiotics significantly (P<0.05) improved the survival of gourami 96.67% post infection with A. hydrophila RifR. Keywords: A. hydrophila, Bacillus NP5, L. plantarum, O. gourami, probiotic ABSTRAK Penelitian ini bertujuan untuk mengevaluasi aplikasi probiotik tunggal dan multispesies dalam pencegahan penyakit Motile Aeromonad Septicaemia (MAS) yang disebabkan oleh Aeromonas hydrophila pada ikan gurami (Osphronemus gourami). Penelitian terdiri atas uji penghambatan in vitro bakteri probiotik tunggal dan multispesies terhadap A. hydrophila RifR, dan uji in vivo aplikasi probiotik untuk gurami. Uji in vivo, terdiri dari lima perlakuan dan lima ulangan, yaitu: kontrol negatif (K-) kontrol positif (K+); (B) ikan dengan pakan suplementasi Bacillus NP5 RifR 1% dan diinfeksi A. hydrophila RifR; (L) pakan komersial dengan penambahan probiotik L. plantarum CipR 1% dan infeksi A. hydrophila RifR; (BL) ikan dengan suplementasi campuran Bacillus NP5 RifR 0.5% dan L. plantarum CipR 0.5% serta diinfeksi A. hydrophila RifR. Benih gurami (29.57 ± 1.00 g) dipelihara di dalam akuarium bervolume 45 L dengan kepadatan 10 ekor/m3 selama 50 hari, dengan pakan bersuplemen probiotik 3 kali sehari. Uji tantang dilakukan dengan menginjeksikan suspensi sel patogen A. hydrophila RifR (106 CFU/mL) secara intramuscular pada hari ke 41. Hasil uji in vitro menunjukkan bahwa probiotik tunggal dan multispesies dapat menghambat pertumbuhan sel A.hydrophila RifR di organ hati dan ginjal secara signifikan (P<0.05). Hasil uji in vivo menunjukkan perlakuan aplikasi probiotik tunggal dan multispesies mampu meningkatkan kinerja pertumbuhan, keragaman mikrobiota usus. Respons imunitas, resistansi terhadap A. hydrophila RifR dan kelangsungan hidup gurami di semua perlakuan pakan bersuplemen probiotik secara signifikan lebih tinggi dibandingkan kontrol positif. Perlakuan terbaik adalah probiotik multispesies meningkatkan kelangsungan hidup ikan sebesar 96.67% secara signifikan (P<0.05) pascainfeksi A. hydrophila RifR. Kata kunci: A. hydrophila, Bacillus sp. NP5, L. plantarum, O. goramy, probiotik