Application of Bacillus probiotic to prevent Aeromonas hydrophilla infection in Clarias sp.

Abstract

<p class="BasicParagraph" align="center"><strong>ABSTRACT</strong></p><p class="BasicParagraph" align="center"><strong> </strong></p><p class="Pa2">The aim of this study was to test the effectiveness of a probiotic <em>Bacillus </em>for the prevention of motile aeromonad septicemia (MAS) disease caused by <em>Aeromonas hydrophila </em>in African catfish (<em>Clarias gariepinus</em>). The study consisted of the inhibition testing of <em>A. hydrophila </em>by <em>Bacillus </em>(<em>in vitro</em>) and the application of probiotic in African catfish (<em>in vivo</em>). The <em>in vivo </em>test, consisted of five treatments such as the addition of probiotic <em>Bacillus </em>P4I1 RifR, <em>Bacillus </em>P4I2 RifR, <em>Bacillus </em>P4I1 RifR + <em>Bacillus </em>P4I2 RifR (Kom), positive control (K+; only added with <em>A. hydrophila</em>) and negative control (K-; without probiotic nor <em>A. hydrophila </em>addition). African catfish (13.35±2.80 g) was maintained in 15 aquariums (40 L in volume) with 30 fishes each for 30 days. Probiotic bacteria was applied in water once a day, whereas pathogenic bacteria <em>A. hydrophila </em>RifR (103 cfu/mL) were added once in earlier treatment (except for the negative control). The result showed that the optimal concentration of <em>Bacillus </em>to inhibit <em>A. hydrophila </em>on <em>in vitro </em>test was 104 cfu/mL. <em>In vivo </em>test showed that the addition of probiotic in media of cultivation could reduce the number of <em>A. hydrophila</em>, improve immune response, and also increase the survival of African catfish compared to positive control. Application of probiotic P4I1 RifR showed the highest survival (92.23%) of all treatments.</p><p class="Default"> </p>Keywords: <em>Bacillus</em>, <em>Clarias gariepinus</em>, <em>motile aeromonad septicemia</em>, probiotic<br /><p class="BasicParagraph"> </p><p class="BasicParagraph"> </p><p class="BasicParagraph" align="center"><strong>ABSTRAK</strong></p><p class="BasicParagraph"> </p><p class="Pa2">Penelitian ini bertujuan untuk menguji efektivitas probiotik <em>Bacillus </em>dalam pencegahan penyakit <em>motile aeromonad septicaemia </em>(MAS) yang disebabkan oleh <em>Aeromonas hydrophila </em>pada ikan lele dumbo (<em>Clarias gariepinus</em>). Penelitian terdiri atas pengujian penghambatan bakteri probiotik <em>Bacillus </em>terhadap <em>A. hydrophila </em>secara <em>in vitro</em>, dilanjutkan dengan aplikasi pada budidaya ikan lele dumbo (<em>in vivo</em>). Pada uji <em>in vivo</em>, penelitian terdiri atas lima perlakuan yaitu budidaya ikan lele dumbo dengan penambahan probiotik <em>Bacillus </em>P4I1 RifR, <em>Bacillus </em>P4I2 RifR, kombinasi probiotik <em>Bacillus </em>P4I1 RifR + <em>Bacillus </em>P4I2 RifR (Kom), kontrol positif (K+; hanya ditambahkan <em>A. hydrophila</em>) dan kontrol negatif (K-; tanpa pemberian probiotik dan <em>A. hydrophila</em>). Ikan lele dumbo (13,35±2,80 g) dipelihara pada akuarium volume 40 L dengan kepadatan 30 ekor/akuarium selama 30 hari. Bakteri probiotik ditambahkan pada media pemeliharaan ikan setiap hari, sedangkan bakteri patogen <em>A. hydrophila </em>RifR (103 cfu/ mL) diberikan sekali pada awal pemeliharaan (kecuali pada kontrol negatif). Hasil penelitian menunjukkan bahwa konsentrasi terbaik pada penghambatan <em>in vitro </em>adalah dengan penambahan <em>Bacillus </em>104 cfu/mL. Hasil uji <em>in vivo </em>menunjukkan perlakuan penambahan probiotik pada media budidaya efektif dapat menekan jumlah bakteri <em>A. hydrophila</em>, memperbaiki respons imun, dan meningkatkan kelangsungan hidup ikan lele dumbo dibanding kontrol positif. Perlakuan probiotik P4I1 RifR memberikan hasil terbaik dengan tingkat kelangsungan hidup tertinggi yaitu 92,23%.</p><p class="Default"> </p><p>Kata kunci: <em>Bacillus</em>, <em>Clarias gariepinus</em>, <em>motile aeromonad septicemia</em>, probiotik</p><br class="BasicParagraph" /><p> </p>