Antibiofilm of metabolites of the Proteus myxofaciens JB 20B for the prevention and treatment of vaname shrimp infected with Vibrio harveyi bacteria

Abstract

Vibrio harveyi is one of the common bacteria that cause disease in vaname shrimp. The aim of this study is to determine the efficacy of bacterial metabolites Proteus myxofaciens JB 20B as an antibiofilm agent in the prevention and treatment of V. harveyi infected vaname shrimp (Litopenaeus vannamei). The experimental design included eight treatments and three replicates: K- (negative control), K+ (positive control), PCA and PGA (antibiotic control 50 g/100ml for preventive and treatment), PCE (preventive extract 0.1 ml/Kg feed), PCS (preventive supernatant 20 ml/Kg feed), PGE (treatment extract 0.1 ml/Kg feed), and PGS (treatment supernatant 20 ml/Kg feed). On day 15^th, vaname shrimp were intramuscularly infected with 10⁶ CFU/mL of V. harveyi. Examining clinical symptoms, viewing histology, assessing total hemocyte count, phagocytosis activity, phenoloxidase activity, respiratory burst, and growth performance. According to the findings of this study, the treatment of bacterial metabolites P. myxofaciens JB 20B (PCE, PCS, PGE, and PGS) is superior to the positive control (K+) treatment in terms of reducing shrimp hepatopancreas necrosis, increasing the value of total hemocyte count, phagocytosis activity, phenoloxidase activity, respiratory burst, and growth performance of vaname shrimp through feeding in both prevention and treatment. The use of P. myxofaciens JB 20B bacterial metabolites to control V. harveyi infection in vaname shrimp yielded the best results in the supernatant treatment.

Keywords: antibiofilm, biofilm, Proteus myxofaciens JB 20B, vannamei shrimp, Vibrio harveyi

ABSTRAK

Vibrio harveyi merupakan salah satu bakteri penyebab penyakit pada udang vaname. Tujuan dari penelitian ini adalah untuk mengetahui efektivitas metabolit bakteri Proteus myxofaciens JB 20B sebagai agen antibiofilm dalam pencegahan dan pengobatan udang vaname (Litopenaeus vannamei) yang terinfeksi V. harveyi.  Rancangan penelitian ini terdiri dari delapan perlakuan dan tiga kali ulangan: K- (kontrol negatif), K+ (kontrol positif), PCA dan PGA (kontrol antibiotik 50 g/100ml untuk pencegahan dan pengobatan), PCE (ekstrak pencegahan 0,1 ml/Kg pakan), PCS (supernatan pencegahan 20 ml/Kg pakan), PGE (ekstrak pengobatan 0,1 ml/Kg pakan), dan PGS (supernatan pengobatan 20 ml/Kg pakan). Pada hari ke-15, udang vaname diinfeksi secara intramuskular dengan 10⁶ CFU/mL V. harveyi. Memeriksa gejala klinis, melihat histologi, menilai jumlah hemosit total, aktivitas fagositosis, aktivitas phenoloxidase, respiratory burst, dan performa pertumbuhan. Berdasarkan hasil penelitian ini, perlakuan metabolit bakteri P. myxofaciens JB 20B (PCE, PCS, PGE, dan PGS) lebih unggul dibandingkan dengan perlakuan kontrol positif (K+) dalam hal mengurangi nekrosis hepatopankreas udang, meningkatkan nilai jumlah hemosit total, aktivitas fagositosis, aktivitas phenoloxidase, respiratory burst, dan performa pertumbuhan udang vaname melalui pemberian pakan pasca infeksi baik pada pencegahan maupun pada pengobatan. Penggunaan metabolit bakteri P. myxofaciens JB 20B untuk mengendalikan infeksi V. harveyi pada udang vaname memberikan hasil terbaik pada perlakuan supernatan.

Kata kunci: antibiofilm, biofilm, Proteus myxofaciens JB 20B, udang vaname, Vibrio harveyi