Pengaruh probiotik Lactobacillus spp. Dad13 terhadap sistem imun humoral mencit Balb/C yang diinfeksi Salmonella typhimurium

KUSUMAWATI, Ika Dyah, Dr.Ir. Eni Harmayani, M.Sc

2006 | Tesis | S2 Bioteknologi

Isolat lokal bakteri asam laktat (BAL) Lactobacillus spp. Dad13 (disebut Dad13), diisolasi dari susu fermentasi tradisional, diketahui berpotensi sebagai agensia probiotik. Penelitian ini bertujuan untuk mempelajari pengaruh probiotik Dad13 terhadap sistem imun humoral mencit Balb/C yang diinfeksi dengan Salmonella typhimurium. Tujuan khusus penelitian yaitu untuk mengetahui pengaruh perbedaan waktu pemberian Dad13 antara sebelum dan bersamaan infeksi S. typhimurium terhadap respon imun humoral mencit Balb/C. Pengujian awal berupa uji kemampuan anti patogenistik Dad13 terhadap Salmonella secara in vitro dengan metode difusi agar. Pengujian lanjutan secara in vivo dilakukan terhadap 20 ekor mencit Balb/C jantan, umur 6-8 minggu, yang diberi perlakuan probiotik Dad13 selama 1 minggu secara oral forced feeding dengan pakan standar AIN-93. Mencit terbagi dalam 4 grup perlakuan yaitu pemberian Dad13 tanpa infeksi, Dad13 sebelum infeksi, Dad13 bersamaan infeksi, dan infeksi tanpa Dad13. Suspensi sel Dad13 diberikan sebanyak 100 μL dengan populasi sel 1010 CFU/mL per-hari pada minggu ke-3 untuk grup Dad13 sebelum infeksi, sedang untuk grup Dad13 tanpa infeksi dan Dad13 bersamaan infeksi suspensi sel diberikan pada minggu ke-4. Infeksi Salmonella dilakukan secara oral 1x, sebanyak 100 μL dengan populasi sel 109 CFU/mL pada minggu ke-4 untuk semua grup kecuali grup dengan perlakuan Dad13 tanpa infeksi. Deteksi efek pemberian probiotik Dad13 terhadap sistem imun humoral mencit Balb/C dilakukan melalui pengukuran sekresi antibodi, yaitu IgA dan IgG spesifik terhadap Salmonella. Sampel analisa berupa serum dan cairan mukosa usus diambil 2 minggu setelah infeksi Salmonella. Sampel dianalisa menggunakan metode ELISA (Enzyme-linked Immunosorbent Assay). Pengujian juga dilakukan terhadap pH cairan mukosa usus, total BAL dan Salmonella pada digesta, berat dan asupan pakan mencit selama perlakuan. Hasil penelitian menunjukkan perbedaan waktu pemberian probiotik Dad13 antara sebelum dan bersamaan infeksi Salmonella memberikan efek respon imun humoral mencit Balb/C yang berbeda nyata (p<0,05). Titer IgG dan IgA sirkulasi serta IgA sekresi meningkat secara nyata pada mencit yang diberi Dad13 bersamaan infeksi. Pemberian Dad13 tanpa infeksi menunjukkan nilai pH cairan mukosa usus paling rendah (pH 6,9). Tidak ada perbedaan berat dan konsumsi pakan pada semua perlakuan. Pengujian in vitro menunjukkan Dad13 memiliki zat anti mikrobia yang bersifat ekstraseluler dan memberi penghambatan terhadap Salmonella. Dari penelitian ini dapat disimpulkan bahwa pemberian Dad13 bersamaan infeksi memberikan efek respon imun humoral yang lebih signifikan dibandingkan dengan sebelum infeksi.

An indigenous strain of lactic acid bacterium (LAB) identified as Lactobacillus spp. Dad13 (Dad13), isolated from traditional fermented milk, was found to be potential as probiotic. The aim of this research was to study the effect of probiotic Dad13 on humoral immune response of Balb/C mice infected with Salmonella typhimurium. The specific objective was to find out the effect of different Dad13 consumption time Dad13 (before and along with infection of S. typhimurium) on the humoral immune response of Balb/C mice. Initial experiment was conducted to check the ability of Dad13 to inhibit the growth of Salmonella by in vitro with agar diffusion method. The next experiment was conducted by in vivo trial on 20 males of Balb/C mice, age of 6-8 weeks, fed with AIN-93 standard diet. The mice were assigned into 4 groups. Each group received the following treatments, ie. Dad13 only, Dad13 before infection, Dad13 along with infection and Salmonella infection only. A portion of 100 μl Dad13 cell suspensions were given by oral forced feeding for a week with cell concentration 1010 CFU/mL per day, at week 3 for group of Dad13 before infection and at week 4 for group of Dad13 only and Dad13 along with infection. Salmonella infection (109 CFU/mL) was given once orally to all groups except group treated with Dad13 only. The humoral immune response of Balb/C mice was detected 2 weeks after infection by measuring the antibodies secretion of IgG and IgA specific Salmonella from samples serum and mucosal intestinal liquid using ELISA (Enzyme-linked Immunosorbent Assay) method. The pH of mucosal intestinal liquid, LAB and Salmonella counts of digesta, weight as well as total feed consumption of Balb/C mice were also analyzed. The result indicated that humoral immune response of Balb/C mice consuming Dad13 before and along with Salmonella infection were significantly different (p<0,05). Dad13 consumption along with Salmonella infection increased circulated IgG and IgA also secretion of IgA. Mice of all treatments showed similar weight and total feed consumption, but group of mice with Dad13 consumption only without Salmonella infection gave lower pH value than other treatments (pH 6.9). In vitro trial also indicated that extra cellular extract of Dad13 inhibited the growth of S. typhimurium in agar. It can be concluded that feeding of Dad13 probiotic along with infection increased humoral immune response more significantly compare to before infection.

Kata Kunci : Probiotik Dad13,Imunitas,Salmonella typhimurium, Probiotic, Lactobacillus sp. Dad13, Immunity, Salmonella typhimurium