摘要：ABSTRACT This study was aimed to evaluate the effectiveness of Bacillus sp. NP5 paraprobiotic administration through commercial feed on growth performance, immune response, and resistance of Nile tilapia against Streptococcus agalactiae infection. Bacillus sp. NP5 paraprobiotic was produced through heat-inactivation at 95°C for 1 h, then performed a viability test on tryptic soy agar (TSA) media and incubated for 24 hours. Paraprobiotics could be used whether the bacteria did not grow on the TSA media. This study used a completely randomized design, containing three treatments with five replications, i.e. 1% (v/w) probiotic addition, 1% (v/w) paraprobiotic addition, and no addition of probiotic or paraprobiotic (control). The experimental fish were reared for 30 days. On day 31 of rearing, fish were challenged with S. agalactiae (10 7 CFU/mL) through intraperitoneal injection route, while the negative control was injected with PBS. This study results significantly improved growth performances and immune responses (P<0.05), compared to control after 30 days of probiotic and paraprobiotic Bacillus sp. NP5 administration. After challenge test, increased immune responses in probiotic and paraprobiotic of Bacillus sp. NP5 treatment had higher survival rates (P<0.05) than positive control. The administration of Bacillus sp. NP5 probiotic and paraprobiotic through commercial feed were effective in increasing growth performance, immune response, and resistance of Nile tilapia against S. agalactiae infection.
其他摘要：ABSTRACT This study was aimed to evaluate the effectiveness of Bacillus sp. NP5 paraprobiotic administration through commercial feed on growth performance, immune response, and resistance of Nile tilapia against Streptococcus agalactiae infection. Bacillus sp. NP5 paraprobiotic was produced through heat-inactivation at 95°C for 1 h, then performed a viability test on tryptic soy agar (TSA) media and incubated for 24 hours. Paraprobiotics could be used whether the bacteria did not grow on the TSA media. This study used a completely randomized design, containing three treatments with five replications, i.e. 1% (v/w) probiotic addition, 1% (v/w) paraprobiotic addition, and no addition of probiotic or paraprobiotic (control). The experimental fish were reared for 30 days. On day 31 of rearing, fish were challenged with S. agalactiae (107 CFU/mL) through intraperitoneal injection route, while the negative control was injected with PBS. This study results significantly improved growth performances and immune responses (P<0.05), compared to control after 30 days of probiotic and paraprobiotic Bacillus sp. NP5 administration. After challenge test, increased immune responses in probiotic and paraprobiotic of Bacillus sp. NP5 treatment had higher survival rates (P<0.05) than positive control. The administration of Bacillus sp. NP5 probiotic and paraprobiotic through commercial feed were effective in increasing growth performance, immune response, and resistance of Nile tilapia against S. agalactiae infection.
关键词：Bacillus sp;NP5; Nile tilapia; paraprobiotic; Streptococcus agalactiae
其他关键词：Bacillus sp; NP5; Nile tilapia; paraprobiotic; Streptococcus agalactiae
