Judul: Efficacy of Streptococcus agalactiae Oral Vaccine with Different Doses in Tilapia (Oreochromis niloticus)
Abstrak: Ikan nila (Oreochromis niloticus) merupakan salah satu komoditas air tawar unggulan yang mengalami peningkatan produksi, namun masih belum memenuhi target produksi setiap tahun. Hal tersebut disebabkan oleh penyakit streptococcosis di pembesaran ikan nila yang penyebabnya adalah Streptococcus agalactiae. Vaksinasi adalah salah satu upaya penanggulangan penyakit ikan yang dapat diaplikasikan secara oral melalui pakan. Penelitian ini bertujuan menguji efikasi vaksin oral Streptococcus agalactiae pada ikan nila dengan penerapan dosis yang berbeda serta menganalisis sistem imun spesifik dan nonspesifik ikan nila yang divaksinasi. Ikan nila yang digunakan memiliki bobot awal 10,72 ± 0,95 g dan panjang 8,72 ± 0,44 cm. Pemeliharaan berlangsung selama 30 hari dan uji tantang selama 14 hari dengan bakteri S. agalactiae. Perlakuan yang diterapkan meliputi kontrol negatif (K-), kontrol positif (K+), 105 CFU/g pakan (A), 107 CFU/g pakan (B) dan 109 CFU/g pakan (C). Setelah vaksinasi, ikan dipelihara selama 30 hari dan diberi pakan komersial secara at satiation. Hasil penelitian menunjukan aplikasi vaksin oral mampu meningkatkan kelangsungan hidup relatif, serta respons imun berbeda nyata (P<0,05) dibandingkan kontrol. Vaksinasi dengan dosis 107 CFU/g pakan sudah dapat memberi proteksi terhadap serangan S. agalactiae dan meningkatkan kekebalan spesifik yang terlihat pada peningkatan level antibodi., Tilapia (Oreochromis niloticus) is one of the leading freshwater commodities which has increased production, but it still does not meet the annual production target. This is caused by streptococcosis disease which is the cause is Streptococcus agalactiae in the grow-out of tilapia. Vaccination is one of the efforts to control fish diseases that can be applied orally through the feed. This study aimed to test the efficacy of Streptococcus agalactiae oral vaccine in tilapia with different doses applied and analyze the specific and non-specific immune systems of vaccinated tilapia. The tilapia used had an initial weight of 10,72 ± 0,95 g and a length of 8,72 ± 0,44 cm. Maintenance lasted for 30 days and trials for 14 days with S. agalactiae. The treatments applied included a negative control (K-), positive control (K+), 105 CFU/g feed (A), 107 CFU/g feed (B), and 109 CFU/g feed (C). After vaccination, fish were reared for 30 days and fed commercial feed on at satiation. The results showed that oral vaccine application was able to increase relative survival and immune response and was significantly different (P<0,05) compared to controls. Vaccination with a dose of 107 CFU/g of feed was able to provide protection against S. agalactiae attacks and increase specific immunity as seen in the increase in antibody levels.
Keyword: dose, tilapia, protection, Streptococcus agalactiae, oral vaccine

Judul: Polyvalent Vaccine DNA on Tilapia (Oreochromis niloticus) to Prevent Streptococcosis
Abstrak: Pathogen that causes tilapia to develop Streptococcosis is pathogenic bacterium Streptococcus agalactiae. This study aimed to test the polyvalent DNA vaccine on tilapia (Oreochromis niloticus) infected with Streptococcosis which causes mass mortality in tilapia. The test fish in this study had a weight range of 6.73±2.25 grams with length of 7.45±2.54 cm. Streptococcus agalactiae bacterial isolates were obtained from the Aquatic Organism Health Laboratory. Tilapia was vaccinated using Streptococcus agalactiae vaccine, Aeromonas hydrophila vaccine, polyvalent vaccine dose 2.5 ng µL-1 , dose 5 ng µL-1 and dose 10 ng µL-1 and negative positive controls were only injected with PBS (Phosphate Buffered Saline) solution. Tilapia was then challenged using Streptococcus agalactiae bacteria with a density of 106 CFU mL -1 for 0.1 mL in 14 days. Parameters were performed before vaccination, after vaccination and after the trial. The test parameters observed were total erythrocytes, total leukocytes, hemoglobin levels, hematocrit levels, differential leukocytes, phagocytic activity, Relative Percent Survival (RPS), growth rate and antibody titer. Vaccination with polyvalent DNA vaccine was able to increase non-specific immune responses (total leukocytes, lymphocyte percentage, and phagocytic activity) and specific in the form of increasing antibody titers from tilapia. The survival of vaccinated tilapia was better than the control. Based on research data, the highest RPS value was found in the 10 dose polyvalent vaccine treatment. The 10 dose polyvalent vaccine RPS value was 75.56%., Patogen yang menyebabkan ikan nila terserang penyakit Streptococcosis adalah bakteri patogen Streptococcus agalactiae. Penelitian ini bertujuan menguji vaksin DNA polivalen pada ikan nila (Oreochromis niloticus) yang terinfeksi penyakit Streptococcosis penyebab kematian massal pada ikan nila. Ikan uji dalam penelitian ini memiliki kisaran bobot 6,73±2,25 g dengan panjang 7,45±2,54 cm. Isolat bakteri Streptococcus agalactiae diperoleh dari Laboratorium Kesehatan Organisme Akuatik. Ikan nila divaksin dengan menggunakan vaksin FKC, VDP dosis 2,5 ng µL-1, VDP dosis 5 ng µL-1, VDP dosis 10 ng µL-1. serta kontrol negatif dan positif hanya disuntik larutan PBS (Phosphate Buffered Saline). Ikan nila selanjutnya dilakukan uji tantang dengan menggunakan bakteri Streptococcus agalactiae dengan kepadatan 106 CFU mL-1 sebanyak 0,1 mL selama 14 hari. Pengamatan parameter dilakukan sebelum vaksinasi, setelah vaksinasi dan setelah uji tantang. Parameter uji yang diamati yaitu, total eritrosit, total leukosit, kadar hemoglobin, kadar hematokrit, diferensial leukosit, aktivitas fagositik, Relative Percent Survival (RPS), laju pertumbuhan dan titer antibodi. Vaksinasi dengan vaksin DNA polivalen mampu meningkatkan respons imunitas non spesifik (total leukosit, persentase limfosit, dan aktivitas fagositik) dan spesifik berupa peningkatan titer antibodi dari ikan nila. Kelangsungan hidup ikan nila yang divaksinasi lebih baik dibandingkan kontrol. Berdasarkan data penelitian, nilai RPS tertinggi terdapat pada perlakuan vaksin polivalen dosis 10. Nilai RPS vaksin polivalen dosis 10 yaitu 75,56%.
Keyword: DNA vaccine, fish, pathogen, polyvalent, Streptococcus agalactiae

Judul: Metrik Einstein (Anti-) Self-Dual Berdimensi Empat dengan Metode Cartan
Abstrak: Gravitational field equation can be formulated in differential forms (differential geometry), which describes gravity as a manifestation of the curvature of space-time. Curvature of space-time is characterized by a metric that satisfies the gravitational field equation. With differential forms it can be formulated the (anti-) self-dual Einstein equation, which is a modification of the Cartan structure in (anti-) self-dual basis. Calculation of (anti-) self-dual metric with (anti-) self-dual Einstein equation is simpler than the calculation using Christoffel symbols.
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