摘要：Febrianti R, Khasani I, Rosada KK2021Assessing the susceptibility of the selected gourami (Osphronemus goramy) to Aeromonas hydrophilaNusantara Bioscience 13: 111-120A breeding program to improve the growth performance of the gourami fish was carried out through selection methods that produced faster growth gourami (selected population)The purpose of this study was to determine the susceptibility of the selected gourami to Aeromonas hydrophila infection based on tolerance limits (LD50) and investigated clinical signs post-injection of the pathogenic bacteriaThe challenge test by intramuscular injection of Ahydrophila was done to the fingerling fish (15-20 g) for 14 days post-infectionThe population of the tested fish was obtained from six families, selected gourami (SP), and non-selected control (CP) groupsPhosphate buffered saline (PBS) as control and several doses of the pathogen, 102, 104, 105, 106, 107, and 108 CFU/mL of Ahydrophila, were injected into the fishFish mortality and clinical signs were observed dailyThe fish mortality was confirmed by isolating bacteria in the fish which showed clinical signs, followed by biochemical characterization of the isolated bacteria using API 20E and PCRThe LD50 of Ahydrophila to the selected population (9.70 × 105 CFU/mL) was higher than that of the control (6.50 × 104 CFU/mL)On the final day of the test, the accumulation mortality of CP (63.33±5.77%) higher than that in SP (33.33±5.77%)Based on the output test statistics, it was known that there was a significant difference between the mortality and clinical signs of SP and CPThe data suggested that the selected gourami were more resistant to Ahydrophila infection than that of the controlThe Ahydrophila infection caused most of the major clinical signs, including mass mortality of the fishThe biochemical and PCR test ensure that fish mortality was caused by Ahydrophila infection.
