Characterization of pathogenic bacteria in eel Anguilla bicolor bicolor

Abstract

This research aimed to characterize bacteria caused disease in eel Anguilla bicolor bicolor. The research was conducted in two steps. The first step included the isolation and identification of bacteria from the disease infected glass eel (average body length: 5.0 ± 0.5 cm, average weight: 0.5 ± 0.1 g). The observation were colony and cell morphology, physiology, and biochemical characterization of bacteria, hemolysis test, and bacteria identification performed by KIT API 20 E, KIT API 20 Strep, and KIT API 20 Listeria. The second step was Koch's postulate, tested on healthy elver with an average length of 15.00 ± 0.65 cm and weight of 3.00 ± 0.75 g. The results showed three dominant species of bacteria suspected as a causative agent in eel, namely: Aeromonas hydrophila, Streptococcus agalactiae, and Listeria grayi. Koch's postulates test proved that the Aeromonas hydrophila and Streptococcus agalactiae were virulent to Anguilla bicolor bicolor. Thus, A. hydrophila and S. agalactiae were disease-causing agent bacteria in eel.Keywords: Anguilla bicolor bicolor, bacteria, A. hydrophila, S. agalactiae. ABSTRAKPenelitian ini bertujuan untuk mengkarakterisasi bakteri penyebab penyakit pada ikan sidat Anguilla bicolor bicolor. Penelitian ini dilakukan dalam dua tahap. Tahap pertama meliputi isolasi dan identifikasi bakteri dari ikan sidat kondisi sakit pada stadia glass eel. Ukuran panjang ikan sidat rata-rata 5 ± 0,5 cm dan bobot ratarata 0,5 ± 0,08 g, pengamatan bentuk morfologi koloni dan morfologi sel, karakterisasi fisiologi, dan biokimia bakteri, serta uji hemolisis, dan identifikasi jenis bakteri dengan KIT API 20 E, KIT API 20 Strep, dan KIT API 20 Listeria. Tahap kedua yaitu uji postulat Koch pada ikan sidat kondisi sehat stadia elver yang berukuran panjang rata-rata 15 ± 0,65 cm dan bobot rata-rata 3 ± 0,75 g. Hasil penelitian diperoleh tiga jenis bakteri dominan yaitu Aeromonas hydrophila, Streptococcus agalactiae, dan Listeria grayi. Uji postulat Koch membuktikan bahwa bakteri A. hydrophila dan S. agalactiae bersifat virulen pada ikan sidat Anguilla bicolor bicolor. Dengan demikian maka bakteri A. hydrophila dan S. agalactiae sebagai bakteri penyebab penyakit pada ikan sidat.Kata kunci: Anguilla bicolor bicolor, bakteri, A. hydrophila, S. agalactiae

Identification of Micro-organisms (Parasites and Bacteria) which are Potential as Pathogenic Agent in Glass Eel of Anguilla spp. at the Eel Capture Location, Sukabumi, West Java

“…Ideally, the study was continued by conducting LD 50 test, however in this study we compared to the results of a study which had been conducted by Wahjuningrum et al, (2018) CFU/mL and 10 5 CFU/mL consecutively.…”

“…While Listeria grayi was not lethal or caused death of 50% eels which were used as the experimental material (Wahjuningrum et al, 2018). This study was conducted by Koch's postulate method, in which bacterial isolates were injected into the body of the eels.…”

“…becomes one of the fishery commodities which has high potential to be expanded in Indonesia. Eel is very popular in some countries such as Japan, South Korea, China and Taiwan (Wahjuningrum et al, 2018) as a protein source having high economic value. Eel has high nutritional value particularly vitamin A, E, and unsaturated fatty acids (EPA dan DHA) (Seo et al, 2013).…”

“…The eel culture is expected to be able to comply the eel export need for the world. Data showed that the global need for eel is 250,000 ton and the largest consumer is Japan consuming 150,000 ton (Wahjuningrum et al, 2018). The high need of eel for export provides opportunities for Indonesia to improve the yield of eel culture.…”

Isolation and identification of bacteria and parasites in glass eel (Anguilla spp.)

“…Several types of parasitic and bacterial pathogens in eel but have not specifically explained the epizootiology of each type of pathogen found. Temporary suspicion, the main cause of this condition, among others, is due to post-transportation syndrome and co-infection of several infectious disease agents at the beginning of eel rearing [4,5,20].…”