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A prebiotic treatment of edwardsiellosis in striped catfish (Pangasianodon hypophthalmus) Valentin Eckart, Biochem A threat, not only to catfish The pathogenic, gram-negative bacterium Edwardsiella ictaluri is widely known as the causative agent of the enteric septicaemia of catfish (ESC) and was first reported in the United States in channel catfish (Ictalurus punctatus) (Hawke et al., 1981). Subsequent reports have shown that this bacterium also infects non-catfish species like Nile or hybrid red tilapia. In general, clinical signs of E. ictaluri infections may vary between species, but visceral white spots have been described in most of them. The misinterpretation of these symptoms, as those of other diseases (Dong et al., 2019), makes the actual spread of edwardsiellosis somewhat unclear and it should be further monitored. An economic challenge Today, edwardsiellosis has become one of the most important infectious disease problems in the commercial catfish industry. In Asia, E. ictaluri is causing bacillary necrosis of pangasius (BNP) in striped catfish (Pangasianodon hypophthalmus). Natural disease outbreaks are reported in all ages of fish, with high mortality rates of 50 – 90% (Crumlish et al., 2002; Dung et al., 2004). The Vietnamese industry highly relies on striped catfish farming, with an annual production volume of about 1.4 million tons (VASEP, 2019). Hence, declining production, high fish mortality and increased costs for the treatment of E. ictaluri infections can lead to huge economic losses. Lack of specific treatments In order to counteract the economic impact of E. ictaluri, the industry has been working on the development of pathogen-specific vaccines that already reduce the mortality rate during the production of
Aquafeed: Advances in Processing & Formulation Vol 12 Issue 2 2020
