Edwardsiellosis is one of the important bacterial diseases of fish causing severe economic losses in aquaculture worldwide. In Ethiopia, information on fish pathogenicEdwardsiella species is scanty. This study was conducted to isolate and determine the extent of occurrence of fish pathogenic Edwardsiella species from apparently healthy fish harvested for human consumption from the gulf of Lake Tana, Ethiopia. Bacteriological analysis of 124 tissue specimen (42 intestine, 42 liver and 40 kidney) obtained from 42 fish (Nile Tilapia, barbus and African catfish) resulted in 10 isolates of which one isolate was presumptively identified as Edwardsiella tarda from the kidney of Nile tilapia. Further molecular identification using species-specific PCR assay supported the presumptive identification as Edwardsiella tarda resulting a prevalence rate of 2.3%. The isolation of E.tarda from the kidney of apparently healthy fish indicates subclinical infection which may eventually develop to disease in the event of stress factors. Although disease outbreaks is not a common scenario in wild fish due to the sparse population, such infection could turn out into epidemics hat it been in aquaculture setting. Thus the finding has important implication for future aquaculture activities around the Lake and public health safety due to the zoonotic importance of the bacterium particularly in immune compromised individuals consuming uncooked or undercooked fish meal.
Keywords: African Catfish, Barbus, Edwardsiella, Ethiopia, Lake Tana, Nile Tilapia, species