Edwardsiella Species Infection in Fish Population and Its Status in Ethiopia

摘要

The genus Edwardsiella (E.) is a Gram-negative, glucose fermentative, catalase positive, and capable of producing H 2 S and indole (except E. ictaluri). It comprises the three previously isolated E. tarda, E. hoshinae, E. ictaluri and the two recently isolated E. piscicida, E. anguillarum species. Except E. hoshinae, other Edwardsiella spp. are pathogenic to fish, and only E. tarda is known to cause human infection. Pathogenic Edwardsiella spp. uses the virulence factors that include flagellin, adhesin, hemolysin, type III and type VI secretion systems to gain entry into and survive within the host. The status and distribution of edwardsiellosis in fish and its public health significance in Ethiopia is poorly understood, and thus needs further studies as aquaculture is growing in the country. Since differentiation of Edwardsiella spp. based only their phenotypic characteristics is less discriminatory than their genotypic characteristics, thus phenotypic studies should always be followed by genetic analysis of the bacterium. Therefore, the objective of this seminar paper is to review Edwardsiella infections in fish, its zoonotic importance and status in Ethiopia.