Hafnia alvei as an opportunistic pathogen causing mortality in brown trout, Salmo trutta L

Abstract

Strains of Hafnia alvei caused mortalities in brown trout, Salmo trutta L., following intraperitoneal injection with LD50 values ranging between 1.3 x 10(4) and 2.5 x 10(7) bacteria fish(-1). These values are considered to represent a high to moderate degree of virulence. Virulent strains were isolated from non-fish sources. Fish surviving the LD50 values continued to harbour the organism in the kidney, suggesting the establishment of a carrier state.