The ability of Edwardsiella tarda to hemolyse red blood cells was investigated. Most E. tarda strains (> 80%) produced a hemolysin when assayed by either an agar overlay or contact-dependent hemolysis technique. This activity was cell-associated (CAH) and not released into the culture supernatant under routine conditions. When quantified, E. tarda strains significantly produced 30-40-fold highe...

Infection with Edwardsiella tarda, a gram-negative bacterium, causes high morbidity and mortality in both marine and freshwater fish. Outer membrane vesicles (OMVs) released from gram-negative bacteria are known to play important roles in bacterial pathogenesis and host immune responses, but no such roles for E. tarda OMVs have yet been described. In the present study, we investigated the prote...

Bacterial small non-coding RNAs (sRNAs) are known as novel regulators involved in virulence, stress responsibility, and so on. Recently, a lot of new researches have highlighted the critical roles of sRNAs in fine-tune gene regulation in both prokaryotes and eukaryotes. Edwardsiella tarda (E. tarda) is a gram-negative, intracellular pathogen that causes edwardsiellosis in fish. Thus far, no sRN...

We previously reported that high virulent strain (NUF251) of Edwardsiella tarda has an ability to prevent the production of reactive oxygen species by macrophages, and is even capable of surviving and multiplying within Japanese flounder (Paralichthys olivaceus) peritoneal macrophages, whereas the low virulent strain (NUF194) has no such ability. In this study, we found that NUF251 and NUF194 i...

Columnaris disease is the second leading cause of mortality in pond raised catfish in the southeastern United States. It is second only to enteric septicemia of catfish (ESC) caused by the bacterium Edwardsiella ictaluri. Most species of fish are susceptible to columnaris following some type of environmental stress and when water temperatures are in the upper part of their preferred temperature...

Edwardsiella tarda and Flavobacterium columnare are two important intracellular pathogenic bacteria that cause the infectious diseases edwardsiellosis and columnaris in wild and cultured fish. Prediction of major histocompatibility complex (MHC) binding is an important issue in T-cell epitope prediction. In a healthy immune system, the T-cells must recognize epitopes and induce the immune respo...