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ARS Home » Southeast Area » Stuttgart, Arkansas » Harry K. Dupree Stuttgart National Aquaculture Research Cntr » Research » Publications at this Location » Publication #120529
Title: THE EFFECT OF INCUBATION TEMPERATURE AND DIFFERENT SALINITY LEVELS ON THE EXPRESSION OF THE OUTER MEMBRANE PROTEIN PROFILE OF EDWARDSIELL'A TARDA.

Author
item Darwish, Ahmed
item NEWTON, JOSEPH - AUBURN UNIVERSITY
item PLUBM, JOHN - AUBURN UNIVERSITY

Submitted to: Journal of Aquatic Animal Health
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 9/1/2001
Publication Date: 9/30/2001
Citation: DARWISH, A.M., NEWTON, J., PLUBM, J. THE EFFECT OF INCUBATION TEMPERATURE AND DIFFERENT SALINITY LEVELS ON THE EXPRESSION OF THE OUTER MEMBRANE PROTEIN PROFILE OF EDWARDSIELL'A TARDA.. JOURNAL OF AQUATIC ANIMAL HEALTH. 2001. v.13. p.269-275.

Interpretive Summary: Edwardsiella tarda is a bacterial pathogen that exists free in the aquatic environment and infects a wide variety of hosts: fish, amphibians, reptiles, birds, mammals, and man. This pathogen can cause different symptoms in man such as diarrhea with salmonella-like food poisoning and life threatening wound infections. The outer membrane proteins of E. tarda are one of the factors that make the bacteria capable of causing an infection. Despite the importance of these outer membrane proteins there has been very few studies done on them. In this research, different strains of E. tarda were grown at different environmental conditions and the production of the outer membrane proteins was investigated. The different outer membrane proteins produced by the bacteria were characterized. The study also demonstrated that different stains produce different proteins at different environmental conditions. This information will be useful for controlling the bacteria through effective vaccine and drugs development.

Technical Abstract: The outer membrane proteins (OMP), prepared with sodium N-lauroyl sarcocinate from 10 fish isolates of Edwardsiella tarda, were examined using sodium dodecyl sulfate-polyacrylamide gradient gel electrophoresis. The OMP profile of E. tarda (ATCC 15947; the type strain of E. tarda) was used as a reference. The OMP profile of the type strain E. tarda cultured at 25 ?C had four major protein bands; 40, 36.5, 34, and 28.5 kDa and a large number of minor proteins ranging in size from approximately 10 to 120 kDa. A comparison between the OMP profiles of the E. tarda isolates revealed differences between the isolates. The 34 or 36.5 kDa outer membrane protein bands were not consistent in five E. tarda isolates. Moreover, two major bands of 47 and 44 kDa were present in only two E. tarda isolates. The incubation temperature of 25 and 35 ?C had no effect on the outer membrane protein profiles of 9 out of 10 of the E. tarda isolates. To evaluate the effect of salinity, the 10 E. tarda isolates were cultured in brain heart infusion broth (BHIB) containing 0.5, 1.5 and 3.0 % sodium chloride. The reactions of E. tarda isolates to the different salinity levels were placed into three groups; the first group expressed more or fewer protein bands at 1.5 % sodium chloride. The second group lost major bands at 3 % salinity while the third group had no change in the OMP profile with salinity. The outer membrane protein profile differences observed between the isolates and their different reactions to salinity levels suggest that E. tarda is not a homogenous species.