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ARS Home » Southeast Area » Stoneville, Mississippi » Warmwater Aquaculture Research Unit » Research » Publications at this Location » Publication #315248
Title: Identification of differentially regulated proteins of Edwardsiella ictaluri during iron restriction

Author
item DUMPALA, P - Mississippi State University
item Peterson, Brian
item LAWRENCE, M - Mississippi State University
item KARSO, A - Mississippi State University

Submitted to: PLOS ONE
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 6/25/2015
Publication Date: 7/13/2015
Citation: Dumpala, P.R., Peterson, B.C., Lawrence, M., Karso, A. 2015. Identification of differentially regulated proteins of Edwardsiella ictaluri during iron restriction. PLoS One. 10(7):e0132504.doi.

Interpretive Summary: Edwardsiella ictaluri is a Gram-negative facultative anaerobe intracellular bacterium that causes enteric septicemia in channel catfish. Iron is an essential inorganic nutrient of bacteria and is crucial for bacterial invasion. Reduced availability of iron by the host may cause a significant stress for bacterial pathogens and is considered a signal that leads to significant alteration in virulence gene expression. However, the precise effect of iron-restriction on E. ictaluri protein expression is unknown. The purpose of this study was to identify differentially expressed proteins of E. ictaluri during in vitro iron-restricted conditions. A total of 50 unique expressed proteins at a minimum of 2-fold difference in expression due to iron-restriction were detected. The numbers of up- and down-regulated proteins were 37 and 13, respectively. The identified proteins are known to be involved in processes like virulence, pathogenesis, signal transduction, and cell survival. This information will be used to better understand the mechanisms of enteric septicemia in catfish.

Technical Abstract: Edwardsiella ictaluri is a Gram-negative facultative anaerobe intracellular bacterium that causes enteric septicemia in channel catfish. Iron is an essential inorganic nutrient of bacteria and is crucial for bacterial invasion. Reduced availability of iron by the host may cause a significant stress for bacterial pathogens and is considered a signal that leads to significant alteration in virulence gene expression. However, the precise effect of iron-restriction on E. ictaluri protein expression is unknown. The purpose of this study was to identify differentially expressed proteins of E. ictaluri during in vitro iron-restricted conditions. We applied two dimensional difference gel electrophoresis for determining differentially expressed proteins and MALDI TOF/TOF MS for protein identification. Gene ontology and pathway-based functional modeling of differentially expressed proteins was also presented. A total of 50 unique differentially expressed proteins at a minimum of 2-fold (p = 0.05) difference in expression due to iron-restriction were detected. The numbers of up- and down-regulated proteins were 37 and 13, respectively. We noted several proteins, including EsrB, LamB, MalM, MalE, FdaA, and TonB-dependent heme/hemoglobin receptor family proteins responded to iron restriction in E. ictaluri.