Page Banner

United States Department of Agriculture

Agricultural Research Service

Research Project: Integrated Aquatic Animal Health Strategies

Location: Aquatic Animal Health Research

Title: Recombinant goose-type lysozyme in channel catfish: lysozyme activity and efficacy as plasmid DNA immunostimulant against Aeromonas hydrophila infection

Authors
item Wei Pridgeon, Yuping
item Klesius, Phillip
item Dominowski, Paul -
item Yancey, Robert -
item Kievit, Michele -

Submitted to: Fish and Shellfish Immunology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: August 16, 2013
Publication Date: August 13, 2013
Repository URL: http://handle.nal.usda.gov/10113/58418
Citation: Wei Pridgeon, Y., Klesius, P.H., Dominowski, P.J., Yancey, R.J., Kievit, M.S. 2013. Recombinant goose-type lysozyme in channel catfish: Lysozyme activity and efficacy as plasmid DNA immunostimulant against Aeromonas hydrophila infection. Fish and Shellfish Immunology. 35:1309-1319.

Interpretive Summary: The objectives of this study were: 1) to investigate whether recombinant channel catfish lysozyme g produced in E. coli expression system possesses any lysozyme activity; and 2) to evaluate whether channel catfish lysozyme g plasmid DNA could be used as an immunostimulant to protect channel catfish against Aeromonas hydrophila infection. Recombinant CC-Lys-g produced in Escherichia coli expression system exhibited significant lytic activity against Gram-positive and Gram-negative bacteria. The over-expression of recombinant lysozyme-g offered significant protection to catfish gill cells against A. hydrophila infection. When channel catfish were injected with recombinant lysozyme g along with an adjuvant QCDCR, the transcriptional level of lysozyme g was significantly increased. When lysozyme-g over-expressed fish were challenged with a highly virulent A. hydrophila strain, no fish died at two days post lysozyme-g treatment. Our results suggest that recombinant lysozyme g could be used as a novel immunostimulant to offer immediate protection to channel catfish against A. hydrophila infection.

Technical Abstract: The objectives of this study were: 1) to investigate whether recombinant channel catfish lysozyme g (CC-Lys-g) produced in E. coli expression system possesses any lysozyme activity; and 2) to evaluate whether channel catfish lysozyme g plasmid DNA could be used as an immunostimulant to protect channel catfish against A. hydrophila infection. Recombinant CC-Lys-g produced in Escherichia coli expression system exhibited significant (P < 0.05) lytic activity against Gram-positive Micrococcus lysodeikticus and Gram-negative A. hydrophila. When pcDNA3.2-vectored recombinant channel catfish lysozyme-g (pcDNA-Lys-g) was transfected in channel catfish gill cells G1B, the over-expression of pcDNA-Lys-g offered significant (P < 0.05) protection to G1B cells against A. hydrophila infection. When channel catfish were intraperitoneally injected with pcDNA-Lys-g along with an adjuvant QCDCR, the transcriptional level of Lys-g was significantly (P<0.05) increased. When pcDNA-Lys-g injected fish was challenged with a highly virulent A. hydrophila strain AL-09-71, pcDNA-Lys-g offered 100% protection to channel catfish at two days post DNA injection. Macrophages of fish injected with pcDNA-Lys-g produced significantly (P<0.05) higher amounts of reactive oxygen species and nitric oxide than that of fish injected with pcDNA vector alone at two days post DNA injection. Taken together, our results suggest that pcDNA-Lys-g could be used as a novel immunostimulant to offer immediate protection to channel catfish against A. hydrophila infection.

Last Modified: 10/1/2014