ARS | Publication request: Changes of serum myeloperoxidase and nitric oxide in the early stage of Edwardsiella ictaluri infection in channel catfish, Ictalurus punctatus

Submitted to: Journal of Fish Diseases
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: January 2, 2012
Publication Date: March 6, 2013
Citation: Yeh, H., Klesius, P.H. 2013. Changes of serum myeloperoxidase and nitric oxide in the early stage of Edwardsiella ictaluri infection in channel catfish, Ictalurus punctatus. Journal of Fish Diseases. 36:441-446.

Interpretive Summary: Edwardsiella ictaluri is a Gram-negative bacterium and causes farmed-raised channel catfish enteric septicemia. It is estimated that catfish producers lose 30 – 40 million dollars annually to this disease. Development of a monitoring system for assessing fish health in the current intensive aquaculture is in great demanding. Because blood is primary for collection and transportation of many nutritional and harmful materials, serum is the best target for searching potential indicators for infectious diseases. Previously, we noted the some channel catfish expressed sequence tags (EST) were changed after they were infected with Edwardsiella ictaluri. In this study, we found that serum myeloperoxidase increased within 24 hours after infection, while nitric oxide (NO) reached the peak at day 7 post infection. In addition, the mortality occurred between day 4 and day 5 post infection. Whether the mortality correlates with the changes of myeloperoxidase and NO in catfish sera is under investigation. The findings suggest that incorporation of monitoring serum myeloperoxidase and NO in the aquacultural management may benefit the producers in controlling infectious disease. This study is related to the goal of ARS National Program 106-Aquaculture, Component 4C-Prevention of Diseases.

Technical Abstract: Enteric septicemia of catfish (ESC), caused by Edwardsiella ictaluri, is an important farm-raised channel catfish, Ictalurus punctatus (Rafinesque), disease. The development of a monitoring system for assessing the catfish health status in hatcheries and ponds is in great demanding. Because of the easy access of blood, which collects and transport many normal and abnormal materials, serum is an attractive place to begin with for searching potential biomarkers for infectious diseases. Previously, we observed the up-regulation of some expressed sequence tags (EST) after channel catfish infected with Edwardsiella ictaluri. In this communication, we examined two serum components-myeloperoxidase and nitric oxide-in the early stage of ESC in channel catfish. Our data demonstrate that serum myeloperoxidase increased within 24 hr after infection, while nitric oxide (NO) reached the peak at day 7 post infection. In addition, the mortality occurred between day 4 and day 5 post infection. Whether the mortality correlates with the changes of myeloperoxidase and NO in catfish sera is under investigation. The findings were interesting and indicated that incorporation of monitoring serum myeloperoxidase and NO in the aquacultural management may benefit the producers in controlling infectious disease.