Skip to main content
ARS Home » Southeast Area » Stuttgart, Arkansas » Harry K. Dupree Stuttgart National Aquaculture Research Cntr » Research » Publications at this Location » Publication #369074
Research Project: The Role of Mucosal Surfaces and Microflora in Immunity and Disease Prevention

Location: Harry K. Dupree Stuttgart National Aquaculture Research Cntr

Title: Characterization of TLR-4 in Fathead minnow challenged with Columnaris (Flavobacterium columnare) in an ultra-low flow system

Author
item RENUKDAS, NILIMA - University Of Arkansas At Pine Bluff
item KELLY, ANITA - University Of Arkansas At Pine Bluff
item KAIMAL, SINDHU - University Of Arkansas At Pine Bluff
item Farmer, Bradley

Submitted to: Genbank
Publication Type: Database / Dataset
Publication Acceptance Date: 10/3/2019
Publication Date: 9/1/2019
Citation: Renukdas, N., Kelly, A.M., Kaimal, S., Farmer, B.D. 2019. Characterization of TLR-4 in Fathead minnow challenged with Columnaris (Flavobacterium columnare) in an ultra-low flow system. Genbank Accession No. . MN163026.

Interpretive Summary:

Technical Abstract: Toll-like receptors (TLRs) play important role in the innate immune system in response to a wide range of pathogen infections. Among various identified TLRs, TLR4 recognizes the lipopolysaccharides of gram-negative bacteria, such as Flavobacterium columnare. Columnaris disease, caused by the bacteria F. columnare, is one of the most serious bacterial infections affecting the aquaculture industry today. Columnaris is transmitted horizontally from fish to fish and is highly contagious. Outbreaks commonly follow a stressful event such as overcrowding, low dissolved oxygen, or high ammonia and nitrite concentrations. Arkansas baitfish farms routinely suffer substantial losses due to columnaris disease. Columnaris outbreaks occur in fathead minnow (Pimephales promelas) are prominent post-harvest while they are being held in vats prior to being sold. The goal of this study was to determine if the TLR4 is expressed in fathead minnows challenged with F. columnare when stocked at different densities and held at different temperatures. A columnaris disease challenge tank study in an ultra-low flow system was conducted at three different fathead minnow stocking densities; 400/m3, 800/m3 and 1600/m3 and at two different temperatures; 22 deg C and 28 deg C. All treatments were triplicated. LSU- 04-066 strain of F. columnare was used in the disease challenge of fathead minnows. Dissolved oxygen, flow, total ammonia nitrogen, and fish mortality were recorded post-challenge for 48 hrs. Total mortality (100%) occurred in challenged tanks within 24 h at all fish densities held at 28 deg C and within 30 hrs at 22 deg C. Tank water and fish tissue (gill, kidney, and spleen) samples were processed for the presence of columnaris using real time PCR. TLR4 gene sequence was identified from fish tissue RNA by using real time RT-PCR.