Humoral Antibody Response of the Tilapia Oreochromis niloticus Against Cichlidogyrus spp. (Monogenea)

Abstract

The humoral immune response of the tilapia Oreochromis niloticus was evaluated using a direct ELISA. Serum was tested from fish infected with Cichlidogyrus spp. (Monogenea) and from fish injected intraperitoneally with the Cichlidogyrus spp. antigenic extract, i.e., 150 microl of the Cichlidogyrus spp. saline extract diluted in Freund's complete adjuvant (FCA) (1:1) were inoculated intraperitoneally at day 0, followed by 2 dosages of 50 microl of the same Cichlidogyrus spp. saline extract diluted in Freund's incomplete adjuvant (FIA) (1:1) at weeks 2 and 4, respectively. The humoral response was also evaluated by the double immunodiffusion test (DID) and by serum protein and total immunoglobulin (Ig) determinations. The IgM OD values in the hyperimmune fish were significantly higher than in the infected and uninfected fish groups. In the DID test, a precipitation (antigen-antibody) band was observed between the Cichlidogyrus spp. saline extract and hyperimmune sera, but not with the other groups. Increases in serum protein concentration and total Igs were observed in the immunized fish at weeks 2 and 10 postinjection. Results from this study suggest that tilapia is capable of producing an induced humoral immune response against an antigenic extract of Cichlidogyrus spp.

Endosulfan increases seric interleukin-2 like (IL-2L) factor and immunoglobulin M (IgM) of Nile tilapia (Oreochromis niloticus) challenged with Aeromona hydrophila

“…A direct ELISA assay (Aquatic Diagnostic Ltd., Stirling, U.K. C04-HRP/01) was used to detect specific IgM according the manufacturer's instructions. This method was also successfully used by Sandoval-Gio et al (2008) in Nile tilapia [20]. The only difference consisted in the type of antigen used in the experiment.…”

Non-lethal detection of DNA from Cichlidogyrus spp. (Monogenea, Ancyrocephalinae) in gill mucus of the Nile tilapia Oreochromis niloticus

“…Serological tests based on enzymelinked immunosorbent assay (ELISA) identify IgM antibodies specific for Cichlidogyrus spp. (Sandoval-Gío et al 2008). A major limitation of both of these techniques is that they are invasive to the host.…”

Parasite fauna of farmed Nile tilapia (Oreochromis niloticus) and African catfish (Clarias gariepinus) in Uganda

“…This territorial behaviour increases the proximity to and maintains continuous exposure to freeswimming stages of protozoans, crustaceans and digenetic trematodes cercariae. The strong immune resistance elicited against further invasion of ectoparasites by O. niloticus (Sandoval-Gio et al 2008) could explain the low intensity recorded during the survey. With regard to endoparasites, O. niloticus feeds mainly on phytoplankton and macrophytes (Getachew and Fernando 1989;Dempster et al 1993), although zooplankton and benthic organisms also contribute to the diet (Philippart and Ruwet 1982;Njiru et al 2004;Bwanika et al 2006;Peterson et al 2006;Oso et al 2006).…”