Systemic and Cutaneous Mucus Antibody Responses of Channel Catfish Immunized against the Protozoan ParasiteIchthyophthirius multifiliis

Differences in virulence between two serotypes of Ichthyophthirius multifiliis

“…In channel catfish, antibodies specific for I. multifiliis can be detected in serum within 7 to 12 d following infection and within 12 d in the skin , Xu et al 2004). However, antibody titers do not peak until at least 4 wk after infection , Maki & Dickerson 2003. Although antibodies recognizing I. multifiliis can be detected within 1 to 2 wk, the results of these experiments clearly demonstrate that initial phases of the humoral response are not sufficient to prevent complete mortality caused by the massive third round of infection by NY1 around Day 14.…”

Response and function of cutaneous mucosal and serum antibodies in barramundi (Lates calcarifer) acclimated in seawater and freshwater

“…The response in Asian sea bass is, however, clearly different from that recorded in eels (Anguilla anguilla) [3] and channel catfish (Ictalurus punctatus) [16] in which a high serum antibody titre was induced by direct immersion. However, in the study of EsteveGassent et al [3], the eels were immersion vaccinated three times, 12 days apart, thus it was the secondary immune response that was being measured.…”

“…The results in eel may also reflect the use of a Vibrio bacterin compared with our experimental S. iniae bacterin as Vibrio bacterins tend to induce a very potent protective response by immersion [17]. In catfish, immersion in live theronts of Ichthyophthirius multifiliis was used and resulted in significant stimulation of the serum antibody response [16] and it may be that live agents were able to invade and colonise resulting in prolonged exposure to antigen. In contrast to immersion, intraperitoneal injection induced high serum antibody levels in almost all fish corroborating earlier observations [1,12,13,16].…”

Effect of gamma irradiation on inactivation of Ichthyophthirius multifiliis trophonts and its efficacy on host response in experimentally immunized rainbow trout (Oncorhynchus mykiss)

“…The 3 stages in the life cycle of the parasite are an infective theront, a parasitic trophont, and a reproductive tomont (2). It is difficult to control this parasite using chemotherapy after penetration into fish skin and gills.…”

“…Thus, vaccination against I. multifiliis can be considered an alternative to chemical treatments to prevent mortality (2) in fish. A number of studies have indicated that whole-cell trophonts, theronts, and ciliary protein preparations or recombinant i-antigen proteins of this parasite are able to induce an acquired immune response in numerous fish species, including the channel catfish (Ictalurus punctatus), trout (Salmo gairdneri), and carp (Cyprinus carpio) (2)(3)(4)(5). Trophonts are commonly inactivated by using 1%-4% formalin (5) or freezing (5) and used for immunization at different doses (5).…”