The therapeutic use of isometamidium chloride against Cryptobia salmositica in rainbow trout Oncorhynchus mykiss.
Rainbow trout Oncorhynchus mykiss injected intramuscularly with isometamidium chloride (0.01 or 0.1 mg kg-1) at 3 wk post-infection and given a booster 2 wk later had significantly lower parasitaemias than infected controls. Packed cell volume increased after treatment and remained higher than in infected controls. The concentration of isometamidium in plasma was highest at 2 wk after injection and then declined. An intramuscular dose of 1.0 mg kg-1 of isometamidium chloride at 1, 2 and 3 wk postinfection (preclinical) significantly reduced the parasitaemia in rainbow trout 2 wk after treatment. A booster at 9 wk postinfection (chronic disease phase) reduced the parasitaemia further in all fish. The packed cell volume in these fish was higher than in infected controls. Treatment at 5, 6, and 7 wk postinfection (acute disease) had no effects and parasitaemias in treated fish were higher than in infected controls; also, anti-Cryptobia salmositica antibodies and titres of complement-fixing antibody were higher in these than in infected controls. Incubation of immune plasma or complement with isometamidium for 3 h did not affect the lytic titres of complement-fixing antibodies nor rainbow trout complement.
Ardelli
B F
BF
Department of Zoology, College of Biological Science, University of Guelph, Ontario, Canada.
Woo
P T
PT
D000818:Animals; D000913:Antibodies, Protozoan / Q000097:blood; D000953:Antigens, Protozoan / Q000737:chemistry; D003168:Complement Fixation Tests / Q000662:veterinary; D004797:Enzyme-Linked Immunosorbent Assay / Q000662:veterinary; D005393:Fish Diseases / Q000188:drug therapy* / Q000469:parasitology; D006400:Hematocrit / Q000662:veterinary; D016830:Kinetoplastida / Q000276:immunology / Q000472:pathogenicity*; D017686:Oncorhynchus mykiss / Q000469:parasitology*; D018512:Parasitemia / Q000662:veterinary; D010617:Phenanthridines / Q000097:blood / Q000627:therapeutic use*; D011528:Protozoan Infections / Q000188:drug therapy; D011529:Protozoan Infections, Animal; D011897:Random Allocation; D014344:Trypanocidal Agents / Q000097:blood / Q000627:therapeutic use*
D000913:Antibodies, Protozoan; D000953:Antigens, Protozoan; D010617:Phenanthridines; D014344:Trypanocidal Agents; C000702:isometamidium chloride