Jm. Njoroge et al., THE EFFICACY OF IVERMECTIN AGAINST LABORATORY STRAINS OF HELIGMOSOMOIDES-POLYGYRUS (NEMATODA), International journal for parasitology, 27(4), 1997, pp. 439-442
A susceptible strain of Heligmosomoides polygyrus was selected for 15
generations with increasing doses of ivermectin (0-6 mg/kg). A passage
strain was developed, parallel with the ivermectin-selected strain, t
o control for changes due to rapid passage from mouse to mouse. The LD
(50)s of the 8th and 15th generations of the ivermectin-selected strai
n were 1.5 times that of the susceptible strain. The LD50 of the passa
ge strain at generations 8 and 15 remained similar to that of the susc
eptible strain. Ivermectin efficacy was lower against the L4 stage tha
n against the adult stage in the susceptible strain, the ivermectin-se
lected strain and the passage strain at generation 8. (C) 1997 Austral
ian Society for Parasitology. Published by Elsevier Science Ltd.