UCLA

One of the behaviors of parasitic nematodes that is essential for successful parasitism is host seeking, a complex behavior requiring nematodes to integrate sensory cues to find suitable

hosts in which to complete their life cycles. Olfaction is a critical component of this response; many nematode parasites use carbon dioxide and other host-produced volatiles to locate their hosts. I investigated the odor responses of four species of skin penetrating mammalian-parasitic nematodes: the rat parasites Strongyloides ratti and Nippostrongylus brasiliensis, the possum parasite Parastrongyloides trichosuri, and the human parasite Strongyloides stercoralis. For comparison, I also profiled responses of the insect parasites Heterorhabditis bacteriophora and Steinernema carpocapsae, as well as those of the free-living nematode Caenorhabditis elegans. The mammalian parasites were found to show significant response to some components of human/mammalian odors, though the matter of attraction to live hosts remains unresolved. Likewise, clustering analysis grouping species by odor responses was inconclusive.