DIFFERENTIATION BETWEEN THE HUMAN HOOKWORMS ANCYLOSTOMA-DUODENALE ANDNECATOR-AMERICANUS USING PCR-RFLP

There are 2 major species of hookworms that infect humans, Ancylostoma duodenale and Necator americanus. Although traditionally considered t o be identical for treatment purposes, there are significant life hist ory differences between the species that must be considered for the ra tional design of chemotherapeutic and immunoprophylactic control strat egies. However, identification of the species infecting a particular p opulation has been problematic, as the eggs of the 2 species cannot be reliably differentiated by classical parasitological methods. A PCR-b ased technique for the differentiation of hookworm species that infect humans is reported. A fragment of the 3' untranslated region of the c AMP-dependent protein kinase catalytic subunit gene was amplified from A. duodenale and N. americanus genomic DNA using primers derived from the corresponding A. caninum cDNA. Digestion of the amplified DNA wit h the restriction enzymes HpaII, MboI, TaqI, and ThaI generated specif ic restriction fragment patterns unique to each species. The technique can distinguish between pure and mixtures of hookworm DNA and can amp lify DNA from a single egg. The primers also amplify the fragment from the DNA of several other species of hookworms that infect humans and other animals. The technique is fast, simple, and hookworm specific an d represents a considerable savings in time over current methods used for distinguishing between human hookworm infections.