hookworms山东大学邮件系统Hookworms.pptVIP

Hookworms Hookworms The hookworms cause hookworm disease, which is one of the five major parasitic disease in China(malaria, shistosomiasis, filariasis, kala- azar and hookworm disease). At least two species of hookworms infect man, Necator americanus and Ancylostoma duodenale. They live in small intestine. I.?? Morphology 1. Adults: They look like an odd piece thread and are about 1cm. They are white or light pinkish when living. ♀is slightly larger than♂.The male’s posterior end is expanded to form a copulatory bursa. 2. Eggs: 60×40 μm in size, oval in shape, shell is thin and colorless. Content is 2-8cells. Scanning electron micrograph of the mouth capsule of Ancylostoma duodenale, note the presence of four teeth, two on each side. Scanning electron micrograph of the mouth capsule of Necator americanus, another species of human hookworm.? Note the presence of two cutting teeth“. Ancylostoma duodenale - copulatory bursa and spines of male(a side view) Copulatory bursa of N. americanus(a side view) Morphologically it is not possible to differentiate between A. duodenale and N. americanus. Interference contrast. ×400. Enlarged by 5.4. 3.The Morphological Differences between Two species of Hookworms _____________________________________________________ A. duodenale N. americanus ______________________________________________________ Size larger smaller ______________________________________________________ Shape single curve, looks like C double curves, looks like S ______________________________________________________ Mouth 2 pairs of ventral teeth 1peir of ventral cutting plates ____________________________________________________________ Copulatory circle in shape oval in shape Bursa (a top view) (a top view) ____________________________________