Chapter 25,part C Microbial Diseases of the Digestive System
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings B.E Pruitt & Jane J. Stein Chapter 25, part C Microbial Diseases of the Digestive System
Helminthic Diseases of the Digestive System Trichinella 1.0% Percentage of world population infected Flukes(liver,lung) 1.5% Tapeworms 3.0% Schistosomes 6.0% Enterobius 10% Hookworms 21% Ascaris 30% 3 5678910 11 Number of people infected(100 millions) Figure 25.21
Helminthic Diseases of the Digestive System Figure 25.21
Tapeworms 。Taenia spp Sucker Transmitted as cysticerci Scolex Hooks in undercooked meat Cysticerci may develop in humans Neck Diagnosed by observing proglottids and eggs in Testis feces Genital pore 。Treatment with Ovary praziquantel Neurocysticercosis may require surgery Mature proglottid will disintegrate and release eggs Figure 12.27
Tapeworms Figure 12.27 • Taenia spp. • Transmitted as cysticerci in undercooked meat • Cysticerci may develop in humans • Diagnosed by observing proglottids and eggs in feces • Treatment with praziquantel • Neurocysticercosis may require surgery
Tapeworms Fluid-fillec Figure 25.22
Tapeworms Figure 25.22
Hydatid Disease Echinococcus granulosus 。Definitive host: Dogs,wolves 。Intermediate host: Brain Sheep and other herbivores; Left orbit Humans (eye socket) 。Transmitted by ingesting E. granulosis eggs 。Treatment is surgical Figure 25.23
Hydatid Disease Figure 25.23 • Echinococcus granulosus • Definitive host: Dogs, wolves • Intermediate host: Sheep and other herbivores; Humans • Transmitted by ingesting E. granulosis eggs • Treatment is surgical
Echinococcus granulosus ⑥Scoleces from Egg (30-38μm) cyst attach to ①Adult tapeworm intestine and releases eggs, grow into which are adults excreted by definitive host Scolex (a)Adult tapeworm ⑤Definitive host eats inter- Larvae develop mediate into hydatid host, Definitive host cysts ingesting Brood capsule cysts Scolex Larva ②Intermediate host ingests ③Eggs hatch,and eggs Hydatid larvae migrate to liver or lungs cyst Intermediate host (b)Life cycle Intermediate host Figure 12.28
Echinococcus granulosus Figure 12.28
Pinworms Enterobius vermicularis Definitive host:Humans Transmitted by ingesting Enterobius eggs Treatment with pyrantel pamoate or mebendazole
Pinworms • Enterobius vermicularis • Definitive host: Humans • Transmitted by ingesting Enterobius eggs • Treatment with pyrantel pamoate or mebendazole
Pinworms Mouth -Intestine Mouth Ovary -Genital pore Anus Intestine Testis E9g (55um Genital Spicules long) pore Anus Larva Male (2-5 mm long) Female (a)Adult pinworms (8-13 mm long) (b)Pinworm egg Figure 12.29
Pinworms Figure 12.29
Hookworms Larvae in soil hatched from eggs shed in feces Larvae bore through skin;migrate to intestine Treated with mebendazole
Hookworms • Larvae in soil hatched from eggs shed in feces • Larvae bore through skin; migrate to intestine • Treated with mebendazole
Hookworms Hookworm Intestinal mouth mucosa Figure 25.24
Hookworms Figure 25.24