Tiêu đề PART 3-CESTODES (S).pdf ✅

PHARMACEUTICAL MICROBIOLOGY WITH PARASITOLOGY: LECTURE PREPARED BY: RACHEL M. ORDOÑEZ, RPh | ULS-PHARMACY INSTRUCTOR | 2ND SEMESTER A.Y. 2023-2024 HELMINTHS • Helminths are elongated flat or round worm like parasites measuring few millimeters to meters. • They are eukaryotic ___________________________ organisms. • They belong to two phyla – (a) _______________________________ and (b) ______________________________. DIFFERENCES BETWEEN THE THREE CLASSES OF HELMINTHS PROPERTIES NEMATODES CESTODES TREMATODES Phyla ________________________ ________________________ ________________________ Shape Elongated, cylindrical and unsegmented ___________________-like and ___________________ ________________-like and ___________________ Head end No sucker, no hooklets. Some have well developed buccal capsule Suckers present, some have attached hooklets Suckers present No hooklets Alimentary canal Complete from mouth to anus Absent Present but incomplete Body cavity ________________________ ________________________ ________________________ Sexes ________________________ ________________________ ________________________ Life cycle Requires one host (except filarial worms and Dracunculus) Requires two hosts (except Hymenolepis and Diphyllobothrium) Requires three hosts (except Schistosoma) CESTODES General morphology of Cestodes: - In their life cycle, they exist in three (3) morphological forms: (1) __________, (2) __________, and (3) _______________. • Adult worm is usually found in the intestine of men and animals. • Cestodes are long, segmented, flattened dorsoventrally, tape-like worms hence called “______________________.” • They are __________________. • Cestodes vary from few millimeters to several meters. _______________________________ is the smallest tapeworm (1-4 cm) where as ______________________ is the longest measuring 10 meters or more. • Adult worm consists of three parts: (1) _______________________, (2) _________________________, and (3) ___________________________
o Head – organ of attachment; may or may not possess suckers or bothria. o Neck – it is where the segments arise. o Strobila – body or trunk of the cestodes; consists of a number of segments or proglottids that bear the reproductive organs. The length of the tapeworm varies based on the number of segments. INTESTINAL CESTODES 1. Diphyllobothrium latum • _____________________________________________________. • Common name: ___________________________________ or __________________________, _________________________ • Habitat: the adult worm resides in the small intestine (jejunum and ileum) of humans. • It is the longest tapeworm infecting man, measuring up to 10 meters or more with over 3,000 proglottids. • Definitive host: __________________ (dogs, cats, and foxes are the other rare definitive hosts) • Intermediate host: (1) First intermediate host – fresh water copepods (2) Second intermediate host – fresh water fishes (salmon, pike, perch, and trout) • Morphology: o Head/Scolex – spoon shaped, bears two longitudinal grooves called “________________” by which it attaches to the small intestine. o Neck – It is unsegmented and longer than the head. o Strobila – there are more than 3,000 segments. • Mode of transmission: humans get infection by ingestion of undercooked fresh water fish. • Laboratory diagnosis: stool examination – the diagnosis is made readily by the detection of characteristic eggs in the stool and proglottids that may be discharged in the stool. • Pathogenesis and Clinical features: o Most of D. latum infections are asymptomatic. o Minor manifestations may include abdominal discomfort, diarrhea, vomiting, weakness, and weight loss or rarely acute abdominal pain and intestinal obstruction, cholecystitis. o Vitamin B12 deficiency – the adult worm absorbs large quantities of B12 and interferes with its ileal absorption; leads to the development of “_____________________________________”. • Treatment: o ________________________ – drug of choice and is given 5-10 mg/kg once. o ________________________ – used as an alternative treatment. o ________________________ - should be given if B12 deficiency is manifested. • Prevention: o Proper cooking of fish (10 minutes at 50 degrees Celsius) o Deep freezing (-10 degrees Celsius for 24 hours) – for the people who eat raw fish. 2. Taenia species • Two important members are: (1) Taenia saginata and, (2) Taenia solium DIFFERENCES BETWEEN T. saginata and T. solium FEATURES T. saginata T. solium Common name _________________________________ _________________________________ Intermediate host _________________________________ _________________________________ Definitive host _________________________________ _________________________________ Scolex • Large and quadrangular • Four suckers present which may be pigmented • No rostellum, no hooklets • Small and globular • Four suckers present – not pigmented • With rostellum, armed with 2 rows of large and small hooklets – that is why it is called as “______________________________” Length _________________________________ _________________________________

3. Hymenolepis spp. DIFFERENCE H. nana H. diminuta Common name _________________________________ - considered to be the most common tapeworm infection throughout the world infecting 50- 75 million people. _________________________________ Host _________________ is the only host, occasionally insects as intermediate host DH: _____________________________ IH: _____________________________ Life cycle Both direct and indirect cycle Only indirect cycle occurs; always needs insects Adult worm Length _________________________________ _________________________________ Scolex Bears four suckers with rostellum and hooklets Bears four suckers, with rostellum but no hooklets Proglottids _________________________________ _________________________________ Egg Smaller, _________________________ Larger, __________________________ Human infection _________________________________ _________________________________ Infective form _________________________________ - Mode of transmission Men acquire the infection by: (1) ingestion of food and water contaminated with eggs; (2) autoinfection with their own eggs released in the small intestine. - Clinical features and Pathogenicity • H. nana infection is usually asymptomatic. • When infection is intense and the worm burden exceeds 1000-2000 worms, patient develop symptoms like: (1) _____________________________ (2) _____________________________ (3) _____________________________ (4) _____________________________ (5) _____________________________ - Treatment • ________________________ – the treatment of choice; given 25mg/kg once. • ________________________ – used as an alternative and is given 500 mg bid x 3 days - 4. Dipylidium caninum • Common name: ____________________________ • This is a common tapeworm of ____________ and ____________. • Habitat: ___________________ • Morphology: o Adult worm is 10-70 cm long o Scolex contains four (4) oval suckers and is armed with rostellum and 1-7 rows of hooklets. o Host: ▪ DH: ______________________________ ▪ IH: _______________________________ o Mode of transmission: man acquires infection by ingestion of flea. o Clinical features: ▪ Mostly, asymptomatic, but rare symptoms are reported like: (1) ___________________________ (2) ___________________________ (3) ___________________________ (4) ___________________________ (5) ___________________________