Nematodes – Microbiology – Flashcards
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| Respiratory infxn, worse steroids |
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| Strongyloides |
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| Enterobius vermicularis |
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| Morphology: Helminth, nematode-small white worm Pathogenesis/Life-cycle: Fecal-oral transmission -> eggs ingested -> hatch in duodenum and jejunum and mature in ileum and LI -> mate in colon -> at night females migrate out to lay eggs in perianal skin -> scratch -> autoinnoculation and fecal-oral Clinical: Perianal itchiness (vaginal), can be asymptomatic *most common intestinal Helminth in the USA Diagnosis: Scotch tape test at night to look for eggs Epidemiology: Worldwise including USA, very prevalent-20-40 million cases, common in school age children |
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| Ascaris lumbricoides |
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| Morphology: Helminth (largets one!) - pearl white worm Pathogenesis/Life-cycle: Fecal-oral transmission -> eggs ingested -> hatch in SI -> larvae invade intestinal wall -> bloodstream to lungs -> coughed-up -> swallowed -> mature into adults in SI -> east host food and lay eggs that pass in stool Clinical: Asymptomatic, eosinophilc pneumonitis (Loeffler's syndrome), malnutrition and weight loss. Bowel obstruction may be presenting symptom Diagnosis: In stool detect eggs, accompanied by eosinophila Epidemilogy: 1/4 world population infected; distributionis worldwise; especially in impoverished areas, KIDS |
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| Respiratory nematodes |
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| Strongyloides, Ancylostoma, necator, ascaris |
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| black-fly |
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| Onchocerca (river blindness) |
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| Wurcheria |
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| filariasis, elephantitis |
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| Loeffler's syndrome |
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| Ascaris, eosinophila & hypersensitivity |
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| Trichurius trichura (whipworm) |
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| Morph: helminth, nematode Pathogenesis/life-cycle: fecal-oral -> ingest -> go to colon -> attach to mucosa of cecum with long tail -> mature into adult -> tail imbeds in epithelial mucosa whil the head remains in the lumen clinical: diarrhea, abdominal pain, rectal prolapse from severe tenesmus Diagnosis: in stool, detect eggs: barrell shaped with polar plugs Epidemiology: SE Asia, sub-Saharan Africa, Caribbean islands, low SES and where human feces is used as fertilizer |
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| skin snip diagnosis |
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| Onchocerca |
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| Strongyloides stercoralis |
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| Morph: Helminth pathogenesis: Larvae penetrate skin on bare feet -> bloodstream to lungs -> swallowed -> larvae grow to adults in SI and mate -> female lays eggs in mucosa -> leads to inflammation, pain and diarrhea -> larvae can exit in stiool or repenetrate host: lungs, csf, other organs clinical: pneumonia from dragging GI bacteria into lungs (gram negatives, enterococcus), bacteremia and G- sepsis in immunocomp. diarrhea and GI pain Dx: in stool detect larvae (not eggs) eosinophila Epi: worldwide including southern USA |
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| Ancytosoma duodenale, Necator americanus |
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| hookworms Motphology: Helminth Pathogensis/Life-cycle: Larvae penetrate skin on bare feet (intact) -> bloodstream to lungs -> swallowed -> larvae grow to adults in SI -> use cutting plates to attach to mucosal wall -> such blood -> eggs passed in feces -> mature to infectious larvae Clinical: Gastroenteritis and Anemia, pneumonitis, eosinophilia, mental and physical growth retardation, pruritis and edema at entry Dx: in stool, detect eggs Epidemiology: Worldwise, up to 1.3 billion people infected; Afr, Asia, SA #1 caue of childhood anemia in developing countrieis |
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| Wuchereria bancrofti |
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| Morph: Helminth - nematode Pathogenesis/Life-cycle: Infected mosquitoes (Culex) introduce larvae -> penetrate skin and go to lymphatics -> in lymphatics mature into adults (lives for up to 7 yrs) -> adults produce microfilariae, which live between blood (transmissable) and lymphatics clinical: chronic lymphadema leads to elephantiasis, cannot be corrected even with treatment that kills larvae; wrose in legs and scrotum Dx: detect microfilariae in Blood At Night!! Epi: Tropical areas worldwise, mosquito vector |
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| Culex mosquito |
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| Wuchereria bancrofti |
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| Onchocerca volvulus |
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| Morph: Helminth, nematode Pathogenesis/Life-cycle: Black fly that lives near river bites -> releases larvae into skin -> larvae move to subcutaneous tissue, where adults live -> microfilariae can migrate to eyes -> microfilariae can also try by ingested by mosquitoes, who lay their eggs on the flies Clinical: Blindness (River blindness) if migrate to eyes, hyperpigmentation and pruritus if migrate to skin Dx: skin biopsy to look for microfilariae Epi: Afr mostly, with some foci in Latin Amr and middle east |
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| Dracunliasis |
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| Morph: Helminth - nematode Pathogenesis: Drink water with copepods that ocntain larvae -> larvae penetrate host stomach and intestinal wall -> enter retroperitoneal space -> females go to skin surface and form blister -> foot itches -> larvae released into water Clinical: foot pain and itchiness, bacterial superinfection possible Dx: In stool detect larvae (not eggs), eosinophila Epi: Afr and India, can help interrupt cycle by filter water through nylon mesh tx: mechanisl extraction of worm over several days |
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| Tapeworms |
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| Cestodes |
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| Taenia Saginata |
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| Ingestion of gravi proglottid by pig or cattle (water, food, etc) -> release of eggs into intestine -> enter into circulation -> seeding of muscle forms larval cyst -> human infection by the consumption of raw/undercooked meat -> attachment to intestine by scolex -> establish residnecy -> fecal-oral transmission -> if humans ingest the gravid proglottid (eggs) the infxn will dissmeinate and form cysts -> blindness, neurocysticercosis, encephalitis no hooks on scolex; beef tapeworm Dx: Stool sample (proglottid) Epi: Human consumption of cysts from infected carrier (ie meat); carrier acquires from infected food/water (think feces) |
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| Taenia solium |
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| Ingestion of gravi proglottid by pig or cattle (water, food, etc) -> release of eggs into intestine -> enter into circulation -> seeding of muscle forms larval cyst -> human infection by the consumption of raw/undercooked meat -> attachment to intestine by scolex -> establish residnecy -> fecal-oral transmission -> if humans ingest the gravid proglottid (eggs) the infxn will dissmeinate and form cysts -> blindness, neurocysticercosis, encephalitis pork; ova ingestion from P2P -> neurocysticercosis Dx: Stool sample (proglottid) Epi: Human consumption of cysts from infected carrier (ie meat); carrier acquires from infected food/water (think feces) |
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| #1 cause of new onset adult seizures in the developing world |
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| parastic infections! Taenia soliu (pork) |
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| Taenia saginata |
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| beef tapeworm (cestode), no hooks on scolex |
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| Taenia solium |
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| Pork, ova ingestion from P2P -> neurocysticercosis |
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| Cetodes |
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| Tapeworms |
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| Tapeworms, info |
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| Classification: Cestodes (faltworms with scolex-head for sucking and proglottids - infectious segment containing eggs) Pathogenesis/life-cycle: parasite infectious cycle in other animal, humans, become incidental host Dx: stool sample Species: D. latum - human consumption of cysts from infected carrier (ie sushi) E. granulosus - carrier acquires from infected food/water (think dog feces and sheep farmers) |
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| Diphyllobothrium latum |
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| fish, macrocytic anemia (B12 deficiency) |
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| Echinoccus granulosus |
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| consumption of dog tapeworm eggs; lung & liver (water lily sign and salty coughts) -> hydatic cysts in liver carrier acquries from infected food/water (think dog feces and sheep farmers) |
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| Trematodes |
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| flukes, snails |
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| Trematodes, info |
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| Classification: Flukes, hermaphroditic (escept shisto), eggs with operculum (lid) Pathogenesis: Parasite (schisto causes host immune response); snail infected by larvea -> release motile form into water -> infect humans -> sets up shope in venous system and release eggs -> eggs go to many sites causesing a granulomatous inflammatory response Dx: Stool sample for S mansoni, urine sample for S hematobium, skin biopsy for cercarial dermatitis Epi: SNAIL hosts, penetrate intract skin |
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| Tremataodes, specieis |
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| S. mansoni S. hematobium Fasciola hepatica Clonorchis sinensis Paragonimus westermani |
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| Schistosoma mansoni info |
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| tropics (Afr and brazil); eggs in mesenteric venules -> liver dmg (hepatitis and portal HTN) and also lung and spine stoll sample |
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| Schistosoma hematobium |
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| Afr and Middle East; eggs in GU veins -> hematuria, bladder cancer and obstructive uropathy urine sample for dx |
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| Avian schisto |
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| Cercarial dermatitis (Cananda) skin biopsy |
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| Fasciola hepatica |
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| raw watercress, enter liver/bile ducts Stool: F hepatica |
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| Clonorchis sinensis |
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| Opisthorcis family, Chinese liver fluke, faw freshwater fish; invades bile ducts --> pigmented gallstones --> cancer |
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| Paragonimus westermani |
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| lung fluke, raw shellfish in E Asia, mimics TB cavities in lung (look for eosinophilia), some CNS |
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| Bacillus anthracis |
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| Morphology: Gram + Spore-forming bacillus, faculatative anaerobe Virulence factors: Capsule, protective antigen (PA), edema factor (EG), lethal factor (LF), edema toxin (PA + EF), lethal toxin (PA + LF) Clinical: inhalational disease: two stages, inhalation of spores; cutaneous anthrax: results from depostion of organsim onto non-intact skin; GI antrax: restuls from ingestion of spores Dx: culture, PCR, immunohistochemical staining, ELISA Epi: Spores (inhaled, through broken skin, ingeted); no P2P |
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| Variola |
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| Small Pox Morph: DNA virus; orthopoxvirus family, Pox in Box (complex capsid) Infectious Propertieis: Small inoculum; Aerosol spread Clinical: oral or resp mucosa --> LN --> asymp viremia to lymph organs (day 3 or 4) --> 2nd viremia (day 8) -> fever, malaise, delirium, 15-40% mortality Dx: Not chicken pox; all pustules are at the same stage Epi: Eradicated; 1 case is EMERGENCY; not contagious until onset of rash (face/arms first) Tx: Vaccine (vaccinia/cowpox) led to eradication in 1977; no loonger given; can vaccinate up to 4 days post-exposure; supportive care (antivirals) |
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| Amastogotes in macrophages |
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| Leishmania |
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| blackwater fever |
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| P. falciparum |
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| Malaria vector |
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| Anopheles |
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| Culex vector for... |
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| West Nile, (Wurcheria), SLE, EEE, WEE |
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| Aedes aegypti |
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| Yellow Fever, Dengue Fever |
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| Ixodes tick |
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| Borrelia, Babesia microtii, ANaplasma |
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| Toxo - protozoa or fungs? |
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| protozoa |
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| ehrlichia chaffeensis vector |
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| Americanum tick |
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| Ricketttsia rickettsii vector |
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| Dermacantor |
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| Creeping eruptions |
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| Ancylstoma brazillense (dog hookworm) |
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| Bladder cancer |
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| Schistosoma hemtobium ("male period") |
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| autoinfect |
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| Stronguloides |
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| autoinoculate |
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| Enterobius (pinworm) |
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| sandbox/sandy beach |
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| Toxocara canis/cati |
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| consuming cysts in undercooked pork |
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| Trichinella spiralis |
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| endemic conjunctivitis |
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| adenovirus |
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| retinitis in immunocomproised |
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| CMV |
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| heterophilic antibodies |
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| EBV |
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| DNA virus RNA-dependent DNA polymerase |
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| HepB |
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| Dane particles |
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| Hep B (surface antigen in excess) |
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| leading cause HCC |
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| Hep B |
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| leadng cause of corneal blindess in us |
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| HSV-1 |
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| Cowdry type A |
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| HSV-1 |
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| E6 |
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| p53, HPV |
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| E7 |
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| Rb, HPV |
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| Only DNA virus to replicated in cytoplasm, own DNA dep DNA poly |
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| poxvirus |
