CLS – Microbiology – Flashcards
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| Malaria Definite Host |
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| Mosiquitos ingest gametocytes from host and undergoes maturation cycle. Injects sporozoites into host |
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| Malaria ( Life Cycle) |
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| Mosiquito (female anopheline sp) Involved in sexual stage(sporogony) |
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| Malaria Human Host |
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| Asexual cylce(schizongeny) |
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| Malaria species identification |
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| appeareance of specific stages(trophozoites, merozoites and gametocytes) inside RBC and the appearance of the RBC |
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| Paroxysm three stages |
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| cold, hot, and sweating stages |
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| Malaria clinical differentiation |
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| This is done btw falciparum and non-falciparum |
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| Non falciparum species invade certain populations of RBC- so infected RBC are limitied |
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| Falciparum species affects any RBC!! Death can occur within 3 days! |
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| Malaria- clinical significance |
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| Chills, fever, splenomegalogy, anemia, circulatory changes Blackwater fever: dark urine due to massive hemoglobinuria |
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| P. vivax and P. ovale |
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| Typically invade younger RBC reticulocytes. Paroxysm is 48 hours |
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| P. malariae |
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| Invade older RBC! Paroxysm lasts 72 hours |
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| P. falciparum |
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| invade any RBC!! paroxysm lasts 36-48 hrs |
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Release of merozoites: Can cause: |
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| asynchronous- remitted fever synchronous- paroxysmal fever |
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| Relapse/recrudescence |
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| Secondary attack from continuing development |
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| Diagnosis of Plasmodium parasite in thick and thin smears of periphreal blood |
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| thick smears for detection, thin smears for identification |
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| Malaria staining is done by Giemsa |
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| nucleus stains red, cytoplams-blue, vacuoles-clear, merozoites clump around hemoglobin-golden, malarial pigment will appear as stained dots througout RBC. |
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| P.vivax -Identification |
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| Infected RBC -enlarged; Schuffners dots- usually present ;Trophozoite: amoeboid, vacuolated and spread out. multiple organisms in one cell may have dble chromatin Merozoites: mature schizont has 12 -18 merozoites |
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| P. malariae |
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| Infected RBC are smaller; Schuffners dots not usually present(Ziemanns dots if present), organism tends to be compact not spread out. Merozoites: mature schizont has 6-12 merozoites Band form(trophozoite stretched across cell) |
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| P. Falciparum identification |
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| Infected RBC normal size, may see 50% or more of RBC infected. Trophozoites- may only see ring form and gametocyte stages! RBC membranes becomes sticky in the infected cells and cells tend to adhere to endothial lining of capillaries of internal organs. Ring form tends to be on the periphery of RBC! Meozoites-mature schizont has 8-24 merozoites. Gametocytes- characteristic and diagnostic cresent or sauage shaped |
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| P. Ovale- identification |
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| Infected cells are usually enlarged and oval. Typically may have irregular edges. Schuffners dots common! Trophozoites- same as P. vivax and P. malariae Merozoites- similar to P. Malariae 6-12 in the mature schizont |
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| Babesia (microti) |
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| Transmitted by ticks. Malaria like illness therefore can be mistaken for malaria. Intaerythrocytic forms are similar to P. falciparum and is found in pairs and tetrads. |
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| Enterobius Vermicularis (pinworm) Eggs |
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| Female lives in intestine, transits anus at night. she deposits her eggs on the perineum. Lays upto 10,000 most frequent symptom is an itchy butt Eggs transmitted orally and are resistant to drying so remain viable for days. Takes about 1 month from ingestion of egg for female to lay her eggs Life span of adult is 2 months |
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| Enterobius vermicularis- Morphology of adult |
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| Male 2-5mm blunt tail Female 8-13 mm pointed tail(pinworm) Cuticle contails lateral alae with cephalic alae |
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| Enterobius Vermicularis morphology of egg |
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| 50-60 by 20-30um thick dble layered shell, flat on one side |
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| Enterobius Vermicularis-Diagnosis |
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| Look for eggs and or adult worms. Eggs are not usually found in feces. Do scotch tape test- no need to explain here, but must be done in the am prior to defecating or bathing. |
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| Trichuris Trichuris (whipworm) |
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| Adults live in the intestine (threaded into the mucosa) Produces a localized ulceration and hemorrhage. Can also cause a prolapse of colon or rectal mucosa through anus. |
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| Trichuris Trichuris-Eggs |
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| Eggs are passed into the enviornment eggs mature in 2 weeks time, and mature eggs are ingested. Females pass about 2,000 eggs daily |
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| Trichuris Trichuris- Lab diagnosis |
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| Wet mount-looking for immature eggs. Adults: 30-50mm (1) slender, thread like anterior portion ("whip"). (2) thick, posterior portion ("handle") Eggs: 50-55 by 22-24um Barrel-shaped, bile stained , thcik shell and mucoid plugs at either end, unembryonated |
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| Ascaris lumbricoides- Adults |
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| Adults are very large (6-12 inches) with heavy infection of adult worms: abdominal pain, malabsorption, retarded growth, intestinal obstruction. Adults tend to migrate to other areas of the body( appendix, bile duct, mouth, nose, ear) |
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| Ascaris lumbricoides-eggs |
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| eggs are:passed into the soil, mature in about 3 weeks. When eggs are ingested they penetrate the intestinal mucosa,enter portal system,go to the heart and lung, get coughed up and swallowed. Ends back up in the intestine and grows to adult. If eggs are depostited in liver abcesses may appear. |
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| Ascaris lumbricoides pathogenicity related to hosts immune repose, larval migration effects and mechanical effect of adult worms and nutritional problems |
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| Clinical signs from larvae lung involvement due to hypersensitivity-Occasional death from repiratory failure. |
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| Ascaris lumbricoides |
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| larvae: 2mm by 75um Eggs: fert: 45-75 by 35-50um, oval, thick shelled,bile stained, central zygote unfertilized 85-95 by 43-47um thin shell, internal contents are a mass of highly refractive granules |
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| Anaskis |
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| Fish version of ascaris, lifecycle involves marine mammals and fish! So infection comes from eating raw or undercooked fish and the ingestion of larval stage found in fish. |
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| Anaskis-Clinical |
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| Symptoms evident with in hours upto 5 days and iclude nausea, vomiting, severe epigastric pain due to infestation of the larva embedded in gastric and intestinal mucosa |
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| Anaskis- Diagnosis |
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| demonstration of larva(surgery, gastrscopy and vomitting) usually misdiagnosed |
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| Taxocara canis |
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| Dog and cat version of ascaris |
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| Taxocara canis |
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| Responsible for visceral larva migrans Adult worm in dog or cat..eggs reach soil and Human ingest eggs. Larva from egg end up in tissue..do not have adult worm in humans |
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| Taxocara canis |
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| Taxocara canis |
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| Severity is realted to the number and location of the lessions and the hosts degree of sensitization. The liver, lungs, skeletal muscle , brain and eyes are the areas most frequently involved.. death can occur! |
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| Taxocara canis-Diagnosis |
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| Hard to confirm- May test eye fluid, most infections are sublcinical Larvae: 300-400um by 15-20um Eggs:(will not find in humans) T. Canis: thick shell, markedly pitted surface(golf ball) 75-85-um T. cati- slightly smaller, finely pitted surface |
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| Capillaria phillippinesis |
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| Lives in small intestine Found in Phillippines, Thailand, Japan, egypt, Iran |
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| Capillaria phillippinesis- Morphology |
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| Adults: 2-4.5mm Eggs:36- 45 by 21um Polar plugs( may be hard to see), striated shell, typically more rectangular that T. trichura |
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| Capillaria phillippinesis- Clinical |
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| Humans get from eating larvae frm undercooked fresh water fish. Adult worms produce an auto-infective cycle results in numerous organisms in the intestine. Stools are numerous(5-10 per day), with large volkume and increased amount of fat. Malabsorption syndrome and 20% death rate(pneumonis, heart failure, hypokalemia, cerebral edema) infection lasts about 6-12 months. |
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| Caplilaria hepatica |
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| Lives in Liver. Adult lives in rodent liver(1-4mo. Eggs get depostited onto tissue. Liver is eaten by another animal and eggs pass out into soil where the are embryonated and host aquires infection. |
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| Caplilaria hepatica-clinical |
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| Difficult to diagnose as are eggs are trapped in the liver and are not passed into the feces. Liver biopsy may not be useful. symptoms invove the liver. |
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| Caplilaria hepatica-Morphology |
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| Eggs 51-67 by 30-35um Prominent striated shell, polar plugs. Whens seen in feces, usually transient Resembles T, trichurus |
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| Hookworm-Adults |
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| Live attached to intestine and extract blood |
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| Hookworm-Eggs |
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| Pass into the soil. Larva develop into rhabditiformlarva that into flariform larva |
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| Hookworm Two organisms |
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| Ancyclostoma duodenal Necator americanus |
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| Ancyclostoma duodenal |
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| "old world" Europe, Africa, CHina, Japan, India |
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| Necator americananus |
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| "new world" western hemisphere Africa, South pacific, India |
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| Hookworms |
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| contact with the skin, flariform larva penetrate the epidermis, travel via the lymph system to the heart and then to lungs. They get coughed up and then swallowed and mature in the intestine. |
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| Hookworm-clinical |
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| "ground itch" at site of penetration minor lung involvement Intestinal disturbances Acute infections: nausea, vomitting, fatigue, diarrhea,blood loss (.03-.20 ml per day/worm Chronic Infection: iron defecient anemia May have intense disire to eat dirt. |
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| Hookworm-diagnosis |
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| Identification of eggs in feces( adults remain attached to intestine) and hypochromic, microcytic anemia |
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| Hookworm-Morphology Egg |
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| Identical for both genera smooth thin shell |
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| Hookworm-Morphology Egg |
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| Identical for both genera smooth thin shell |
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| Hookworm-Morphology larvae |
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| Same in both genera rhabditiform: 250-300 by 15-20um Long buccal canal,genital primordium small Filariform: pointed tail, sheathed |
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| Hookworm infective, first and third stages |
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| infective stage:flariform larvae first stage larvae: rhabditiform(free-living, non infective Third stage: filariform (non-feeding, infective) |
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| Ancylostoma braziliensis |
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| Found in dogs and cats as well as other species. Found in tropics and subtropics, but also in the SE part of USA. Source of most infections are from sandy soil, sand boxes and beaches |
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| Ancylostoma braziliensis-Clinical |
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| Sever itching, creeping eruption occurs aling the tract the larva is traveling within the epidermis. Larva can travel cm a day, may get secodary bacterial infection from scratching |
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| Ancylostoma braziliensis simialr to hook worm excetp filariform laravae does not develop beyond deep layers of the epidermis and life cycle does not complete in humans |
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