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10 Cards in this Set
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is the primary cause of amoebic meningoencephalitis which is a rare fatal disease with a sudden onset of headache, fever, stiff neck, lethargy and coma in healthy people Trophozoite are about 10-15 um in dia and produce broadly round lobopodian that can transform into flagellate. Cyst are single walled, spherical. Nonpathogenic forms: N. gruberi & N. australiensis. Pathogenesis: amoebas splashed or inhaled onto the olfactory epithelium migrate up the olfactory nerve to the brain and spread via subarachnoid space= meninges Epidemiology: often in hot or warm freshwater (lakes, rivers, and hot springs); Minnesota Dx: CSF, CNS tissue Trx: Amphotericin B and miconazole |
NAEGLERIA FOWLERI |
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Gen Appearance: Trophozoites are 25-40 um in dia with characteristic spine-like pseudopodia. Cysts are double walled, usually polygonal and spherical. LC: free living inhabitants of soil and of fresh and salt water usually acts as opportunistic pathogens in immunocompromised or debilitated individuals in whom the cause pneumonitis or dermal ulceration. Brain: insidious, slowly progressive and usually fatal encephalitis ~ granulomatous amebic encephalitis: healthy ~ ulcerating keratitis, improper use of sterilized contact lenses. Infective forms: trophozoite Pathogenesis: Encephalitis is caused by hematogenous spread from superficial or pulmonary lesions to the brain. Keratitis results from contamination of superficial corneal abrasions. Dx: brainscans, biopsies or spinal tap Agents that infects humans: >A. culbertsoni ➢A. polyphaga ➢A. castellanii ➢A. astronyxis ➢Some: A. hatchetti, A. rhysodes, A. divionensis, A. lugdunensis & A. lenticulata Calssifications: Group I- species that have large trophozoites with cysts that range from 16-35 um ~A. astronyxis, A. comandoni, A. tubiashi, A. byersi Group II- includes by far the largest number of species, with cysts measuring around 18 um or less ~A. castellanii, A. polyphaga, A. rhysodes, A. hatchetti Group III- consists of species with subtle differences in cyst morphology, also measuring 18 um or less ~ A. culbertsoni, A. royreba, A. lenticulate sequencing of rDNA are used |
ACANTHAMOEBA SPECIES |
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Sometimes called Neobalantidium/Balantioides Large ciliated protozoan, only ciliate known capable of infecting humans. Associated with swine, as its primary reservoir host Epi: occurs worldwide specially in areas where pigs are raised and sanitation is inadequate Pathogenesis: mostly are asymptomatic. When present, may be acute or chronic with abdominal symptoms. Complications of associated diarrhea or dysentery can occur. Symptoms may be severe in immunocompromised persons. Extraintestinal infections are rare but potentially serious. Peritonitis and liver abscesses are noted following rupture of fulminant colonic ulcers
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BALANTIDIUM COLI |
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possess whiplike locomotor known as flagella. Special organs: sucking disk, axostyle and undulating membrane* and rudimentary mouth known as cytosome They inhabit visceral organs and non-tissue invader |
ATRIAL FLAGELLATES |
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Only the pathogenic intestinal flagellates that inhabit the small intestine Trophozoite is pear-shape or teardrop shape. Concave sucking disk serves as nourishment point of entry. There are 4 pairs of flagella, with characteristic movement of jerky falling leaf. Cysts is ovoid, smooth, well defined wall and contains two-four nuclei. Pathology: general malabsorption of fats and carbohydrates – steatorrhea, impaired absorption of Vit B12, folate, carotene with the passage of foul smelling and bulky stool Dx: presence of trophozoite in stool Epi: warm & moist climates particularly in children. Associated in poor sanitation & hygiene, and overcrowding, homosexual practices –”gay bowel syndrome” |
GIARDIA LAMBLIA |
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Inhabits the cecal region of the large intestine. Trophic stage is pear shape as a result of a spiral groove extending through the middle half of the body. Has three free anterior flagella (two short, one long) and a delicate flagellum lying within cytosome. Numerous food vacuole, with a characteristic movement of stiff-rotary fashion (corkscrew motion) Cystic is lemon shape, ropunded at one end and conical in the other with knob- like protuberance (nipple shaped cyst) |
CHILOMASTIX MESNILI |
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Previously classified as amoeba. Their karyosome slits into four or more fragments with fine achromatic fibrils and provided with two nuclei. Small round trophozoite provided with two nuclei, pseudopodia is blunt and leaf-like with sluggish movement. |
DIENTAMOEBA FRAGILIS |
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Trophic is pyriform in shape with cytosome, prominent axostyle, four anterior flagella, single nucleus and undulating membrane with marginal flagellum. Movement is jerky (tumbling movement). Pathology: the only pathogenic trichomonas. Vaginal walls are inflamed with petechial hemorrhage and the surface of vagina is covered with coagulated material containing WBC, RBC and Tric. Disquamation is also seen. Vaginal secretions is greenishyellow in color, with intense itching and burning sensation. Dx: urine, urethral secretions, vaginal & cervical secretions. Semen, and prostatic secretions Epi: The incidence of infection is 10 – 25 % in women and higher in-groups in which feminine hygiene is deficient Contaminated toilet seat and towel Males as asymptomatic carriers, passing of baby’s in birth canal can also cause infection in babies. |
TRICHOMONAS VAGINALIS |
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Inhabits oral cavity, has four flagella and undulating membrane that does not reach the posterior end of the body Transmission happens through droplet spray from mouth, kissing, or common use of contaminated dishes & drinking glasses. Dx: swabbing of tartar between gingival margin of gums |
TRICHOMONAS TENAX |
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Inhabits the caecum, trophozoite has five anterior flagella, posterior flagellum projecting from an undulating membrane. Axostyle extends from the anterior end to the posterior end along the mid-axis MOT: ingestion of contaminated food and water with trophozoite passes in diarrheic stool. |
TRICHOMONAS HOMINIS |
