Protozology Flashcards
- Nagana
1) Species name of causative agents
2) Morphology
3) Range of susceptible hosts, modes of infection
4) Life cycle
5) Clinical signs
6) Pathology Not characteristic
7) Diagnosis
8-10) Other questions
1) Trypanosoma Vivax, T. Congolense, T. Brucei brucei
2) 10-14 um, large, elongated nucleus, flagellum, undulating membrane, kinetoplasm (?)
3) Horse, cattle, camel in tropical Africa.
- Either cyclica -> need biological vector, or non-cyclica -> Mechanical transmission
- Arthropod vector: Tse-tse flies (Male and Female!)
4) Fly ingests trypomastigote while feeding on blooda -> Parasite reproduces asexually in fly’s gut -> Fly injects trypomastigote
- Heterogenous, not host-specific
5) ACUTE: Haemorrhages on mucous membrane, lymphoid enlargement, inflammatory- necrotic changes in spleen, CNS, genitals
CHRONIC: Spleen and lymphnodes shrunken, anaemia, CHF
6) Pathology: Not characteristic
7) Peripheral blood sample or LN sample – detect trypomastigote
-Examine in phase-contrast microscope
8-10) ?
- Dourine
1) Species name of causative agents
2) Morphology
3) Range of susceptible hosts, modes of infection
4) Life cycle
5) Clinical signs
6) Pathology Not characteristic
7) Diagnosis
8-10) Other questions
1) Trypanosoma Equiperdum (variation of T. Brucei evansi)
2) 10-40 um, has kinetoplast and flagellum, large nucleus
3) Horse and donkey
-Transmitted venerally (coitus) or galactogenically (homoexenous)
4) Multiplies in genital mucosaa -> parasitaemia -> Reach skin and peripheral nerves
5) Genitalsa: Oedema of genitals and central abdomen, inflammation, ulceration
-Skin: Dollar spots on withers, thorax, neck
-Nerves: Ascending motor paralysis
6) Pathology: Not characteristic
7) Peripheral blood sample, scraping of genitals, puncture of dollar spots In parasitaemia -> Fresh blood sample (motile trypomastigotes)
8-10) Other questions ?
- Leishmaniosis
1) Species name of causative agents
2) Morphology
3) Range of susceptible hosts, modes of infection
4) Life cycle
5) Clinical signs
6) Pathology Not characteristic
7) Diagnosis
8-10) Other questions
1) Leishmania Tropica, L. Infantum (ca), L. Donovani, L. Chagasi
2) Smaller, thinner than trypanosomas
-In host (vertebrates) -> Amastigote (IC) = no visible ext. flagella In vector (sand fly) -> Promastigote (EC) = long flagella
3) Human, dog, cat (rare), in Mediterranean countries
-Infection: Transplacental, fighting, mating
-Predisposing factors needed -> Immunodeficiency
4) Vector ingests parasite while feeding on blood -> mastigote released in gut and parasite reproduces as promastigote -> host infected with promastigote when bitten by fly -> Promastigote enter macrophages and reproduce as amastigote = INDIRECT life cycle
5) Cutane form (dog): L. Tropica -> Alopecia, dermatitis, ulcers
-Visceral form (dog): L. Donovai -> LN, spleen, liver enlargement, anaemia, diarrhoea
6) Pathology: Not characteristic
7) Amastigote (in host): Smears and scraping
-Biopsy (LN, spleen, liver), serology
8-10) Other questions ?
- Giardiosis
1) Species name of causative agents
2) Morphology
3) Range of susceptible hosts, modes of infection
4) Life cycle
5) Clinical signs
6) Pathology Not characteristic
7) Diagnosis
8-10) Other questions
1) Giardia Duodenalis
2) Pear-shaped, 10-20 um, 2 nuclei, 2 axocystoles, 2 median bodies, 4 pairs of flagella = TROPHOZOITES
Ovoid, 10-15 um, 2 or 4 nuclei, 4 median bodies = CYSTS
3) Human, mammals (mainly dogs), birds
-Infection through drinking water, coprophagy (ingest cysts)
4) Cysts through drinking water -> develop into trophozoites in intestines -> Cysts passed in faeces = DIRECT life cycle
5) Usually asymptomatic
-Young dogs: Malabsorption, pancreatic insufficiency -> Emaciation, poor growth, yellow + slimy diarrhoea
6) Pathology: Not characteristic
7) Trophozoites: from faecal smear with Lugol solution (vegetative state)
-Cysts: Floatation with zinc-sulphate (infectious stage)
8-10) Other questions ?
- Trichomonosis of the cattle
1) Species name of causative agents
2) Morphology
3) Range of susceptible hosts, modes of infection
4) Life cycle
5) Clinical signs
6) Pathology Not characteristic
7) Diagnosis
8-10) Other questions
1) Trichomonas Foetus
2) 12-17 um, flattened, 3 forward flagella, 1 backwards
3) Cattle
During coitus (establishment on genital mucosa) -> insemination w/ bulls
4) Establishes on genital mucosa during coitus -> Move up vagina and reaches uterus -> Flushed back into vagina 2-3 days before estrus -> spontaneous clearance from females (following abortion or failed fertilization)
5) Bulls: Inapparent, sometimes inflammation of praeputial mucous memb., swelling
-Cows: Vestibulitis, vaginitis, ascending endometritis, early abortion, anestrus (fertilisation problems)
6) Pathology: Greyish-yellow papules on chorion of foetus
7) Collect vaginal/urethral discharge -> centrifuge and examine sediment. Giemsa-staining.
8-10) Other questions ?
- Trichomonisis of birds
1) Species name of causative agents
2) Morphology
3) Range of susceptible hosts, modes of infection
4) Life cycle
5) Clinical signs
6) Pathology Not characteristic
7) Diagnosis
8-10) Other questions
1) Trichonomas Gallinae
2) 6-18 um, lemon-shaped, 4 forward flagella, 1 short backwards
3) Young pigeons, sometimes turkey, chicken
-Inf. Through crop milk = Young
-During kissing or contaminated drinking water = Adult (carriers)
4) Direct life cycle, predisposing factors needed for infection
5) Young: Depression, ruffled feathers, anorexia, dyspnoea, death. Foul odour from mouth, pendulous crop, necrosis in mouth, pharynx
6) Yellow diphteric membrane in mouth, pharynx, oesophagus, crop Hepatic form -> necrotic lesions in liver, heart, air sacs
7) Smear from lesions examined w/ phase contrast microscopy
8-10) Other questions ?
- Histomonosis
1) Species name of causative agents
2) Morphology
3) Range of susceptible hosts, modes of infection
4) Life cycle
5) Clinical signs
6) Pathology Not characteristic
7) Diagnosis
8-10) Other questions
1) Histomonas Meleagradis
2) -Trophozoite, rounded, pleiomorphic
-Caecum: 1 flagellum < 30 um
-Tissues: Amoeloid < 15 um
3) Young turkey (up to 14 weeks), other birds
-Inf. through Heterakis nematode -> Carries Histomonas!
4) Found in egg of Heterakis Gallinarum -> indirect life cycle
5) Loss of appetite, diarrhoea, yellow faeces, lethargy
6) “Black head” – cyanotic comb, waddle and head. Deep, circular necrotic foci in liver – sharp edges. Yellow, necrotic material in caecal lumen.
-Generalised: Necrotic lesions in spleen, lungs, kidneys
7) Smears from edge of lesions, use phase contrast microscopy Detection is difficult.
8-10) Other questions ?
Coccidiosis in general
- Species name
- Morphology
- Life cycle
- Species name: Eimeria species, Isospora species
- Morphology: -Unsporulated oocyst: 15-50 um, oval, refractive shell, micropyle (pore) covered by cap. Zygote inside (nucleated mass of protoplasm)
- Sporulated oocyst: 15-50 um, oval, 4 sporocysts; each containing 2 sporozoites
- Schizont: Can reach 300 um in diameter (= Globidium), contains Merozoites
- Merozoite: 5-10 um, crescent shaped
- Life cycle: Oocysts passed in faeces of infected host -> oocyst completes development in environment into sporulated form (infective stage) -> sporulated oocyst ingested by host -> oocyst “exupt” in SI; small Sporozoites infect the cells lining the SI -> the parasites reproduce asexually (schizogony/morogony) in the cells, producing merozoites -> these infect more intestinal cells -> after several generations of asexual reproduction, oocysts are produced (sexual reproduction – gametogony)
- Coccidiosis of the chicken
1) Species name of causative agents
2) Morphology
3) Range of susceptible hosts, modes of infection
4) Life cycle
5) Clinical signs
6) Pathology Not characteristic
7) Diagnosis
8-10) Other questions
1) Eimeria tenella, E. Necatrix, E. Brunetti, E. Acervulina, E. Maxima, E. Mitix, E. Precox
3) Usually flocks aging 3-6 weeks
-Breeder and layer replacement stock aging 10-14 weeks
-Inf. per os
5) Depends on species, light/heavy inf., virulence and host resistance
-TNB: Tenella, Necatrix, Brunetti -> Loss of skin pigmentation, soft + bloody faeces
-Other spp.: Watery diarrhoea, poor growth, decreased egg prod.
6) PM exam. Is most important: Location + type of lesions
-E. tenella: Cecum! Extensive haemorrhages w/ unclotted blood in lumen, dilation and thickening of wall, deep erosions in epithelium
-E. Necatrix: Jejunum + ileum! Haemorrhages, thickened wall, unclotted blood in lumen, scattered white spots = “Salt and pepper” spots
-E. Brunetti: Lower SI, prox. Caecum, colon, rectum! Haemorrhagic, catarrhal exudate and coagulative necrosis, petechiae in rectum = “Ladder like” pattern
-E. Maxima: Middle of SI! Inflamed, ballooned and slack, slightly orange/salmon pink excudate in lumen.
-E. Acervulina: Duodenum! White foci or transverse bands which are ladder-like. Watery content in lumen. Only heavy infection.
-E. Mitis/E. precox: No macroscopic leasions
7) Unsporolated oocyst – floatation of FRESH faecal sample
-Smears – paler body, easier to see nucleus
-Oocyst counting (OPG) – McMaster method
8-10) Other questions:
-Coccidiosis of geese: E. Anseris, E. Nocens
-Renal coccidiosis: E. Truncata
- Coccidiosis of the cattle and small ruminants
1) Species name of causative agents
2) Morphology
3) Range of susceptible hosts, modes of infection
4) Life cycle
5) Clinical signs
6) Pathology Not characteristic
7) Diagnosis
8-10) Other questions
1) 21 species! E. Bovis, E. Zuernii
3) Calves (2-6 months) in crowded, unsanitary conditions -Per os infection
5) Mild inf. are asymptomatic. Anorexia, fever, rectal prolapse, emaciation, rapid death.
Haemorrhagic and viscous diarrhoea – mucous shreds or blood (E. zuernii). Rarely cerebral disorders: Tetanic convulsion, nystagmus
6) Large intestine! Catarrhal to diphteroid enteritis with mucosal oedema and diffuse haemorrhages
7) Unsporulated oocyst: Floatation (not enough for diagnosis..?)
-Sporulated oocyst: Iodine staining
-McMaster method – Oocyst counting (OPG)
8-10) Other questions ?
- Liver and intestinal coccidiosis of the rabbit
1) Species name of causative agents
2) Morphology
3) Range of susceptible hosts, modes of infection
4) Life cycle
5) Clinical signs
6) Pathology Not characteristic
7) Diagnosis
8-10) Other questions
BILIARY COCCIDIOSIS
1) Eimeria stiedai
3) Usually after weaning – 1-2 months
-Per os infection
5) Usually subclinical.
Anorexia, jaundice, digestive problems
6) Cirrhosis (grey-yellow nodules) in liver and hepatomegaly; biliary hyperplasia, cholangitis; thickening of CT bw. bile duct and hepatic tissue: Acute =thin, Chronic=thick.
7) -Unsporulated oocyst: Floatation (fresh sample)
8-10) Other questions ?
INTESTINAL COCCIDIOSIS
1) 10 species – E. intestinalis & E. flavescens
3) Usually after weaning: 1-2 months
-Per os inf.
5) Usually subclinical, may see increased water consumption, anorexia, diarrhoea w/ mucous or blood, death within few days
6) -E. intestinalis: SI! Haemorrhagic enteritis, thickened mucosa
-E. Flavescens: LI! Haemorrhagic enteritis, thickened mucosa
(E. Magna: Pinhead-sized white nodules in ileum)
7) Unsporulated oocyst: Floatation. McMaster: OPG (good in these cases)
8-10) Other questions ?
- Coccidiosis of the pig and carnivores
1) Species name of causative agents
2) Morphology
3) Range of susceptible hosts, modes of infection
4) Life cycle
5) Clinical signs
6) Pathology Not characteristic
7) Diagnosis
8-10) Other questions
PIG
1) Isopora suis
2) -Sporulated oocyst: round/oval, 20 um, with 2 sporocysts each containing 4 sporozoites
3) Usually 8-15 days old
-Per os infection
5) Yellow diarrhoea (never bloody), dehydration
6) Jejunum and ileum! Lesions in mucosa (several developmental stages present)
7) Diagnosis Floatation of sporulated oocyst! Autofluorescence microscopy!
8-10) Other questions
CARNIVORES
1) DOG – Isospora canis, I. Ohioensis, I. Burrowsi (big->small) CAT – Isospera felis, I. Rivolta
2) Sporulated oocyst: 2 sporocysts with 4 sporozoites in each
3) Young dogs and cats in unsanitary conditions
5) Mainly subclinical inf., may observe emaciation, dehydration, anaemia
6) Catarrhal/haemorrhagic enteritis, several develop. stages in scraping
7) Unsporulated oocyst: Floatation Staining: Kinyoun, Ziehl-Neelson
8-10) Other questions ?
- Cryptosporidiosis of mammals
1) Species name of causative agents
2) Morphology
3) Range of susceptible hosts, modes of infection
4) Life cycle
5) Clinical signs
6) Pathology Not characteristic
7) Diagnosis
8-10) Other questions
1) Cryptosporidium parvum, C. Muris
2) Oocyst: 5-8 um, nearly spherical or elliptical, observe internal structures (4 sporozoites)
3) Many domesticated animal species, especially young calves. Per os inf.
4) DIRECT: Oocysts are passed in host’s faeces -> Oocysts become sporulated (in environment, infective) -> Host is infected per os (water, contaminated feed) -> oocysts “excyst” in SI -> asexual reprod. In SI -> oocysts produced and passed with faeces
5) Young calves (1-3 weeks): Acute diarrhoea with mucus shreds, sometimes blood C. Parvum – Anorexia, fever, dehydration, death
6) Catarrhal enteritis in ileum!
-C. muris – Disorders in digestive glands of the abomasum
7) Oocysts: Floatation w/ Sheather’s sugar solution
-Immuniological methods: IF w/ monoclonal AB, ELISA
-Molecular technologies: A variety of PCR tests
8-10) Other questions ?
- Cryptosporidiosis of birds
1) Species name of causative agents
2) Morphology
3) Range of susceptible hosts, modes of infection
4) Life cycle
5) Clinical signs
6) Pathology Not characteristic
7) Diagnosis
8-10) Other questions
1) Cryptosporidium Baileyi, C. Meleagradis
2) ?
3) Many species, esp. young chickens
-Aerogenous infection route!
4) Same as in mammals
5) Subclinical in case of light infection
-Respiratory signs: Coughing, sneezing, dyspnea, nasal discharge, eye inf.
6) Inflammation of air sacks, pneumonia, sinusitis. Histological changes may be seen almost everywhere
7) As in mammals; best staining is Kinyoun, Ziehl-Neelson
8-10) Other questions ?
- Toxoplasmosis
1) Species name of causative agents
2) Morphology
3) Range of susceptible hosts, modes of infection
4) Life cycle
5) Clinical signs
6) Pathology Not characteristic
7) Diagnosis
8-10) Other questions
Zoonotic!
1) Toxoplasma Gondii
2) Sporulated oocyst: 2 sporocysts w/ 4 sporozoites in each Cyst: Very pale, crescent shaped, 200 um, round, thin wall
3) -Intermediate host: many mammalian and bird species
-Definitive host: Domestic cats and their relatives
-Per os infection
4) INDIRECT! Unsporulated oocyst shed w/ cat’s faeces (for 1-3 weeks) -> Oocysts sporulate in environment (become infective) -> Intermed. Host (e.g. mouse) ingests contaminated soil/water/plants -> oocyst transforms into Tachyzoites after ingestion -> Tachyzoites localise in neural and muscle tissue and develop into Brodyzoites there -> IM host is eaten by cat -> Cat becomes infected (can also become infected from eating sporulated oocysts directly)
-Livestock, humans can also be infected if they ingest oocytes
5) Usually latent infection. Signs related to affected organ.
CAT: Rarely encephalitis, enteritis, pneumonia (also dog)
Pregnant EWE, SOW, WOMAN: Abortion (retained or mummified) HUMAN: Mental disorders, newborn blindness (vertical transmission)
6) Related to extraintestinal development
-Necrotic and inflammatory foci with cysts in organs
7) -Unsporulated oocyst in cats faeces: Floatation
-Immunolodiagnostic tests: Sabin-Fieldmann antibody dye test, complement fixation test
8-10) Other questions
-Alters intermediate host’s behaviour so that they become unafraid of final host
