Protozoa Flashcards
Trypanosoma spp. having undulating membrane:
T. brucei brucei, T. congolense
T. vivax – Inconspicuous undulating membrane
Stages of Tryponosoma spp. having undulating membrane:
Trypomastigote
Epimastigote
Which trypanosome stage is intracellular?
Amastigote
Which has flagellum, but no undulating membrane?
Promastigote
Which does not have flagellum?
Amastigote
Which phenotype of trypanosomes has the kinetoplast anteriorly next to the nucleus, and is also provided with short undulating membrane?
Epimastigote
Which cells do Trypanosomes invade?
WBCs, macrophages
Trypanosoma found in old world and new world.
Trypanosoma vivax (South America only)
For how long does Trypanosoma have…?
Many years
Salivaria vs. Stercocaira; which occur in South America?
Both. These are the Trypanosomes group.
What is the size range of trypanosomes?
8-39um
Name of the cutaneous inflammation after an infection / infiltration with Trypanosoma:
Chancre
Nagana caused by:
Trypanosoma vivax, T. congolense, T. brucei
Spp. not effected by Nagana:
Wild animals (reservoir role) and certain breeds of cattle (N’Dama, zebu are resistant. Ru. Eq. Sus. Ca. effected
Which is the largest among the causative agents of Nagana?
T.brucei brucei (15-39 um)
Largest Trypanosoma from the following:
Trypanosoma brucie brucie (15-39 um)
Which Trypomastigote has a large undulating membrane?
Tryponosoma brucei brucei
What is the most frequent cause of death in Nagana?
Congestive heart failure
Which region of Africa does the acute, more rapid form of sleeping sickness (T. rhodensiense) occur?
Eastern
Trypanosoma evansi causes:
Mal de caderas / Surra
The causative agent of Surra (mal de caderas):
Has broad host spectrum – Horse, dog, camel, elephant, humans.
Which host has asymptomatic Trypanosoma evansi infection?
Cattle
Surra caused by which parasite?
Trypanosoma evansi
Surra is found where in the world?
North Africa, Asia, Central and South America
The vector of T. brucei evansi plays a role as:
Mechanical vector
Mal de Caderas symptoms:
Oedema of limbs
Which animal has asymptomatic T. brucei evansi infection:
Cattle, water pig (since these are reservoirs)
Trypanosoma cruzi causes:
Chagas’ disease
The amastigote of Trypanosoma cruzi occurs?
In mesenchymal cells
Amastigote (mesenchymal cells) – Infected cells rupture, disintegrating amasitgotes elicit an inflammatory response - Epimastigote – Trpomastigote (infect new cells and tissues, muscle, nerves)
How can dogs be infected with Trypanosoma cruzi?
Eating bugs
The amastigote of Trypanosoma cruzi occurs where?
Mesenchymal cells
Which phenotype is not characteristic of Trypanosoma cruszi?
Promastigote
See amastigote, epimastigote, and (in the blood stream) trypomastigote.
What is not caused by Trypanosoma cruzi?
Megalomania
Which has the biggest kinetoplast or soma from the 4 Trypanosoma?
T. Cruzi
How can the kissing bugs inoculate Trypanosoma cruzi in a host?
With their faeces
Trypanosoma brucei equiperdum causes:
Dourine (exanthema coitale paralyticum)
Which trypanosoma species causes asymptomatic infection in dogs?
T. equiperdum (does not effect dogs)
Which species does the causative agent of Dourine belong to?
T. brucei
In scientific terms, what is a dollar spot?
Uritricia
Which ocular problem does Dourine not cause?
Nystagmus (strabism), lachrymation, mydriasis
Dourine caused by:
Trypanosome brucei subsp. Equiperdum
Dourine has been found where in the EU in the last 10 years?
Italy
What is the main sign seen towards the end of Dourine?
Paralysis, mainly in hindlimbs Genitals → Skin → Nerves
4
Geographic locations and symptoms of following Trypanosoma diseases:
Nagana: Central Africa, south of the Sahara region - Haemorrhages on mucosal surfaces, inflammatory-necrotic changes, death due to congestive heart failure
Sleeping Sickness: Africa - Leptomeningitis followed by cerebritis
Surra / Mal de caderas: EU, North Africa, Asia, Central and South America - Oedema, neurological (Horse) and ocular (Dog) signs, etc.
Chagas’ disease: South and Central America - “mega signs” like cardiomegaly, mega-oesophagus, megacolon
Dourine: Third world countries, Italy - “dollar spots” Genitals – Skin – Nerves
Which of the following is detected by Giemsa staining of blood smear? MCQ
Theileria
Trypanosoma
What type of biological vector does Salivaria-type Trypanosoma have?
Biological vector - Glossina spp. (Tsetse flies)
Mechanical vector – Stomoxys and Tabanus spp. (blood-sucking flies)
Which phenotype/form is possible for the pathogenesis of Leishmania?
Amastigote
Amastigote host; intra-cellular in macrophages. Promastigote sand-fly; vector.
Leishmania develops from:
Amastigote
Incubation period of Leishmania?
Several years
After an incubation period of 3 months to 7 years, chronic outcome.
Leishmaniosis vector is:
Sandfly (Phleobotomus)
The sandflies can be the vector of the pathogens of which disease?
Leishmaniosis
How can host be infected by Leishmania?
Female sand-fly. Vector disease. Via biting.
Leishmania transmission can be:
All
Vector borne. Trans-placental. Sand-fly.
What is/are characteristic of pathogenesis of leishmaniosis? (MCQ)
MPS killing amastigotes Hyper-globulinemia
Visceral form of Leishmania?
Distended intestines, melena, conjunctiva problems, hyperaemic spleen, PU, PD.
Symptoms of Leishmania?
Cutaneous form – Hair loss, hyper-keratosis, desquamation, seborrhoea, small papules, ulcers, crusts, excessive long clawa (onychogryphosis)
Visceral form – Lymph nodes spleen and liver enlarge, fever, anaemia, emaciation, muscle atrophy, ataxia, somnolence, lethargy, anorexia, vomit, diarrhoea, cachexia, PU, PD, ocular signs, rhinitis, coughing, epistaxis, melena
Cause of death in Leishmania?
Renal insufficiency/failure (kidney insufficiency)
Which country lacks autochthonous cases (indigenous, native) of Leishmaniosis?
Germany
What is the approximate size of Giardia:
Trophozoite – 11-17 um
Cyst - 10-20um
How do humans get giardia?
Swimming, contaminated drinking water, washing food with water, surfaces
How do chickens get Giardiasis?
Infection per os. Infected water. Water-borne infection.
How Giardia infects?
Via contaminated water (swimming, drinking water, washing food), food, surfaces, caprophagy
Where can we find Giardia extra-intestinally?
Bile and pancreatic ducts; liver and pancreas.
Giardia cyst location?
Environment (infectious form)
Giardia trophozoite location?
Host (vegetative form). In intestine, bile duct, pancreatic duct.
Which Giardia duodenalis occurs in dog?
Genotypes A-D (ABCD) (A-G genotypes exist)
Difference between Trichomonas and Tritrichomonas?
Trichomonas 4 flagella Birds Tritrichomonas 3 flagella Cattle
If the following are present, more susceptible to Trichomonas: MCQ
Vitamin A deficiency
How do pigeons acquire Trichomonas?
Young pigeons (squabs) – Via feeding of regurgitated feed content Pigeons – Via kissing or from contaminated drinking water
General feature of Trichomonas in pigeons?
Penguin-like posture (birds stand upright with head high and neck straight)
What is the characteristic lesion in the hepatic form of pigeon Trichomonosis?
Pea-size necrosis
What is/are the worst consequences in Trichomonosis in Cows?
Early abortion (1st trimester, before 4th month) – Early abortion in 6-16th week via absorption or elimination Pyometra – Greyish-white, odourless fluid swarming with Trichomonas
Age when bulls are susceptible to Trichomonas spp.:
Above 3 years
How does Trichomonas gallinae reach the liver in birds?
From navel
Hepatic form – Through navel of squabs into the liver – Greyish-yellow, pea-sized necrotic foci
Geographical region with Tritrichomonas problems?
Certain states of America (e.g. Florida, Nevada, California, etc.)
How does Tritrichomonas foetus live in the genital tract?
Epi-cellularly
Which can be found in earthworms?
Histomonas meleagridis – Heterakis earthworm as a transport host.
Predisposing factor of Histomonosis:
Turkeys kept together with chickens (asymptomatic carriers, frequently Heterakis infected)
Liver of Histomonas infection pathologically seen as:
Dry cut surface
Characteristic, greyish-yellow, circular, deep/sunken, necrotic foci 1-2cm or more in diameter. The border of the lesions shows sharp demarcation, and the dry-cut surface shows concentric structures due to expanding necrosis of the hepatocytes on the periphery. Pathognomic lesions!
Characteristics of Histomonosis disease in birds?
Cyanosis of the head (blueish colour)
Also, weakness, dropping of wings, drowsiness, yellow diarrhoea, death within days
Which clinical sign is not characteristic of turkey Histomonosis?
Head cyanosis (no cyanosis of head not wattles in turkey)
Entamoeba histolytica morphology:
4 nuclei, 8-20 um Trophozoite Amoeboid form, in mucosa and tissues, ring-like nucleus, endosomes (karysome), RBCs in cytoplasm, no mitochondria (mitosome instead, pseudopodia for movement). 10-20um Cyst Round (cf to Giardia which is oval!), 4 nuclei, blunt chromatidal bars. 8-10um
Which of the following is/are characteristic of Entamoeba histolytica trophoziotes? MCQ
Eccentric endosome
Phagocytised RBCs
What causes anosmia (loss of smell)?
Entamoeba histolytica
Entamoeba attacks:
RBCs
Where does the skin abscess of Entamoeba come from?
Abscess in liver
Peritonits, pleuritis (if abscesses rupture). Skin: Erythema, alopecia, hyper-keratosis (desquamation)
Acanthamoebosis
Free-living, soil inhabitant, opportunistic amoebae
Chronic granulomatosus encephalitis is caused by:
Acanthamoeba castellani
What is chronic granulomatous amoebic encephalitis (GAE) in humans caused by?
Acanthamoeba castellani
How can a dog become infected with Acanthamoeba castellani?
Dog - From water, contact with still water, through skin lesion. Opportunism if dog with Distemper.
Horse – Via inhalation, through skin lesion.
Naegleria morphology:
10-12 um, rounded Trophozoite Biflagellar form Cyst
< 20 um, with a single amoebostome
Swim large distances in water
10-12 um, uni-nucleated, round, ostiolum (tiny opening for excystation)
What is shape and size of Naegleria cyst?
Uni-nucleated, osteolum, rounded, 10-12 um
What is the form Naegleria fowleri does not have?
Provided with one flagellum
N. fowleri has biflagellar form
What is the acute primary amoebic meningoencephalitis (PAM) in humans caused by?
Naegleria fowleri
What disease does Naegleria fowleri cause?
Primary amoeboid meningoencephalitis
What is true for infection with Amoeba? (?)
Large nucleus. Large cyst.
Specific for opportunist amoebas? (?)
Big nucleus
Detection of Klossiella:
Sporocysts – Urine:Sodium hydrogencarbonate. Centrifuge. Examine sediment.
Sporoblasts – Basophil staining, bilaminar membrane projections on the surface.
What belongs to Alveolata (meaning ‘with cavities’, group of protists)
Apicomplexa, Ciliophora
Where does the merozoite develop?
Inside schizont
Eimeria (Coccidiosis) imp.
Many questions on Eimeria spp. Refer to lab questions as well
Which statement is not true for the development of Eimeria species?
Schizogony occurs in gametogony. (It occurs in Schizogony)
True: Schizogony is initiated epithelially or sub-epithelially. Sporulated oocysts are more resistant than unsporulated ones. Occurrence of meronts with few merozoites is not characteristic.
Pre-disposing factors to Eimeria:
Young age, intensive (crowded, accelerated keeping), insufficient nutrition (lack of vitamins, protein in the feed), litter (deep), neglected hygienic measures, inter-current infections.
Which Eimeria species occurs extra-intestinally?
E. ninakohyakimovae in Goats’ lymph nodes and gall bladder
E. danoilovi in Ducks. Lesions in cerebellum.
Difference between Isospora and Eimeria spp.?
Only Eimeria has cap, micropyle, and residual bodies.
Location of Eimeria spp.
E. tenella - caecum - haemorrhage E. necatrix - SI - haemorrhage E. brunetti - rectum - haemorrhage E. maxima - mid-SI - moderate patho E. acervulina - duodenum E. mitis - the whole intestinal length -subclinical coccidosis E. mivalti -subclinical coccidosis E. praecox - SI -subclinical coccidosis
Different Eimeria spp. asking for most pathogenic stage:
E. tenella - 2nd Schizont
E. brunetti, E. necratix - 2nd Schizogony
E. brunetti - 2nd Schizogony, 3rd Gametogony
How many Eimeria spp. cause haemorrhagic lesions in small intestine of chicken?
Three (E. necratrix, E. maxima, E. brunetti)
How many Eimeria spp. cause haemorrhagic or fibrinous lesions in the caeca?
Two (E. tenella, E. brunetti)
Which Eimeria in the small intestine does not cause haemorrhages?
Not E. acervulina nor E. mitis
What Eimeria causes haemorrhagic or fibrinous lesions in the caeca?
E. Brunetti
Which Eimeria spp. in chicken is:
Highly pathogenic: E. tenella, E. necratrix
Moderately pathogenic: E. maxima
Less pathogenic: E. acervulina, E.mitis
Which Eimeria causes ladder-like white bands?
E. acervulina
Eimeria acervulina location:
Duodenum (heavier infection extending to the jejunum)
Which Eimeria spp. is complimentary to E. acervulina? (?)
E. mitis maybe, since both cause sub-clinical signs in chicken (less pathogenic)
Location of Eimeria tenella: MCQ
Caecum
Epithelial cells – Lymphocytes – Macrophages – Crypt epithelium
Which is the most pathogenic? E. tenella or E. acervulina?
E. tenella
Which is/are the most pathogenic stage(s) of E. tenella?
2nd schizont
Location of Eimeria maxima: MCQ
Jejunum
Occasionally in the duodenum, ileum
Which Eimeria sp./spp. cause(s) typically coagulation necrosis?
E. brunetti
Which Eimeria sp./spp. have 6-7 day pre-patent period?
E. tenella
E. necatrix
(5 days pre-patent period in E. brunetti, E. maxima)
Which is most probably not found in chicken?
E. duodenalis, E. flavescens
No neurological symptoms?
Eimeria of turkey
Chicken, Turkey, Pigeon, Duck. Duck → Causes cerebellar lesions.
Which Eimeria species does not occur behind the small intestine?
E. meleagridis
Which turkey coccidium is at most forward?
E. meleagrimitis (jejunum, duodenum, ileum)
The most pathogenic turkey coccidium?
E. adenoiedes
E. gallopavonis
E. meleagrimitis
(Not pathogenic – E. meleagridis)
Which one is not found in turkey?
E. duodenalis (found in Pheasant)
What is the characteristic colour of necrotic debris during E. adenoeides coccidiosis? (?)
white
Which one causes catarrhal haemorrhagic inflammation in Pheasant?
E. colchici
Where does Eimeria labbeana and E. columbarum develop?
Pigeon, middle of small intestine
Eimeria labbeana. In which spp. and organ?
Pigeon – Small intestine
Goose kidney coccidium?
E. truncata
Eimeria kotlani is in which species?
Goose - Intestinal coccidiosis (also E. nocens, E. anseris)
Which coccidia has 4 sporocysts with 4 sporozoites in each?
Wenyonella philiplevinei (coccidiosis of duck)
How many Eimeria spp. does not cause haemorrhages in the small intestine?
One – E. anatis no haemorrhages
Haemorrhages in Ducks (3) – Tyzzeria perniciosia, E. danailovi, Wenyonella philiplevinei
Coccidiosis of Horse
E. leuckarti – Small intestine
What characteristic lesion of Horse coccidiosis in small intestine?
Catarrhal-inflammatory changes
Cause of Horse coccidiosis?
E. leuckarti
What type of oocyst is E. leuckarti?
80 um, piriform, (thick, dark brown wall and large micropyle)
Coccidiosis of Cattle
E. zuernii E. bovis E. ellipsoidalis E. alabamensis E. auburnensis
Which Eimeria spp. is highly pathogenic in cattle?
E. zuernii
E. bovis
Which Eimeria spp. is found in cattle?
E. bovis and E. zuernii are the most pathogenic in cattle
Which Eimeria sp. may have a high pathogenicity similar to E. zuernii? (?)
E. alabamensis
According to notes, the following have similar pathogenicity in cattle:
E. zuernii – E. bovis (most)
Sinead Darmanin
E. alabamensis – E. aubernensis E. ellipsoidalis (least)
Coccidiosis of Small Ruminants
Sheep: E. ovinoidalis (most pathogenic) E. bakuensis E. crandallis E. parva E. ahsata
Goat: E. ninakohlyakimovae (most pathogenic) E. arloingi E. christenseni E. caprina
Sheep Eimeria spp. and what it causes in the intestine:
E. ovinoidalis, E. crandallis, E. parva Diffuse hyper-plasia and thickening of the wall of the caecum (occasionally of the colon), with necrosis, roughness, and small haemorrhages on the mucosal surface.
E. baukuensis, (E. arloingi - Goat) Greyish-white, flat/protuberant hyper-plastic nodules. Occasionally 4-7 mm polyp-like growths (enlarged villi) in the posterior small intestine: Nest of gamonts, many oocysts.
Which Eimeria species occurs in Goat?
E. ninakohlyakimovae (occurs extra-intestinally)
Coccidiosis of Rabbit – Liver Coccidiosis
E. stiedai
Which of the highly pathogenic Eimeria species is in right location?
E. flavescens in caecum
Which of the following is correct?
E. irresidua – Jejunum
Rabbit coccidiosis:
Small intestine x3: E. intestinalis E. magna E. irresidua Large intestine x2 E. flavescens E. piriformis
Coccidiosis of the Pig
E. deblicki E. polita E. scabra E. spinosa (non-pathogenic) Isospora suis (pathogenic)
What is not characteristic during Pig coccidiosis?
Haemorrhagic enteritis
Where are the lesions caused by Isospora suis mostly situated?
Jejunum
Which genus has sporulated oocysts with 2 sporocysts?
Isospora
Sporulated Isospora oocysts contain 2 sporocysts, and 4 sporozoites in each, with a wall without micropyle, containing neither oocyst residual body nor Stieda body
Coccidiosis of Carnivores
Dog: Isospora canis I. ohioensis I. burrowsi Cat: Isospora felis I. rivolta
Difference between Isospora and Eimeria?
Only Eimeria has cap, micropyle, and residual bodies.
Difference between Neospora and Isospora?
Isospora do not have microcpyle in wall. Isospora oocysts do not have residual or stieda body.
If Eimeria oocysts are recognised in Dog faeces, then: (?)
Belong to dogs as hosts, no pathological significance Pseudoparasites
If Dog passes Eimeria in faeces (are detectable):
Not diagnostic
Since in carnivores:- Healthy animal may also shed oocysts.
Dog coccidiosis:
Host specific, homoxenous parasites (with paratenic host only!)
Which species does not have Eimeria spp.?
Carnivores (have Isospora spp.)
Locations of Cryptosporidium spp.:
C. parvum - Small intestine (ileum) - Ruminants, rodents, humans
C. muris - Abomasum /
Stomach (primates) - Rodents, rabbits, ruminants, carnivores, humans
C. andersoni - Abomasum / Stomach - Ruminants, humans
Which genus has sporulated oocysts with 4 free sporozoites?
Cryptosporidium
Which genus has sporulated oocysts without sporocysts?
Cryptosporidium
Size of Cryptosporidiosis oocyst?
5-6 (-8 inc. mammalian) Mammalian 5-8 um
What are the characteristics of Cryptosporidium baileyi oocysts?
6-7um, oval
Crpyosporidium infection:
Per os infection. Mainly with water (water-borne). Aerogen via coughing, dust, or spray.
Which form of Cryptosporidiosis has the most severe outcome in mammals?
C. parvum (due to apoptosis)
Cryptosporidium parvum more likely in:
Immunocompromised animals (opportunism) Giardia (concurrent infection)
Cryptosporidium andersoni in:
Gastric glands of bovine abomasum. Older calves.
Which Cryptosporidium sp./spp. occur(s) frequently in post-weaned or older calves? (MCQ)
C. bovis
C. ryanae
C. andersoni
Which is not characteristic of Avian cryptosporidiosis?
Hepatic
Characteristic: Respiratory, intestinal, renal
Cryptosporidium baileyi not in: (location and host)
True: In chicken (location depends on route of infection)
In which location will Cryptosporidium baileyi not establish?
Stomach
Which form of Cryptosporidiosis has the most severe outcome in Broilers?
Respiratory form
In which host does Toxoplasmosis play a large role in abortion?
Sheep (In mid-gestation)
Also small ruminants, humans. Sometimes pigs.
Hammondia hammondii is similar to:
Toxoplasma gondii
Which are the routes of infection of Toxoplasma?
Oral – Via meat containing cysts / sporulated oocysts Galactogenic
Trans-placental
Parenteral
What kind of meat do humans get Toxoplasma from?
Venison, lamb, and pork mainly. Undercooked meat like deer, pork and lamb.
How do humans get Toxoplasma?
Soil work, unwashed vegetables, oocyst in water, contact with cats.
Difference between Neospora and Isospora?
Isospora do not have microcpyle in wall. Isospora oocysts do not have residual or stieda body.
What are potential consequences of Neosporosis in dogs? MCQ
(Neospora is a form of paralysis in dogs, and abortion in cattle) Poly-radiculo-neuritis (ascending form of hind-limb paralysis) Dysphagia
Dermatitis (generalized form is a disseminated form with pol- or pyogranumatous-ulcerative dermatitis)
Neospora caninum of dogs causes: (final and intermediate host)
Poly-radiculo-neurits
When does Neospora caninum cause abortion?
Cows – Abortion between 3rd-7th month of gestation (early foetal death may entail resorption, later
causes mummification, autolysis)
Due to tachyzoites (parasitaemia) of the mother. Neospora is a cause of paralysis in dog and abortion in cattle.
What is the characteristic gestation period of Neosporosis related abortion in cows? (intermediate host)
4-6 months
Neospora hughesi causes:
Equine protozoal myelmoencephalitis (EPM)
Who does Hammondiosis affect?
Final Host: Dog, fox, coyote (H. heydorni and H. triffittae in canids) , cat (H. hammondi) (Carnivores)
Intermediate Host: Ruminants, guinea pigs, mice, deer dogs (Prey species)
Clinical signs of Hammondia spp.:
H. hammondi - Only in intermediate host. Depression, anorexia, myocarditis, death in mouse, rat. Final host no symptoms.
H. heydorni - No clinical signs.
To whom are Hammondia spp. closely related genetically?
Toxoplasma gondii
Hammondiosis causes symptoms in what?
Cat, Dog
Usually sub-clinical in cats. H. heydorni can cause diarrhoea in immuno-compromised dogs.
Which species shed Hammondi cysts?
Cats only, via faeces.
Which species is related to pathological signs in Hammondia?
Mouse – Depression, anorexia, myositis, myocarditis, death.
Besnoitia species are:
Obligatory hetero-xenous (the majority obligatory)
Size of besnoitia cyst?
3- 800 um, visible to the naked eye
What is the direction of spreading bovine Besnoitiosis in Europe?
South-west to east
Besnoitia vector:
Tabanus, Stomoxys (blood-sucking insects transmit mechanically the cystozoites = hetero-xenous)
Where does the Besnoitia cyst occur?
Sclera. Pathognomic. Cysts occur in the sclera (pathognomic), respiratory muscles, genital mucosa.
Endothelium (cystozoites, surrounded by connective tissue reaction). Sclera-derma stage: Dermis, sub-cutaneous tissue (also in the cornea, sclera, conjunctiva, mucosa of respiratory and genital organs, serosal surfaces).
Which statement is not true for Besnoitia besnoiti?
It ́s most important intermediate host is the cat. (Intermediate host is cattle, wild ruminants). True: It can be transmitted by vectors. The cyst is visible to the naked eye. Develops in the endothel.
Which domestic animals have zoonotic Sarcocystis sp./spp.?
Pig, cattle
Pig – S. suihominis Cattle – S. hominis
Ruminants Sarcocystiosis pathogenesis:
Dalmeny disease – General haemorrhages diathesis (petechial and diffuse haemorrhages everywhere)
Haemogregarines characteristics:
Micro- and macro-gamonts develop next to each other
In Klossiella there is:
Free sporocyst to discharge via urine. Sporocyst with 10-15 sporozoites in it.
Which animal is pathogenically affected by Klosseliosis?
Horse (K. equi) and Mouse (K. muris)
Hepatozoon host:
Dog, fox, jackal, (cat)
True for hepatozoon:
Oocyst develops in ticks
Biological vectors – Hard ticks mainly Rhipicephalus sanguineus, R. turanicus, Amblyomma maculatum
Hepatozoon americanum develops in which tissue?
In muscles (myocardium!)
Specific for Hepatozoon americanum:
Schizonts with mutli-lamellar wall (onion-like)
What is the last developmental stage in Hepatozoon canis of dog?
Gamont (appear in the blood 5 weeks PI)
Location of Hepatozoon canis:
Neutrophils, granulocytes, WBCs
What is characteristic of Hepatozoon canis oocysts?
Very large, visible to the naked eye (0.3 – 1 mm)
Which infective form in tick of Hepatozoon canis?
Oocyst
How can canine Hepatozoonosis be diagnosed?
Finding gamonts in the blood (Elliptic gamonts in WBCs; mainly neutrophil granulocytes)
Haemosporinids
Hetero-xenous parasites. Fertilized zygote is motile. No sporocyst, conoid.
Plasmodiosis (Malaria)
Which malaria is crescent shaped?
Malaria falciparum – Its gametocytes have a crescent or banana shape.
Which stage is missing in Plasmodium?
No syzygium nor sporocyst
Plasmodium doesn’t have this?
Sporocyst
What cells are infected with Plasmodium?
MPS, RBC, lymphocytes, and liver.
In Plasmodium species, where does the primer exo-erythrocytic schizogony take place?
Mammals – Liver parenchyma cells
Birds – MPS of skin, then of various organs
Followed by endo-erythrocytic merogony in:
RBCs, within PV, continuing repeatedly and synchronising.
Which Plasmodium causes the appearance of Schüffner dots in red blood cells?
P. ovale and P. vivax
Which Plasmodium species is not pathogenic to humans?
P. simium
Humans – P. falciparum, P. vivax, P. malariae, P. ovale
What is the most important biological vector of Plasmodium gallinaceum (chicken)?
Culex/Aedes mosquitoes – For birds
Anopheles mosquitoes – For mammals
Which isn’t a characteristic of Haemoproteosis?
Lung emphysema
Characteristic: Lung oedema, haemorrhages on the heart, megalo-schizonts in heart
Where does Haemoproetus develop?
Development in the vector for 1-2 weeks
Vectors of Haemoproteus spp.?
Biological vectors Forest flies (Hippoboscidae spp.) Biting midges (Culicoides spp.)
Where does the first schizogony of Haemoproteus spp. take place?
In endothelial cells
Haemoproteus can be detected:
Pigmented gamonts in RBCs (sausage-like, next to…then encircling the nucleus)
Which is correct for Haemoproteus?
Sausage-shaped gamont inside RBCs
Sausage-like in RBCs next to the nucleus (since Haemoproteus spp. are bird protozoa, and their RBCs have a nucleus)
Which Leucocytozoon species occurs in chicken?
L. caulleryi
Which are the vectors of Leucocytozoon species?
Biological vectors:
Blackflies (Simulidae)
Biting midges (Culicoides spp.)
Leucocytozoon first schizogony takes place where?
In liver parenchymal cells (spleen and other organs, depending on spp.)
Which is absent from the lifecycle of Leucocytozoon species?
Sporokinete
Which is the location of Leucocyotzoon sp. don’t usually cause any haemorrhage, necrosis?
Mucous membranes
Cause haemorrhages, necrosis in: Lungs, liver, spleen, kidneys, gall bladder, ovary, oviduct, and muscles.
Piroplasmosis
Piroplasmosis characteristics:
Heteoxenous parasites
No oocyst, conoid (together with Haemosporinids called ‘Aconidasida’)
Breed predisposition to Babesia in Dogs:
Spaniel
Also Doberman, Pekingese, Yorkshire terrier, Irish setter. More resistant – Beagle, Fox terrier
Sub-clinical – German shepherds
Transmission of Babesia:
Via ticks
Which ticks are vector of large Babesia spp?
Eq: Dermancentor marginatus
Bo: Boophilus spp. + Haemaphysalis punctuata
Ca: Dermacentor reticularis
Babesia canis transmitted by Ixodes ricinus and Dermacentor reticulatus?
False – D. reticularis only
Which genus/ genera include(s) tick sp./spp. that is/are vectors of large babesiosis? MCQ
Haemaphysalis
Dermacentor
What transmits horse Babesia?
B. caballi’s vector is Dermacentor marginatus
Mode of Babesia transmission:
Trans-ovarial (Female) Trans-stadial Intra-stadial (Male)
Which is the vector of the zoonotic European Babesiosis?
Ixodes ricinus
Zoonotic babesia = B. divergans = Ixodes ricinus (Babesia vector)
Can humans get Babesia from dogs?
False
Babesia incubation period:
4-21 days
What is the incubation period of canine Babesiosis?
5-20 days
Form of Theileria that occurs in RBCs?
Piroplasm
n.b. Both Theileria and Babesia have piroplasms (merozoite form in the shape of Maltese cross)
What is not characteristic of equine Theileriosis? (Theileria equi, formerly Babesia equi)
Do not see neurological signs.
See haemoglobinuria, haemorrhages, melena, pre-natal infection.
Which Theileria spp. is pathogenic?
Theileria equi (Horse) Theleria annulata (Cattle)
Which is not in South America?
Theliera parva (in East Africa) and Babesia microti (in North America, Europe)
Which Theileria sp. spp. is/are pathogenic?
T. equi T. parva T. lawrencei T. annulata T. hirei
First schizogony of Cytauxzoon felis occurs in:
MPS cells (RES, mostly macrophages)
Vectors of Cytauxzoonosis?
Dermacentor variabilis Amblyomma americanum
Which genus does the vector of Cytauxzoon felis belong to?
Amblyomma
What is primarily responsible for the pathogenic effect of Cytauxzoon felis?
Occlusion of blood vessels by schizonts
Balantidium coli:
Vegetative form 50-150 um (ovoid, vestibulum, cytostome) Cyst 40-60 um (spherical, thick-walled)
(related spp. Buxtonella sulcate; cattle)
What is Blastocytosis similar to?
Genetic diversity in Blastocystosis hominis similar to Cryptosporidium genus.
How does Blastocysta infect?
Opportunistic parasite in humans, in case of diet change that influences the gut flora. Non-invasive. Infection – Faecal-oral route, or waterborne.
What is the smallest in Blastocysta?
Cyst (3-6 um)
Vacuolar form 2-200 um
Into which larger taxonomical category do Blastocystis spp. belong to?
Stramenophila protist
Which is in Alveolate group?
Meaning ‘with cavities’. Group of protists. Ciliates, Apicomplexa, etc.
Alveolata is related to:
Apicomplexan parasites
Microspora
Homo-xenous, obligatory intra-cellular parasites (no mitochondria)
In the spore: One polar body, spiral duct and sproplasm
Genera: Encephalitzoon, Enterocytozoon (hu), Nosema (bee)
What is the approximate size of Encephalitozoon cuniculi spores?
2um (1.5-2 um)
In what can Encephalitozoon spores be found? MCQ
Urine
Renal tubular cells
Kidney
Brain
Staining Encephalitozoon cuniculi:
Ziehl Nielsen
India ink
It is more a fox symptom than a dog in case of Encephalitozoonosis:
thickened arterial wall, smaller diameter
Which clinical sign is not characteristic of Encephalitozoonosis?
Posterior paralysis
Effects kidney and brain. See neurological, ocular, and renal signs.
What is characteristic effect of the pathology of Encephalitozoonosis?
Chronic interstitial nephritis
How can infection with Encephalitozoon cuniculi be aquired?
Prenatally
Horizontal via urine, prey animals, water OR Vetrical trans-placental
Representatives of which orders are primarily affected by Encephalitozoon cuniculi?
Lagomorpha, Carnivora
