q & a (protozoa)
TRANSCRIPT
PROTOZOA
1. Subphylum: Sarcomastigophora (Honigber and Balamuth, 1963)
1.1. Flagellates
1.2. Hemoflagellates1.2.1. Hemoflagellates1.2.2. Mucosoflagellates
1.3. Amoebas1.3.1. Intestinal Amoebas
2. Subphylum: Ciliophora (Doflein, 1910)
2.1. Balantidum coli
2.2. Symbiotic ciliates
3. Subphylum: Apicomplexa (Levine, 1970)
3.1. Coccidians3.1.1. Eimeria3.2.1. Isospora3.3.1. Cryptosporidium3.4.1. Toxoplasma3.5.1. Neospora3.6.1. Hammondia 3.7.1. Sarcocystis
3.2. Equine Protozoal Myeloencephalitis Organism 3.2.1. Besnotia 3.2.2. Klossiella 3.2.2. Hepatozoon
PROTOZOA Phylum: Sarcomastigophora
Subphylum: Mastigophora Class: Zoomastigophora
Order: KinotoplastideaFamily: TryponosomatidaeFamily: Cryptobiidae
Order: TrichomonadidaFamily: TrichomonadidaeFamily:
MonocercomonadidaeFamily: RetortamonadidaeFamily: CochlosomatidaeFamily: Hexamitidae
Subphylum: Sarcodina Family: Endamoebidae Family: Vahlkampfidae Family: Hartmannellidae
Phylum: ApicomplexaClass: SporozoeaSubclass: Coccidia
Order: EucoccidiideaFamily: EimeriidaeFamily:
SarcocystidaeFamily:
HaemogregarinidaeSuborder: Haemisporina
Family:Plasmodiidae
Subclass: PiroplasmaOrder: Piroplasmida
Family: BabesiidaeFamily: Thileriidae
Phylum: Microspora
Class: Microsporea
Phylum: Myxozoa
Class: Myxosporea
Phylum: Ciliophora
Class: Kinetofragminophorea
Order: Rickettsiales
INTRODUCTION OF
PROTOZOA
1. General Characteristics
1.1. Unicellular animals
1.2. Do not have a chlorophyll - containing chromatopores
1.3. Mode of nutrition is holozoic
1.4. Have a well-defined nucleus
1.5. Do not have a rigid cell wall1.5.1. Marked variation in size and shape
2. Nucleus
2.1. Eukaryotic (protozoa) 2.1.1 Nucleus enclosed in a membrane
2.2. Prokaryotic (bacteria) 2.2.1. Nucleus dispersed in cytoplasm
2.3. Number of nucleus in protozoa is usually one
2.4. Others have more than one
2.5. Types of nucleus2.5.1. Vesicular nucleus
2.5.1.1. Has nuclear membrane w/c bounds the nucleoplasm in which, lying more or less central, is an intranuclear body, the endosome (or kayrosome) or nucleolus
2.5.1.1.1.Endosome is devoid of DNA
2.5.1.1.2.Nucleolus has DNA
2.5.1.1.3. Seen in Mastigophora and Sarcodina
3. Cytoplasm
3.1. Extranuclear part of the protozoan cell3.2. Has 2 parts: Outer ectoplasm & Inner endoplasm
4. Locomotion
4.1. Movement is by gliding
4.2. Locomotory organelles4.2.1. Pseudopodia
4.2.1.1. Used by amoeba-like organisms4.2.1.2. Temporary; formed when required &
retracted when not needed
5. Organelles of nutrition
5.1. Pseudopodia5.1.1. Organelles for amoeba-like organisms
5.2. Cytosome5.2.1. An opening through w/c food particles are
engulfed & passed to food vacuoles5.2.2. In ciliates the cytosome may be lined with cilia
w/c further assist in ingestion of food
5.3. Food vacuole5.3.1. Occurs in cytoplasm & contains particulate
material in various stages of digestion
6. Nutrition of Protozoa
6.1. Holophytic 6.1.1. Forms which possess chlorophyll6.1.1.2. None of this form of veterinary importance
6.2. Holozoic6.2.1. Utilizes preformed food 6.2.2. Food ingested by pseudopodia or through a
cytosome & passes to a food vacuole for digestion
6.3. Saprozoic6.3.1. Absorbs nutrients through the body wall, these
being utilized directly by the organisms
7. Excretion of waste products
7.1. Occurs directly through the body wall
7.2. By means of contractile vacuoles which periodically discharge waste material through the body wall or, in a few instances, through the anal pore
8. Reproduction of Protozoa
8.1. Asexual
8.1.1. Binary fission8.1.1.1. Commonest form of asexual reproduction8.1.1.2. Two daughter cells result from a
“parent” cell8.1.1.3. Division being along the longitudinal
axis8.1.1.3.1. Ciliates divide along
the transverse axis8.1.1.4. Nucleus divides first and cytoplasmic
division follows
8.1.2. Schizogany8.1.2.1. nucleus divides several times before the cytoplasm does8.1.2.2. In some forms the nucleus of parent cell divides mitotically into a large number of nuclear bodies, each of which becomes associated with a portion of the cytoplasm & little or nothing of the parent cell remains except the greatly expanded limiting membrane
8.1.2.2.1. Dividing form is known as schizont8.1.2.2.2. Daughter forms are merozoites
8.1.3. Budding8.1.3.1. Two or many daughter forms are produced by the
“parent” cell.8.1.3.2. There is usually an unequal fragmentation of the
nucleus & cytoplasm8.1.3.3. The budded forms are separated off and then grow
to full size
8.1.4. Endopolyogeny8.1.4.1. This is an internal budding whereby new progeny is
formed within the parent cell8.1.4.2. Endodyogeny is a simplified form of endopolyogeny,
resulting in 2 daughter cells8.1.4.3. Seeen in forms such as Toxoplasma & Sarcocystis
8.1.5. Sporogony8.1.4.1. follows syngamy
8.2. Sexual8.2.1. Conjugation
8.2.1.1. Occurs in ciliate8.2.1.2. Two organisms pair and exchange nuclear material (from the micronucleus)8.2.1.3. Individuals separate & nuclear reorganization takes place
8.2.2. Syngamy8.2.2.1. Two gametes fuse to form a zygote8.2.2.2. Males gamete is a microgamete
8.2.2.2.1. Produce from microgamonts or microgametocyte8.2.2.3. Female gamete is a macrogamete
8.2.2.3.1. Produce from macrogamonts or macrogametocytes
8.2.3. Gametogony8.2.3.1. Process of gamete formation8.2.3.2. Isogamy - gametes are similar in size8.2.3.3. Anisogmy - gametes of different sizes
Life Cycle of Trypanosoma
ParasitesIntermediate Host (IH)/ Stage In IH
Cyclical Development occurs in IH
Final Host
Stage in w/c multiplication occurs in Final Host
Locali-zation
Trypanosoma vivax1
Glossina spp./MT Proboscis Cattle, sheep, goat, buffalo, camels antelope6 (long forms)
T
Trypanosoma uniforme1
Glossina spp/MT Proboscis Cattle, sheep, goat, antelope (short forms)
T
Trypanosoma congolense2
Glossina spp/MT Proboscis & midgut
All domestic animals & wild game animals: antelope, zebra, warthog, elephant (short forms)
T
Trypanosoma dimorphon2
Glossina spp/MT Proboscis & midgut
Cattle, sheep, horses, pigs (long forms)
T
Trypanosoma simiae2
Glossina spp/MT Proboscis & midgut
Cattle, horses, pig (polymorphic)
T
Trypanosoma suis3
Glossina spp/MT Midgut & salivary glands
Pigs (short forms)
T
ParasitesIntermediate Host (IH)/ Stage In IH
Cyclical Development occurs in IH
Final Host
Stage in w/c multiplication occurs in Final Host
Locali-zation
Trypanosoma brucei4
Glossina spp/MT Midgut & salivary glands
Domestic animals & antelopes (polymorphic)
T Intra-cellular tissues fluid
Trypanosoma rhodesiensi4
Glossina spp/MT Midgut & salivary glands
Man & antelopes (polymorphic)
T
Trypanosoma gambiense4
Glossina spp/MT Midgut & salivary glands
Man (polymorphic)
T Lymph nodes & CNS
Trypanosoma evansi5
Stomoxys, Liperosa, Tabanus
Mechanical transmission
Cattle, camels, equines, dogs, etc
T
Trypanosoma equinum5
Trypanosoma equiperdum5
Mechanical by coitus
Equines (polymorphism inconstant)
1 Section Salivaria, Subgenus Duttonella; 2Salivaria, Subgenus Nannomonas; 3Salivaria, Subgenus Pscnomonas; 4Salivaria, Subgenus Trypanozoon (cyclically transmitted); 5Salivaria, Subgenus Trypanozoon (mechanically transmitted; 6Reservoir host ; MT= Metacyclic Trypomatigote; T = Trypomastigote
ParasitesIntermediate
Host (IH)/ Stage In IH
Cyclical Development occurs in IH
Final Host
Stage in w/c multiplication
occurs in Final Host
Locali-zation
Trypanosoma theileri1
Tabanus & Haematopota
Posterior station
Bovine esp Cattle
Trypomastigote & epimastigote
Lymph nodes & inner organs
Trypanosoma melophagium1
Melophagus ovinus/ metacyclic trypomastigote
Posterior station
sheep
Trypanosoma thedori1
Hippoboscid fly Lipoptena caprina/ metacyclic trypomastigote
Posterior station
goats
Trypanosoma lewisi2
Ceratophyllus fasciatus/ metacyclic trypomastigote
Posterior station
rats
Trypanosoma nabiasi2
Spilopsylla cuniculi/ metacyclic trypomastigote
Posterior station
rabbit
Trypanosoma rangeli2
Triatomid bugs/ metacyclic trypomastigote
Posterior station
Man, dog, cat, opossum, monkey, man, dog & cat
ParasitesIntermediate
Host (IH)/ Stage In IH
Cyclical Development occurs in IH
Final Host
Stage in w/c multiplication
occurs in Final Host
Locali-zation
Trypanosoma cruzi3
Ruduviidae/ metacyclic trypomastigote
Posterior station/ monomorphic
Dogs, cats, pigs, foxes, ferrets, squirrels, & monkeys & man
TrypomastigoteAmasstigote – dividing form
Heart muscles & Visceral organs
Cryptobia borreli
Leeches/metacyclic trypomastigote
Fresh water fishes (rainbow & brown trouts, coho & king salmon)
trypomastigote blood
Cryptobia brachialis
Leeches/metacyclic trypomastigote
Marine fishes trypomastigote Gill filaments
Cryptobia cyprini
Leeches/metacyclic trypomastigote
Carp, golfish trypomastigote blood
1 Section Stercoraria, Subgenus Megatrypanum; 2Stercoraria, Subgenus Herpetosoma; 3Stercoraria, Subgenus Schizotrypanum
Life Cycle of Leishmania
ParasitesIntermediate
Host (IH)/ Stage In IH
Cyclical Development occurs in IH
Final Host
Stage in w/c multiplication
occurs in Final Host
Locali-zation
Leishmania donovani1
Phlebotomus/ promastigote
midgut Human, cause of Kala-azar. Dog & roents serves as reservoir hosts
amastigote
Leishmania infantum1
Phlebotomus chinensis/ promastigote
midgut Man. Dog, fox, jackal, porcupines as reservoir hosts
amastigote
Leishmania chagasi1
Phlebotomus chinensis/ promastigote
midgut Human & dogs.Dogs & crab-eating fox reservoir hosts
amastigoe Liver, spleen bone marrow
Leishmania tropica2
Phlebotomus/ promastigote
midgut Man & dogs. Gerbils & rodents are reservoirs
amastigoe Macrophages, endothelial cells, skin lymph nodes
ParasitesIntermediate
Host (IH)/ Stage In IH
Cyclical Development occurs in IH
Final Host
Stage in w/c multiplication
occurs in Final Host
Locali-zation
Leishmania aethiopica2
Phlebotomus longipes/ promastigote
midgut Man. Reservoir host is rock hyraxes
amastigoe Skin
Leishmania majori2
Phlebotomus papatasi/ promastigote
midgut Wild mammals & man. Tree rat, pocket mouse & cotton & vesper rats are reservoirs
amastigoe Skin
Leishmania mexicana mexicana3
Lutzomyia olmeca/ promastigote
midgut Dogs, cats, pigs, foxes, ferrets, squirrels, & monkeys & man
amastigoe Ear
Leishmania mexicana amazonensis3
Lutzomyia flaviscutellata/ promastigote
midgut Rodents. Rarely infects man. Rodents reservoirs
amastigoe
Leishmania braziliensis braziliensis4
Lutzomyia paraensis, Lut. wellcomei/ promastigote
midgut Forest rodents are reservoir hosts. Man
amastigoe Skin mucous membrane
ParasitesIntermediate
Host (IH)/ Stage In IH
Cyclical Development occurs in IH
Final Host
Stage in w/c multiplication
occurs in Final Host
Locali-zation
Leishmania braziliensis guyanensis4
Lutzomyia anduzei/ promastigote
midgut Dog & man amastigoe Skin
Leishmania braziliensis panamensis4
Lutzomyia trapidoi/ promastigote
midgut Sloths, porcupines & rodents are reservoirs
amastigoe Skin
Leishmania peruviana4
Lutzomyia verrucarm & Lut, peruensis/ promastigote
midgut Dog is reservoir host
amastigoe Skin
1Cause of Visceral leishmaniasis; 2Old World Cutaneous leishmaniasis; 3American Cutaneous leishmaniasis or ‘Leishmania mexican complex; 4’Leishmania braziliensis complex’
Morphology & Life Cycle of Protozoa
Parasite Morphology Multiplication Localization Host
Tritrichomonas foetus
Pear-shaped, w/ 3 anterior flagella, 1 post. flagellum, undulating membrane extends posteriorly
Longitudinal binary fission
Bull – preputial cavity; cow – vagina
Cattle. May occur in zebu, pig, horse & deer
Tritrichomonas suis
Pyriform shaped w/ 3 ant. Flagella, undulating membrane runs entire length of body
Binary fission Stomach, nasal passages, cecum & small intestine
pig
Tritrichomonas equi
Pyriform-shaped w/ 3 anterior flagella & undulating membrane
Binary fission Cecum & colon horse
Tritrichomonas eberthi
Crescent-shaped w/ 3 anterior flagella & undulating membrane
Binary fission ceca Chicken, turkey & duck
Tritrichomonas enteritis
Do do Cecum & Colon
Ox & zebu
Parasite Morphology Multiplication Localization Host
Tritrichomonas muris
Do do Cecum & colon Rats, mouse, hamster, wild rodents
Tritrichomonas minuta
Do do Cecum & colon Rat, house mouse & golden hamsters
Tritrichomonas caviae
Do do Cecum & colon Guinea pig
Trichomonas gallinae
Pyriform-shaped w/ 4 anterior flagella & undulating membrane, no post. Flagellum
do Upper digestive tract
Pigeon, turkey, dove, chicken, hawk, eagle
Trichomonas phasioni
Do do intestine pheasant
Trichomonas vaginalis
Do do Vagina, prostate & urethra
man
Trichomonas tenax
Do do Mouth Man & monkey
Trichomitus rotunda
d0 do Colon & cecum pigs
Parasite Morphology Multiplication Localization Host
Trichomitus wenyoni
Do do Colon & cecum Rats, mice, hamster & rhesus monkeys
Tetratrichomonas buttreyi
Do do Colon & cecum pig
Tetratrichomonas gallinarum
Pear-shaped w/ 4 ant flagella & 1 posterior flagellum
do Lower digestive tract & liver
Turkey, guinea fowl, quail & fowl
Tetratrichomonas ovis
Pyriform-shaped w/ 4 ant. Flagella, undulating membrane & 1 trailing flagellum
do cecum sheep
Tetratrichomonas pavlovi
do do cecum Calves
Tetratrichomonas microti
do do cecum Rat, mouse, vole hamster, rodents
Pentatrichomonas hominis
Ova to pear-shaped w/ 5 free ant flagella, undulating membrane
do intestine Man & primates
Parasite Morphology Infection /Multiplication
Localization/Pathogenicity
Host
Monocercomonas ruminantium
Pyriform-shaped w/ 3 anterior flagella, a post flagella , no undulating membrane
binaryfission Rumen cattle
MonocercomonasPistillum & M. minuta
Do binaryfission Cecum (non-pathogenic)
Guinea pig
Histomonas meleagridis
Pleomorphic, has 3 flagella
Stages: invasive stage – cecal &
liver lesions vegetative
stage – center of lesion resistance
stage Infection: ingestion of
embryonated eggs of
cecal worm
Ingestion ofEmbryonatedeggs of ceca wormBinary fission
Ceca (primary) & liverCause of blackhead in turkeys
Turkey, chicken, peafowl, pheasant, guinea-fowl
Parasite Morphology Infection /Multiplication
Localization /Pathogenicity
Host
Parahistomonas wenrichi
Similar to histomonas, but has 4 flagella
Ingestion ofEmbryonatedeggs of ceca wormBinary fission
Ceca (non-pathogenic)
Gallinaceous birds, chiefly pheasant
Chilomitus caviae
Elongate body, 4 anterior flagella
Binary fission Cecum (non-pathogenic)
Guinea pig
Hexamastix robustus & H. caviae
Pyriform, has 6 flagella one of which is trailing
Binary fission Cecum (non-pathogenic)
Guinea pig
Enteromonas hominis
Pyriform or spherical, has 3 flagella & one trailing flagellum
Binary fission cecum Man, primates, hamster, rat & rabbits
Enteromonas suis
Do do do pig
Ebteromonas caviae
Do do do Guinea pig
Parasite Morphology Infection /Multiplication
Localization /Pathogenicity
Host
Costia necatrix & C. pyriformis
Ovoid to pyriform, has 4 flagella (2 short & 2
long)
do skin Fresh-water Fish
Cochlosoma anatis
Oval body which is broad anteriorly & narrow posteriorly, has 6 flagella
do Posterior large intestine & ceca (catarrhal enteritis)
Domestic & wild ducks
Hexamita meleagridis
Pear-shaped, 2 nuclei, has 6 anteior & 2 posterior flagella
Longitudinal binary fission & invasive form, which penetrated epithelialcells, schizogony
Duodenum & small intestine (catarrhal enteritis)
Turkey, quail, partridge, pheasant, chicken
Parasite Morphology Infection /Multiplication
Localization /Pathogenicity
Host
Hexamita columbae
do do Small intestine (catarrhal enteritis)
pigeon
Hexamita muris do do Posterior intestine & ceca (enteritis)
Rats, mouse & hamsters
Hexamita pitheci do do Large intestine Rhesus monkey
Hexamita salmonis
do do intestine Goldfish, salmonids
Hexamita intestinalis
pyriform do Intestine (acute catarrhal enteritis
Fresh water fishes
Giardia lamblia Pear-shaped which has been cut in half longitudinally
do Duodenum & other parts of small intestine
Monkeys, pigs, budgerigars. Man (colon).
Parasite Morphology Infection /Multiplication
Localization /Pathogenicity
Host
Giardia canis do do Duodenum & jejunum
dog
Giardia cati do do Small intestine (non-pathogenic)
cat
Giardia chincillae do Small intestine & duodenum (severe blood-stained diarrhea)
chinchilla
Giardia bovis do do Small intestine ox
Giardia muris do do do mouse
Entamoeba histolytica
w/ quadrinucleate cyst moved by pseudopodia
do (cystic form
occurs in vertebrate hosts)
Intestine (amoebic dysentery of man)
Man, monkey, dog, cat, rat & pig. Experimentally rat, mouse, guinea-pig & rabbit
Parasite Morphology Infection /Multiplication
Localization /Pathogenicity
Host
Entamoeba coli do do Cecum & colon (non-pathogenic)
Man & monkey
Entamoeba gingivalis
do do Mouth & gingival tissue around teeth (harmless)
Man & primates
Entamoeba canibuccalis
do do mouth Dogs & cats
Entamoeba equibuccalis
do do mouth horses
Entamoeba suigingivalis
do do mouth pig
Entamoeba invadens
do do Intestine & liver (amoebiasis)
Reptiles, lizards & snakes
Acanthomoeba spp.
do do Lungs (fatal gangrenous pneumonia)
bull
Q & A (PROTOZOA)
1. The following are the morphological characteristics of protozoa except:
a. Unicellular animalsb. have a chlorophyll-containing
chromatoporesc. mode of nutrition is holozoicd. have a well-defined nucleuse do not have a rigid cell wall
Ans: (b ) protozoas do not have chlorophyll
2. The following are characterizes of the nucleus of protozoa except?
a. nucleus is eukaryoticb. nucleus is prokaryoticc. number of nucleus is usually 1 or more than oned. may be vesicular or compacte. none of the above
Ans: (b ) prokaryotic nucleus, which is dispersed in cytoplasm, is that of bacteria; ukaryotic nucleus, which is enclosed in a membrane, is that of protozoa; some protozoa usually have 1 others have more than 1; vesicular nucleus , exemplified by Mastigophora, and Sarcodina; and compact nucleus, exemplified by ciliates as macronucleus, are nuclei of protozoa
a. pseudopodiab. flagellac. cliliad. undulipodiae. all of the above
3. Which of the following is a locomotory organelle or protozoa?
Ans: (e ) Pseudopodia are amoeba-like, which are formed when required and retracted when not required; flagella are whip-like structures, which may be attached to the body of protozoa by an undulating membrane; cilia are fine, short, flagella-like structures; and undulipodia are term for both flagella & cilia
4. The following are the types of protozoa according to forms of nutrition except:
a. holophyticb. holozoicc. zaprozoicd. cytosome
Ans: (d ) cytosome is a nutrition organelle of protozoa. The other choices are the forms of nutrition: holophytic is a form which possesses chlorophyll ; holozoic is form which utilizes preformed food but has to digest it in food vacuole before the food can be utilized; zaprozoic is a form which utilizes preformed food that is already utilizable
Ans: (d ) cytosome is an opening through which food particles are engulfed. It is lined with cilia. Other choices: pseudopodia are amoeba-like movement; cilia are fine structures used for engulfing of food; and food vacuole is for enzymatic disgestion.
5. Which of the following nutrition organelles of protozoa that is an opening through which food particles are ingested?
a. pseudopodiab. ciliac. food vacuoled. cytosomee. all of the above
6. Which of the following asexual reproductions of protozoa that is characterized by multiple divisions of the nucleus?
a. binary fissionb. schizogonyc. buddingd. Endopolyogenye. Sporogony
Ans: (b ) Schizogany is asexual reproduction of protozoa in which the nucleus divides several times before the cytoplasm does, resulting in formation of multiple daughter cells. The dividing form is known as schizont and the daughter form is called merozoites. Other choices: binary fission is one in which parent cell divides along its longitudinal axis, resulting in formation of only 2 daughter cells; budding is one in there is unequal fragmentation of nucleus an cytoplasm, resulting in formation of buds. Usually 2 or more buds are produced and separated off and then grow to full size; endopologeny is an internal budding whereby new progeny is formed within the parent cell. Endodyogeny is a simplified form of endopolyogeny, resulting in 2 daughter cells; and sporogony is characterized by formation of spores (sporozoites)
7. Which of the following is a sexual reproduction of protozoa in which there is gamete formation?
a. conjugationb. syngamyc. gametogonyd. endopolyogenye. Sporogony
Ans: (c ) gametogony is a sexual reproduction in which there formation of male and female gametes. Other choices: conjugation & syngamy are sexual reproduction, in the former two organisms pair & exchange nuclear materials and in the latter the male and female gametes fuse to form a zygote. The other two (endopolyogeny & sporogony are asexual reproduction
8. The following are associated with gametes formation except:
a. microgametesb. macrogametec. isogamyd. anisogamye. syngamy
Ans: (e ) syngamy is a sexual process of reproduction. The other choices: microgametes are small & are male game; macrogametes are big and are female gametes; and isogamy & anisogamy are gametes of similar and different sizes, respectively.
9. The following are stages of development of Family Trypanosomatidae except:
a. Trypomastigoteb. Epimastigotec. Promastigoted. Amastigotee. Leptomonas
Ans:(e ) Leptomonas is a genera of the family, the members of which are found in invertebrates. The other choices are stages of development of family Trypanosomatidae: Trypomastigote (trypanosome) is blade-like w/ kinetoplast posterior to the nucleus & usually near the posterior extremity, undulating membrane well developed & a free flagellum present; Epimastigote stage (crithridial) is blade-like, kinetoplast lies anterior to the nucleus, undulating membrane short & a free flagellum present; Promastigote (leptomonad) is blade-like w/ kinetoplast at the anterior tip of body, no undulating membrane & a membrane & flagellum absent.
10. The following species of Trypanosoma belong to anterior station except:
a. Trypanosoma theilerib. Trypanosoma lewisic. Trypanosoma theodorid. Trypanosoma cruzie. Trypanosoma vivax
Ans: (e ) Trypanosoma vivax belongs to Salivaria (anterior station form), subgenus Duttonella. The rest belong to Stercoraria (posterior station forms)
11. The following trypanosomes are transmitted mechanically except:
a. Trypanosoma evansib. Trypanosoma equinumc. Trypanosoma equiperdumd. Trypanosoma brucei
Ans: (d ) Trypanosoma brucei is transmitted cyclically, which means that the parasite undergoes cyclical development in an arthropod intermediate host. The other choices are transmitted mechanically, meaning the trypanosome does not undergo development inside an arthropod host. T. evansi is transmitted by biting lice such as Tabanus, Stomoxys & Lyperosia. T. equinum is transmitted mechanically by biting insects. T. equiperdum is transmitted mechanically by
Ans: (a ) trypomastigote is the form of T. evansi found in a fly
12. What developmental stage of Trypanosoma evansi is transmitted by Stomoxys or Tabanus to
animal host?
a. Trypomastigoteb. Epimastigotec. Promastigoted. Amastigotee. Leptomonas
a. 8-9 minutesb. 9-10 minutesc. 10-15 minutesd. 15-18 minutese. 18-20 minutes
13. Trypanosoma evansi does not survive in the proboscis of a fly for how long?
Ans: (c ) trypanosomes do not survive for more than 10-15 minutes in the proboscis of an insect
14. Concerning the multiplication of trypanosomes, in which part of the body of does division
commence?
a. nucleusb. cytoplasmc. kinetoplastd. flagellae. undulating membrane
Ans: (c ) No sexual process has been observed in the life cycle of trypanosomes & multiplication is by binary or multiple fission. Division commences at the kinetoplast followed by nucleus & then the cytoplasm.
15. Concerning polymorphic forms of trypanosomes, what form is capable of division in cyclically transmitted?
a. long formb. intermediate formc. stumpy formd. short forme. slender form
Ans: (e ) In cyclically transmitted strain of trypanosome only the slender form is capable of division
16. Concerning cyclical transmission of trypanosome, which of the following forms is capable of infecting Glossina spp.?
a. long formb. intermediate formc. stumpy formd. short forme. slender form
Ans: (c ) stumpy form of trypanosome cyclically transmitted is capable of infectingGlossina spp.
17. Trypanosoma uniforme is pathogenic to the following vertebrate hosts except:
a. cattleb. sheepc. anteloped. goats
Ans: (d ) T. uniforme infects cattle, sheep, goats & antelopes but is non-pathogenic for goats
18. The following game animals act as reservoir hosts for Trypanosoma congolense except:
a. antelopeb. zebrac. warthogd. elephante. cattle
Ans: (e ) the trypanosome is the principal cause of the disease ‘nagana’ in cattle.
19. Which of the following animals is Trypanosoma simiae highly pathogenic & is transmitted mechanically by Stomoxys & Tabanus?
a. warthogb. cattlec. horsed. pige. camels
Ans: (d ) The trypanosome is highly pathogenic in both camels & pigs. Although it is transmitted cyclically by Glossina spp., in pig the protozoa is transmitted mechanically by Tabanus & Stomoxys. In Warthog, which serves as a natural host of the parasite, cattle, & horse the organism is transmitted cyclically by Glossina & it non-pathogenic
20. Which of the following animals serves as reservoir hosts of Trypanosoma evansi for equines?
a. cat & dogb. camel & elephantc. Rabbits & ratsd. buffalo & cattlee. pig & guinea pigs
Ans: (d ) cattle & buffalo are considered to be the main reservoirs of the infection for equines
21 Which of the following may serve as a reservoir host of Trypanosoma equinum for the equine
infection?
a. dogsb. cattlec. Sheepd. goatse. capybara (Hydrochoerus capybara)
Ans: (e ) Capybara serves as a reservoir host of T. equinum for horses. Dogs, cattle, sheep & goats in that order, can be affected by the organism.
22. Which of the following animalsis resistant to Trypanosoma equiperdum infection?
a. cattleb. horsesc. donkeysd. dogse. rats
Ans: (a ) cattle is resistant to T. equiperdum. Horese & donkeys are highly infected; dog may be infected with some strains; & rats are susceptible
23. Which of the following is the principal reservoir hosts of Trypanosoma cruzi in South
American?a. dogs & catsb. pigs & foxesc. armadillo & opossumd. squirrels & ferrete. foxes & monkeys
Ans: (c ) Armadillo & opossum are the principal reservoirs of T. cruzi in South America. Other hosts are may be infected & serve as reservoir hosts in other countries
24. The following are the mode of transmission of Tritrichomonas foetus in cow except:
a. coitusb. artificial inseminationc. gynecological examination
d. direct contact
Ans: (d ) Choices “a”, ‘b” and “c” are the mode of transmission of Tritrichomonas foetus