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Protozoa 1
Fichas del conjunto (177)
- 1On what scale are protozoa measured?Microns
- 2Does coccidiosis have a single causal organism?No - broad range of causal organisms
- 3What are the 3 types of parasitic protozoal infection?Enteric pathogens
Haemoparasites
Systemic pathogens - 4Do enteric protozoa have direct or indirect life cycles?Both
- 5Give 2 routes of transmission of enteric protozoaWater borne
Soil transmitted - 6Do haemoparasitic protozoa have direct or indirect life cycles?Indirect
- 7What is the route of transmission of haemoparasites?Vector-borne
- 8Give 2 symptoms caused by haemoparasitesFever
Anaemia - 9What are systemic protozoa?Not limited to GI or circulatory system
- 10What are the 3 phyla that parasitic protozoa belong to?Phylum sarcomastigophora
Phylum ciliophora
Phylum apicomplexa - 11What are the 2 sub-phyla within phylum sarcomastigophora?Subphylum sarcodina
Subphylum mastigophora - 12Which group is included within the sarcodina?Amoebae
- 13How do sarcodina move?Processes or pseudopodia
- 14How do mastigophora move?Flagella
- 15How do ciliophora move?Cilia
- 16How do apicomplexa move?Body flexion
- 17What is unusual about the phylum apicomplexa?All are parasitic
- 18What is the function of the apical complex?Invasion of host cells
- 19What are the 2 divisions of apicomplexa?Coccidia
Piroplasms - 20What is the difference between coccidia and piroplasms?Coccidia usually enteric
Piroplasms vector borne - 21Give 6 examples of coccidiaEimeria
Toxoplasma
Neospora
Cryptosporidium
Isospora
Sarcocystitis - 22Give 2 examples of piroplasmsBabesia
Theileria - 23Give 5 examples of flagellatesLeishmania
Trichomonas
Trypanosoma
Giardia
Histomonas - 24Give an example of a pathogenic ciliateBalantidium
- 25When can ciliate protozoa be non-pathogenic?Some are part of the normal commensal flora in the rumen
- 26Define definitive hostOne in which a parasite reaches maturity and usually reproduces sexually
- 27Define intermediate hostOne in which a parasite develops but does not reach maturity or carry out sexual reproduction
- 28Define vectorIntermediate host that carries and transmits developmental stages to another host
- 29What is meant by a direct life cycle?Only definitive host required
- 30What is meant by an indirect life cycle?Requires both definitive and intermediate hosts
- 31What is meant by a vector-borne life cycle?Requires both definitive host and intermediate host vector
- 32What are Coccidia?A group containing many apicomplexan parasites
- 33What is the term for the active, motile stage of a coccidian parasite?Zoite
- 34What is produced by sexual reproduction in coccidia?Oocysts
- 35Give 4 structural components of the apical complexRhoptries
Microneme
Polar ring
Conoid - 36What is the first stage of apicomplexa entry into host cell?Receptor detects host cell
- 37What is the second stage of apicomplexa entry into host cell?Re-orientation so apical complex is in contact with host cell
- 38What is the third stage of apicomplexa entry into host cell?Apical complex forms parasitic vacuole
- 39What is the final stage of apicomplexa entry into host cell?Motile part of apical complex allows protozoa to enter cell within parasitic vacuole
- 40What is unusual about the asexual reproduction of apicomplexa?Asynchrony between nuclear division and division of cytoplasm
Causes formation of intermediate multinuclear phases - 41What is the term for this form of asexual reproduction in the apicomplexa?Schizogony
- 42What are schizons?Multinuclear stages of apicomplexa
- 43Describe the basic coccidian life cycleHost infected by ingesting infective oocysts
One or more asexual cycles of schizogony
Sexual cycles via gametes fusing to produce oocysts
Oocysts sporulate in environment so become infective - 44What is the term for the individual units that burst from host cells in asexual reproduction and can infect other cells?Merozoites
- 45Which cells are infected by coccidia?Intestinal epithelial cells
- 46What are the male and female forms of gamete in protozoa?Microgamete = male form
Macrogamete = female form - 47Describe the structure of sporulated coccidian oocystsEach oocyst contains 4 sporocysts
2 sporozoites within each sporocyst - 48What process produces merozoites?Schizogony (asexual reproduction)
- 49What process produces sporozoites?Sporulation of oocysts
- 50Give 2 examples of protozoa that can cause coccidiosisEimeria
Iospora - 51In which livestock animal is Eimeria most important?Poultry
- 52Does Eimeria have a direct or indirect life cycle?Direct
- 53Describe the life cycle of EimeriaOocyst ingested and sporozoites released
Sporozoites enter epithelial cells of gut
Several cycles of schizogony releasing merozoites
Some merozoites form microgametes and macrogametes
Sexual reproduction = oocyst
Oocyst sporulates in environment - 54What is the pre-patent period for Eimeria?84-138 hours
- 55Give 3 parasite-related factors that affect the severity of coccidiosisParasite species
Infection of deep or superficial cell layers
Infection of distal or proximal parts of the gut - 56Give 3 host factors that affect the severity of coccidiosisAge
Immunity
Density of infection - 57Why are young animals more susceptible to coccidiosis?Acquired immunity is good
- 58Give 3 environmental conditions required for sporulation of coccidia oocystsWarmth
Humidity
Oxygen - 59Why can intensive housing increase the incidence of coccidia?High host density
- 60How long can infective oocysts persist in the environment?Months or even years
- 61What is the pathology caused by E. tenella in poultry?Inflammation and haemorrhage in caecum
- 62Which Eimeria species infects poultry?E. tenella
- 63Which 2 Eimeria species infect cattle?E. bovis
E. zuernii - 64Which 2 Eimeria species infect sheep and goats?E. crandallis
E. ovinoidallis - 65What is the location of Eimeria in poultry?Caeca
- 66What is the location of Eimeria in cattle?Caecum and colon
- 67What is the location of Eimeria in sheep and goats?Caecum and colon
- 68What is the symptom of Eimeria in poultry?Diarrhoea with blood
- 69What are 2 symptoms of Eimeria in cattle?Diarrhoea with blood
Tenesmus (straining to defecate) - 70What is the symptom of Eimeria in sheep and goats?Severe diarrhoea with blood
- 71Give 3 pieces of information that may be obtained from faecal oocyst countsSpecies of parasite
Number of oocysts
Stage of infection - 72Give 2 host factors that must be taken into account in diagnosis of coccidiosisHost species
Clinical context - 73Give 4 diagnostic tests for coccidiosisFaecal oocyst counts
Specific identification of sporulated oocysts
Post mortem examination of intestines
Molecular diagnostic aids - 74Give 2 drugs that can be used to control coccidiosisVaccine available for poultry
Coccidiostats in feed - 75How can hygiene reduce incidence of coccidiosis?Between batch hygiene including disinfection
- 76How can housing management reduce incidence of coccidiosis?Reduced crowding
- 77How can water management reduce incidence of coccidiosis?Improved drainage around water points
- 78How can feed management reduce incidence of coccidiosis?Reduced faecal contamination of feed
- 79How can flooring reduce the incidence of coccidiosis?Wire floors break faeco-oral transmission
- 80Which species of crytosporidium is pathogenic in humans and domestic animals?Cryptosporidium parvum
- 81Give 2 clinical signs of cryptosporidiumIntermittent anorexia
Profuse watery diarrhoea - 82What is meant by cryptosporidium auto-infection?Sporulation can occur in intestine of host
Therefore, sporozoites produced by host can go on to infect the same host with no environmental stage - 83Why is there no treatment for cryptosporidium?Normally self-limiting
- 84In which animals or people is cryptosporidium most dangerous?Immunocompromised
- 85What happens to thin-shelled oocysts produced by cryptosporidium?Re-infect host tissue
- 86What happens to thick-shelled oocysts produced by cryptosporidium?Passed in faeces and are IMMEDIATELY infective
- 87Why can cryptosporidium oocysts survive well in the environment?Resistant to environmental conditions
- 88Why can cryptosporidium oocysts be resistant to disinfection?Resistant to chlorination
- 89Where in the host cell does cryptosporidium develop?Space between cytoplasm and cell membrane
- 90What causes the symptoms of cryptosporidium such as diarrhoea?Infected microvilli destroyed when parasite leaves cell
- 91What is the apporximate size of Cryptosporidium oocysts?3-5 micrometres
- 92Give 2 reasons why Cryptosporidium can contaminate the water supplySmall size means the oocysts can easily pass through normal water filtration systems
Highly resistant to chlorination - 93Does Cryptosporidium have a wide or narrow host range?Wide host range
- 94Give 3 reservoirs of Cryptosporidium infectionBirds
Wildlife
Livestock - 95Give 2 ways that humans can become infected with CryptosporidiumWater supplies contaminated with infected animal faeces
Close contact with infected animals, especially calves - 96Give 2 ways Cryptosporidium incidence in calves can be reducedHygiene
Batch rearing - 97Which drug can be used as a prophylactic treatment of Cryptosporidium?Halofunginone
- 98What are sarcocystidae?Group of coccidian parasites
- 99Give 3 examples of sarcocystidaeToxoplasma
Neospora
Sarcocystitis - 100How is the life cycle of Sarcocystidae different to Eimeria?Indirect life cycle
Sexual reproduction occurs in definitive host and asexual stages occur in intermediate hosts - 101What is Toxoplasma gondii?Apicomplexan protozoan parasite
- 102Which animals can be infected with Toxoplasma gondii?Infects most species of warm blooded animal, including humans, causing the disease toxoplasmosis
- 103What is the definitive host of Toxoplasma gondii?Members of the cat family (Felidae)
- 104What are the intermediate hosts of Toxoplasma gondii?Large number including sheep and rodents
- 105Give 2 reasons why Toxoplasma gondii is dangerous to humansCan cause abortion and foetal abnormality
Significant infections in immunocompromised humans e.g. with HIV - 106Why is Toxoplasma gondii of economic significance in sheep farming?Causes abortion
- 107Does Toxoplasma gondii cause infection in the definitive host?Little disease - shedding of oocysts is transient
However, congenital transmission can cause weakness and death of kittens - 108Give 2 ways that cats can become infected with Toxoplasma gondiiIngesting sporulated oocysts
Ingesting cysts from infected animals such as rodents - 109What are tachyzoites?Develop rapidly in intermediate host and cause cell rupture = fever
- 110What are bradyzoites?Intracellular development slowed by host immunity
Hence insread of rupturing the cell, parasite divised to form a large cyst or bradyzoite within the cell - 111Why can Toxoplasma gondii infection resume if the host becomes immunosuppressed?Bradyzoites remain dormant for many years then re-activate to generate another cycle of tachyzoite dispersal
- 112What is the motile form of Toxoplasma gondii?Tachyzoites
- 113Give 2 ways humans can become infected with Toxoplasma gondiiIngestion of sporulated oocysts
Ingestion of under-cooked meat containing bradyzoite cysts - 114How is Toxoplasma gondii infection transmitted from the mother to the foetus?Tachyzoites transmitted across placenta
- 115Describe the structure of Toxoplasma gondii oocytes2 sporocysts
Each contains 4 sporozoites - 116What is the shape of tachyzoites?Crescent shaped
- 117In which stage of Toxoplasma gondii infection are tachyzoites present?Acute
- 118What is the shape of bradyzoites?Comma shaped
- 119In what stage of Toxoplasma gondii infection are bradyzoites present?Chronic or latent phase
- 120What protects bradyzoites from the host immune response?Psuedocyst wall
- 121Give 2 tissues in which Toxoplasma gondii bradyzoites may encystMuscle
Brain - 122What is the consequence of a ewe being infected with Toxoplasma gondii early in gestation?Abortion = barren ewe
- 123Give 2 clinical signs that a ewe has been infected with Toxoplasma gondii mid-gestation and abortedWhite lesions on placental cotyledons
Mummification of dead foetus - 124What is the consequence of a ewe being infected with Toxoplasma gondii late in gestation?Still-born or weak lambs
- 125Why will Toxoplasma gondii not cause repeat abortion?Strong immunity develops so subsequent pregnancies are normal
- 126What happens if Toxoplasma gondii infection occurs during first 2 months of gestation?Foetal death with subsequent expulsion or mummification
- 127What happens if Toxoplasma gondii infection occurs during last 2 months of gestation?Apparently normal lambs aborted in last month OR carried to term and born dead/weak
- 128What are symptoms of acute phase Toxoplasma gondii in humans?Flu like e.g. muscle aching, swollen lymph nodes
- 129Give 3 consequences of human infection with Toxoplasma gondii during pregnancyAbortion
Foetal abnormality
Eye problems in young children - 130What can be caused by Toxoplasma gondii infection in very immunosuppressed people?Damage to brain, eyes or other organs
- 131Give 3 methods of diagnosing Toxoplasma gondii in sheepImmunofluorescent staining of antigen in foetal tissues
White spots on cotyledons of aborted placenta
Rising antibody titre in aborting ewes - 132How can cats be prevented from passing Toxoplasma gondii to sheep?Control of domestic cats
Vermin and cat-proof feed bins - 133Give 2 ways that Toxoplasma gondii can be controlled medicinally in sheepAnti-coccidials mid pregnancy
Vaccination 3 weeks before tupping - 134What is the vaccine for Toxoplasma gondii in sheep made up of?Live vaccine containing strain unable to form bradyzoites in muscle tissue so cannot complete life cycle
- 135What temperature should meat be cooked to in order to prevent infection with Toxoplasma gondii?66 degrees Celsius
- 136When do oocysts from cat faeces sporulate?2-3 days
- 137For how long do cats transiently shed Toxoplasma gondii oocysts?1-2 weeks
- 138Why can neutering farm cats help prevent transmission of Toxoplasma gondii?Mostly shed oocysts when young or pregnant
- 139What does neospora caninum cause in cattle?Abortion
Congenital neonatal infection - 140What is the definitive host of Neospora caninum?Dog
- 141Which dogs may be affected by Neospora caninum?Puppies less than a year old
- 142Give 2 symptoms of Neospora in dogsEncephalitis causing neurological signs including paralysis
Myocarditis - 143Why are the abortions caused by Neospora caninum different to those caused by Toxoplasma gondii?Neospora caninum can cause repeat abortions
- 144What are the 2 possible outcomes for calves cogenitally infected with Neospora caninum?Stillborn or weak due to encephalomyelitis
Some born asymptomatic but females will carry the infection and abort their first pregnancy - 145What is encephalomyelitis?Infection of brain and spinal cord
- 146Give 3 ways dogs can become infected with Neospora caninumDirect life cycle in the dog
Eating contaminated placental material
Ingesting bradyzoites from intermediate hosts e.g. cattle and sheep - 147What are exogenous Neospora infections?Infections resulting from ingestion of infective forms
- 148What are endogenous Neospora infections?Infections resulting from re-activation of bradyzoites during pregnancy
- 149What is the principle route of transplacental transmission of Neospora in cattle?Endogenous infection
- 150What are the infective forms of Neospora in cattle?Sporulated oocysts
- 151What are the infective forms of Neospora in dogs?Sporulated oocysts
Tachyzoites
Bradyzoites - 152Can humans act as an intermediate host for Neospora?No
- 153In which 2 species can endogenous trans-placental transmission of Toxoplasma gondii occur?Humans
Cats - 154How is Neospora caninum diagnosed?Histology and immunostaining of aborted foetal tissue, especially brain
- 155How can infection of cattle with Neospora by dogs be reduced?Prevent contamination of animal feed with dog faeces
- 156How can infection of farm dogs with Neospora be reduced?Prevent them gaining access to offal such as placental material
- 157How can an existing Neospora infection be removed from a cattle herd?Culling of seropositive cows and their offspring
- 158How can introduction of Neospora into a herd by replacement animals be avoided?Purchasing from seronegative herd
- 159Is a vaccine available for Neospora?Inactivated tachyzoite vaccine available only in the US
- 160What is sarcocystitis?Genus of protozoa infecting mammals, birds and reptiles
- 161Does sarcocystitis have a direct or indirect life cycle?Indirect
- 162How does sarcocystitis affect the carnivore definitive host?Asymptomatic gut infection
- 163How does sarcocystitis affect the herbivore intermediate host?Cysts in muscle and other tissue may lead to clinical signs
- 164What is the name of the cattle-dog sarcocystitis?S. bovicanis
- 165What is the name of the sheep-dog sarcocystitis?S. ovicanis
- 166What is the name of the cattle-human sarcocystitis?S. bovihominis
- 167What is the term for cysts that develop in the muscle of the sarcocystitis intermediate host?Sarcocysts
- 168What type of reproduction occurs in the sarcocystitis definitive host?Asexual and sexual reproduction cycles in the gut
- 169What type of reproduction occurs in the sarcocystitis intermediate host?Asexual reproduction in endothelial cells
- 170What can S. bovicanis cause in the definitive host?GI disturbance
- 171Where does S. bovicanis develop in the cow?Develops in blood vessels
Encysts in muscle tissue - 172Give 2 possible symptoms of S. bovicanis in the cowPost mortem lesions
Myeloencephalitis - 173How can sarcocystitis be identified in the intermediate host during meat inspection?Microscopic cysts within muscle
- 174Which organism causes Equine Protozoal Myeloencephalitis?Sarcocystitis neurona
- 175Give 2 symptoms of Equine Protozoal MyeloencephalitisCaudal ataxia
Weakness - 176What causes the symptoms of Equine Protozoal Myeloencephalitis?Sarcocysts develop in CNS
- 177What is the normal life cycle of S. neurona?Opossum definitive host
Intermediate host is bird, skunk or armadillo
Horse is accidental or 'dead-end' host
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- (Parasitology) Animal Disease 1 Fichas sobre Protozoa 1, creado por Florence Edwards el 29/01/2017.
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- Florence Edwards
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