Quiz 2 revision Flashcards
Describe the diagnosis and control/ prevention of Amoebiasis
Stools are collected as samples for faecal microscopy which can include wet mount & staining, antigen test, serology
Looking for cysts in the faeces
Prevention would be to be use good hygiene and avoid handling food if infected
Describe the pathogenesis of Amoebiasis
Mature cysts are ingested
There is Excystation into trophozoites
This will then multiply and form cysts and go straight through the intestinal tract and enable the faeces to infect another source
Describe the pathogenesis
There can be other animals that become infected after ingesting faeces that is also infected
Describe the diagnosis and control/prevention of Toxoplasmosis
Serology, although tissue cysts may be observed in stained biopsy specimens
PCR can also be used to detect T. gondii DNA in amniotic fluid
Describe the pathogenesis
Toxoplasmosis
In a human host, the parasite from tissue cysts, most common in muscle, myocardium, brain and eyes, and these cysts may remain throughout the life of the host
(The trophozoites are released when the cysts rupture and they will develop in the cells)
Unsporulated oocysts are shed in an faeces
Oocysts take 1-5 days to sporulate in the environment and become infective. Intermediate hosts in nature become infected after ingesting soil, water or plant material contaminated with oocyst
The oocysts transform into tachyzoites after ingestion. They localise in muscle tissue
Other animals can then be infected after ingesting infected tissues containing cysts
Describe the lifecycle and pathogenesis of Giardia
There is contamination of water or food with infective cysts. Then ingested into GIT
Once in the Gastrointestinal Tract the Cyst will then form into a trophozoites and then that’s what will replicate via binary fission
They will then form cysts that will infect the faeces
What is the fungi body structure?
- Most common body structures are multicellular filaments and single cells
The cell walls are composed of Chitin, a polysaccharide)
In multicellular fungi, the hyphae form an interwoven mass called mycelium that infiltrates the fungi’s food source
Some fungi have fruiting bodies
Describe the Chytrid families
- They are decomposers and parasites
- They can be both single celled and multicellular
- They are grouped together as their spores are flagellated
Describe the zygomyctes
- Responsible for causing food to rot
- Can act as decomposers or parasite or as commensal symbionts
- During reproduction they reproduce a sturdy structure
called zygospoangia
These are resistant to freezing and drying and are metabolically inactive
Describe glomeromycetes
- they supply minerals and other nutrients to the plant forming mutualistic partnership
Describe Ascomycetes
- Have a common feature which is to produce spores in a saclike sci
- They can be unicellular yeast, but many are elaborate cup and fungi and morels
- They can have repro cycles with both asexual and sexual components
Describe Basidiomycetes
- Importnat decomposers of wood and other plant material
- Have a long lived heterokayrotic state in which each cell has two nuclei
What is the importance of fungal growth in antimicrobial products?
Fungi secrete Penicillin which is an antibiotic
What is the definition of parasitism?
An organism that lives on or in a host organism and get its food from or at the expense of its host
Describe the general features and classification of Protozoa
Most are motile which is achieved by cilia, flagella and pseudopodia
Many have a. feeding/ reproducing form = trophozoite
Some form cysts = a hardy resting form with a capsule that can survive adverse conditions
- EXCAVATA
- RHIZARIA
- AMOEBOZOA
- ALVEOLATA
What are the general features and classifications of Helminths?
They are multicellular invertebrates with elongated flats or round bodies
Some are motile and they have oragan system. The external surface is covered by a cuticle
They have hooks, suckers, teeth and plates
What are the classifications of Helminths?
2 Classification
- Platyhelminthes: Flatworms
These include tapeworms and flukes - Nemahelminths: Roundworms
How do you diagnose, control and prevent helminth diseases?
can be diagnosed by analysing stool samples for larvae and prevented by proper use of hygiene
Describe the asexual and sexual reproduction of fungi
Mycelium produces spore-produces structures, usually hyphae, and they release spores which then germinate and then form mycelium
Sexual reproduction
Describe the asexual and sexual reproduction of fungi
Mycelium produces spore-produces structures, usually hyphae, and they release spores which then germinate and then form mycelium
Sexual reproduction
Two mycelium fuse their cytoplasm and enter the heterokaryotic stage where the is a fusion of nuclei
A zygotę forms and then undergoes meiosis, releases spores and undergoes germination to form mycelium.
Provides variation
Lifecycle and pathogenesis of Ascaris
Humans eats embryonate eggs and the hatched larvae enter circulation and migrate to lungs
Larvae are coughed up and swallowed and maturation proceeds in the small intestine
Lifecycle and pathogenesis of Taenia
Humans are infected by eating cysticerci in poorly cooked tissues. Cysts except, develop to worm and attach with hooks and suckers to Sil wall. Worms produce proglottid segments
Mature proglottids contains eggs which are shed in human faeces
