(OLD) IAS 61 + 65 Flashcards
What is cell wall of fungi made of?
Glucan 60%
Protein 30%
Chitin 10%
What component is there in fungi cell embrane
Ergosterol
What are the three types of fungi?
Yeast- unicellular
Moulds- multicellular
Thermodimorphic fungi- Yeast at 37C and mould at 25C
Name 2 types of yeasts
Candida albicans
Cryptococcus neoformans
What mechanism does yeasts reproduce?
Budding
Which stain is used for cryptococcus neoformans?
Indian ink staining
A negative stain which stains the background of the fungi, shows the capsule of C neoformans
What are the long branching filaments that moulds form?
hyphae
What structure does hyphae form
mycelium
How does moulds reproduce?
Asexual or sexual reproduction
Name 3 types of moulds?
Aspergillus fumigatus Dermatophytes: Trichophyton Epidermophyton Microsporum
Name a type of dimorphic fungi
Talaromyces marneffei
Penicillium marneffei
What fungi will have a higher chance to infect us when we have low neutrophil level? (Neutropenia)
Aspergillus fumigatus
What fungi have a higher chance to infect us with HIV infection?
Cryptococcus neoformans
Talaromyces marneffei
Name two types of superficial infections by fungi
Candidiasis
Dermatophytosis
Name two types of candidiasis
Oral thrush
Vaginal thrush
Name three types of dermatophytosis
Tinea pedis (foot) Tinea capitum (scalp, hair) Tinea unguium (nails)
What can we use to visualize mould
KOH smear
What can we use to visualize candida
Gram smear
What can we use to visualize cryptococcus neoformans
Indian ink smear
What method to detect aspergillus fumigatus
Nucleic acid detection
How does polyenes work
It complexes with ergosterol on the cell membrane and disrupt the fungal plasma membrane
Name the two types of polyenes
Nystatin
Amophotericin B
How does azoles work
Inhibit ergosterol synthesis
Name three types of azoles
Fluconazole
Itraconazole
Voriconazole
How does nucleoside analogues work? Name a type of it?
Inhibit DNA synthesis
5-flucytosine
How does echinocandins work?
Inhibit cell wall synthesis
Name 3 types of echinocandins
Caspofungin
micafungin
anidulafungin
Is candida albicans exogenous infection or endogenous?
Endogenous infection
Where is the reservoir of candida albicans
Skin
GI tract
Female genital tract
How to culture C. albicans
Agar plates (pus) Broth culture (blood)
What antigen is present in serum of candida albicans
Beta D-glucan
Are there any vaccines for C. albicans?
No
Treatment for superficial candidasis
Nystatin Fluconazole (refractory cases)
Treatment for systemic candidiasis
Fluconazole
Amphotericin B
Term for single cell parasites
Protozoa
Term for multicellular parasites
Helminths
Name the three types of helminths
Nematodes
Trematodes
Cestodes
Term for parasites living in body AND term for parasites living on the surface of body?
Endoparasites AND Ectoparasites
Infection and infestation
Invasion of endoparasites inside the body VS external parasitism by ectoparasites
What is the term for parasite host that harbours the adult or sexual stages of the parasite?
Definitive host
What is the term for parasite host that harbours the intermediate or larval stages of the parasite?
Intermediate host
What is the function of cyst
Cyst wall protects the organism so the organism can survive
Term for the stage of parasite that is causing the disease
Trophozoite
What are nematodes
Their appearance?
Roundworms
Elongated and cylindrical in appearance
What are trematodes
Their appearance?
Flukes
Flat, leaf-like structure
Are trematodes hermaphordites
Yes
They have male and female sex organs inside their bodies
What intermediate host does trematodes require?
Freshwater snails
What are cestodes
Their appearance
Tapeworms
Long, segmented adult worms
Give an example of cestodes
Taenia solium
Result of ingest eggs of Taenia solium
Develop into neurocysticercosis
Result of ingest cysticerci
Develop into an adult worm
Two types of arthropods: insects and arachnids
Differences?
Insects: have 3 pairs of legs
Arachnids: have 4 pairs of legs
The genus of protozoa that causes malaria infection
Plasmodium
What is the natural vector of malaria
Female Anopheles mosquitoes
What are the other routes of transmission for malaria
Blood transfusion
Contaminated needles
Congenital (through placenta)
The most dangerous type of malaria
Name the parasite
Why
Falciparum malaria
By plasmodium falciparum
High levels of parasitaemia
Name the 2 types of parasites that relapse would occur for malaria
Plasmodium vivax
Plasmodium ovale
Name the stage for the sporozoites remain latent in the liver
Hypnozoite stage
Name the stage for the sporozoites multiplying in the liver
exoerythrocytic stage
What will the sporozoites infect after going into the bloodstream
Red blood cells
Define relapse
Recurrence of symptoms after complete initial clearing of parasitaemia due to re-invasion of blood stream by exo-erythrocytic stages
Therefore, we need to kill the hypnozoites
Define recrudescence
Recurrence of symptoms after initial parasitaemia is reduced to a very low level but not completely cleared
In laboratory diagnosis of malaria, what method is used?
Examination of blood films
Antigen detection in blood
Nucleic acid amplification
What stain is used in the blood films during lab diagnosis of malaria?
Giemsa stain
