MIcro Exam III – Lectures 14-16 – Flashcards
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| What are cell walls of fungi composed of? |
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| Chitin and glucan. |
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| What does the cell membrane of a fungi contain? |
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| Ergosterol. |
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| T/F Most fungi are aerobes. |
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| True. |
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| T/F Fungi typically infect immunosuppressed. |
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| True. |
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| How do fungi disperse spores? |
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| Throwing them - raise up fungal head (conidia and other names). |
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| Which form of fungi is single cell? |
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| Yeast - asexual budding, divide by fission. Single cell - typically in you. |
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| Which form of fungi grows as long hyphae? |
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| Mold - free living, multi-cellular. May have conidia - asexual reproductive elements. |
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| How are fungi diagnosed? |
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| Growth/culture, Microscopy (may digest keratin w/ KOH), Antibody/antigen/Molecular Biology. |
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| How is microscopy done for diagnosing fungi? |
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| Digestion of keratin w/ KOH. |
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| How are fungi classified by body location? |
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| Superficial, cutaneous, subcutaneous, systemic. |
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| Where are superficial fungal infections located? |
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| Hair/skin, non-destructive. |
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| Name 2 superficial fungal infections? |
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| Tinea nigra - black patches on soles of hands/feet, Tinea versicolor - altered pigmentation - usually hypo. |
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| Where do cutaneous fungal infections reside? |
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| Skin, hair nails. |
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| What do cutaneous fungi secrete and what does it do? |
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| Keratinase - crumbles the skin/nails, loss of hair. |
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| Name some examples of cutaneous fungi? |
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| Tinea corpis, Tinea curis, Tinea pedis, Tinea capitis, Tinea unguium, Candida albicans. |
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| How are cutaneous fungi treated? |
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| Imidazoles & Griseofulvin. |
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| What causes oral thrush? |
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| Candida albicans. Patches of white exudate w/ reddish base. Can also cause vaginal infections. |
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| What do subcutaneous fungal infections cause? |
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| Deeper layers of skin/muscle/CT. |
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| What causes rose gardener's disease? |
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| Sporothrix scheckii - skin lesions, can be systemic. |
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| What is a long term subcutaneous infection? |
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| Chromomycosis. |
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| What does Cryptococcus neoformans cause? |
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| Inhaled into lungs, not dimorphic, goes systemic if immunosupressed. |
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| T/f Cryptococcus neoformans is not dimorphic? |
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| True - YEAST only. |
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| How are systemic fungi treated? |
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| Amphotericin B - Systemic treatment. |
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| Histoplasmosis capsulatum, Blastomycosis dermatidis and Cocoidiomycosis immitis are examples of what? |
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| Systemic fungi. |
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| What part of the cell wall is targeted for fungal infection? |
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| Glucan synthesis, chitin synthesis. |
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| What is the target for caspofungin and micafungin? |
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| Cell wall - Glucan synthesis. |
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| What is nikkomycin a target for? |
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| Chitin synthesis - cell wall. |
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| What is the mechanism of Azoles? |
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| Cell membrane of fungi - ergosterol synthesis. Fluconazole and ketconazole. |
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| What is the mechanism of Polyenes? |
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| Affect the egosterol pathway - Amphotericin B and Nystatin. |
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| What is Aphotericin B? |
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| A Polyene. |
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| What is the target for Griseofulvin? |
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| Inhibits mitotic spindle formation - used for superficial and dermatophytes. |
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| What is the target for Flucytosine? |
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| Nucleic acid synthesis Inhibitors. |
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| What is the target for Sordarins and Azasoradins? |
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| Protein synthesis inhibition. |
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| What is Blastomyces dermatitidis cause? |
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| Blastomycosis - resp. infection inhaled - Ohio and Miss. river valleys and Great Lakes. |
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| How is Blastomyces dermatitidis treated? |
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| Anphotericin B. |
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| What does Coccidioides immitis cause? |
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| Mild lung infection - found in the desert SW US. Lesions in lung. Coccidiodomycosis. |
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| How does Coccidioides immitis treated? |
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| Amphotericin B. |
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| What does Histoplasma capsulatum cause? |
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| Histoplasmosis - most recover, problem w/ immunocompromised - causes TB like granulomas. Endemic in Miss and Ohio RV - bird bat droppings. |
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| How is Histoplasma capsulatum treated? |
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| Aphotericin B. |
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| What does Cryptococcus neoformans cause? |
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| Opportunistic - usually asymptomatic, can cause pneumonia and cryptococcal meningitis. Spread by soil, pigeon droppings (CACA). |
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| What are the fungi that is monomorphic? |
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| Candida albicans, Cryptococcus neoformans, Aspergillus. |
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| What does Candida albicans cause? |
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| Opportunistic, cutaneous, oral, vaginal. |
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| How is Cryptococcus neoformans treated? |
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| Aphotericin B - for over 6 mos. |
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| How is Candida albicans treated? |
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| Nystatin or Amphotericin B. |
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| What does Aspergillus cause? |
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| Most common invasive mold, worldwide because they are saprobes, causes mycetoma in lungs, Type I Hypersensitivity rxn. |
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| How is Aspergillus treated? |
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| Aphotericin B. |
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| What does Tinea cause? |
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| Yeasts, Cutaneous. |
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| How are Tineas treated? |
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| Topical azones, dandruff shampoo. Causes chronic persisten skin pigment changes. |
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| How is Sporothrix shcenckii treated? |
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| Potassium Iodide. |
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| What does Pneumocystis jirovecii cause? |
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| Only a problem for immunosuppressed - cause pneumocystis pneumonia. |
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| How is Pneumocysts jirovecii treated? |
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| Trimethorpim-sulfamethoxazole. |
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| What other problems can fungi cause? |
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| Allergy - Type I Hypersensitivity, Toxins - aflatoxin, Mycormycosis - hard tissue necrosis in patients w/ poorly controlled diabetes. |
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| How does a cyst help a protozoa? |
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| Allows them to resist the env. |
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| What is the feeding form of a protozoa called? |
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| Trophozoite. |
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| What are protozoa? |
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| Single celled eukaryotes. |
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| T/F Protozoa are part of the normal flora. |
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| False. |
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| How are protozoas grouped? |
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| By how they move and their life cycle. |
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| Describe Trichomonas vaginalis. |
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| Flagellate, STD, can live in oral cavity too - no disease. Many are asymptomatic, 5-20% of women, 2-10% of men. |
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| What is the reservoir for Trichomonas vaginalis? |
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| Men. |
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| How is Trichomonas vaginalis treated? |
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| Metronidazole. |
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| T/F Giardia is resistant to chlorine. |
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| True - need to filter/boil. |
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| T/F Giardia can't spread person to person. |
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| False - it can spread. |
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| How is Giardia treated? |
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| Metronidazole. |
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| Where is Giardia found? |
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| Lakes, streams, mountain resorts. |
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| What is the reservoir for Giardia lamblia? |
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| Beavers/muskrats. |
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| T/F Giardia is a Ciliophora. |
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| False - flagellate. |
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| Name an amoeba. |
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| Entamoeba histolytica. |
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| What does Entamoeba histolytica cause - where does it live? |
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| Diarrhea - can exist in oral cavity. |
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| How is Entamoeba histolytica spread? |
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| Institutions - fecal/oral of cysts & in homosexual male population - asymptomatics can also pass it. |
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| How is Entamoeba histolytica prevented? |
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| Chlorination of water/filtration. |
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| T/F Entamoeba histolytica can spread to liver/lung/brain in immunosuppressed. |
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| True. |
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| How is Entamoeba histolytica treated? |
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| Metronidazole. |
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| Name a sporozoa? |
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| Toxoplasma gondii, Malaria. |
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| What is the reservoir for Toxoplasma gondii? |
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| Cats - cysts in feces - get it from eating infected mice. |
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| What are the symptoms of Toxoplasma gondii? |
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| Flu like symptoms. |
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| Who is at risk for Toxoplasma gondii? |
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| Immunosuppressed and pregos - can cause abortion or neuro problems in the baby. |
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| How is Toxoplasma gondii detected? |
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| Serology/screening/amniotic PCR. |
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| What is the vector for malaria? |
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| Mosquito. |
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| What do mosquitoes transmit to you with malaria? |
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| Sporozites - they go to the liver and reproduce - may have dormant liver phase. |
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| What happens in the malarial lifecycle? |
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| Sporozites go to liver, then hepatocytes rupture and morozoites enter the bloodstream and infect RBCs. |
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| How is malaria treated? |
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| Quinines and Doxycycline. |
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| What are parasites in the animal kingdom called? |
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| Metazoans. |
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| T/F Helminths are exogenous parasites. |
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| True. |
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| What is the protective cuticle on flatworms called? |
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| Tegument. |
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| What is reproduction like in the helminths? |
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| Large scale, much energy. |
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| What are round worms called? |
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| Nematodes. |
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| What does Trichinella spiralis live in? |
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| Pork/game - undercooked. |
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| Where do Trichinella spiralis go in your body? |
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| Muscles - larvae die and calcify there. |
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| T/F Trichinosis is fatal. |
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| True if it gets to your heart/brain/lungs, typically asymptomatic though. |
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| What are flatworms called? |
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| Platyhelminthes. |
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| What are Trematodes? |
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| Flatworms - flukes - leaf shaped body - Schistosomes. |
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| What is a tapeworm called? |
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| Cestodes - proglottids - absorb nutrients thru body - Taenia for example. |
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| T/F Arthoropods are ectoparasites. |
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| True. Can directly cause disease OR be intermediate hosts/vectors. |
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| T/F Arthoropods cause Type II Hypersensitivity. |
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| False - Type I. |
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| What kingdom do Microsporidians belong to? |
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| Fungi - even tho it seems like they belong as Protozoa. |
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| What is in the kingdom Chromista? |
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| Blastocystis hominis - role in human health is debated. |
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| What is the role of Blastocystis hominis in human health? |
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| Debated - not treated. |
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| What is antigenic variation? |
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| Changing coat - how protozoa and worms avoid your I/S. Plasmodium/Giardia. |
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| What is molecular mimicry? |
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| Looks like host antigen so you don't respond. Plasmodium. |
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| How do Taenia/Schistosomes conceal their antigenic sites? |
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| Coat themselves with host molecules - ex. MHC - to avoid your I/S. |
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| Who lives intracellularly to avoid your I/S? |
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| Plasmodium/Toxoplasma. |
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| Which protozoa immunosuppress and how? |
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| Schistosomes - suppress T and B cells. |
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| What part of your I/S fight parasites? |
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| IgE, Eosinophils, Th2. |
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| T/F Haemophilus are gram-positive facultative aerobes streptococci. |
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| False - Gram - facultatively coccobacilli. |
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| T/F Haemophilus is not part of your normal flora. |
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| False - normal flora of mouth - found in plaque biofilms, salive, mucosa. |
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| What infections do Haemophilus cause? |
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| Dentoalveolar infections, acute sialadenitis (salivary gland infection), infective endocarditis. |
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| Describe Actinobacillus. |
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| Gram - microaerohilic or capnophilic, coccobacilli. |
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| What is often a co-infection with Actinomyces? |
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| Actinobacillus. |
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| What virulence factos does Actinomyces have? |
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| Fimbria and others. |
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| What does Actinobacillus cause? |
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| Found in perio pockets - implicated in aggressive forms of perio disease. |
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| Describe Eikenella. |
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| Gram - fac. anaerobe coccobacilli. |
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| Where is Eikenella found? |
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| Plaque biofilms in healthy mouths & with perio disease. |
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| What does Eikenella cause? |
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| Dentoalveolar abscesses, infective endocarditis; possible chronic forms of perio disease. |
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| Describe Capnocytophaga. |
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| CO2 dependent Gram - rods. |
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| Where is Capnocytophaga found? |
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| Plaque, mucosa, saliva. |
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| Who does Capnocytophaga infect? |
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| Immunocompromised - destructive perio disease. |
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| What bacteria produces IgA protease? |
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| Capnocytophaga. |
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| Describe Porphyromonas gingivalis. |
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| Gram - anaerobic pleomorphic rods, non-motile. |
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| What bacteria degrades collagen? |
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| Porphyromonas gingivalis. |
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| What does Porphyromonas gingivalis cause? |
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| Perio disease, also part of normal flora. |
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| Where is Porphyromonas gingivalis found? |
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| Gingival crevice and subgingival plaque in small numbers. |
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| What are Porphyromonas gingivalis virulence factors? |
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| Produces proteases - a haemolysin, collagen degrading enzyes and cytotoxic metabolites, large capsule, fimbriae. |
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| Describe Prevotella. |
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| Gram - pleomorphic anaerobic rods. |
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| T/F Prevotella is part of the normal flora. |
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| True. |
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| Where is Prevotella found? |
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| Perio pockets, dental plaque, dentoalveolar abscess. |
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| Describe Fusobacterium. |
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| Gram - anaerobic. |
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| What causes halitosis? |
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| Fusobacterium - produce Ammonia and Hydrogen Sulfide. |
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| Where is Fusobacterium found? |
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| Gingival crevice and tonsils, perio infections, gingivitis, dentoalveolar abscess. |
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| Describe Leptotrichia. |
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| Gram - filaments anaerobes. |
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| Where is Leptotrichia found? |
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| Plaque - no known disease association. |
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| Describe Wolinella. |
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| Gram - anaerobic bacilli. |
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| What does Wolinella cause? |
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| Destructive perio disease. |
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| Describe Selomonas. |
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| Gram - anaerobic rods. |
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| What does Selomonas cause? |
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| Found in gingival crevice, no known disease association. |
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| Describe Treponema. |
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| Motile Gram - anaerobic helical/spirillum. |
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| What does Treponmea cause in the mouth? |
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| Found in gingival crevice, ulcerative ginigivits, destructive perio disease. |
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| Name the most common supragingival bacteria? |
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| Streptococci. |
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| Name the 4 most common species of Strep in the mouth. |
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| Mutans, Salivarius, Anginosus, Mitis. |
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| What 5 species make up subgingival plaque? |
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| Actinomyces, Prevotella, Porphyromonas, Fusobacterium, Veillonella. |
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| What role does saliva play in bacterial growth? |
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| Provides pellicel for adhesion, nutrient source, clumping, non-specific defense factors, maintain pH. |
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| What do bugs hydrolyze sucrose to? |
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| Dextrans, glucans, and fructans/levans. |
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| How do dextrans help bacteria? |
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| Make a sticky surface for other bugs. |
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| How do glucans help bacteria? |
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| Used to store energy. |
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| How do fructans/levans help bacteria? |
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| Additional storage - when broken down plaque gets more acidic. |
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| How do bacteria stick to teeth? |
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| Both are negatively charged, so you need Ca2+ ions make a bridge between enamel and pellicle and bug - or they use fimbriae pili, flagella to bind to glycoproteins of the pellicle. |
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| How do bacteria in a biofilm communicate? |
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| Quorum sensing molecules for communication - Control genes for polysaccharide production, reduce metabolism, Control production of virulent factors. |
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| What is the role of biofilms in gingivitis and periodontitis? |
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| Pellicle formation, bacteria attach to pellicle. |
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| What is the main etiological agent of perio disease? |
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| Flora inhabiting subgingival plaque. |
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| What is the specific plaque hypothesis? |
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| Key organisms cause the disease - fusobacteria and spirochetes in necrotizing ulcerative gingivits, Actinobacillus in perio disease. |
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| What is the non-specific plaque hypothesis? |
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| Disease caused by a wide range of non-specific organisms - virulence factors of many bacteria, some can substitute for others, so plaque cause disease no matter what it's composition. |
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| Which - non spec or spec plaque hypothesis is correct. |
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| Both? |
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| What is the ecological plaque hypothesis? |
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| Host mounts Imm. Resonse, inflammation leads to GCF, which feeds Gram - anaerobes. These suppress Gram + bacteria and shift the flora. This overwhelms host defenses. |
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| T/F Gram + bacteria are most prevalent in the ecological plaque hypothesis. |
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| False - Gram -. |
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| What 4 types of bacteria are normal oral flora? |
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| Gram + bacilli, Gram - bacilli (most concentrated), Veillonella, and Gram + cocci. |
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| What changes occur in plaque bacteria with perio disease? |
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| Changes from aerobic, non-motile, gram + cocci to Gram - anaerobic motile bacilli. |
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| What species increase in perio disease? |
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| Actinobacillus either alone or w/ Capnocytophaga spp. and Porphyromonas gingivalis. |
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| What bacteria predominate in ulcerative gingivitis? |
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| Fusobacterium nucleatum and oral spirochetes. |
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| What are microsporidians? |
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| Small, obligate intracellular parasites that lack mitochnodria. |
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| What is a cluster of hyphae that forms a mat called? |
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| Mycelium |
