5.3 Micro Flashcards
Mycoses a/w birds
Histoplasmosis (bird, bat droppings) Cryptococcus neoformans (pigeons) Chlamydia psitacci (parrots) Avian influenza West Nile Virus
What pts commonly get cryptococcal meningitis?
AIDS pts
What is candida intertrigo?
Candida rash under breasts, in skin folds of obese pts
What opportunistic fungal infection can penetrate the cribiform plate?
Mucor and Rhizopus
Get rhinocerebral and frontal lobe abscesses, can be deadly.
Why are mucor and rhizopus mostly in DKA pts?
proliferates in blood vessel walls when there is excess ketone and glucose available.
(also common in leukemia pts, not for this reason)
Onychomycosis
Fungal infection of nail bed
Caused by Tinea ungium
Rx griseofulvin (takes longer), terbinafin
What mycoses might be seen in spelunkers?
Histoplasmosis (found in bird/bat droppings)
Arthroconidia
Barrel-shaped form contained in Cocci
Some barrels are empty, allowing cocci to be light enough to be carried in air.
What causes cauliflower skin lesions?
Blastomycosis
List the antifungal meds
Amphotericin B Nystatin Azoles Flucytosine Caspofungin Terbinafine Griseofulvin
What antifungal should be used for bad systemic infections?
Amphotericin B
What is used to treat Sporothrix?
Itraconazole
How do the azoles inhibit fungi?
Inhibit fungal ergosterol synth by inhibiting the P450 enz that converts lanosterol to ergosterol
What hormones do azoles inhibit?
Corticosteroids, testosterone
can cause gynecomastia
Gardnerella vaginalis vs Trichomonas vaginalis
Gardnerella = gram-neg bacteria causing vaginosis (not STD necessarily). Fishy, clue cells, not painful.
Trichomonas- protozoan (triangle-shaped) causing vaginitis- foul-smelling green discharge. Itching/burning.
Treat both with metronidazole.
Most common protozoal infection in US
Trichomonas vaginalis or Giardia
Which protozoa causes liver dmg?
Entamoeba histolytica- causes liver abscess.
Malaria life cycle: looks like a diamond ring:
Trophozoite in RBCs
Malaria life cycle: Ruptures cell host
Merozoite
Rupture causes fever cycles
Malaria life cycle: replicates intracellularly
Schizont
Malaria: cell form injected by Anopheles
Sporozoite
think of mosq injecting spores
Malaria: banana shaped cell
Gamateocyte of plasmodium falciparum
White patches on sides of tongues
might be candida, but if it’s on sides, may be Oral Hairy Leukoplakia- opportunistic infection by EBV!
Causes endocarditis in IV drug users
Candida albicans
or S. epidermiditis
Spaghetti and meatball appearance
Tinea versicolor
What are fungal cell walls made of?
Ergosterol (fungi equivalent of cholesterol).
Ergosterol is inhibited by Terbinafine or the -azoles
Cause of bacterial dysentery vs amoebic dysentery
Bacterial: shigella
Amoebic: Entamoeba histolytica
In both strongyloides and ascaris, the eggs are coughed up/swallowed. How do they get into the body to begin with?
Stronglyoides: larvae in soil penetrate skin
Ascaris lumbricoides: eggs are ingested from contaminated food
Worm in undercooked pork
Taenia solium
swiss cheese appearance of brain- can get seizures, altered mental status, coma, death
Infection Leads to squamous cell carcinoma of bladder
Schisto hematobium
