M1 Part 3

Question 1

Microscopy of Clinical Specimens
1. for rapid microscopic examination of specimens; Quick Screening
- key target
- remarks
- useful in
- now supplemented w/ _____ or ____
2. for culture ID
- key target
- remarks
- ____ & ____ are commonly made using this to visualize features like conidia, conidiopores, hyphae
components:
- kill organisms
- preserves & clears fungal elements
- stains chitin in fungal cell walls

Answer 1

1. SALINE WET MOUNT
   - YEASTS, HYPHAE
   - MOLDS
   - CANDIASIS
   - KOH / FLUOROSCENT STAINS
2. LACTOPHENOL COTTON BLUE
   - MOLDS
   - PERMANENT MOUNT
   - TEASE MOUNTS & SCOTCH TAPE PREP
   components:
   - PHENOL
   - LACTIC ACID
   - COTTON BLUE

Question 2

Microscopy of Clinical Specimens
1. for direct detection of fungal elements in keratinized tissue; direct specimen
- key target
- remarks
- addition of ____ or ____ improves visualization
- ____ KOH digests keratin and clears background
2. detects yeasts & pseudohyphae esp Candida spp; esp helpful in blood, sputum, CSF for yeast detection
- key target
- remarks
- fungi generally appear gram _____
- ____ stain poorly due to their dense cell walls

Answer 2

1. POTASSIUM HYDROXIDE PREP
   - SKIN, NAIL FUNGI
   - CLEARS KERATIN
   - CALCOFLOUR WHITE or PARKER UNK
   - 10-20%
2. GRAM STAIN
   - CANDIDA SPP
   - YEAST APPEARS GRAM POS
   - GRAM POS
   - MOLDS

Question 3

1. differentiates partially acid fast organisms from other filamentous bacteria and fungi(____ spp)
   - key target
   - remarks
   - cold method for partially acid fast
   - fluoroscent technique that enhances detection sensitivity
2. demonstrates polysaccharide capsule of C. neoformans in CSF; for cryptococcus
   - key target
   - remarks
   - encapsulated yeast appears ___ against dark bg
   - sensitivity is lower compared to
   - now largely replaced by _____ antigen tests due to higher sensitivity

Answer 3

1. ACID FAST STAIN (Nocardia spp)
   - PARTIALLY ACID FAST ORGANISMS
   - MAY USE FLUORESCENCE
   - MODIFIED KINYOUN
   - AURAMINE-RHODAMINE STAIN
2. INDIA INK
   - CAPSULE
   - LOW SENSITIVITY; CSF
   - CLEAR HALO
   - CRYPTOCOCCAL ANTIGEN TESTING
   - LATERAL FLOW ANTIGEN TESTS

Question 4

1. stains pilysaccharides in fungal cell walls magenta; tissue fungi
   - key target
   - remarks
   -useful in tissue sections for _____
   - does not reliably stain _____
2. fluoroscent dye that binds to cellulose and chitin; sensitive detection
   - key target
   - remarks
   - fungal elements fluorescence appear _____ or _____ under UV
   - ____ is added to dissolve bg keratin and debris
   - sensitivity is higher than ____ or ____ for detecting fungal elements

Answer 4

1. PAS
   - MOST FUNGI
   - MAGENTA STAIN
   - INVASIVE MYCOSES
   - ACTINOMYCTES
2. CACLOFLOUR WHITE
   - ALL FUNGI
   - NEEDS FLUOROSCENCE MICROSCOPE
   - APPLE GREEN OR BLUE WHITE
   - KOH
   - KOH or GRAM STAIN