Special Media & Tests for Differentiation: A Micro Deck Flashcards
Rapid Pyrrolidonyl arylamidase (PYR) test positive
Group A Strep pyogenes
Enterococcus (group D strep)
Egg Yolk Agar + Vitamin K and Hemin (factor X) is positive for lecithinase and negative for lipase
Clostridium perfringens
Naglar Test
Clostridium perfringens
lecthinase +, tests for toxin which forms precipitate with antitoxin on the plate
Reverse cAMP Test shows an arrowhead appearance
Clostridium perfringens
(blood agar make a single streak perpendicular to streak of group B strep (s. agalactiae) and the heme becomes synergistic leading to an arrow head appearance)
Glows coral red under wood lamp/UV light due to porphyrin ring structure
Erythrasma
Photochromogen yellow-orange in light of colonies
both Mycobacterium Kansasii and mycobacterium marinum
Multinucleated giant cells with cowdry type A intranuclear inclusions
HHV-2
Smooth colonies with olive/black color and are halophilic
Tinea nigra
Small clusters of seed shaped spores
Tinea nigra
Spaghetti and meatball appearance
Pityriasis/Tinea Versicolor
Fluorsce Golden yellow on Wood’s lamp
Pityriasis/Tinea Versicolor
Smooth-wallled, banana-like clusters aka beaver tail appearance
Epidermophyton spp.
Black dot appearance of hair
Tinea capitis
Amastigotes inside of macrophages and the presence of trophozoites that look like avovado’s with tails
Leischmaniasis
High eosinophilia, microfilariae on miscroscopy
Loiasis
