Cytology of Infectious/Inflammatory Disease

Question 1

what are the most common infectious organisms observed in cytologic samples?

Answer 1

bacteria

Question 2

how do bacteria stain with Romanowsky-type stains?

Answer 2

dark blue

Question 3

what is some evidence of bacterial infection?

Answer 3

most conclusive: intracellular organisms
degenerate neutrophils are considered evidence
not finding bacteria does not rule out

Question 4

what are the common bacterial stains?

Answer 4

gram stain
acid-fast stain

Question 5

what are the common fungal stains?

Answer 5

gomori’s methenamine silver
periodic acid schiff

Question 6

what are some issues with gram stain?

Answer 6

inadequate or inconsistent decolorization
precipitation of stain
gram-negative organisms more difficult to find
poor staining of cells and other structures

Question 7

what do Clostridial spp look like?

Answer 7

anaerobic
gram positive rods

Question 8

what causes tetanus associated with penetrating wounds?

Answer 8

Clostridium tetani

Question 9

can Clostridium spp be found in low numbers in normal feces?

Answer 9

yes

Question 10

what are some common filamentous bacteria?

Answer 10

Actinomyces sp
Nocardia sp

Question 11

what are filamentous bacteria commonly found with?

Answer 11

penetrating wounds

Question 12

how do Actinomyces sp and Nocardia sp stain?

Answer 12

gram positive

Question 13

where are Mycobacterium sp found?

Answer 13

intracellular in macrophages

Question 14

what does Mycobacterium sp cause?

Answer 14

granulomatous or pyogranulomatous inflammation, often with multinucleated giant cells

Question 15

what is a bacterium that does not stain with romanowsky stains?

Answer 15

Mycobacterium sp due to high lipid content of cell wall

Question 16

where might non-hemotropic mycoplasmas infect?

Answer 16

respiratory or urogenital tracts

Question 17

which Mycoplasma sp infects dogs?

Answer 17

Mycoplasma canis

Question 18

many infectious fungi are ______________________________________ in the environment

Answer 18

dimorphic: both yeast and hyphal forms

Question 19

in fungal infections, what is typically present?

Answer 19

only one form: yeast or hyphae

Question 20

what is generally required to identify fungal hyphal infections?

Answer 20

culture: appearance may suggest a group but not definitive

Question 21

what are the two broad divisions of fungal hyphal infections?

Answer 21

dematiaceous (pigmented)
non-pigmented

Question 22

what do infectious yeasts usually have?

Answer 22

distinct border due to cell wall

Question 23

what are infectious yeasts typically accompanied by?

Answer 23

granulomatous or pyogranulomatous inflammation

Question 24

what do Cryptococcus neoformans look like?

Answer 24

variably sized, round to oval yeast
thick, non-staining polysaccharide capsule with thin cell wall
narrow-based budding

Question 25

Cryptococcus gattii has identical morphology, but is considered ________________________

Answer 25

more pathogenic

Question 26

what does india ink staining do?

Answer 26

fills background area to highlight yeast/capsule

Question 27

where is Blastomyces dermatitidis most common?

Answer 27

moist soil:
Mississippi
Missouri
St. Lawrence and Ohio river valleys
Great Lakes

Question 28

what does Blastomyces dermatitidis look like?

Answer 28

prominent, thick cell wall
broad-based budding
big blue balls with broad-based budding

Question 29

where is Coccidioides immitis most common?

Answer 29

southwest US

Question 30

what do Coccidioides immitis look like?

Answer 30

very large
thick cell wall
no external budding
endospore-forming spherules in tissue

Question 31

what do Histoplasma capsulatum look like?

Answer 31

small, round yeast
basophilic nucleus and thin cell wall

Question 32

what does Sporothrix schenckii look like?

Answer 32

variably-shaped yeast
3-5 micrometer in diameter
thin, clear cell wall and pale blue cytoplasm

Question 33

what infections do Malassezia pachydermatis cause?

Answer 33

opportunistic fungal organism of skin and ear canal

Question 34

what do Candida albicans look like?

Answer 34

thin-walled, dense-staining budding yeast
medium-based budding
may form pseudohyphae

Question 35

dogs infected with Leishmaniasis typically have __________________

Answer 35

hypergolbinemia

Question 36

what does Cryptosporidium parvum cause?

Answer 36

diarrhea, especially in young ruminants
zoonotic