(8) Flashcards
What type of molecule is found in the cell wall of acid-fast bacteria?
Mycolic acids
What is the primary stain of the Ziehl-Neelsen acid-fast procedure? Decolorizer? Counterstain?
Primary stain- carbolfuchsin (lipid-soluble & penetrates the waxy cell wall)
Decolorizer- acid alcohol
Counterstain- brilliant green
What color do acid-fast cells appear after the acid-fast procedure? Non-acid-fast?
Acid-fast cells are reddish-purple
Nonacid-fast cells are the color of the contrasting counterstain
What genus of bacteria can be detected using the acid-fast procedure?
Mycobacterium
What disease can be diagnosed using the acid-fast procedure?
Leprosy and tuberculosis
Insoluble, mucoid, extracellular material surrounding some bacteria; composed of mucoid polysaccharides or polypeptides that repel most stains
capsule
Is the capsule staining procedure a negative stain, positive stain, or both?
Negative stain
What is the medical importance of a capsule?
A capsule stain is a differential stain used to detect cells capable of producing an extracellular capsule. Capsule production increases virulence in some microbes (such as the anthrax bacillus Bacillus anthracis and pneumococcus Streptococcus pneumoniae) by making them less vulnerable to phagocytosis.
What stains are used in a capsule stain?
Maneval’s stain & congo red stain
What color is the capsule after staining?
The capsule is unstained and appears as a white halo between the cells and the colored background
Dormant, highly resistant form of bacterium; produced only by species of Bacillus, Clostridium and a few others; dormant form of the bacterium that allows it to survive poor environmental conditions
endospore
spores are resistant to heat and chemicals because of a tough outer covering made of this protein. It also resists staining.
keratin
An actively metabolizing & growing cell.
vegetative cell
a cell that forms spores
spore mother cells
middle of the cell
central
at the end of the cell
terminal
between the end and middle of the cell
subterminal
round & shaped like a sphere
spherical
oval
ellipitical
A heterotroph that digests dead organic matter; a decomposer
saprophytes
produces spores
sporulate
start growing from a seed
germinate
What is the purpose of the steam in an endospore stain?
The steam forces the malachite green into the endospores
What stains are used in an endospore stain?
Primary stain- malachite green (forced into the spores by heat)
Decolorization-water (removes stain from cells, but not spores)
Counterstain- safranin
What color is the endospore and vegetative cells after staining in an endospore stain?
Endospore- green
Vegetative cell- red
What genera produce spores?
Bacillus and Clostridium
Which culture would have more spores: 24 hr culture OR 72 hr culture?
A 72 hour culture
