Study Microbio Flash Cards

 
Pile Management Card
Microbio

loading
TTC
triphenyl tetrazolium chloride, is colorless but acts as artifical electron acceptor so when it is reduced by normal bacterial activity, it turns pink. if it spreads from a stab, bacteria is motile.
gram stain reagents
crystal violet (used to be aniline-gentian violet) as primary stain, then iodine as mordant (allows better complex formation between dye and target), decolorizing agent as ethyl alcohol, and then safranin red as counterstain
bipolar staining
baccili can show this, when ends stain deeply and the middle very little
corynebacterium species; shape
club-shaped or swollen at one end, occasional branching
mycobacterium; shapes
club-shaped or swollen at one end, occasional branching
mycoplasma; shapes
lack rigid cell walls so assume variety of shapes (coccoid, rodlike, L shape)
pleomorphism
bacteria can exhibit considerable variation in size and shape even in the same species and culture
streptococcus species; deviation
if taken from colony on solid medium, don't show chains but do show chains if taken from broth medium
neisseria genus, cocci; in broth
in broth, show flattened sides so they resemble beans
mycobacterium species; arrangements
clumps on smears because of waxy cell walls, and in a broth, grow in chains/cords
corynebacterium species; arrangements
lying side by side or at sharp angles as in palisade or chinese character formation
micrococcus species; arrangements
cubical packets of 4 or 8 cells
Staphylococcus; arrangements
irregular clumps
streptococcus genera; arrangements
chains
bacillus genera; arrangements
chains
neisseria genus, cocci; arrangements
pairs
streptococcus pneumoniae; arrangement
pairs
klebsiella pneumonia; arrangement
pairs
gram negative rod arrangements
single
shapes of bacteria (4)
spherical (coccus), rod-shaped (bacillus), curved (comma), helical (spiral or spirillum)
acid-fast staining
for mycobacterium whose cell walls have too much lipid for gram staining to be effective; use basic fuschin (red), decolorize, and then restain with methylene blue.
anionic dyes
bacteria repulse the negative charge so negative staining; ex. nigrosin and eosin
cationic dyes
bacteria are negatively charged at pH 7; so these bind to bacteria and give color
ex. crystal violet, safranin red, methylene blue and basic fuschin
colonial morphology; different terms (6)
density, texture, elevation, cohesiveness, shape and margin
culture characteristics (3)
odor production, pigment production and colonial morphology
MSA
mannitol salt agar; 7.5% NaCl, so selective for mainly staphylococci which survive in high salt concentrations (selective), and has mannitol and pH indicator (differential) which turns yellow if mannitol is fermented
MAC
macconkey agar; used to isolate enterbacteriaceae and other enteric negative rods. bile salts and crystal violet inhibit positive bacteria, negative cocci and fastidious negative rods (selective). differential for lactose-fermenters
CNA
columbia nalidixic acid agar; sheep blood agar with nalidixic acid which inhibits growth of negatives and most positive rods (selective)
SBA
sheep blood agar; TSA, SNA or BHI with 5% sheep blood for more fastidious pathogens. is differential for bacteria with different hemolytic activity (alpha = green, beta = clear, gamma = none)
BHI
brain heart infusion; cultivate and maintain more fastidious bacteria; such as Neisseria sp. and Streptococcus sp.; can also be used for non-fastidious bacteria
TSA
trypticase soy agar; used for general cultivation and maintenance; for non-fastidious bacteria such as E.coli, staphylococcus sp. and bacillus sp.
SNA
supplemental nutrient agar; used for general cultivation and maintenance; for non-fastidious bacteria such as E.coli, staphylococcus sp. and bacillus sp.
NA
nutrient agar; used for general cultivation and maintenance; for non-fastidious bacteria such as E.coli, staphylococcus sp. and bacillus sp.
microorganism used in epidemic lab
serratia marcescens, pink at 30C and colorless at 37C
Place this card into pile: