amtmicro813 Flashcards
(141 cards)
5 species with capsules:
-mucoid, antigenic/serotype
-Cryptococcus neoformans
-Strep/Kleb pneumo
-H.influ, N.meningitis
5 nonmotile
Flagella etc
Mono/Amphi/Peri…
Lopho…
-Kleb, Shigella
-Bacillus anthracis
-Corneybacterium
-L.mono at 35C
Flagella etc
Mono/Amphi/Peri…flagellus at one,both,all around
Lopho…tuft of flagella at a polar end
KB etc…
0.5 McFarland std adjust turbidity of inoculum
inoculate, wait at least 5 min but not more than 30 before putting on disks
smaller zone means too much moisture
measure diameter of outer zone, MIC is mininum inhibitory concentration
penicillin/methicillin best indicators of disk storage
agar 4.0, MH 150mm, ph 7.2
E test is MIC on a plastic triop
D test is double diffusion, looks like a D flattened zone of inhibition to clindamycin
…
Describe hemolysis:
alpha prime:
alpha:
beta:
gamma:
Describe hemolysis:
alpha prime: aplha surrounded by beta
alpha: incomplete, green
beta: complete, transparent
gamma: no hemolysis
QC:
dry heat oven:
autoclave/wet:
QC:
dry heat oven: B.subtilis
autoclave/wet: B.stearothermophilus
-dry=shorter bacillus
-wet=longer bacillus
7 sterilization methods…
1 most effective…
1 used if media can’t be heated…
6 sterilization methods…
-1 most effective…autoclave
-1 used if media can’t be heated…filtration
-boiling
-dry heat/flame
-fractionalization
-glutarldehyde: cold sterilization
-ethylene oxide gas
3 antiseptics: tissue
3 disinfectants: surfaces
-one best for viruses,spores,TB,fungi
antiseptics:
-alcohol, iodine, hydrogen peroxide
disinfectants:
-chlorine best for viruses, spores
-phenol
-quaternary ammonium
Smears:
-thin enough can see individual cells
-2 swabs best: culture, gram
-1 swab only: culture media first then roll swab for gram, slide isnt sterile
Morphology: 1
00 objective x 10 ocular=1000x
Cocci
-clusters, chains, pairs, tetrad arrangements
-diplo means pairs
-staphylo means irregular clumps/clusters
Bacilli
-cccobaccilli and fusiform baccilli arrangementes
Spirochetes
Stains
-METHYLENE BLUE: simple stain, only one dye
-GRAM: differential stain
-10sec each, rinse in between, air dry, oil objective
1.)crystal violet stains thick peptidoglycan wall with teichoic acid of GP, purple-blue
2.)iodine/mordant: fixes CV in GP; mordant combines with dye forms insoluble complex, fixes CV
3.)alcohol-acetone: decolorizes CV out of GN
4.)safrannin: counterstain for GN, pink-red
-WRIGHT:
*type of Romanowsky stain
*Methanol fixes the cells to the slide.
*Eosin Y is an acidic anionic dye *methylene blue is basic cationic dye
*buffer
*acid components of the cell (nucleus, cytoplasmic RNA, basophilic granules) stain blue or purple
*basic components of the cell (hemoglobin, eosinophilic granules) stain red or orange.
WRIGHT-GIESMA
-Giemsa stain is combined with the Wright’s Stain, the color brightens to a reddish-purple in the cytoplasmic granules
INDIA INK
-Cryptococcus neoformans, because of its large polysaccharide capsule, can be visualized by the India Ink stain.
Organisms that possess a polysaccharide capsule exhibit a halo around the cell against the black background created by the India Ink.
-Nigrosin
-cells negative charge repels stain
Acid fast stain
-ACID FAST: mycobacterium/TB
*Hard to decolorize due to mycolic acid and thus retain primary stain
*carbol fuchin, acid alcohol, methylene blue
*Pos pink, Neg blue/green
1.)Kinyoun: cold/no heat
-carbolfuschin
-phenol not heat for penetration
-MB or malachite green counter
2.)ZielNeelson: hot
-carbolfushin primary,
-heat to penetrate
-acid/ethanol to decolorize
-MB counterstain
3.)Fluorochrome:
-dye absorbs UV, emits higher wavelength
-more sensitive
-bright yellow orange, dark back
-auramine/rhodamine primary
-acid alcohol decolorizer
-K permanganate counter
YEAST/FUNGI
-Calcofluor white
-10% KOH to break down debris/mucous
-pos is bluish white flurescence
Most abundant NF in throat…
Most common pathogen in throat…
NF: alpha heme strep (viridans)
pathogen: S.pyogenes
Nasopharygeal swab for these 3…
Throat swab for this…
Nasopharygeal: upper respiratory
H.influ, N.mening, B.pertusis
Throat swab:
Strep pyogenes
3 GPC in clusters aerobic that are catalase+
4 GPC in chains/pairs aerobic catase -
3 GPC in clusters aerobic that are catalase+
-Staph, CNS (epi,sapro), micrococcus
4 GPC in chains/pairs aerobic catase -
-Strep(A pyogens,B agalactiae)
-enterococcus, group D
Differentiate CNS S.epi from S.sapro with…
-both cat+, coag neg
S.epi…skin
S.sapro..UTI
Differentiate S.epi from S.sapro with…
S.epi…suspectible to Novobiocin
S.sapro..resistant to Novobiocin
Grp… strep susceptible to…
How many units…
Grp…strep resistant to…
GrpA:
Bacitracin
0.02-0.04
GrpB: resistant to Bacitracin
Differentitate Grp A from GrpB strep
-both cat neg
Grp A..
-sensitive to
-1 test pos for
Grp B…
-resistant to
-2 tests are pos for
Group A sensitive to Bacitracin
-PYR pos
Group B resistant to Bacitracin
-CAMP, hippurate +
Both enterococcus and Grp D hydrolyze…
Differentiate these two with…
-enterococcus
-Grp D
both hydrolyze esculin
-enterococcus grows in NaCl
-Grp D doesn’t
What diff GPC aerobic from aerobic GNDC
GPC…
GNDC…
oxidase: purple
-drop reagent on colony
-rub colony filter paper, drop reagent
-rub colony on filter with reagent
*but do not use nichrome loop it will give false pos
GPC oxidase neg
GNDC oxidase pos
Alpha heme strep…
what diff between the two…
S.pneumo…
Viridians
S.pneumo:
-bile soluble, optochin susceptible
viridans:
-optochin resistant
Sugar fermentation…
N.gonn..
N.mening..
N.lac..
Moraxella..
-two test pos for
N.gonn=glucose
N.mening=glucose, maltose
N.lac=glucose,maltose, lactose
Moraxella=none
-DNase pos
-Butyrate esterase pos
2 genera GNDC, oxidase pos…
how to diff..
Neiserra, Moraxella
sugars
Best media for gonococci/meningcocci…
what is main agar, 3 antibiotics, additonal
Modified is Thayer Martin plus
-trimethoprim lactate(inhibits proteus swaming)
Thayer Martin
-enriched choc agar
-colistin, nystatin, vancomycin inhibit other bacteria/fungi
-incubate with increase CO2
Martin Lewis: better at inhibiting yeat than TM
NYC
GC-LECT
JEMBEC: transport/growth N.gonn
Chocolate agar:
-enriched, blood lysed supplies X(hemin),V(NAD)
-increased CO2
-Haemopholis/Neisseria
Two genera that caues pelvic inflammatory disease
N.gonn
-no cotton or calcium alginate swab
Chylamydia trachomatis
-no wooden shaft
best in incubate genital for 3 days
Betalactamase: enzyme by bacteria against beta lactam antibiotics
-do on primary isolation because plasmid coding will be lost by subculturing
-cephalosporin chromogenic color change to pink
-acidometric: turns yellow
-iodometric
…
SALMONELLA AND SHIGELLA
IN STOOL
-Salmonella and Shigella don’t ferment lactose
-Only Salmonella makes H2S
*bile salts to select
*all 3 differentiate LF and H2S
-H2S indicator sodium thiosulfate
*not the same H2S in TSI
(ferric amm.citrate/sulfate)
Hektoen enteric (HE):
-selects for S/S by inhibiting normal GI flora with bile salts, blue/fuschin
-nonpathogens have color
-differentiates LF
-Shigella/Salmonella don’t ferment lactose and don’t change color
-differentiates H2SH2S(NaThiosulfate,Ferric amm.citrate), Salmonella H2S black
Xylose lysine deoxycholate(XLD):
-selects S/S by inhibiting GNR/GP with deoxycholate
-Shigella doesn’t ferment xylose, sucrose, lactose
-differentiates: sugars/LF, H2S(Salmonella black)
-phenol red
Salmonella/Shigella(SS):
-selects by inhibiting other enterics with bile salts, brilliant green
-differentiates: LF, H2S
Gram negative broth:
-S/S from stools/rectal swabs
-selects for S/S by inhibiting GP with deoxycholate and citrate salts
…