RBCs in Urine
Hyphae
Slide of Stool
Gram positive Cocci
Mycobacerium Tuberculsis (Ziehl-Neilsen stain)Ziehl Neelson Staining:
• 1. Cover with tissue paper• 2. Flood slide with carbolfuchsin, the primary stain, for 2 minutes while heating with steam.
• 3. Remove paper cover, decolorize slide with a mixture of hydrochloric acid and ethanol.
• 4. Counter stain with methylene blue.
Urease Test:
Indicator --- Phenol Red
Urease producing org. will convert urea in test tube to ammonia, pH becomes alkaline, the indicator becomes red.
Urease +ve --- Red --- H.pylori, Proteus, Klebsiella, Yersinia, Enterocolitica
Urease -ve --- Yellow --- Salmonella, Shigella.
Triple Sugar Iron:
contains Ferous Sulfate, 3 sugars(glucose, lactose, sucrose) (glucose in 1 tenth the conc. Of other sugars)
Butt – poorly oxygenated area
Slant – inclined well oxygenated area
In the presence of (A)cid the indicator will turn --- yellow (sugar fermented acid produced)
in the prescense ofAl(K)aline the indicator will remain --- pink
if lactose is not fermented but the glucose is... butt will be yellow(no O2) but on slant the acid will be oxidised so it will be red.
H2S production--- black
Interpretation
(slant/deep/gas/H2S) (organisms)
A A + - Klebsiella, Enterobacter, E.Coli
K A - - Shigella, Serratia
K A + + Salmonella, Proteus
K K - - Pseudomonas
A A - - Vibrio
A A + + Citrobacter
K A - + S. typhi
Oxidase Test:
It is used to differentiate aerobic n facultative aerobes from anaerobes based on the formers oxygen utilization ability n the presence of oxidase enzyme.Phenylene diamine dihydrochloride(subd. 4 oxidase) acts as an electron receptor and gets oxidized to produce purple or black colour.
Oxidase +ve --- Purple --- P.aeru, vibrio, nisseria, brucella n pasturella
Oxidase -ve --- E.coli, salmonella, shigella
Specimen/Slide --- filter paper showing purple colour.
Motility Test:
semisolid agar --- 0.4% conc. Of agar is used
medium is made in an upright position
a straight wire is used to innoculate at centre of medium
Interpretation
motile org. produce haze --- E.coli n Salmonella, Proteus
non motile org. produce discrete line --- Klebsiella, Shigella
DNAse test:
is used to identify S.Aureus that produces deoxyribonuclease enzymesContains
• Dnase
• NaCl
• Agar
+ve is seen as a clearing around the colonies
Citrate Test:
differentiates family of enterobacter based on their utilization of citrate as a source of carbon.
Contents :
Sodium Citrate --- Source of carbon
Ammonium Phosphate --- source of nitrogen
org. that extract carbon also extract nitrogen, turn medium alkaline
Indicator --- Bromothymol Blue (blue at alkaline pH, green at acidic)
Simmons Citrate agar is used 4 culture, slope of medium streaked, incubated at 37 deg 4 24 hrs.
Interpretation
Citrate Test +ve --- Blue --- Citrobacter, Klebseilla, Salmonella
Citrate Test -ve --- Green --- E.Coli
thank you
ReplyDelete