Friday, October 28, 2011
3rd Year MBBS PARASITOLOGY (Pathology) OSPE by UHS
Ancyclostoma Duodenale egg
Ancyclostoma Egg
Ascaris Lubricoids
Ascaris Egg
Entamoeba Histolytica
Enterobius Egg
Giardia
Trichomonas
Trypanosoma
Trypanosoma
3rd Year MBBS Microbiology Slides and Tests
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
