OSPE REVISION PATHOLOGY BDS 2ND YEAR / 3RD YEAR MBBS
BDS 2ND YEAR OSPE SLIDES 2011 DR EJAZ WARIS Associate Professor Histopathology FMHC
Chocolate agar Chocolate agar (CHOC) - is a non-selective, enriched growth medium. It is a variant of the blood agar plate. It contains red blood cells, which have been lysed by heating very slowly to 56 °C. Chocolate agar is used for growing fastidious (fussy) respiratory bacteria, such as Haemophilus influenzae. These bacteria need growth factors, like NAD and hematin, which are inside erythrocytes; thus, a prerequisite to growth is lysis of the red blood cells
A nutrient culture medium that is enriched with whole blood and used for the growth of certain strains of bacteria. Contains mammalian blood (usually sheep or horse), typically at a concentration of 5–10%. BAP are an enriched, differential media used to isolate fastidious organisms and detect hemolytic activity. β-hemolytic activity will show complete lysis of red blood cells surrounding colony, while α-hemolysis will only partially lyse hemoglobin and will appear green. γ- hemolysis (or non-hemolytic) is the term referring to a lack of hemolytic activity.
micropipetteA pipette used to measure very small volumes of liquids.
Salmonellashigella agar plate with h2s producing colonies
The Lowenstein-Jensen medium, popularly known as LJ medium, is a growth medium specially used for culture of Mycobacterium, notably Mycobacterium tuberculosis. When grown on LJ medium, M. tuberculosis appears as brown, granule-like colonies. The media must be incubated for a significant length of time, usually four weeks, due to the slow doubling time of M. tuberculosis compared with other bacteria (15-20 hours).
Cysteine Lactose Electrolyte Deficient agar (CLED) CLED agar is used to isolate and differentiate urinary tract bacteria, since it inhibits Proteus species swarming and can differentiate between lactose fermenters and non- fermenters.
MacConkey agar (MAC)A selective and differential media used to differentiate between Gram negative bacteria while inhibiting the growth of Gram positive bacteria. The addition of bile salts and crystal violet to the agar inhibits the growth of most Gram positive bacteria, making MacConkey agar selective. Lactose and neutral red are added to differentiate the lactose fermenters, which form pink colonies, from lactose nonfermenters that form clear colonies.
Sabouraud agar is used to culture fungi and has a low pH that inhibits the growth of most bacteria; also contains the antibiotic gentamicin to specifically inhibit the growth of Gram-negative bacteria.
TripleSugar Iron medium is a differential medium that can distinguish between a number of Gram-negative enteric bacteria based on their physiological ability (or lack thereof) to: a. metabolize lactose and/or sucrose b. conduct fermentation to produce acid c. produce gas during fermentation d. generate H2S.
The medium contains 1.0% each of sucrose and lactose and 0.1% glucose. If only glucose is fermented, acid produced in the butt will turn it yellow, but insufficient acid products are formed to affect the methyl red in the slant. However, if either sucrose or lactose are fermented, sufficient fermentation products will be formed to turn both the butt and the slant yellow. If gas is formed during the fermentation, it will show in the butt either as bubbles or as cracking of the agar. If no fermentation occurs (as for an obligate aerobe), the slant and butt will remain red.