Question 1

why would one use macconkey agar to plate throat, sputum, and wound cultures? what are they looking for?

Accepted Answer

Agar: It is just a method of growing the bacteria so as to determine the sensitivity to antibiotics.

Question 2

what are the nutrients are in nutrient agar?

Accepted Answer

Sugar and Beef: Sugar and beef extract (bouillon). The sugar provides the energy via glucose and the beef provides protein. Gelatin is used to solidify the agar.

Question 3

is eating agar agar a good way to increase your fibre intake?

Accepted Answer

No: typically used as gelatin component.

Question 4

why we do not use jelly instead of agar as a medium for the growth of bacteria?

Accepted Answer

Jelly - solid or liq: Microbiologists want their bacteria to be on a well-defined, predictable, relatively pure media, so that everyone agrees on the resulting growth pattern, shape, color, etc. Preference is given to solid media (agar plates) or liquid media (broth). Therefore, new media, especially variable in components and textures, are rarely used.

Question 5

cled medium preferred over mcconkey agar in uti because?

Accepted Answer

Bacteriology: Cled medium helps to prevent swarming of proteus over the surface of the plate.  When this occurs it can overgrow and prevent identification of other organisms which may have been present. Am unaware that there is universal acceptance that this is preferred over mcconkey, and am also not familiar with the frequency with which proteus creates a problem.

Question 6

what does "beta-hemolysis on cna blood agar plate" mean?

Accepted Answer

Lab finding: It is a white zone around the colonies of bacteria.

Question 7

why mycobacteria tuberculosis cannot be cultured on blood agar?

Accepted Answer

TB culture: Tb is difficult to culture and culture results often take months.  Lowenstin-jensen and middlebrook agars are the culture medias used to grow tb.

Question 8

how could clostridium botulinum be cultured on agar?

Accepted Answer

'Botox' organism: Clostridium botulinum is the bacterial species that produces the 'botox' toxin. It is actually a very dangerous bacterium and I would not advocate any sort of 'experiments' with that.  Leave that to the experts who have biosafety labs.  
Of note, those who do home canning should be aware of cans that are swollen or seemingly abnormal - they could harbor the bacteria and it's deadly toxin.

Question 9

does tb cause hemolysis of blood agar? and what of hemolysis?

Accepted Answer

Question unclear: If you are asking a microbiology lab question about whether mycobacterium tuberculosis  growth produces hemolysis, it is not generally grown on blood agar, generally does not produce hemolysins.  It is generally cultured on specialized media and the type of hemolysis is not an issue in its identification.

Question 10

how long does it take for streptococcal pharyngitis to grow on agar in petri dishes?

Accepted Answer

Up to 2 days: Generally if it hasn't grown in 2 days or less then it is not going to. A throat culture would be considered negative after no growth in 48 hours.

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Doctor answers about:

Macconkey agar

A member asked:

Why would one use macconkey agar to plate throat, sputum, and wound cultures? what are they looking for?

A member asked:

What are the nutrients are in nutrient agar?

A member asked:

Is eating agar agar a good way to increase your fibre intake?

A member asked:

Why we do not use jelly instead of agar as a medium for the growth of bacteria?

A member asked:

Cled medium preferred over mcconkey agar in uti because?

A member asked:

What does "beta-hemolysis on cna blood agar plate" mean?

A member asked:

Why mycobacteria tuberculosis cannot be cultured on blood agar?

A member asked:

How could clostridium botulinum be cultured on agar?

A member asked:

Does tb cause hemolysis of blood agar? and what of hemolysis?

A member asked:

How long does it take for streptococcal pharyngitis to grow on agar in petri dishes?

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