TREATMENT of bacteria (1 Viewer)

[Tuna]

I was wondering if you could help us out on the treatment of bacteria with CAPSULE. Thanks

 

[Survivor39]

I was wondering if you could help us out on the treatment of bacteria with CAPSULE. Thanks

Antibiotics.

 

[Tuna]

Some Capsule bacteria are resistant to antibiotics due to the outer layer and thin peptidoglycan.

 

[Survivor39]

Autoclave 121 oC for 15 min
Disinfectants (70% ethanol)

 

[Survivor39]

Some Capsule bacteria are resistant to antibiotics due to the outer layer and thin peptidoglycan.

I think you are confused with Capsule and Cell wall.

A capsule is a polysccharide layer that has a variety of functions, including serum resistance and prevent phagocytosis. This is especially evident in urinary pathogenic E. coli (UPEC) that can evade host immune response.

You are right in that SOME capsule may prevent the action of antibiotics. However, you are not correct in saying that it is due to the outer layer and a thin layer of peptidoglycan.

Here, you referred to the cell wall of gram negative bacteria, which is composed of an outer membrane (similar to cell membrane) and a peptidoglycan layer. This is NOT the capsule. The capsule surrounds the cell wall (external to the outer membrane).

The cell wall MAY help in pumping antibiotics out of the cell, different to preventing the entry of antibiotics like capsule.

I hope this helps.

 

[Tuna]

Yes it does. If I have bacteria growing in my throat (shiny ones - which I grew them on agar plate) should I wash my throat with high conc. salt or take antibiotics?

 

[Survivor39]

well.. a lot of bacteria can have shiny appearance. It usually prevent them from drying, rather than use it to cause you any disease.

Most of the bacteria in your throat are commensal anyway. Unless you have identify this particular bacterium as Streptococcus pyrogenes, you shouldn't worry too much.

If you do have S. pyrogenes, a number of antibiotics is useful against it. e.g maybe penicillin (most of the time the bacterium is resistant), erythromycin, or tetracycline.

 

[Tuna]

Thanks. A question on penicillin why are some more effective than others? ( when we measure the diameter of our agar plates, the effective ones have a larger diameter compared to the smaller non-effective one)

 

[Survivor39]

Do you mean why some antibiotics are more effective than others? Antibiotics act differently. Some like penicillin or methicillin act on the cell wall. Erythromycin act on the ribosome and prevent gene expression. Some antibiotics act on the membrane. So their mechanisms of action make them different in their effiency (hence the size of zone of inhibition).

Also, the zone size will depdend on the state of your bacteria when you put them on your agar plate. For penicillin or any other beta-lactam antibiotics, they are most effective when your bacteria are in the exponential phase (actively growing), therefore, allowing the antibiotics to inhibit cell wall formation. They will NOT be effective when they are resting because no new cell wall is being formed. But some other antibiotics punches holes on the cell membrane don't care whether the cell is dividing or resting. So for resting bacteria, you may find some antibiotics more effective than others, while this is reversed when you inoculate an actively dividing batch of cells.

When you use antibiotics discs, notice that they have different concentrations? Do you think this might have an effect?

 

[Tuna]

Yes antibiotic, forgot sorry. Different concentrations could be the factor however, during the experiment the concentrations varied with antibiotics.

The highest concentration used was 30 mg by the antibiotic called Oxytatracycline. The inhibition zone, in mm, of S. aureus was 26, compared to Penicillin with the concentration of 5 mcg the Inhibition Zone was 32 mm.

The concentration would matter to an extent but wasn't shown in the experiment though.

What have you found interesting in Microbiology lately?

 

[Survivor39]

Even though the concentrations vary, this is not that important when looking for bacterial sensitivey/resistant. As long as you whether they are resistant or sensitive, that's all it matters for a sensitive test.

The concentration is set that way to reflect the maximum achievable concentration in the body. That's why each antibiotic disc has a different concentration.

Anyway, anything interesting microbiology.. hmmm, plasmid biology is actually more difficult than I thought (but interesting).

How about you?

 

[+Po1ntDeXt3r+]

If you do have S. pyrogenes, a number of antibiotics is useful against it. e.g maybe penicillin (most of the time the bacterium is resistant), erythromycin, or tetracycline.

penicillin G via IM injection or penicillin V via oral would be the appropriate treatment
alternatively amoxicillin for children

for:
penicillin allergies. - erythromicin... or macrolides like clarithromycin
or
Oral cephalosporins... but the penicillin is the drug of choice..

tho this is only if a person has a sore throat... not realli a good idea for prophaylaxis..

my 2 cents

 

[Tuna]

Anyway, anything interesting microbiology.. hmmm, plasmid biology is actually more difficult than I thought (but interesting).

How about you?

To me, many things about microbiology are interesting! I'm filled with microbes! They are eating and growing on our flesh.