The Search for Better Health Challenge Question!

[Survivor39]

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Hi everyone. I will post a series of interesting questions which relates to and extend beyond the materials you have learned in the HSC Biology course. I hope all of you inspired biologists in the future, like me, will find this interest and think about how fansinating biological sciences can be!

The Search for Better Health Challenge Question
(Difficulty: 9/10)

In this section of the course, you have learned about the immune system, and how phagocytosis is important in the defence against infection. However, some bacteria cannot be phagocytosed. Why?

[Dr_Doom]

Because they need to be coated in antibodies? But there are no B cells present at the time ? :S

[thejosiekiller]

hahah you need some knowledge of bacteria and mechanisms by which they escape the "immunological radar" at times

hint: some research into microbiology texts would help kiddies with this question

[Dr_Doom]

lol it's too hard to find info on this off google... Can you just tell me ? :P

[Survivor39]

Originally Posted by Dr_Doom

Because they need to be coated in antibodies? But there are no B cells present at the time ? :S

Antibodies can bind onto bacterial surface and help phagocyte to engulf the bacteria. This process is called opsonisation, which just means the antibody make the bacteria more "tasty" to the phagocytes.

But this process is not always neccessary. :P

Hint: what helps bacteria to survive inside the host? Do they have some protective barrier? What might be the purpose of having protective barrier?
Do you think bacteria causes disease by having 1 bacterial cell?

[+Po1ntDeXt3r+]

mycobacterium TB mech.. is the only one i can think off the top of my head :P

wait i know another.. cant think of its name tho :S
if all fails... host factors lolz :P

[Survivor39]

point.. is this another one of your "attempted" response or just random information again??

MTB obviously can be phagocytosed.. What are you talking about? They "want" to be phagocytosed by macrophages to hide inside the host cell and hence, evade the immune system. But my question is on how bacteria can prevent phagocytosis.

[+Po1ntDeXt3r+]

random.. u said evade the host..

and MTB evades the host for the 1st 3 weeks :P... actualli i wanted to know the answer ... in the middle of exam prep myself

[simplistic]

wat about the fact that some pathogens "abuse" phagocyctes in the sence that some will directly kill them some will hide with in them and lay dormant inside ... or that stomach ulcer thing were it created a protective thingy around itself to prevent stomach acids from denaturing its enzymes ?

[thejosiekiller]

also antigenic variance on the surface of the organism itself- from memory its either one strain of staph that is capable of this and maybe N. gono

not sure though

[Survivor39]

Originally Posted by simplistic

wat about the fact that some pathogens "abuse" phagocyctes in the sence that some will directly kill them some will hide with in them and lay dormant inside ... or that stomach ulcer thing were it created a protective thingy around itself to prevent stomach acids from denaturing its enzymes ?

This is a good attempt. The bacterium you are talking about is Helicobacter pylori, which can actually secrete an enzyme called urease, which break down stomach urea into ammonia. In the process, ammonia neutralises the surrounding stomach acid, and make the condition more favourable for H. pylori survival.

Unfortunately, this has got nothing to do with phagocytosis evasion.

[Survivor39]

Originally Posted by thejosiekiller

also antigenic variance on the surface of the organism itself- from memory its either one strain of staph that is capable of this and maybe N. gono

not sure though

Good answer. But what else?

Come on!! Please use my hints!!

***Do you think bacteria causes disease by having 1 bacterial cell??

[simplistic]

omg !!!!!!!!!!
4 pnts from bio :
for a microbe to be classifeid as pathogenic it need to
1.be present in high virulence
2.surviev on host without being destroyed by the host natural defence system \
3.4.and the rest not related to this

also some bacteria have endospore ....*mindless grabage*