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  #1  
Old 11-30-2011
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Question Cystic Fibrosis Resistent to Typhoid!

like G6PD deficient patients are resistant to malaria..why cystic fibrosis patients are resistant to typhoid???

does anyone know the reason?
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  #2  
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no one is replying..ppl just used to visit the thread n walk away..
share your knowledge..
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  #3  
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I did a quick search of the literature.

"The type IVb pilus of the enteropathogenic bacteria Salmonella typhi is a major adhesion factor during the entry of this pathogen into gastrointestinal epithelial cells. Its target of adhesion is a stretch of 10 residues from the first extracellular domain of cystic fibrosis transmembrane conductance regulator (CFTR)."

From the abstract of "Structural basis of typhoid: Salmonella typhi type IVb pilin (PilS) and cystic fibrosis transmembrane conductance regulator interaction".
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  #4  
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hw nice of u..
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  #5  
Old 12-02-2011
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Quote:
Originally Posted by targetsept12 View Post
like G6PD deficient patients are resistant to malaria..why cystic fibrosis patients are resistant to typhoid???

does anyone know the reason?
thnxx target. i was also curious
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  #6  
Old 12-03-2011
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Default does this mean in cystic fibrosis patient CFTR IS ABSENT

Quote:
Originally Posted by ALittleTeaPot View Post
I did a quick search of the literature.

"The type IVb pilus of the enteropathogenic bacteria Salmonella typhi is a major adhesion factor during the entry of this pathogen into gastrointestinal epithelial cells. Its target of adhesion is a stretch of 10 residues from the first extracellular domain of cystic fibrosis transmembrane conductance regulator (CFTR)."

From the abstract of "Structural basis of typhoid: Salmonella typhi type IVb pilin (PilS) and cystic fibrosis transmembrane conductance regulator interaction".
if salmonella typhoid requires CFTR for adhesion, it mean it can cause typhoid only when CFTR is present, is that right
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Info For further info

http://www.journals.elsevierhealth.c...00882/abstract
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  #8  
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Quote:
Originally Posted by CHAKRAM View Post
there is nothing fruitful in this link.
wht do u want to say.??
plz post it here
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  #9  
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Quote:
Originally Posted by CHAKRAM View Post
if salmonella typhoid requires CFTR for adhesion, it mean it can cause typhoid only when CFTR is present, is that right
nope its not like tht.
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  #10  
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i think 'alittle teapot' is going on right way..explained nicely
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Quote:
Originally Posted by targetsept12 View Post
i think 'alittle teapot' is going on right way..explained nicely
Originally Posted by CHAKRAM
if salmonella typhoid requires CFTR for adhesion, it mean it can cause typhoid only when CFTR is present, is that right

CHAKRAM and "alittle teapot" both are right on their way

if salmonella tyhphi requires CFTR for pathogenesis,and in cystic fibrosis pt.CFTR is deficient thats why CF pt.is resistant to salmonella typhi,is that right?
if not then please explain
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  #12  
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Quote:
Originally Posted by riya_rai84 View Post
Originally Posted by CHAKRAM
if salmonella typhoid requires CFTR for adhesion, it mean it can cause typhoid only when CFTR is present, is that right

CHAKRAM and "alittle teapot" both are right on their way

if salmonella tyhphi requires CFTR for pathogenesis,and in cystic fibrosis pt.CFTR is deficient thats why CF pt.is resistant to salmonella typhi,is that right?
if not then please explain
woooooaaa..kya logic he boss

i dont knw the reason.. if anyone knws the reason plz post it here.. me & riya are waiting
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Quote:
Originally Posted by targetsept12 View Post
woooooaaa..kya logic he boss

i dont knw the reason.. if anyone knws the reason plz post it here.. me & riya are waiting
lolllzzzzz.. he is flirting.. hw romantic!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!:coo l:
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Quote:
Originally Posted by targetsept12 View Post
woooooaaa..kya logic he boss

i dont knw the reason.. if anyone knws the reason plz post it here.. me & riya are waiting
Cholera:
cholera toxin requires normal host CFTR proteins to function properly, it was hypothesized that carriers of mutant CFTR genes benefited from resistance to cholera and other causes of diarrhea.Further studies have not confirmed this hypothesis.

Typhoid:
Normal CFTR proteins are also essential for the entry of Salmonella typhi into cells, suggesting that carriers of mutant CFTR genes might be resistant to typhoid fever. No in vivo study has yet confirmed this. In both cases, the low level of cystic fibrosis outside of Europe, in places where both cholera and typhoid fever are endemic, is not immediately explicable.

Diarrhea:
carriers of a single mutant CFTR chromosome had some protection from diarrhea caused by lactose intolerance, prior to the appearance of the mutations that created lactose tolerance.

Tuberculosis:
Another possible explanation is that carriers of the gene could have some resistance to TB.
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Quote:
Originally Posted by riya_rai84 View Post
Cholera:
cholera toxin requires normal host CFTR proteins to function properly, it was hypothesized that carriers of mutant CFTR genes benefited from resistance to cholera and other causes of diarrhea.Further studies have not confirmed this hypothesis.

Typhoid:
Normal CFTR proteins are also essential for the entry of Salmonella typhi into cells, suggesting that carriers of mutant CFTR genes might be resistant to typhoid fever. No in vivo study has yet confirmed this. In both cases, the low level of cystic fibrosis outside of Europe, in places where both cholera and typhoid fever are endemic, is not immediately explicable.

Diarrhea:
carriers of a single mutant CFTR chromosome had some protection from diarrhea caused by lactose intolerance, prior to the appearance of the mutations that created lactose tolerance.

Tuberculosis:
Another possible explanation is that carriers of the gene could have some resistance to TB.
nice job. from wher did u find it?
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  #16  
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Quote:
Originally Posted by riya_rai84 View Post
Cholera:
cholera toxin requires normal host CFTR proteins to function properly, it was hypothesized that carriers of mutant CFTR genes benefited from resistance to cholera and other causes of diarrhea.Further studies have not confirmed this hypothesis.

Typhoid:
Normal CFTR proteins are also essential for the entry of Salmonella typhi into cells, suggesting that carriers of mutant CFTR genes might be resistant to typhoid fever. No in vivo study has yet confirmed this. In both cases, the low level of cystic fibrosis outside of Europe, in places where both cholera and typhoid fever are endemic, is not immediately explicable.

Diarrhea:
carriers of a single mutant CFTR chromosome had some protection from diarrhea caused by lactose intolerance, prior to the appearance of the mutations that created lactose tolerance.

Tuberculosis:
Another possible explanation is that carriers of the gene could have some resistance to TB.
u always do your work by heart.. thts really impressive.. kip it up riya
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  #17  
Old 12-04-2011
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Default simple explanation. will clear all the doubts..

In normal person, CFTR is chloride channel which regulates flow of Na+ , Cl- ,H2O across epithelial lining of Airway, Biliary tree, Intestine, Vas deferense, Sweat ducts & Pancreatic ducts.

see, Eccrine sweat is an isotonic fluid which travells through Eccrine duct to skin surface. Simultaneously Cl- is reabsorbed via CFTR & Na+ follows it.

Thus, the main function of CFTR (in every normal persons) is production of hypotonic sweat.

this function is altered in cystic fibrotic patient( mutation CFTR gene plays role here).

S.typhi can only causes typhoid in presence of normal CFTR channel..

so, querry solved!! CF patients are resistant to typhoid..

cheeeeeeerrrssss
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  #18  
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Quote:
Originally Posted by targetsept12 View Post
In normal person, CFTR is chloride channel which regulates flow of Na+ , Cl- ,H2O across epithelial lining of Airway, Biliary tree, Intestine, Vas deferense, Sweat ducts & Pancreatic ducts.

see, Eccrine sweat is an isotonic fluid which travells through Eccrine duct to skin surface. Simultaneously Cl- is reabsorbed via CFTR & Na+ follows it.

Thus, the main function of CFTR (in every normal persons) is production of hypotonic sweat.

this function is altered in cystic fibrotic patient( mutation CFTR gene plays role here).

S.typhi can only causes typhoid in presence of normal CFTR channel..

so, querry solved!! CF patients are resistant to typhoid..

cheeeeeeerrrssss
so aptful explanation, target..
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