Typhoid Systemic Toxicity Mechanism - USMLE Forums
USMLE Forums Logo
USMLE Forums         Your Reliable USMLE Online Community     Members     Posts
Home
USMLE Articles
USMLE News
USMLE Polls
USMLE Books
USMLE Apps
Go Back   USMLE Forums > USMLE Step 1 Forum

USMLE Step 1 Forum USMLE Step 1 Discussion Forum: Let's talk about anything related to USMLE Step 1 exam


Reply
 
Thread Tools Search this Thread Display Modes
  #1  
Old 04-12-2011
USMLE Forums Scout
 
Steps History: 1 + CK
Posts: 91
Threads: 17
Thanked 108 Times in 37 Posts
Reputation: 118
Bacteria Typhoid Systemic Toxicity Mechanism

Typhoid fever is transmitted fecal-orally. How does the bacterium responsible for this disease cause systemic manifestations?

A. Neurotoxin elaboration
B. Intestinal perforation
C. Endotoxin elaboration
D. Invasion of enteric blood vessels
E. Invasion of macrophages
Reply With Quote Quick reply to this message
The above post was thanked by:
apx85 (04-12-2011), doc_study (04-13-2011)



  #2  
Old 04-12-2011
USMLE Forums Guru
 
Steps History: Not yet
Posts: 298
Threads: 45
Thanked 718 Times in 210 Posts
Reputation: 728
Default

D) Invasion of enteric blood vessels

Salmonella is an invasive organism
Reply With Quote Quick reply to this message
  #3  
Old 04-12-2011
USMLE Forums Scout
 
Steps History: 1 + CK
Posts: 91
Threads: 17
Thanked 108 Times in 37 Posts
Reputation: 118
Default

Quote:
Originally Posted by apx85 View Post
D) Invasion of enteric blood vessels

Salmonella is an invasive organism
no sorry
Reply With Quote Quick reply to this message
The above post was thanked by:
apx85 (04-12-2011)
 
  #4  
Old 04-12-2011
USMLE Forums Newbie
 
Steps History: ---
Posts: 7
Threads: 0
Thanked 2 Times in 2 Posts
Reputation: 12
Default B

Intestinal perforation
Reply With Quote Quick reply to this message
The above post was thanked by:
apx85 (04-12-2011)
  #5  
Old 04-12-2011
USMLE Forums Scout
 
Steps History: 1 + CK
Posts: 91
Threads: 17
Thanked 108 Times in 37 Posts
Reputation: 118
Default

Quote:
Originally Posted by Mermiz View Post
Intestinal perforation
absolutely not
Reply With Quote Quick reply to this message
The above post was thanked by:
apx85 (04-12-2011)
  #6  
Old 04-12-2011
USMLE Forums Guru
 
Steps History: Not yet
Posts: 298
Threads: 45
Thanked 718 Times in 210 Posts
Reputation: 728
Default

Quote:
Originally Posted by tinhi View Post
no sorry
Then I would have to say Invasion of Macrophages :sorry:
Reply With Quote Quick reply to this message
  #7  
Old 04-12-2011
USMLE Forums Master
 
Steps History: 1+CK+CS
Posts: 590
Threads: 31
Thanked 1,230 Times in 411 Posts
Reputation: 1254
Default

Quote:
Originally Posted by apx85 View Post
Then I would have to say Invasion of Macrophages :sorry:
That's what I would say, too...

Salmonella does invade through the intestines, but not violently - it elaborates a factor that encourages M cells (M for microfold) to "ruffle" and allow entry. It is presented to macrophages, but replicates and travels inside of the macrophages, so its replication and dissemination are fairly protected.
Reply With Quote Quick reply to this message
The above post was thanked by:
apx85 (04-12-2011)
  #8  
Old 04-12-2011
USMLE Forums Master
 
Steps History: 1+CK+CS
Posts: 590
Threads: 31
Thanked 1,230 Times in 411 Posts
Reputation: 1254
Default

Gaaaah - but now that I read the question more carefully, perhaps C. Endotoxin elaboration is the best answer. E. is best for why it's systemic, but C. is the proximal cause of the symptoms.
Reply With Quote Quick reply to this message
The above post was thanked by:
apx85 (04-12-2011), doc_study (04-13-2011)
  #9  
Old 04-12-2011
USMLE Forums Scout
 
Steps History: 1 + CK
Posts: 91
Threads: 17
Thanked 108 Times in 37 Posts
Reputation: 118
Default

Quote:
Originally Posted by Mondoshawan View Post
That's what I would say, too...

Salmonella does invade through the intestines, but not violently - it elaborates a factor that encourages M cells (M for microfold) to "ruffle" and allow entry. It is presented to macrophages, but replicates and travels inside of the macrophages, so its replication and dissemination are fairly protected.
excellent

The correct answer is E.

T he first step in the genesis of the disease is:

Salmonella colonizes the intestines → translocation across epithelium → grows in macrophages in Peyer’s patches.
The macrophages provide protection from the immune system, The bacteria replicate rapidly within this cells, and spread to the reticuloendothelial system including liver and spleen, which become enlarged, and potentially gallbladder (possibility of chronic carriers )
Reply With Quote Quick reply to this message
The above post was thanked by:
apx85 (04-12-2011), doc_study (04-13-2011), docoftheworld (05-22-2011), Dr.Nathaly (04-12-2011), heights (04-12-2011), Mondoshawan (04-12-2011), noothan (04-12-2011)
  #10  
Old 04-12-2011
USMLE Forums Scout
 
Steps History: 1 + CK
Posts: 91
Threads: 17
Thanked 108 Times in 37 Posts
Reputation: 118
Default

Quote:
Originally Posted by Mondoshawan View Post
Gaaaah - but now that I read the question more carefully, perhaps C. Endotoxin elaboration is the best answer. E. is best for why it's systemic, but C. is the proximal cause of the symptoms.
Salmonella possesses LPS endotoxin but unlike in pathogens like meningococcus (Neisseria meningitidis), this endotoxin is not a direct cause of systemic disease
Reply With Quote Quick reply to this message
The above post was thanked by:
apx85 (04-12-2011), Mondoshawan (04-12-2011)
  #11  
Old 04-12-2011
USMLE Forums Guru
 
Steps History: Not yet
Posts: 298
Threads: 45
Thanked 718 Times in 210 Posts
Reputation: 728
Default

Good question. What is the treatment? Is it Trimethoprim?
Reply With Quote Quick reply to this message
  #12  
Old 04-12-2011
USMLE Forums Scout
 
Steps History: 1 + CK
Posts: 91
Threads: 17
Thanked 108 Times in 37 Posts
Reputation: 118
Default

Quote:
Originally Posted by apx85 View Post
Good question. What is the treatment? Is it Trimethoprim?
yes I think we can use any of these antibiotics: ampicillin, chloramphenicol, trimethoprim-sulfamethoxazole or Amoxicillin along with rehydration
Reply With Quote Quick reply to this message
The above post was thanked by:
apx85 (04-12-2011), Mondoshawan (04-12-2011)
  #13  
Old 04-12-2011
USMLE Forums Guru
 
Steps History: Not yet
Posts: 298
Threads: 45
Thanked 718 Times in 210 Posts
Reputation: 728
Default

Quote:
Originally Posted by tinhi View Post
yes I think we can use any of these antibiotics: ampicillin, chloramphenicol, trimethoprim-sulfamethoxazole or Amoxicillin along with rehydration
Ok cool. I remember chloramphenicol actually because I heard it is sometimes used in underdeveloped countries because it is cheap, even though it can cause bone marrow suppression
Reply With Quote Quick reply to this message
The above post was thanked by:
Mondoshawan (04-12-2011), tinhi (04-12-2011)
  #14  
Old 04-12-2011
USMLE Forums Scout
 
Steps History: 1 + CK
Posts: 91
Threads: 17
Thanked 108 Times in 37 Posts
Reputation: 118
Default

Quote:
Originally Posted by apx85 View Post
Ok cool. I remember chloramphenicol actually because I heard it is sometimes used in underdeveloped countries because it is cheap, even though it can cause bone marrow suppression
They don't use it anymore because of development of resistance and side effect
Reply With Quote Quick reply to this message
The above post was thanked by:
apx85 (04-12-2011)
  #15  
Old 04-12-2011
USMLE Forums Master
 
Steps History: 1+CK+CS+3
Posts: 1,175
Threads: 38
Thanked 852 Times in 478 Posts
Reputation: 862
Default

Quote:
Originally Posted by apx85 View Post
Good question. What is the treatment? Is it Trimethoprim?
Isn't treatment Ciproflox?

I swear it was Tx of choice.
Reply With Quote Quick reply to this message






Reply

Tags
Microbiology-, Step-1-Questions

Quick Reply
Message:
Options

Register Now

In order to be able to post messages on the USMLE Forums forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.
User Name:
Password
Please enter a password for your user account. Note that passwords are case-sensitive.
Password:
Confirm Password:
Email Address
Please enter a valid email address for yourself.
Email Address:
Medical School
Choose "---" if you don't want to tell. AMG for US & Canadian medical schools. IMG for all other medical schools.
USMLE Steps History
What steps finished! Example: 1+CK+CS+3 = Passed Step 1, Step 2 CK, Step 2 CS, and Step 3.

Choose "---" if you don't want to tell.

Favorite USMLE Books
What USMLE books you really think are useful. Leave blank if you don't want to tell.
Location
Where you live. Leave blank if you don't want to tell.

Log-in

Human Verification

In order to verify that you are a human and not a spam bot, please enter the answer into the following box below based on the instructions contained in the graphic.



Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes


Similar Threads
Thread Thread Starter Forum Replies Last Post
Digoxin Toxicity Ahmed mido USMLE Step 1 Forum 5 06-25-2016 08:44 PM
Systemic Sclerosis and another question Androide89 USMLE Step 1 Forum 3 09-18-2010 08:12 PM
TCA toxicity abhinav USMLE Step 1 Forum 2 03-27-2010 04:38 PM
After Party Toxicity Yallah USMLE Step 1 Forum 3 03-24-2010 12:07 AM
Vitamin C toxicity and Kidney Stones! lemontea88 USMLE Step 1 Forum 10 12-21-2009 10:04 PM

RSS Feed
Find Us on Facebook
vBulletin Security provided by vBSecurity v2.2.2 (Pro) - vBulletin Mods & Addons Copyright © 2017 DragonByte Technologies Ltd.

USMLE® & other trade marks belong to their respective owners, read full disclaimer
USMLE Forums created under Creative Commons 3.0 License. (2009-2014)