Challenging Question #5 - 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 2 CK Forum

USMLE Step 2 CK Forum USMLE Step 2 CK Discussion Forum: Let's talk about anything related to USMLE Step 2 CK exam


Reply
 
Thread Tools Search this Thread Display Modes
  #1  
Old 09-15-2010
Official Advertiser Representative
 
Steps History: ---
Posts: 34
Threads: 12
Thanked 7 Times in 6 Posts
Reputation: 17
Bacteria Challenging Question #5

5) A 15-year-old high school student and several of her friends ate lunch at a local Chinese restaurant. They all were served the daily luncheon special, which consisted of sweet and sour pork with vegetables and fried rice. All the girls developed nausea, vomiting, abdominal pain, and diarrhea within 6 hours of eating lunch. The were all sent to the local emergency department for work-up of their suspected food poisoning. The children are all otherwise healthy and none are on any medication and have no known allergies.

Which of the following is the most likely cause of these symptoms?

A) Bacillus cereus
B) Staphylococcus aureus
C) Clostridium botulinum
D) Clostridium perfringens
E) EHEC (Enterohemorrhagic Escherichia coli)

Explanation will be posted soon....
__________________
_______________________
Try 60 Free Challenging questions with full explanations at:

To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.


Join Us on
To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
(4600+ Fans)
Reply With Quote Quick reply to this message
The above post was thanked by:
speedballz_21 (09-16-2010)



  #2  
Old 09-15-2010
USMLE Forums Scout
 
Steps History: Step 1 Only
Posts: 70
Threads: 0
Thanked 6 Times in 6 Posts
Reputation: 16
Default

A. bacillus cereus
Reply With Quote Quick reply to this message
  #3  
Old 09-15-2010
Chessmatic's Avatar
USMLE Forums Addict
 
Steps History: Step 1 Only
Posts: 114
Threads: 5
Thanked 60 Times in 42 Posts
Reputation: 70
Default

Chinese restaurant means bacillus cereus
that's an old trick
Reply With Quote Quick reply to this message
 
  #4  
Old 09-15-2010
USMLE Forums Newbie
 
Steps History: 1+CK+CS+3
Posts: 6
Threads: 0
Thanked 1 Time in 1 Post
Reputation: 11
Default

Nice! Like the trick!

I learned a new one as well today....

hypercalcemia:
CHIMPANZEES
calcium excess (administration)
hyperparathyroidism
immobility / iatrogenic
metastasis / milk-alkali syndrome
pagetís disease
addisonís disease
neoplasms
excess vit D
excess vit A
sarcoidosis
Reply With Quote Quick reply to this message
The above post was thanked by:
speedballz_21 (09-16-2010)
  #5  
Old 09-15-2010
USMLE Forums Guru
 
Steps History: ---
Posts: 487
Threads: 69
Thanked 296 Times in 133 Posts
Reputation: 316
Default

A) Bacillus cereus...
__________________
258(1)/237(1)/CS pass(1)/YOG 2011/221(1)/6 months USCE/ 3 months observership/4 US LOR /Need visa
To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
Reply With Quote Quick reply to this message
  #6  
Old 09-16-2010
USMLE Forums Guru
 
Steps History: 1 + CS
Posts: 405
Threads: 55
Thanked 528 Times in 155 Posts
Reputation: 538
Default

Bacillus Cereus - Chinese food and Mexican food like Tacos being the buzzwords.
Reply With Quote Quick reply to this message
  #7  
Old 09-16-2010
JaJeeK's Avatar
USMLE Forums Addict
 
Steps History: 1+CK+CS
Posts: 143
Threads: 4
Thanked 178 Times in 59 Posts
Reputation: 188
Default

Quote:
Originally Posted by DermResident View Post
Nice! Like the trick!

I learned a new one as well today....

hypercalcemia:
CHIMPANZEES
calcium excess (administration)
hyperparathyroidism
immobility / iatrogenic
metastasis / milk-alkali syndrome
pagetís disease
addisonís disease
neoplasms
excess vit D
excess vit A
sarcoidosis
That was mentioned here
Causes of Hypercalcemia Mnemonic
Reply With Quote Quick reply to this message
  #8  
Old 09-16-2010
USMLE Forums Newbie
 
Steps History: 1+CK+CS+3
Posts: 6
Threads: 0
Thanked 1 Time in 1 Post
Reputation: 11
Default

haha...thanks...found it on the medical mneumonics site yesterday...
Reply With Quote Quick reply to this message
  #9  
Old 10-14-2010
atr88's Avatar
USMLE Forums Scout
 
Steps History: CK Only
Posts: 57
Threads: 20
Thanked 237 Times in 36 Posts
Reputation: 247
Post

two bacterias are famous for causing diarrhea only in few hours after meal(short common period):
staphylococcus (in Mayonnaise & cream & meat)
Bacillus Cereus (in fried rice)

two common viral causes of diarrhea in children
rotavirus(usually in lower than 2 years old)
norwalk (usually in more than 2 years old)
Reply With Quote Quick reply to this message
  #10  
Old 10-19-2010
TheOneTheOnly's Avatar
USMLE Forums Scout
 
Steps History: ---
Posts: 21
Threads: 4
Thanked 9 Times in 5 Posts
Reputation: 19
Default

Hey guys they have all the answers on their site.

Here it is:

The correct answer is Choice A.

The most likely cause of the patient's symptoms is infection by Bacillus cereus, (Choice A) a Gram-positive rod that causes foodborne illness. Improperly cooked food allows bacterial endospores to survive while subsequent improper refrigeration allows for germination of the bacterial endospores and production of enterotoxins.

Bacillus cereus causes two separate forms of illness: an emetic form and a diarrheal form. Improperly cooked and stored rice is one of the most commonly implicated foods associated with the emetic form. The emetic form is caused by a toxin named cereulide, which leads to nausea and vomiting a short time (2 to 6 hours) after ingestion. The diarrheal form is caused by three toxins: Hemolysin BL, Nonhemolytic Enterotoxin, and Cytotoxin K. Many different types of food are associated with the diarrheal form and symptoms of watery non-bloody diarrhea and abdominal cramps occur 8 to 20 hours after ingestion.

Staphylococcus aureus (Choice B) is a Gram-Positive cocci which is found in clusters. Staphylococcus aureus is coagulase positive and causes a variety of infections including impetigo, cellulitis, osteomyelitis, endocarditis, and myositis. Staphylococcus aureus food poisoning occurs due to the ingestion of preformed toxins (heat and acid-stable staphylococcal enterotoxins). Illness can occur as soon as 4 hours after eating contaminated food. Staphylococcal enterotoxins act directly on neural receptors in the upper gastrointestinal tract which leads to stimulation of the vomiting center of the brain. Typical foods associated with Staphylococcus aureus food poisoning include ham, cream filled pastries, and potato salad.

Clostridium botulinum (Choice C) is a Gram-Positive anaerobic spore forming rod which causes botulism. Botulism is caused by the ingestion of a pre-formed neurotoxin. Botulism toxin prevents the release of the neurotransmitter acetylcholine, which interferes with neurotransmission at peripheral cholinergic synapses. Clinical disease occurs within 12 to 36 hours after ingestion and is characterized by a flaccid paralysis. The cranial nerves are affected first, particularly those involving the eyes causing diplopia and blurred vision. Difficulty swallowing is another early sign. The paralysis descends with subsequent involvement of respiratory muscles. The toxin does not produce systemic signs of fever or sepsis and patients typically succumb to paralysis and respiratory failure.

Clostridium perfrigens (Choice D) is a Gram-Positive anaerobic spore forming rod. Clostridium perfrigens food poisoning often occurs when poultry, meat, or fish is precooked and then reheated before serving. Spores of Clostridium perfrigens resist the first heating and then germinate in the food. Upon ingestion, the organisms sporulate in the intestine and form a heat-labile enterotoxin which inhibits glucose transport, damages the intestinal epithelium, and causes protein loss into the intestinal lumen. Clostridium perfrigens food poisoning is characterized by watery diarrhea, severe cramping, and abdominal pain which begins 8 to 24 hours after the suspected meal. The illness typically lasts 24 hours or less.

Enterohemorrhagic Escherichia coli (Choice E) is a Gram-Negative rod. EHEC occurs by ingestion of contaminated beef which produces SLT I and II (Shiga-like toxin (verotoxin)). The toxin causes rearrangement of actin, damage to microvilli, and systemic toxemia, however, it is not invasive. The diarrhea is copious, watery, and bloody with minimal neutrophils. This diarrhea is associated with serious complications, including hemorrhagic colitis, hemolytic uremic syndrome (HUS), and thrombotic thrombocytopenic purpura (TTP). The particular serogroup associated with Enterohemorrhagic Escherichia coli is O157:H7.
Reply With Quote Quick reply to this message
  #11  
Old 10-31-2010
Seetal's Avatar
USMLE Forums Master
 
Steps History: Step 1 Only
Posts: 919
Threads: 134
Thanked 1,310 Times in 364 Posts
Reputation: 1333
Send a message via MSN to Seetal
Default

yep bacillus cereus from reheated rice (be serius!)
Reply With Quote Quick reply to this message
  #12  
Old 10-31-2010
USMLE Forums Newbie
 
Steps History: Step 1 Only
Posts: 7
Threads: 2
Thanked 4 Times in 2 Posts
Reputation: 14
Default

answer is Bacillus C but explanation is NOT chinneses or Mexican food but Its due to reheated Rice.

thanks
Reply With Quote Quick reply to this message
  #13  
Old 11-15-2010
USMLE Forums Addict
 
Steps History: 1+CK+CS
Posts: 150
Threads: 44
Thanked 95 Times in 27 Posts
Reputation: 105
Default

the causes of acute onset of food poisoning specially includes :

1. Bacillus cereus
2. Staph aureus

since in the question there is the mention of chinese restaurant then its probably caused by consumption of reheated rice ..the culprit being Bacillus cereus....
Reply With Quote Quick reply to this message



Reply

Tags
Infectious-Diseases, Internal-Medicine-, MedicalExams.com, Step-2-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
Challenging Question #4 MedicalExams USMLE Step 2 CK Forum 9 01-23-2011 11:25 PM
Challenging Question #2 MedicalExams USMLE Step 2 CK Forum 9 11-25-2010 07:20 AM
Challenging Question #3 MedicalExams USMLE Step 2 CK Forum 10 10-31-2010 05:19 AM
Challenging Question #1 MedicalExams USMLE Step 2 CK Forum 8 09-16-2010 09:03 AM
60 Free Challenging USMLE Questions - MedicalExams.com MedicalExams USMLE Links & Free Ads 11 09-16-2010 08:36 AM

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)