Results 1 to 6 of 6

Thread: What bacterium is associated almost exclusively with antibiotic-associated diarrhea?

  1. #1
    Join Date
    Aug 2008
    Posts
    6,603
    Rep Power
    47

    Arrow What bacterium is associated almost exclusively with antibiotic-associated diarrhea?

    GI Diseases

    Introduction to Gastrointestinal Diseases - Review Mode - Quiz mode


    Introduction to Gastrointestinal Infections

    Diarrheal diseases are one of the leading causes of death worldwide, with poverty, lack of sanitation, and lack of good nutrition contributing to the vicious cycle of disease, malnutrition, and death. World wide, rotaviruses, E. coli, and Campylobacter jejuni are the leading causes of these illnesses. Amoeba and parasitic worms are also significant problems in many countries. In the US, viruses, Campylobacter, Shigella, and Salmonella are major causes. Pathogenic E. coli is difficult to test for due to the presence of an abundant non-pathogenic intestinal flora containing E. coli, although tests are available for specific strains such as E. coli 0157:H7. C. difficile is a nosocomial cause of a serious diarrhea.


    While not an infection, food intoxication (food poisoning) is a common cause of illness in the US and other countries. The term food poisoning should be reserved for true food intoxications, where bacteria need not be ingested, or if ingested, need not colonize; however, infections acquired from food are often (incorrectly) called food poisoning. The diarrheal infections are of two main types, 1) secretory or watery, and 2) inflammatory. The latter is sometimes referred to as dysentery. The pathogenesis of the two types is fundamentally different and contributes to their different symptomology. In secretory or watery diarrhea a bacterial toxin or virus alters the fluid balance in the intestines.


    In inflammatory diarrhea there is invasion of the intestinal wall with subsequent inflammation and release white blood cells and sometimes red blood cells into the lumen of the intestine. Enteric fever, such as typhoid fever, is a systemic disease that begins in the GI tract, but may not have any GI symptoms. In enteric fevers, the organisms invade through the intestine and become systemic. Chapter 8, pp 241 to 262, of Infectious Diseases in 30 Days by F.S. Southwick (McGraw-Hill, 2003) discusses these diseases from the point of view of a physician in the US (note that Salmonella nomenclature has been changed since this was written, see the Bugs index). After reading this, or the introduction to GI diseases in any Microbiology text book, you should be able to answer the following questions.

    -----------

    Question 1 - Single Best Answer


    What is the primary non-specific host defense protecting the GI tract?

    A) non-specific phagocytes
    B) killer T-cells

    C) complement
    D) stomach acid
    E) constant mucosal surface washing
    Answer with Explanation:
    [HIDE]
    D) stomach acid

    CORRECT!
    Yes! Organisms that are resistant to stomach acid require much lower inocula than organisms that are not. Normal flora also help protect.

    [/HIDE]

  2. #2
    Join Date
    Aug 2008
    Posts
    6,603
    Rep Power
    47

    Default

    Question 2 - (Single Best Answer)


    What easy test detects Salmonella and/or Shigella in a stool sample?


    A) Gram stain
    B) no growth on blood agar
    C) beta hemolysis on blood agar
    D) light color of colonies on EMB or MacConkeys agar plates
    E) acid-fast stain
    Answer with Explanation:
    [HIDE]

    D) light color of colonies on EMB or MacConkeys agar plates

    CORRECT!
    Yes, Shigella and Salmonella cannot ferment the lactose in these two differential and selective media (Gram positives will not grow). E. coli and other related bacteria do ferment lactose, produce acid, and then change color because of pH indicators.


    [/HIDE]

  3. #3
    Join Date
    Aug 2008
    Posts
    6,603
    Rep Power
    47

    Default

    Question 3 - (Single Best Answer)


    Which of the following can reduce the inoculum size necessary to cause illness for Salmonella?

    A) antacids
    B) antibiotics
    C) AIDS
    D) two of the above
    E) all of the above
    Answer with Explanation:
    [HIDE]

    D) two of the above
    CORRECT!
    Yes, the first two answers are correct

    [/HIDE]

  4. #4
    Join Date
    Aug 2008
    Posts
    6,603
    Rep Power
    47

    Default

    Question 4 - (Single Best Answer)


    Which of the following are most likely to be contaminated with Salmonella?



    A) eggs and chicken
    B) beef
    C) milk
    D) apples
    E) raw oysters
    Answer with Explanation:
    [HIDE]

    A) eggs and chicken

    CORRECT!
    Yes, these are the most common sources.

    [/HIDE]

  5. #5
    Join Date
    Aug 2008
    Posts
    6,603
    Rep Power
    47

    Default

    Question 5 - (Single Best Answer)


    What is the major difference in the epidemiology of Salmonella and Shigella?

    A) only elderly people get Shigella
    B) only individuals with AIDS get Salmonella
    C) Shigella is only transmitted from humans, not animals
    D) Shigella can be transmitted by water but Salmonella cannot
    E) only children get Shigella
    Answer with Explanation:
    [HIDE]

    C) Shigella is only transmitted from humans, not animals

    CORRECT!
    Yes, this is true

    [/HIDE]

  6. #6
    Join Date
    Jun 2009
    Posts
    4
    Rep Power
    0

    Default

    thanks!!

Thread Information

Users Browsing this Thread

There are currently 1 users browsing this thread. (0 members and 1 guests)

Similar Threads

  1. WebLinks collection eXcLuSiVeLy By lovestories[Surf the web]
    By love_stories in forum Medicalgeek Gallery
    Replies: 45
    Last Post: 06-14-2010, 01:32 AM
  2. Citrus Disease Bacterium Sequenced
    By trimurtulu in forum Off-Topic
    Replies: 0
    Last Post: 03-07-2009, 10:43 PM
  3. Replies: 0
    Last Post: 02-07-2009, 10:46 PM
  4. Replies: 0
    Last Post: 01-22-2008, 05:32 AM
  5. Exclusively Mobile..!!
    By dr_kals in forum Knowledge Center
    Replies: 0
    Last Post: 11-27-2007, 12:44 AM

Bookmarks

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •