Here's another set of questions.  I didn't put Giardia in here even though one usually treats with antibiotics because I'm going to put it in with parasitology when I get there.

QUESTIONS

1. The family Enterobacteriaceae contains the  group of gram negative rods we call _______________.
   
   They are (choose one):
   
   obligate anaerobes/obligate aerobes/facultative anaerobes.
   
   They are oxidase negative/positive.
   
2. E. coli has a lipopolysaccharide toxin that activates kallikrein, Factor XII, and complement. The name for this toxin is _______________.  Why doesn't it matter if E. coli is alive or dead in the septic patient's circulation?  (In other words, why does the toxin work anyway?)
    
3. Another E. coli toxin disrupts  cAMP & cGMP regulation leading to massive fluid secretion, HCO3-, Na+ & K+ loss into the GI lumen.  This toxin is called an _______________.  The small piece of DNA which determines if an E. coli can produce this toxin, not to mention adhese to the ileal target cell) is called a
   _______________.
    
4. The most important Salmonella species is: _______________.
    
5. Salmonella infection can lead to one of three outcomes:
   
   1) carrier state
   2)  enteric infection
   3) invasive infection.
   
   Which should be treated with antibiotics?
    
6. Salmonella diarrhea is commonly bloody while E. coli diarrhea commonly is not.  Why?
    
7. Campylobacter jejuni is a zoonotic organism.  Is this organism rare in the environment, common, or ubiquitous?
   
   Who would be more resistent to infection:  you or a 10 week old puppy?
    
8. Campylobacter infection is confirmed by culture.  What are the two main unique culture requirements of Campylobacter?
    
9. Another way to diagnose Campylobacter is with a fecal Wright's stain. What is the characteristic appearance of Campylobacter?
    
10. Penicillin          Erythromycin          Tribrissen          Keflex
    
    An MD wants you to treat the family pet as a reservoir for the family's Campylobacter infection.  The pet has diarrhea.  Which antibiotic would you use of the above?  Why might you not use any antibiotics?
     
11. Describe the rationale behind breath hydrogen analysis for bacterial overgrowth of the small intestine.
     
12. What percentage of dogs with EPI also have a significant bacterial overgrowth?
     
13. In bacterial overgrowth will fasting serum folate by up or down
    classically?  How about B12?
     
14. Salmon poisoning is associated with a fluke called _______________; however, the actual agent of the disease is the rickettsia carried by the fluke.  The name of this rickettsia is _______________.
     
15. Complete blanks in the salmon poisoning life cycle:
    
    eggs passed in feces      --->   eggs live 3+ months in environment
     of raccoon or skunk                                        |
           (in nature)                                                  \/
                                                              eggs hatch into miracidia
                                                              which attack a snail called
                                                                      Oxytrema silicula
                                                                         |
                                                                        \/
                                                   There they develop into
                                                       _______________
                                                    break out of the snail &
                                                     attack trout or salmon
                                                                  |
                                                                 \/
                                      Here, they develop into
                                      _______________ and
                              remain up to 5 years waiting to be
                                 eaten by a definitive host. 
                              Prepatency period is 4-5 days.
    
    
    
    
     

ANSWERS

1. These beloved bacteria are called "enterics".  They are facultative
   anaerobes & oxidase negative.
   
   
   
   
    
2. E. coli endotoxin is located in the cell wall & thus even if the
   circulating E. coli are dead, the endotoxin can still cause its effect.
   
   
   
   
    
3. This other E coli toxin is an "enterotoxin."  Plasmids are the little DNA pieces that determine if a bacterium can produce this toxin.
   
   
   
   
    
4. The most important Salmonella species is Sal. Typhimurium
   
   
   
   
    
5. There may be some controversy here but I was taught that antibiotics are bad for Sal carriers as they will prolong carrier state and cause resistence.  Basically the same is true for enteric infections (treatment is by support).  If the infection is invasive, though, then you have sepsis to tangle with and need antibiotics to save your patient's life.
   
   
   
   
    
6. Sal diarrhea is bloody because in addition to the enterotoxin, Sal
   produces a cytotoxin which kills enterocytes.  E. coli does not produce a cytotoxin.
   
   
   
   
    
7. Campylobacter jejuni is thought to be ubiquitous.  The puppy is probably more resistent than you.  In CVT it says that 200-500 organisms will infect a person but 10 to the tenth
   are needed to infect small animal species.  In small animals, Campy is really only a problem for pups & kits < 1 year old.
   
   
   
   
    
8. Campy's unique culture requirements are
   
   1) microaerophilia (it wants 5-10% oxygen only)
   
   2) thermophilia (it wants 42-43 C)
   
   
   
   
    
9. Campy is said to be "seagull" shaped.  It is a Gram negative rod
   (obviously you wouldn't see it as gram negative with a Wright's stain but they say it shows up better with Wright's than Gram).
   
   
   
   
    
10. Erythro is best choice though infection is self-limiting in a matter of days.  Response to antibiotics is also fast (48-72 hours) if you use them.  Some recommend using them simply to reduce shedding of zoonotic bacteria.
    
    
    
    
     
11. Breath hydrogen:  give animal a high carbohydrate meal & measure breath hydrogen in 2-4 hours.  If elevated then you have bacterial overgrowth (the bacteria have produced lots  of hydrogen).  If the elevation occurs after 2-4 hours, you have a
    malabsorption.  The CHO has made it to the colon and the colon bacteria have produced the hydrogen.
    
    
    
    
     
12. My studies show 70% dogs with EPI have signif. overgrowth.
    
    
    
    
     
13. Folate is up in overgrowth, B12 is down  (by now, you better know this one).
    
    
    
    
     
14. The fluke is Nanophyetes salmincola.  The fluke is neorickettsia helminthoeca.
    
    
    
    
     
15. Miracidia  attack the snail and develop into cercaria.  Cercaria attack the fish develop into metacercaria.