Lecture 13- Gram Negative Rods Flashcards
What does the outer membrane of gram negative bacteria contain?
Lipopolysaccharide LPS
What do mycobacteria gram stain as and why?
They stain gram positive because they do not have an outermembrane, but they do not have thick peptidoglycan
Which is more prevalent-
Gram negative cocci or gram negative baccilli
Gram negative baccilli
What chemical is released when gram negative bacteria die?
Endotoxin Lipid A
What is eliminated in Pyrogen Free samples?
Endotoxins
What does the Limulus Amebocyte Lysate Test (LAL) look for?
Endotoxin
What suffix is usually associated with gram negative bacteria?
-ella
Types of Enterobacteriacaea (opportunistic anaerobes)
Escherichia coli
Salmonella
Enterobacter
Shigella
Yersinia
Diseases caused by Esherichia coli
Diarrhea
Neonatal colibacilosis and colisepticemia in calves (scours and meningitis) and puppies
Coliform mastitis
Mastitis metritis
Edema in swine
Pyometra
UTIs
What are the functions of the capsule and siderophores in Esherichia coli?
Capsule- prevent phagocytosis
Siderophores- sequester iron to deplete host
What are the three most studied Esherichia coli toxins?
Heat labile (LT)
Heat stable (Sta)
Shiga-like toxins
What is the most common cause of neonatal Esherichia coli infections in calves resulting in colibacilosis/colisepticemia?
Inadequate colostrum absorption
What strain of Escherichia coli causes edema of the eyelid and smooth muscle in piglets
Shigatoxigenic
What disease does Escherichia coli cause in puppies when infected during parturition?
Colisepticemia
What bacteria is the most common cause of canine pyometra?
Escherichia coli
