Final Micro Quiz

TSA = Non- selective
MSA = Selective

can be readily spread to others where they can infect any organ or tissue in the body

S. epidermidis can cause wound infections and infections of implanted devices
lThis organism produces a biofilm of slime that adheres to living and nonliving surfaces that is not easily penetrated by antimicrobial agents

lStaphylococcus aureus
lCatalase pos.*
lCoagulase pos.
lMannitol pos. (fermentation)
lStaphylococcus epidermidis (and other staph.)
lCatalase pos.
lCoagulase neg.
lMannitol neg.

*Staphylococci are catalase pos., Streptococci are catalase neg.

•Alpha hemolysis (partial)
•
•Beta hemolysis (complete)
•
•Gamma hemolysis (none)

-Staphylococcus aureus, S. epidermidis

or
Streptococcus pyogenes

...

•Gram-positive cocci that hydrolyze sucrose (cane sugar) into glucose and fructose

•Streptococci and lactobacilli produce acids from glucose and fructose
•As the pH drops below 4.8, lactobacilli multiply and produce sufficient acid to remove the calcium from tooth enamel
•These bacilli grow best in an acid environment and enhance the formation of dental carries
•The Snyder Test measures acid production by oral lactobacilli that produce dental carries