Question

After reviewing the chart and past information from previous weeks, create a dichotomous key using at least 10 points to key out the organisms listed.

Staphylococcus aureus

Staphylococcus epidermidis

Streptococcus pyogenes

Streptococcus pneumoniae

Streptococcus agalactiae

Answer 1

Organisms	Is it gram-positive cocci	Is it facultative aerobic	Is it optochin resistant	Is it catalase positive	Is it beta hemolytic	Is it mannitol fermented	Is it capable of DNA hydrolysis	Is it oxidase positive	Is it coagulase positive	Is it novobiocin resistant
Staphylococcus aureus	Yes	Yes	No	Yes	Yes	Yes	Yes	Yes	Yes	Yes
Staphylococcus epidermidis	Yes	Yes	No	Yes	No	No	No	Yes	No	No
Streptococcus pyogenes	Yes	Yes	No	No	Yes	No	No	No	No	Yes
Streptococcus pneumoniae	Yes	Yes	Yes	No	No	No	Yes	No	No	No
Streptococcus agalactiae	Yes	Yes	No	No	Yes	No	No	No	No	No