Lab

4/23/2021 Laboratory Simulation

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CASE REPORT: Annie was outdoors and received multiple mosquito bites. She scratched a lot, even to the point that some had begun to bleed. Several of Annie’s mosquito bites were not healing well, and instead had now become swollen and painful, suggesting an infection. When the infection didn’t respond to several applications of triple antibiotic ointment, Annie’s mother took her to the pediatrics clinic. A sterile swab was used to collect a specimen of pus from the infected site, which was sent to the lab for isolation and stock culture creation. After overnight incubation, the specimen showed significant bacterial growth.

Student: kusum

Case Introduction Questions Based on the information in the case, what organism(s) could or should be suspected to cause this scenario? Select all that apply. Streptococcus pyogenes Staphylococcus aureus Staphylococcus epidermidis

Now that a pure culture has been isolated for you, what would be a good starting procedure to begin classifying your unknown organism?

Gram staining

Collected Lab Data Test Result

4/23/2021 Laboratory Simulation

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Test Result

Gram staining

Gram (+) cocci in clusters

Catalase test Bubbles were noted on slide, unknown bacteria was concluded to be catalase (+)

Mannitol salt agar test Yellow reaction was noted on MSA plate, unknown bacteria grew in high salt and was concluded to ferment mannitol

Coagulase test Clotting was noted in tube, unknown bacteria was concluded to be coagulase enzyme (+)

Unknown bacterium identification Staphylococcus aureus

Completed Dichotomous Key

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