Meet Staphylococcus aureus. Although these cute appearing cocci form cuddly grape-like-clusters on agar culture slides, watch out! Take caution with these gram positive creatures because they can cause many types of infections by creeping through cracks in the skin or mucosal barrier. Although they are often culprits, they can also be cooperative and commensal in nature, acting as part of the normal flora in individuals and their presence does not necessarily indicate infection.

This Daily Doodle is inspired by one of my favorite microbiology study resource “Microbiology Made Ridiculously Simple” by Dr. Mark Gladwin and Dr. Bill Trattler.

I portrayed Staph aureus as a spherical cat because they are cocci in shape and the are cat-alase positive, which means they can produce the enzyme called catalase which converts hydrogen peroxide (H
2O
2) to water and oxygen. The gold metal with a blue ribbon symbolizes their aureus appearance (aureus = gold) and the violet-blue ribbon symbolizes the fact that Staph aureus turns violet-blue on gram stain.

As listed in Microbiology Made Rediculously Simple, Staph Aureus can cause infection through two different methods: direct invasion and by exotoxins:

Direct Invasion

1. Pneumonia
2. Meningitis
3. Osteomyelitis
4. Acute Endocarditis
5. Septic Arthritis
6. Skin infections
7. UTI

Exotoxin Dependent

1. Gastroenteritis (food poisoning)
2. Toxic Shock Syndrome
3. Staphylococcal scalded skin syndrome (SSS)

Here’s a photo of the doodle to show all the memory cues:

Also, just a reminder, don’t forget to wash your hands! Click here to read about “Dirty Paws”, a children’s book that I wrote and illustrated to teach children about the importance of proper hand washing.

Reference

1. Mark Gladwin, Bill Trattler. “Clinical Microbiology Made Ridiculously Simple” Editino 3.

“Meet Staph aureus” Medical Doodle by Michiko Maruyama