Not rare!

streptococcus + sepsis + necrotizing soft tissue infection.

Anyone who has worked with bacteria on agar will be fully aware of streptococcus (Staphylococcus aureus).

Those round yellow blobs that infect areas of the agar.

In my own work I noticed that I had a lot of agar contamination simply because I failed to brush my teeth prior to doing agar work.

We sometimes forget how contaminated our mouths are with all sorts of bacteria living in there.

The there are the masks!