Strain is a type of Use. Strain is a type of Disease. Disease is related to Bacteria. 
Anger is related to Disappointment. Frustration is a type of Disappointment. Working can cause/lead to Frustration. 
Use <--IsA-- Strain --IsA--> Disease <--RelatedTo--> Bacteria 
Anger <--RelatedTo--> Disappointment <--IsA-- Frustration <--Causes-- Working 