I knew about writing user stories for an application that is developed using XP. I have searched and found one of the formats for writing user stories. eg: As a (role) I want (something) so that (benefit).

Do the test engineers need to write the test stories based on these user stories? If so, is there any particular format for writing the test stories?

I would also like to know whether it is mandatory to follow writing test stories for an application to be developed using XP - or can the tester follow the conventional way of writing test cases in a columnar format.
Awaiting for a response.