Front-end frameworks and accessibility

Hi.

Have anyone of you had experience working with front-end frameworks such as Bootstrap, Foundation, MaterializeCSS, and such?

If so, how is your experience with this frameworks, and how good are they at accessibility?
If there are any, wich one comes with most accessibility out of the box, without too much manual writing of code?

We are considering using a front-end framework to build internal (and maybe in the future external) applications at a higher speed then we do nowadays.
But we have to ensure that also screen reader users and other with disabilities can use our applications.

Thanks for all feedback you can give

Best regards David Hole