Dear Elizabeth,
When you say mom has been cultured and twice it has come back Staph and Strep,
the Diclox only will treat the staph. Cephalexin is a better choice for strep
and baby also needs  to treated.
For mom; is shen going to bed and staying there for a couple days? Is she
increasing her fluid intake? Does she feel she is getting good empting of her
breasts?

The literature shows that a woman who has a history of mastitis is more prone
for recurance, there is no reason given for this so one could hypothosize.
Maybe there is an anotomical reason, or she is more susceptible to infections.

For the baby, you mentioned early in your post that the baby had developed an
infection (URI?) and since that time has not done well with nursings.  Has the
baby been evaluated by ENT? If there is any kind of obstruction that is
interferring with baby suck/swallow/breathing, there will be a problem with
nursing. Does the baby make any noise while feeding or between? Something
negative is impacting this baby and before you can bring him back to the
breast this needs to be identified.

You will probably hear this from several of us on Lactnet, but there is NO
reason to wean. Infact I see it as presenting potenial more problems.  Please
ask the docs what is their rationel for this approach.
Good luck. Keep us posted.

Ann Perry RN IBCLC