OK- First thing.
Unless you have other cultures that you did not include, the nurse may have just misspoken in saying you had a "Staph" infections. ( This is a very common bacteria, and she may have just assumed it - doesn't mean she is right).
Second- that second culture- I would need to clarify with the microbiology lab.
Yes, I would insist on a final culture result which you have not included here.
The lab may have meant to include a note that it was the same as the first one- ie a diphtheroid. I can almost guarantee you that the lab did identify it- just your report , as you wrote here is incomplete. That doesn't mean that is a problem- just incomplete.
Now- as far as endocarditis- if you have a normal native valve, then the strep would be a more common cause of endocarditis than the diphtheroid- that diphtheroid may in fact be unrelated- it could have been from a central line, or even your appendix, and does not necessarily have anything to do with your subsequent strep infection. I just cannot be entirely sure without knowing for sure what that second culture was. ( If that second culture in fact was a strep as well... then I would be more suspicious).
Always ask if you need clarification/more information.
POSITIVE feedback & a BONUS are warmly appreciated.
Please note that answers are for information only, do not take the place of an assessment by your doctor,
and does not establish a patient-physician relationship.