Unsure if I try to get this vanc de-escalated - question about interpreting blood cultures

Pt was started on vanc because preliminary came back positive for s. Aureus in one bottle. Sensitivities later reported MSSA. Second bottle so far has shown no growth. It's tempting to go ahead and try to de-escalate based on sensitivities from bottle one, but also thinking I need to wait for final results on bottle two. This is also a fairly sick pt in surgical ICU. I'm a new pharmacist who has just started covering ID and it's been quite a learning curve