Which Diagnostic Test Is Most Appropriate to Confirm the Diagnosis of Cystitis in This Patient

Ms. Reyes, a 35-year-old Female, Presents to the Clinic with Complaints of Dysuria, Frequency and Urgency of Urination. She Denies Any Fever or Flank Pain. on Physical Examination, Suprapubic Tenderness Is Noted. Urinalysis Reveals the Presence of Leukocytes and Nitrites