A 21-year-old woman presents to the office with a 3-day duration of discomfort with urination and increased urinary frequency. She has noted that her urine has a strong odor as well. She denies fever, abdominal pain, back pain, vaginal discharge, or skin rash. She is sexually active and takes oral contraceptive pills. On examination, she is comfortable appearing and afebrile. She has no costovertebral angle tenderness. Abdominal exam is notable only for suprapubic tenderness. Microscopic examination of the sediment of a centrifuged urine sample reveals 10-15 white blood cells per high power field and numerous bacteria. Which additional lab tests would allow you to confirm this diagnosis?