A 35 year old woman presents with increasing urinary frequency, dysuria and cloudy urine to an urgent care centre. She has no significant past medical history. On examination, she is alert and oriented, with suprapubic pain but no loin tenderness. On examination, her temperature is 37.9°C, heart rate is 114 beats per minute, her respiratory rate is 18 breaths per minute, her oxygen saturations are 96% on air and her blood pressure is 128/76 mmHg. Her urine dipstick demonstrated leucocytes +++ and nitrites are positive.
Based on the likely diagnosis, what is the most appropriate initial management step?