Review Question - QID 109742

A 29-year-old woman presents to her primary care provider complaining of lower back pain. She reports a 3 day history of extreme right lower back pain. She also reports mild dysuria. Her past medical history is notable for recurrent urinary tract infections leading to 3 emergency room visits over the past year. Her family history is notable for renal cell carcinoma in her paternal grandfather and diabetes in her father. Her temperature is 99.5°F (37.5°C), blood pressure is 125/75 mmHg, pulse is 82/min, and respirations are 18/min. On exam, she has mild right costovertebral angle tenderness. Radiography demonstrates a vague radiopaque structure in the right lower abdomen. Results of a urinalysis are shown below:

Appearance: Hazy, yellow
Protein: Negative
Specific gravity: 1.029
WBC: 2+
Casts: None
Bacteria: None
pH: 8.9
Blood: Negative
Bilirubin: Negative
Urobilinogen: < 2.0

A urine culture is pending. Which of the following pathogens is most likely responsible for this patient’s condition?