A 20-year-old pregnant woman (gravida II, para I) complains of lower pelvic discomfort, fever, and pain during urination for the past 2 days. She also reports seeing blood in her urine. In the patient, which of the following would be the most likely etiologic agent?
Enterobacter sp. Escherichia coli Proteus vulgaris Pseudomonas aeruginosa