A healthy 21-year-old female presents to the ED with fever, chills, abdominal pain, and constipation. On exam, she is GCS 15, appears well, with mild diffuse abdominal distension. She has recently traveled to Peru. Her vital signs are: T 38.7°C, BP 108/70, HR 47 bpm, O2 saturation 98% RA. Her CBC is normal, with mildly elevated liver enzymes. Her blood cultures are likely positive for: