A 37-year-old presents to the emergency department due to fever and chest pain for the past nine days. The pain is sharp, midsternal, worsens with lying down, and improves with leaning forward. The patient also had an upper respiratory tract infection
one week ago. Temperature is 38.2°C (100.8°F), pulse
is 108/min, respirations are 22/min, and blood pressure
is 140/74 mmHg. On auscultation
there is a friction rub heard at the left lower sternal
border. Laboratory evaluation shows elevated ESR and CRP. ECG is significant for normal sinus rhythm
with diffuse ST segment elevation
of 1 to 2 mm. Which of the following best describes the class of pathogen causing this patient’s symptoms?