A 62-year-old male was seen for low grade fever and weight loss over the past month.

He had undergone aortic valve replacement in 2015 with a bioprosthesis. Transesophageal

echocardiography found no evidence of endocarditis and routine blood cultures were negative.

Mycobacterial blood cultures grew Mycobacterium chimaera.

The patient lived in a rural area, drank well water and had a pond in this back yard with Koi fish.

The most likely source of this Mycobacterial infection is which of the following:

A. Operating room air

B. Bioprosthetic valve

C. Well water

D. Fish pond

E. Intestinal lesion

Where Did This Strange Mycobacteria Come...