This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Bacteriology, Subject name: Microbiology
Tap water scotochromogen is 
Select and explain. 
A. Mycobacterium chelonae, B. Mycobacterium marinum, C. Mycobacterium kanasaii, D. Mycobacterium gordonae
D: Mycobacterium gordonae
Answer: D: Mycobacterium gordonae 
Explanation: M.gordonae often found in tap water (hence called 'the tap water scotochromogen'), is a common contaminant in clinical specimens and a rare cause of pulmonary disease. It differs from scrofulaceum in failing to hydrolyse urea, nicotinamide and pyrazinamide. Ref: Textbook of microbiology; Ananthanarayan and paniker's; 10th edition; Pg: 367