<prompt> A 60-year-old man with a chronic cough, bloody sputum, and marked weight loss is diagnosed as having tuberculosis. A serpentine-like colonial morphology is noted on Lowenstein-Jensen agar. This latter finding is caused by which of the following factors?A large slimy capsuleWax DCoagulaseCord factor  <response>: Ans. D. Cord factora. Virulent strains of M. tuberculosis grow in a characteristic serpentine cordlike pattern, whereas avirulent strains do not.b. Virulence of the organism is correlated with cord factor trehalosedimycolate. 