Which statement about Mycobacterium leprae is NOT true?

Which statement about Mycobacterium leprae is NOT true?

• A. Causes Hansen disease
• B. Difficult to grow in vitro
• C. Easily transmitted from person to person
• D. Usually grows in peripheral limbs of infected patients

Answer: (C)

Mycobacterium leprae is known for causing Hansen disease, its extremely slow growth, and its preference for cooler parts of the body such as skin and peripheral nerves. It cannot be grown on standard artificial media, which is why laboratory culture is notoriously difficult and often relies on animal models like armadillos or mouse footpads. It is not highly contagious and typically requires prolonged close contact for transmission, with many exposures not leading to infection at all. So, the statement that it is easily transmitted from person to person is not true. The other points are correct: it causes Hansen disease, it’s difficult to grow in vitro, and it tends to affect cooler areas of the body, including the skin and nerves rather than spreading widely through the body.

Mycobacterium leprae is known for causing Hansen disease, its extremely slow growth, and its preference for cooler parts of the body such as skin and peripheral nerves. It cannot be grown on standard artificial media, which is why laboratory culture is notoriously difficult and often relies on animal models like armadillos or mouse footpads. It is not highly contagious and typically requires prolonged close contact for transmission, with many exposures not leading to infection at all.

So, the statement that it is easily transmitted from person to person is not true. The other points are correct: it causes Hansen disease, it’s difficult to grow in vitro, and it tends to affect cooler areas of the body, including the skin and nerves rather than spreading widely through the body.