Question

2. The bacterium Mycobacterium leprae causes leprosy in humans.This organism localizes primarily to the skin of extremities, such as the nose, toes, and fingers, where it leads to loss of protective sensation and disfiguring lesions. Temperature is a key factor in its tissue preference; it grows fastest at cooler body sites (~30oC) and more slowly at warmer, more internal sites.

a. Draw a diagram that illustrates the relationship between the growth rate and temperature for M. leprae. Label each axis and indicate the optimum temperature for this organism.

2. Identify one cellular structure that can be adapted for growth at specific

   temperatures.

3. Describe how the cell structure you identified (in the previous question) could be adapted for growth in a cold environment, and explain why this adaptation is important for its function.

Answer 1

The bacterium Mycobacterium leprae causes leprosy in humans.This organism localizes primarily to the skin of extremities, such as the nose, toes, and fingers, where it leads to loss of protective sensation and disfiguring lesions. Temperature is a key factor in its tissue preference; it grows fastest at cooler body sites (~30oC) and more slowly at warmer, more internal sites.

a) Leprosy bacilli Mycobacterium leprae) require lower body temperature for survival and replication, So, in preferential bacterial growth can be seen in peripheral tissues like peripheral nerves, skin, and testis where peripheral body temperature is relatively low. It could be 20,29,30. It's been shown that a temperature of 37°C is unfavorable for intracellular M. leprae viability. M. leprae can propagates both in peripheral tissues and internal organs such as liver.

Fig: Mesophiles is where the maximum growth rate takes place and the temperature ranges from 20 degree C to 30 degree C

The cell wall of M. leprae contains an extensive electron-transparent outer layer that is largely composed of phthiocerol dimycocerosic acid and related glycolipids. It has been proved that the bacterial cell wall contains most of the elements associated with pathogenesis.  M. leprae possesses the highest content of pseudogenes among pathogenic and non-pathogenic bacteria and archaea. The pathogen adaptation into host cells, as the Schwann cells brought the reduction of genome and induced multiple gene inactivation.