Jagdeep Kaur
Mycobacterium tuberculosis (Mtb), the causative agent for TB employs various strategies to favor its intracellular survival. The lipolytic enzymes of Mtb plays crucial role in lipid metabolism, as it provides fatty acids as byproducts. These fatty acids provide energy to dormant bacilli and can also act as precursors for cell wall lipid synthesis. So, these lipases are thought to contribute to virulence and pathogenicity of the bacterium. In this study, we demonstrate the role of Rv0518 in cell wall remodeling. Stress dependent expression of rv0518 was checked in Mtb H37Ra. To analyze the effect on the mycobacterial pathophysiology, we cloned rv0518 gene in pVV16 shuttle vector and expressed in non-pathogenic M. smegmatis mc2155 strain. M. smegmatis expressing Rv0518 were grown along with SDS and Lysozyme to check their effect on cell wall remodeling. Also, the effect of over-expression of Rv0518 on colony morphology, growth pattern, pellicle formation, infection and intracellular survival of the bacterium was analyzed. The expression of Rv0518 was found to be upregulated during nutritive stress. The colonies of MS_Rv0518 were round, shiny and smooth as compared to control MS_vec with irregular wrinkled and dry. Also, MS_Rv0518 was more resistant to SDS and lysozyme treatment which suggests its role in remodelling the mycobacterial cell wall. Moreover,MS_Rv0518 has higher infection rate and
also enhance the intracellular survival in human macrophages; so it might be important for bacterial virulence and pathogenesis