Exploring variations in lipids among drug-resistant and sensitive Mycobacterium tuberculosis by Thin layer chromatography and mass spectrometry

Mycobacterium tuberculosis (M.tb) lipids are important in the host-pathogen interplay, variation in the lipids organization of cell wall can act as an adaptive response. Specific cell wall structures can possibly result in suboptimal intracellular concentrations of anti-TB drugs, which favors the acquisition of drug resistance. Therefore, lipids from M.tb (drug resistant and sensitive) were analyzed by 2D-thin layer chromatography and mass spectrometry. GraphPad Prism was used to perform Mann Whitney-U test to determine the statistical significance. Difference observed for total lipid content among different resistant isolates was insignificant. However, increase in phospholipids was identified in multi-drug resistant (MDR) isolate compared to sensitive isolate. Isoniazid, streptomycin-isoniazid, and isoniazid-ethambutol resistant isolates showed increased alpha-mycolic acids. MDR isolate showed a marginal decrease in alpha- and keto-form. Mycolipenic acid was seen only in sensitive isolate, and mycosanoic acids were observed in all the resistant isolates. Among the resistant isolates, there was an insignificant increase in the total phthiocerol dimycocerosates and sulfolipids. Drug resistance was associated with compositional imbalance of lipids. However, investigations to determine whether the changes notices are induced by the drugs is to be explored, which could give an insight into the drug resistant organisms pathogenesis.