**2.6 Linezolid**

### *2.6.1 Mechanism of action*

It is an Oxazolidinone, useful in treatment of resistant gram positive coccal and bacillary infection. It is primarily bacteriostatic but can exert bactericidal action against some *Streptococci, Pneumococci and B. fragilis* [53, 54].

It acts mainly by inhibiting bacterial protein synthesis, acting at an early step. It binds to the central loop of domain V in the 23S fraction (P site) of the 50S ribosome and interferes with the formation of tertiary N-formylmethionine- tRNA- 70S initiation complex. Hence it stops protein synthesis before it starts.

### *2.6.2 Mechanism of resistance*

Since Linezolid is a synthetic drug, natural resistance to this drug does not occur; hence mutations are mostly acquired.


Genes encoding for Ribosomal proteins have been analyzed by PCR and Amplicon sequencing.

Whole molecular background is elucidated by PCR- Amplicon sequencing and whole genome sequencing [56].
