*4.1.1.1. Spontaneous mutations*

These mutations occur randomly as replication errors or an incorrect repair of a damaged DNA in actively dividing cells, presenting an important mode of generating antibiotic resist‐ ance. They are also called the growth dependent mutations. Quinolone resistance in Escheri‐ chia coli resulted from the mutations in at least seven positions in the gyrA gene or three positions in the parC gene [29]. There are a large number of biochemical mechanisms of an‐ tibiotic resistance related to Spontaneous Mutations. For instance, Mutations in mexR can cause derepression of the mexAB-oprM multidrug efflux operon, causing a multidrug resist‐ ance phenotype in Pseudomonas aeruginosa [30].
