Sélection de quelques mutation phénotypique de Klebsiella pneumoniae et Staphylococcus aureus utilisant la mutagenèse UV

Abstract

This thesis aims to identify and study the effect of ultraviolet radiation on two types of selected bacteria (Staphylococcus aureus and Klebsiella pneumoniae). After being absorbed by the DNA, the latter changes its helical structure as well as its genes, causing a change in the bacteria’s lifestyle. This study was conducted by exposing two bacterial isolates to ultraviolet rays for two different and spaced time periods, for Klebsiella pneumoniae for eight minutes and 16 minutes, and for Staphylococcus aureus a single time period of 16 minutes, in order to determine the rate of bacterial cell death, in addition to the possibility of obtaining phenotypic mutations of resistance. Antibiotic, non-autotrophic and size-changing. The results of exposing Klebsiella pneumoniae and Staphylococcus aureus to ultraviolet radiation showed a large and varied death rate, as well as colonies of different sizes, and no mutations were obtained from the other mutations. In conclusion, the results revealed that an exposure period of 16 minutes was not sufficient to completely eliminate Klebsiella pneumoniae and Staphylococcus aureus but it changed their size.