earticle

영어

This research was conducted to examine the extent bacteria develop antibiotic resistance (ABR) from contemporary and old bacteria, and understand its underlying mechanisms of the process. Common bacteria and B. cereus, S. aureus, E. coli, and S. gallinarum were cultured with various concentrations of antibiotics and underwent agar diffusion tests to determine resistance. Then ABR and non-ABR bacteria were cultured in a single solution and ABR was tested. Plasmid DNA from ABR bacteria were implanted into non-ABR bacteria and resistance of possibly transformed bacteria was tested. Finally, plasmid DNA were extracted from ABR bacteria and inserted to non-ABR bacteria of the same kind through heat shock transformation and resistance determined. Results showed that common bacteria and B. cereus, S. aureus, E. coli, and S. gallinarum have grown ABR to old antibiotics and are starting to develop it on newer antibiotics. Non-ABR bacteria develop stronger ABR under lower concentration of antibiotics through proximity with ABR bacteria. Also, bacteria transformed with ABR plasmid DNA exhibited an ABR trait. It can be concluded many bacteria have adjusted to antibiotics, and they have grown this ABR through exposure to low concentration of antibiotics, proximity with ABR bacteria, and plasmid DNA transformation from ABR bacteria.