Expression analysis of an amoxicillin resistant Escherichia coli strain

Comparison of the whole genome gene expression level of an amoxicillin resistant E. coli strain with the wildtype it was derived from. The process of amoxicillin adaptation of E. coli MG1655 wildtype cells is further descibed in van der Horst, M, J.M. Schuurmans, M. C. Smid, B. B. Koenders, and B. H. ter Kuile (2011) in Microb. Drug Resist. 17:141-147. Resistance to amoxicillin was induced in E. coli by growth in the presence of stepwise increasing antibiotic concentrations. To investigate consequences of the aquisition of amoxicillin resistance the transcriptomic profile of sensitive and resistant cells was compared in the absence and presence of sub-inhibitory (0.25xMIC) amoxicillin concentrations was compared. Total RNA of 3 biological replicates of E. coli MG1655 wildtype cells and amoxicillin resistant cells cultured with (0.25xMIC) or without amoxicillin was hybridized on a 12x135k custom designed microarraychip against one common reference.