| dc.description.abstract | <em><span style="font-size: xx-small;">Objective(s): </span></em><span style="font-family: Cambria,Cambria; font-size: xx-small;"><span style="font-family: Cambria,Cambria; font-size: xx-small;">The major antibiotic efflux pump of </span></span><em><span style="font-family: Cambria,Cambria; font-size: xx-small;"><em><span style="font-family: Cambria,Cambria; font-size: xx-small;">Esherichia coli </span></em></span></em><span style="font-family: Cambria,Cambria; font-size: xx-small;"><span style="font-family: Cambria,Cambria; font-size: xx-small;">is AcrAB-TolC. The first part of the pump, AcrAB, is encoded by </span></span><em><span style="font-family: Cambria,Cambria; font-size: xx-small;"><em><span style="font-family: Cambria,Cambria; font-size: xx-small;">acrAB </span></em></span></em><span style="font-family: Cambria,Cambria; font-size: xx-small;"><span style="font-family: Cambria,Cambria; font-size: xx-small;">operon. The expression of this operon can be kept elevated by overexpression of an activator, MarA following inactivation of MarR and AcrR repressors due to mutation in encoding genes, </span></span><em><span style="font-family: Cambria,Cambria; font-size: xx-small;"><em><span style="font-family: Cambria,Cambria; font-size: xx-small;">marR </span></em></span></em><span style="font-family: Cambria,Cambria; font-size: xx-small;"><span style="font-family: Cambria,Cambria; font-size: xx-small;">and </span></span><em><span style="font-family: Cambria,Cambria; font-size: xx-small;"><em><span style="font-family: Cambria,Cambria; font-size: xx-small;">acrR</span></em></span></em><span style="font-family: Cambria,Cambria; font-size: xx-small;"><span style="font-family: Cambria,Cambria; font-size: xx-small;">, respectively. The aims of this research were to use </span></span><em><span style="font-family: Cambria,Cambria; font-size: xx-small;"><em><span style="font-family: Cambria,Cambria; font-size: xx-small;">E. coli </span></em></span></em><span style="font-family: Cambria,Cambria; font-size: xx-small;"><span style="font-family: Cambria,Cambria; font-size: xx-small;">mutants with or without mutation in </span></span><em><span style="font-family: Cambria,Cambria; font-size: xx-small;"><em><span style="font-family: Cambria,Cambria; font-size: xx-small;">marR </span></em></span></em><span style="font-family: Cambria,Cambria; font-size: xx-small;"><span style="font-family: Cambria,Cambria; font-size: xx-small;">to search for the presence of possible mutation in </span></span><em><span style="font-family: Cambria,Cambria; font-size: xx-small;"><em><span style="font-family: Cambria,Cambria; font-size: xx-small;">acrR </span></em></span></em><span style="font-family: Cambria,Cambria; font-size: xx-small;"><span style="font-family: Cambria,Cambria; font-size: xx-small;">and to quantify the expression of </span></span><em><span style="font-family: Cambria,Cambria; font-size: xx-small;"><em><span style="font-family: Cambria,Cambria; font-size: xx-small;">acrAB</span></em></span></em>
<span style="font-family: Cambria,Cambria; font-size: xx-small;">. </span>
Materials and Methods:
<span style="font-family: Cambria,Cambria; font-size: xx-small;"><span style="font-family: Cambria,Cambria; font-size: xx-small;">The DNA binding region of </span></span><em><span style="font-family: Cambria,Cambria; font-size: xx-small;"><em><span style="font-family: Cambria,Cambria; font-size: xx-small;">acrR </span></em></span></em><span style="font-family: Cambria,Cambria; font-size: xx-small;"><span style="font-family: Cambria,Cambria; font-size: xx-small;">gene in these mutants were amplified by PCR and sequenced. The relative expression of </span></span><em><span style="font-family: Cambria,Cambria; font-size: xx-small;"><em><span style="font-family: Cambria,Cambria; font-size: xx-small;">acrA </span></em></span></em><span style="font-family: Cambria,Cambria; font-size: xx-small;"><span style="font-family: Cambria,Cambria; font-size: xx-small;">and </span></span><em><span style="font-family: Cambria,Cambria; font-size: xx-small;"><em><span style="font-family: Cambria,Cambria; font-size: xx-small;">acrB </span></em></span></em><span style="font-family: Cambria,Cambria; font-size: xx-small;"><span style="font-family: Cambria,Cambria; font-size: xx-small;">were determined by real time PCR. </span></span>
Results:
<span style="font-family: Cambria,Cambria; font-size: xx-small;"><span style="font-family: Cambria,Cambria; font-size: xx-small;">Results showed that W26 and C14 had the same mutation in </span></span><em><span style="font-family: Cambria,Cambria; font-size: xx-small;"><em><span style="font-family: Cambria,Cambria; font-size: xx-small;">acrR</span></em></span></em><span style="font-family: Cambria,Cambria; font-size: xx-small;"><span style="font-family: Cambria,Cambria; font-size: xx-small;">, but none of the mutants overexpressed </span></span><em><span style="font-family: Cambria,Cambria; font-size: xx-small;"><em><span style="font-family: Cambria,Cambria; font-size: xx-small;">acrA </span></em></span></em><span style="font-family: Cambria,Cambria; font-size: xx-small;"><span style="font-family: Cambria,Cambria; font-size: xx-small;">and </span></span><em><span style="font-family: Cambria,Cambria; font-size: xx-small;"><em><span style="font-family: Cambria,Cambria; font-size: xx-small;">acrB </span></em></span></em>
<span style="font-family: Cambria,Cambria; font-size: xx-small;">in comparison with wild type strain. </span>
Conclusions:
<span style="font-family: Cambria,Cambria; font-size: xx-small;"><span style="font-family: Cambria,Cambria; font-size: xx-small;">The effect of </span></span><em><span style="font-family: Cambria,Cambria; font-size: xx-small;"><em><span style="font-family: Cambria,Cambria; font-size: xx-small;">marR </span></em></span></em><span style="font-family: Cambria,Cambria; font-size: xx-small;"><span style="font-family: Cambria,Cambria; font-size: xx-small;">or </span></span><em><span style="font-family: Cambria,Cambria; font-size: xx-small;"><em><span style="font-family: Cambria,Cambria; font-size: xx-small;">acrR </span></em></span></em><span style="font-family: Cambria,Cambria; font-size: xx-small;"><span style="font-family: Cambria,Cambria; font-size: xx-small;">mutation on </span></span><em><span style="font-family: Cambria,Cambria; font-size: xx-small;"><em><span style="font-family: Cambria,Cambria; font-size: xx-small;">acrAB </span></em></span></em><span style="font-family: Cambria,Cambria; font-size: xx-small;"><span style="font-family: Cambria,Cambria; font-size: xx-small;">overexpression is dependent on levels of resistance to tetracycline and ciprofloxacin. </span></span> | en_US |
